Spinal Stenosis of Lumbar RegionAPIDeLeGNCT07026552
Proteomic and Histological Analysis of Ligamentum Flavum in Lumbar Stenosis
An observational study of Spinal Stenosis of Lumbar Region and Spine Degeneration, run by Fondazione Policlinico Universitario Agostino Gemelli IRCCS at 1 site in Italy.
Trial summary
Background Lumbar spinal stenosis (LSS) is a common condition characterized by spinal canal narrowing, often linked to ligamentum flavum hypertrophy (LFH) and degeneration. Fibrotic processes involving elastin and collagen alterations contribute to LF thickening and spinal instability. Read more about this study
- Who is it for?
- Ages 50 to 85 years
- Conditions the study is for
- Spinal Stenosis of Lumbar Region, Spine Degeneration
- How many people
- 100 participants
- Where
- 1 siteItaly
- Study dates
- 15 Jun 2025to 1 Mar 2028
- Phase
- Observational
- Are there results?
- Not yet: the study is under way
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 50 to 85 years
- All sexes
- No healthy volunteers
- Adult, Older adult
Study population: The study population will consist of adult patients (aged 50-85 years) undergoing spinal surgery at the Fondazione Policlinico A. Gemelli IRCCS, a tertiary referral center specializing in neurosurgical care. Patients will be evaluated, assessed for surgical indication, and enrolled in the study at the Neurosurgery Department of the Institution.
Who may be able to join
- Radiological (CT and/or MRI) and clinical evidence of lumbar spinal stenosis (LSS).
- Age range: 50-85 years.
- Signed informed consent, medical records release form, and HIPAA authorization form (or equivalent according to local regulations), reviewed and signed by the patient or legally authorized representatives.
Who cannot join
- Pediatric population and individuals under 50 years of age.
- Concomitant genetic musculoskeletal disorders.
- History of trauma.
- Spinal infections (spondylodiscitis, osteomyelitis, abscess, etc.).
- Presence of spinal tumors or other neoplasms.
Trial locations and contacts
1 site in 1 country. Contact the study team or a site near you to ask about taking part.
Italy1 site, 1 recruiting
- Recruiting
Fondazione Policlinico Agostino Gemelli IRCSS
Rome, RM, 00168
Gianluca Galieri, +39 3298803674, gianluca.galieri01@icatt.it
Gianluca Galieri
About this study
Official title: Proteomic and Histological Analysis of Ligamentum Flavum Hypertrophy and Degeneration in Lumbar Spinal Stenosis: Clinical, Surgical, and Therapeutic Implications
Background Lumbar spinal stenosis (LSS) is a common condition characterized by spinal canal narrowing, often linked to ligamentum flavum hypertrophy (LFH) and degeneration. Fibrotic processes involving elastin and collagen alterations contribute to LF thickening and spinal instability. Despite progress, the molecular mechanisms underlying LFH remain unclear, necessitating targeted diagnostic and therapeutic strategies.
Objective This study aims to analyze the proteomic and histological changes in LFH associated with LSS, correlating molecular signatures with imaging and surgical findings to identify potential therapeutic targets.
Read more
Methods LF samples from LSS patients undergoing surgery will be analyzed using mass spectrometry-based proteomics and histology to identify biomarkers and molecular pathways. Correlations between imaging, intraoperative findings, and molecular profiles will be assessed.
Expected Results The study aims to identify specific biomarkers and molecular pathways involved in LFH, linking them to clinical and imaging findings. Statistical analyses will evaluate associations between molecular alterations and surgical outcomes to define therapeutic targets.
Significance By identifying molecular markers of LFH, this research aims to improve LSS diagnosis and treatment, potentially guiding targeted therapies to slow disease progression and enhance patient outcomes.
Study Design A multidisciplinary team from Fondazione Policlinico Universitario Agostino Gemelli and Università Cattolica del Sacro Cuore will conduct the study, ensuring robust data integration and statistical evaluation.
Conclusion This comprehensive study will provide valuable insights into the molecular and histological modifications associated with LFH in LSS, paving the way for new therapeutic approaches to improve patient outcomes and satisfaction.
Read the detailed description
- INTRODUCTION Lumbar spinal stenosis (LSS) is a highly prevalent condition worldwide, characterized by the narrowing of the spinal canal. Epidemiological studies indicate a high incidence of LSS, influenced by demographic shifts and the increasing burden of age-related musculoskeletal disorders. The etiology of LSS is primarily classified as acquired (degenerative) or congenital, affecting approximately 103 million individuals globally. The degenerative form becomes increasingly common with advancing age. Anatomically, degenerative LSS is subdivided into central, lateral, and foraminal stenosis, with the highest prevalence observed at the L4-L5 level. Key etiological factors include thickening and deformation of the ligamentum flavum (LF), often resulting from reduced disc height, facet joint hypertrophy, or a combination of both. Among these factors, ligamentum flavum hypertrophy (LFH) is recognized as the primary cause of lumbar spinal canal stenosis (LSCS). The LF is a crucial structure connecting the laminae of adjacent vertebrae, composed of approximately 80% elastic fibers and 20% collagen fibers. It plays a vital role in forming the posterior boundary of the spinal canal, preventing excessive flexion of the vertebral column, and maintaining spinal stability. Several studies indicate that individuals with hypertrophic LF exhibit a reduction and disorganization of elastic fibers, accompanied by an increase in collagen fibers, suggesting that LFH is driven by a fibrotic process. Identifying risk factors for LFH remains challenging and is a subject of ongoing debate in the literature; age and mechanical stress are currently considered the most significant contributors. Few studies have focused on elucidating the molecular mechanisms underlying LSS and LFH or on identifying specific diagnostic and prognostic biomarkers. As a result, the pathophysiology and molecular basis of LSS and LFH remain poorly understood, underscoring the need for precise molecular characterization and the development of targeted treatments based on specific molecules. Zhao et al. identified a significant increase in thrombospondin-1 (THBS1) expression in LFH using proteomics and single-cell RNA sequencing in clinical samples. Laboratory experiments demonstrated that THBS1 activates the Smad3 signaling pathway via transforming growth factor β1 (TGF-β1), enhancing the expression of fibrotic markers COL1A2 and α-SMA. A bipedal murine model confirmed the crucial role of THBS1 in LFH development. Additionally, sestrin2 (SESN2), a stress-responsive protein, was shown to suppress THBS1 expression, preventing fibrosis in LF cells. These findings suggest that mechanical overload increases THBS1 production, triggering the TGF-β1/Smad3 pathway and leading to tissue hypertrophy. Suppressing THBS1 expression could provide a novel therapeutic approach for LFH. In another study, Wang et al. found that wild-type amyloid transthyretin (ATTRwt) was present in LF samples from patients undergoing decompression surgery, with amyloid load positively correlating with LF thickness and lumbar LF burden in a dose-dependent manner. Liu et al. reported that hypertrophic LF samples exhibited higher levels of CLU, TGF-β1, α-SMA, ALK5, and phosphorylated SMAD3 proteins compared to non-LFH samples. Mechanical stress and TGF-β1 were found to induce clusterin (CLU) expression in LF cells. Notably, CLU inhibited COL1A2 and α-SMA expression, which were stimulated by mechanical stress and TGF-β1. Mechanistic studies demonstrated that CLU suppressed mechanical stress-induced and TGF-β1-driven SMAD3 activity by inhibiting SMAD3 phosphorylation and nuclear translocation through competitive binding with ALK5. Additionally, PRKD3 stabilized CLU protein, preventing its lysosomal degradation. In vivo experiments showed that CLU attenuated LFH induced by mechanical stress. These results suggest that CLU mitigates LFH by modulating TGF-β1 signaling pathways both in vitro and in vivo, acting as a negative feedback regulator of TGF-β1 and inhibiting fibrotic responses in LF. Zheng et al. discovered that TGF-β1 significantly increased CRLF1 mRNA expression via the SMAD3 pathway. CRLF1 was found to enhance LF fibrosis through the ERK signaling pathway at the post-transcriptional level and was essential for the pro-fibrotic effects of TGF-β1. When CRLF1 was silenced, fibrosis induced by inflammatory cytokines and mechanical stress was reduced. Furthermore, experiments demonstrated that bipedal posture could induce LFH and increased CRLF1 expression in mice. Overexpression of CRLF1 led to LFH in vivo, whereas CRLF1 silencing prevented LFH development in bipedal mice. These studies highlight the critical role of specific molecules in the development and regulation of LFH. However, the pathogenesis remains incompletely elucidated. Further research is required to clarify these mechanisms and develop potential strategies for the prevention and treatment of LFH and LSS.
- OBJECTIVES AND CLINICAL TRIAL AIMS (HYPOTHESIS AND EXPECTED OUTCOMES) The objective of this study is to conduct a comprehensive clinical and proteomic investigation of LFH, comparing molecular profiles of different LF samples within a well-defined patient cohort that meets inclusion criteria and has a statistically significant sample size. Proteomics is a valuable tool for studying diseases at the molecular level, helping to elucidate mechanisms involved in inflammatory responses and biomechanical stress. Specifically, Clinical Proteomics, as applied in this project, focuses on the biomedical application of proteomics and integrates proteomics, epidemiology, clinical chemistry, and medical disciplines, aligning perfectly with the study's objectives. This approach involves determining the total protein expression profile of a specific cell, tissue, or body fluid at a given time, assessing qualitative and quantitative differences between healthy and diseased subjects. This project integrates multiple research units, where clinicians, neurosurgeons, biochemists, and molecular biologists collaborate closely to achieve the desired outcomes, each contributing their expertise to the study.
- STUDY DESIGN 3.1 Study Type: Prospective, single-center observational study. 3.2 Study Duration: The study will commence following approval by the Ethics Committee and will last for 36 months. 3.3 Study Endpoints 3.3.1 Primary Endpoint Investigate molecular and histological aspects through proteomic and microscopic analysis to identify a potential specific pattern in LSS patients, comparing them with a healthy population. 3.3.2 Secondary Endpoints Correlate blood test results (routine clinical blood sampling) with a specific LFH pattern. Assess correlations between preoperative imaging findings and intraoperative and molecular results. 3.4 Experimental Procedures Provide a molecular characterization of the ligamentum flavum in two study populations (non-degenerative disease vs. degenerative disease) through the application of an integrated proteomic approach based on top-down and bottom-up platforms. The data could provide valuable insights into the molecular mechanisms underlying the onset and progression of the disease. Identify molecular biomarkers for clinical applications: The analysis of different ligamentum flavum samples could reveal specific proteins associated with spinal stenosis and clarify the mechanisms regulating these pathways. The identification of these biomarkers could significantly improve the treatment of lumbar spinal stenosis by introducing new therapeutic targets to mitigate inflammatory and hypertrophic responses, slow stenosis progression, and ultimately enhance patients' quality of life.
- STUDY POPULATION (SAMPLE SIZE CALCULATION) Patients undergoing decompression surgery for lumbar spinal stenosis will be compared with patients undergoing surgery for other degenerative spinal diseases.
- DATA ANALYSIS AND SAMPLE SIZE 5.1 SAMPLE SIZE Given the nature of the study, a formal sample size determination is not required. Based on the number of patients treated annually, we estimate enrolling 100 patients who meet the inclusion and exclusion criteria within 24 months and describing their proteomic patterns. Ligamentum flavum samples will be obtained from 50 patients undergoing decompression surgery for lumbar spinal stenosis and compared with samples from 50 patients undergoing surgery for other degenerative spinal diseases. 5.2 HISTOLOGICAL ANALYSIS The samples will be stained and examined to detect changes in the composition of collagen and elastin fibers, cellularity, and the presence of inflammatory markers. Advanced imaging techniques will be employed to quantify tissue alterations. 5.3 MOLECULAR ANALYSIS RNA and protein extracts from ligamentum flavum samples will be analyzed using techniques such as qPCR, Western blotting, and immunohistochemistry to identify gene and protein expression changes related to fibrosis, inflammation, and extracellular matrix remodeling. 5.4 PROTEOMIC ANALYSIS Ligament samples will undergo proteomic analysis using mass spectrometry platforms, employing integrated top-down and bottom-up approaches. 5.5 STATISTICAL ANALYSIS Quantitative variables following a normal distribution will be summarized as mean and standard deviation (SD) or, otherwise, as median and interquartile range (IQR). Categorical variables will be reported as absolute and relative frequencies (percentage). Normality of variables will be assessed using the Shapiro-Wilk test. Comparisons between categorical variables will be performed using the chi-square test or Fisher's exact test. Differences between quantitative variables will be tested using Student's t-test or the Mann-Whitney test. Preoperative and postoperative clinical data, functional outcomes, and imaging results will be collected and correlated with histological and molecular data to identify potential biomarkers and predictors of surgical outcomes through linear regression analysis. Correlation between various parameters will be further evaluated by calculating the Pearson and/or Spearman correlation coefficient. Results will be considered statistically significant at p<0.05. Analyses will be conducted using R statistical software (R, CRAN).
- DIRECT ACCESS TO DATA/ORIGINAL DOCUMENTS The Principal Investigator or their delegates must allow the Regulatory Authority, the Independent Ethics Committee, or the Sponsor (or their delegates) free access and the ability to conduct relevant audits on all original study documentation, including informed consent forms signed by enrolled subjects, relevant medical records, and/or outpatient registers. Individuals granted access to the documentation must take all reasonable precautions to maintain the confidentiality of subject identities in compliance with applicable legislation.
- GOOD CLINICAL PRACTICE REGULATIONS This study will be conducted in accordance with the principles of Good Clinical Practice (GCP) (Group, 1996), the Declaration of Helsinki, and national regulations governing the conduct of clinical trials. By signing the protocol, the investigator agrees to adhere to the procedures and instructions contained therein and to conduct the study in compliance with GCP, the Declaration of Helsinki, and national laws regulating clinical trials.
- Keywords
- Lumbar Spinal Stenosis, Ligamentum Flavum Hypertrophy, Proteomic Analysis, Molecular Biomarkers
- Medical subject headings
- Spinal Stenosis
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
| Study group | Role | What they receive |
|---|---|---|
| Lumbar Spinal Stenosis Surgery Group | This cohort consists of patients undergoing decompression surgery for lumbar spinal stenosis. Tissue and biological fluid samples will be collected intraoperatively to analyze molecular and histological characteristics associated with ligamentum flavum hypertrophy (LFH). | |
| Other Degenerative Spinal Disease Surgery Group | This cohort includes patients undergoing surgery for other degenerative spinal conditions of the spine such as lumbar disk herniation. Ligamentum flavum samples from this group will serve as a comparative control to assess differences in molecular, histological, and proteomic profiles between non-LFH and LFH tissues. |
What is being measured
The primary outcome is the main question the study is designed to answer.
Histological Modifications in the Ligamentum Flavum in Lumbar Spinal Stenosis and Other Degenerative Spinal Diseases
This outcome measures the relative abundance and structural organization of collagen and elastin fibers in ligamentum flavum tissue from patients with lumbar spinal stenosis and other degenerative spinal diseases, using histological staining.
Unit of Measure: Histological score or percentage composition
Measured: Intraoperative sample collection and subsequent laboratory analysis within 12 months post-surgery
Cellularity of Ligamentum Flavum Tissue
This outcome measures the number and density of fibroblasts and other resident cells in the ligamentum flavum.
Unit of Measure: Cells per high power field (HPF)
Measured: Intraoperative sample collection; analysis completed within 12 months post-surgery
Presence of Inflammatory Markers in Ligamentum Flavum
This outcome evaluates the expression of inflammatory markers (e.g., TNF-α, IL-6, CD68) in ligamentum flavum tissue using immunohistochemistry or immunofluorescence.
Unit of Measure: Semi-quantitative histological score or intensity of staining
Measured: Intraoperative sample collection; analysis completed within 12 months post-surgery
Secondary outcomes (5)
Expression of Matrix Metalloproteinases (MMPs) in Ligamentum Flavum Tissue
This outcome quantifies the expression of specific MMPs (e.g., MMP-2, MMP-9) involved in extracellular matrix remodeling in hypertrophied ligamentum flavum.
Unit of Measure: Relative expression (e.g., fold-change via qPCR or densitometric units via Western blot)
Measured: Within 12 months post-surgery, based on sample processing and analysis.
Expression of Transforming Growth Factor-beta (TGF-β) in Ligamentum Flavum Tissue
This outcome evaluates the expression of TGF-β, a key mediator in fibrosis and hypertrophy.
Unit of Measure: Relative expression (e.g., immunohistochemistry score, qPCR fold-change)
Measured: Intraoperative tissue collection; laboratory analysis within 12 months post-surgery
Expression of Bone Morphogenetic Proteins (BMPs) in Ligamentum Flavum Tissue
This outcome investigates the expression of BMPs (e.g., BMP-2, BMP-7) which are implicated in osteogenic changes and fibrosis.
Unit of Measure: Relative expression (e.g., fold-change via qPCR or immunohistochemistry score)
Measured: Intraoperative tissue collection; laboratory analysis within 12 months post-surgery
Correlation Between Histological and Molecular Findings and Preoperative Clinical Presentation
This outcome assesses the relationship between tissue-based findings and clinical parameters such as pain, disability, and imaging severity.
Unit of Measure: Correlation coefficient (e.g., Pearson's r or Spearman's ρ)
Measured: Preoperative clinical data and intraoperative sample analysis; correlation analysis within 12 months
Correlation Between Histological and Molecular Findings and Postoperative Surgical Outcomes
This outcome measures the association between tissue-level findings and surgical outcomes, including postoperative functional recovery (e.g., ODI, VAS, EQ5D).
Unit of Measure: Correlation coefficient (e.g., Pearson's r or Spearman's ρ)
Measured: Intraoperative sample collection and postoperative follow-up at 3, 6, and 12 months
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted18 Jun 2025
- Study start15 Jun 2025
- Primary completion1 Mar 2027 (estimated)
- Study completion1 Mar 2028 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Publications (10)Papers the sponsor has linked to this study.
- Other trials for Spinal Stenosis of Lumbar RegionStudies of the same condition, open and under way.
- More trials run by Fondazione Policlinico Universitario Agostino Gemelli IRCCSThe sponsor's other registered studies.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Observational
- Observational model
- Case-control
- Time perspective
- Prospective
- Enrolment
- 100 participants (estimated)
Sponsor and investigators
- Sponsor type
- University, hospital or other
- Responsible party
- Principal investigator, La Rocca Giuseppe, Fondazione Policlinico Universitario Agostino Gemelli IRCCS
- Investigators
- Giuseppe La Rocca, Principal investigator, Fondazione Policlinico Agostino Gemelli IRCSS
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT07026552
- Sponsor's protocol ID
- ID 7092
- Acronym
- APIDeLeG
- Status last verified
- Aug 2025
- First submitted
- 7 Mar 2025
- Last updated
- 7 Aug 2025
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
Publications
Zheng Z, Ao X, Li P, Lian Z, Jiang T, Zhang Z, Wang L. CRLF1 Is a Key Regulator in the Ligamentum Flavum Hypertrophy. Front Cell Dev Biol. 2020 Sep 18;8:858. doi: 10.3389/fcell.2020.00858. eCollection 2020.
PubMed 33072735Liu C, Li P, Ao X, Lian Z, Liu J, Li C, Huang M, Wang L, Zhang Z. Clusterin negatively modulates mechanical stress-mediated ligamentum flavum hypertrophy through TGF-beta1 signaling. Exp Mol Med. 2022 Sep;54(9):1549-1562. doi: 10.1038/s12276-022-00849-2. Epub 2022 Sep 21.
PubMed 36131026Wang AY, Saini H, Tingen JN, Sharma V, Flores A, Liu D, Olmos M, McPhail ED, Safain MG, Kryzanski J, Arkun K, Riesenburger RI. The Relationship Between Wild-Type Transthyretin Amyloid Load and Ligamentum Flavum Thickness in Lumbar Stenosis Patients. World Neurosurg. 2022 Aug;164:e113-e118. doi: 10.1016/j.wneu.2022.04.008. Epub 2022 Apr 6.
PubMed 35398327Zhao R, Dong J, Liu C, Li M, Tan R, Fei C, Chen Y, Yang X, Shi J, Xu J, Wang L, Li P, Zhang Z. Thrombospondin-1 promotes mechanical stress-mediated ligamentum flavum hypertrophy through the TGFbeta1/Smad3 signaling pathway. Matrix Biol. 2024 Mar;127:8-22. doi: 10.1016/j.matbio.2024.01.005. Epub 2024 Jan 26.
PubMed 38281553Troyer KL, Puttlitz CM. Nonlinear viscoelasticty plays an essential role in the functional behavior of spinal ligaments. J Biomech. 2012 Feb 23;45(4):684-91. doi: 10.1016/j.jbiomech.2011.12.009. Epub 2012 Jan 10.
PubMed 22236525Cheung PWH, Tam V, Leung VYL, Samartzis D, Cheung KM, Luk KD, Cheung JPY. The paradoxical relationship between ligamentum flavum hypertrophy and developmental lumbar spinal stenosis. Scoliosis Spinal Disord. 2016 Sep 5;11(1):26. doi: 10.1186/s13013-016-0088-5. eCollection 2016.
PubMed 27635416Lu QL, Wang XZ, Xie W, Chen XW, Zhu YL, Li XG. Macrophage migration inhibitory factor may contribute to hypertrophy of lumbar ligamentum flavum in type 2 diabetes mellitus. Chin Med J (Engl). 2020 Mar 5;133(5):623-625. doi: 10.1097/CM9.0000000000000680. No abstract available.
PubMed 31996548Tomkins-Lane CC, Battie MC, Hu R, Macedo L. Pathoanatomical characteristics of clinical lumbar spinal stenosis. J Back Musculoskelet Rehabil. 2014;27(2):223-9. doi: 10.3233/BMR-130440.
PubMed 24284271Katz JN, Zimmerman ZE, Mass H, Makhni MC. Diagnosis and Management of Lumbar Spinal Stenosis: A Review. JAMA. 2022 May 3;327(17):1688-1699. doi: 10.1001/jama.2022.5921.
PubMed 35503342Sobanski D, Staszkiewicz R, Stachura M, Gadzielinski M, Grabarek BO. Presentation, Diagnosis, and Management of Lower Back Pain Associated with Spinal Stenosis: A Narrative Review. Med Sci Monit. 2023 Feb 23;29:e939237. doi: 10.12659/MSM.939237.
PubMed 36814366
Study at a glance
From the registry record, last updated by the sponsor on 7 Aug 2025. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Proteomic and Histological Analysis of Ligamentum Flavum Hypertrophy and Degeneration in Lumbar Spinal Stenosis: Clinical, Surgical, and Therapeutic Implications
- ClinicalTrials.gov ID
- NCT07026552
- Acronym / sponsor ID
- APIDeLeG / ID 7092
- Keywords
- Lumbar Spinal Stenosis, Ligamentum Flavum Hypertrophy, Proteomic Analysis, Molecular Biomarkers
- Study type
- Observational
- Recruitment status
- Recruiting
- Enrolment
- 100 participants (estimated)
- Lead sponsor
- Fondazione Policlinico Universitario Agostino Gemelli IRCCSUniversity, hospital or other
- Study start
- 15 Jun 2025 (actual)
- Primary completion
- 1 Mar 2027 (estimated)
- Study completion
- 1 Mar 2028 (estimated)
- First posted
- 18 Jun 2025 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
Background Lumbar spinal stenosis (LSS) is a common condition characterized by spinal canal narrowing, often linked to ligamentum flavum hypertrophy (LFH) and degeneration. Fibrotic processes involving elastin and collagen alterations contribute to LF thickening and spinal instability. Despite progress, the molecular mechanisms underlying LFH remain unclear, necessitating targeted diagnostic and therapeutic strategies.
Objective This study aims to analyze the proteomic and histological changes in LFH associated with LSS, correlating molecular signatures with imaging and surgical findings to identify potential therapeutic targets.
Methods LF samples from LSS patients undergoing surgery will be analyzed using mass spectrometry-based proteomics and histology to identify biomarkers and molecular pathways. Correlations between imaging, intraoperative findings, and molecular profiles will be assessed.
Expected Results The study aims to identify specific biomarkers and molecular pathways involved in LFH, linking them to clinical and imaging findings. Statistical analyses will evaluate associations between molecular alterations and surgical outcomes to define therapeutic targets.
Significance By identifying molecular markers of LFH, this research aims to improve LSS diagnosis and treatment, potentially guiding targeted therapies to slow disease progression and enhance patient outcomes.
Study Design A multidisciplinary team from Fondazione Policlinico Universitario Agostino Gemelli and Università Cattolica del Sacro Cuore will conduct the study, ensuring robust data integration and statistical evaluation.
Conclusion This comprehensive study will provide valuable insights into the molecular and histological modifications associated with LFH in LSS, paving the way for new therapeutic approaches to improve patient outcomes and satisfaction.
Detailed description
- INTRODUCTION Lumbar spinal stenosis (LSS) is a highly prevalent condition worldwide, characterized by the narrowing of the spinal canal. Epidemiological studies indicate a high incidence of LSS, influenced by demographic shifts and the increasing burden of age-related musculoskeletal disorders. The etiology of LSS is primarily classified as acquired (degenerative) or congenital, affecting approximately 103 million individuals globally. The degenerative form becomes increasingly common with advancing age. Anatomically, degenerative LSS is subdivided into central, lateral, and foraminal stenosis, with the highest prevalence observed at the L4-L5 level. Key etiological factors include thickening and deformation of the ligamentum flavum (LF), often resulting from reduced disc height, facet joint hypertrophy, or a combination of both. Among these factors, ligamentum flavum hypertrophy (LFH) is recognized as the primary cause of lumbar spinal canal stenosis (LSCS). The LF is a crucial structure connecting the laminae of adjacent vertebrae, composed of approximately 80% elastic fibers and 20% collagen fibers. It plays a vital role in forming the posterior boundary of the spinal canal, preventing excessive flexion of the vertebral column, and maintaining spinal stability. Several studies indicate that individuals with hypertrophic LF exhibit a reduction and disorganization of elastic fibers, accompanied by an increase in collagen fibers, suggesting that LFH is driven by a fibrotic process. Identifying risk factors for LFH remains challenging and is a subject of ongoing debate in the literature; age and mechanical stress are currently considered the most significant contributors. Few studies have focused on elucidating the molecular mechanisms underlying LSS and LFH or on identifying specific diagnostic and prognostic biomarkers. As a result, the pathophysiology and molecular basis of LSS and LFH remain poorly understood, underscoring the need for precise molecular characterization and the development of targeted treatments based on specific molecules. Zhao et al. identified a significant increase in thrombospondin-1 (THBS1) expression in LFH using proteomics and single-cell RNA sequencing in clinical samples. Laboratory experiments demonstrated that THBS1 activates the Smad3 signaling pathway via transforming growth factor β1 (TGF-β1), enhancing the expression of fibrotic markers COL1A2 and α-SMA. A bipedal murine model confirmed the crucial role of THBS1 in LFH development. Additionally, sestrin2 (SESN2), a stress-responsive protein, was shown to suppress THBS1 expression, preventing fibrosis in LF cells. These findings suggest that mechanical overload increases THBS1 production, triggering the TGF-β1/Smad3 pathway and leading to tissue hypertrophy. Suppressing THBS1 expression could provide a novel therapeutic approach for LFH. In another study, Wang et al. found that wild-type amyloid transthyretin (ATTRwt) was present in LF samples from patients undergoing decompression surgery, with amyloid load positively correlating with LF thickness and lumbar LF burden in a dose-dependent manner. Liu et al. reported that hypertrophic LF samples exhibited higher levels of CLU, TGF-β1, α-SMA, ALK5, and phosphorylated SMAD3 proteins compared to non-LFH samples. Mechanical stress and TGF-β1 were found to induce clusterin (CLU) expression in LF cells. Notably, CLU inhibited COL1A2 and α-SMA expression, which were stimulated by mechanical stress and TGF-β1. Mechanistic studies demonstrated that CLU suppressed mechanical stress-induced and TGF-β1-driven SMAD3 activity by inhibiting SMAD3 phosphorylation and nuclear translocation through competitive binding with ALK5. Additionally, PRKD3 stabilized CLU protein, preventing its lysosomal degradation. In vivo experiments showed that CLU attenuated LFH induced by mechanical stress. These results suggest that CLU mitigates LFH by modulating TGF-β1 signaling pathways both in vitro and in vivo, acting as a negative feedback regulator of TGF-β1 and inhibiting fibrotic responses in LF. Zheng et al. discovered that TGF-β1 significantly increased CRLF1 mRNA expression via the SMAD3 pathway. CRLF1 was found to enhance LF fibrosis through the ERK signaling pathway at the post-transcriptional level and was essential for the pro-fibrotic effects of TGF-β1. When CRLF1 was silenced, fibrosis induced by inflammatory cytokines and mechanical stress was reduced. Furthermore, experiments demonstrated that bipedal posture could induce LFH and increased CRLF1 expression in mice. Overexpression of CRLF1 led to LFH in vivo, whereas CRLF1 silencing prevented LFH development in bipedal mice. These studies highlight the critical role of specific molecules in the development and regulation of LFH. However, the pathogenesis remains incompletely elucidated. Further research is required to clarify these mechanisms and develop potential strategies for the prevention and treatment of LFH and LSS.
- OBJECTIVES AND CLINICAL TRIAL AIMS (HYPOTHESIS AND EXPECTED OUTCOMES) The objective of this study is to conduct a comprehensive clinical and proteomic investigation of LFH, comparing molecular profiles of different LF samples within a well-defined patient cohort that meets inclusion criteria and has a statistically significant sample size. Proteomics is a valuable tool for studying diseases at the molecular level, helping to elucidate mechanisms involved in inflammatory responses and biomechanical stress. Specifically, Clinical Proteomics, as applied in this project, focuses on the biomedical application of proteomics and integrates proteomics, epidemiology, clinical chemistry, and medical disciplines, aligning perfectly with the study's objectives. This approach involves determining the total protein expression profile of a specific cell, tissue, or body fluid at a given time, assessing qualitative and quantitative differences between healthy and diseased subjects. This project integrates multiple research units, where clinicians, neurosurgeons, biochemists, and molecular biologists collaborate closely to achieve the desired outcomes, each contributing their expertise to the study.
- STUDY DESIGN 3.1 Study Type: Prospective, single-center observational study. 3.2 Study Duration: The study will commence following approval by the Ethics Committee and will last for 36 months. 3.3 Study Endpoints 3.3.1 Primary Endpoint Investigate molecular and histological aspects through proteomic and microscopic analysis to identify a potential specific pattern in LSS patients, comparing them with a healthy population. 3.3.2 Secondary Endpoints Correlate blood test results (routine clinical blood sampling) with a specific LFH pattern. Assess correlations between preoperative imaging findings and intraoperative and molecular results. 3.4 Experimental Procedures Provide a molecular characterization of the ligamentum flavum in two study populations (non-degenerative disease vs. degenerative disease) through the application of an integrated proteomic approach based on top-down and bottom-up platforms. The data could provide valuable insights into the molecular mechanisms underlying the onset and progression of the disease. Identify molecular biomarkers for clinical applications: The analysis of different ligamentum flavum samples could reveal specific proteins associated with spinal stenosis and clarify the mechanisms regulating these pathways. The identification of these biomarkers could significantly improve the treatment of lumbar spinal stenosis by introducing new therapeutic targets to mitigate inflammatory and hypertrophic responses, slow stenosis progression, and ultimately enhance patients' quality of life.
- STUDY POPULATION (SAMPLE SIZE CALCULATION) Patients undergoing decompression surgery for lumbar spinal stenosis will be compared with patients undergoing surgery for other degenerative spinal diseases.
- DATA ANALYSIS AND SAMPLE SIZE 5.1 SAMPLE SIZE Given the nature of the study, a formal sample size determination is not required. Based on the number of patients treated annually, we estimate enrolling 100 patients who meet the inclusion and exclusion criteria within 24 months and describing their proteomic patterns. Ligamentum flavum samples will be obtained from 50 patients undergoing decompression surgery for lumbar spinal stenosis and compared with samples from 50 patients undergoing surgery for other degenerative spinal diseases. 5.2 HISTOLOGICAL ANALYSIS The samples will be stained and examined to detect changes in the composition of collagen and elastin fibers, cellularity, and the presence of inflammatory markers. Advanced imaging techniques will be employed to quantify tissue alterations. 5.3 MOLECULAR ANALYSIS RNA and protein extracts from ligamentum flavum samples will be analyzed using techniques such as qPCR, Western blotting, and immunohistochemistry to identify gene and protein expression changes related to fibrosis, inflammation, and extracellular matrix remodeling. 5.4 PROTEOMIC ANALYSIS Ligament samples will undergo proteomic analysis using mass spectrometry platforms, employing integrated top-down and bottom-up approaches. 5.5 STATISTICAL ANALYSIS Quantitative variables following a normal distribution will be summarized as mean and standard deviation (SD) or, otherwise, as median and interquartile range (IQR). Categorical variables will be reported as absolute and relative frequencies (percentage). Normality of variables will be assessed using the Shapiro-Wilk test. Comparisons between categorical variables will be performed using the chi-square test or Fisher's exact test. Differences between quantitative variables will be tested using Student's t-test or the Mann-Whitney test. Preoperative and postoperative clinical data, functional outcomes, and imaging results will be collected and correlated with histological and molecular data to identify potential biomarkers and predictors of surgical outcomes through linear regression analysis. Correlation between various parameters will be further evaluated by calculating the Pearson and/or Spearman correlation coefficient. Results will be considered statistically significant at p<0.05. Analyses will be conducted using R statistical software (R, CRAN).
- DIRECT ACCESS TO DATA/ORIGINAL DOCUMENTS The Principal Investigator or their delegates must allow the Regulatory Authority, the Independent Ethics Committee, or the Sponsor (or their delegates) free access and the ability to conduct relevant audits on all original study documentation, including informed consent forms signed by enrolled subjects, relevant medical records, and/or outpatient registers. Individuals granted access to the documentation must take all reasonable precautions to maintain the confidentiality of subject identities in compliance with applicable legislation.
- GOOD CLINICAL PRACTICE REGULATIONS This study will be conducted in accordance with the principles of Good Clinical Practice (GCP) (Group, 1996), the Declaration of Helsinki, and national regulations governing the conduct of clinical trials. By signing the protocol, the investigator agrees to adhere to the procedures and instructions contained therein and to conduct the study in compliance with GCP, the Declaration of Helsinki, and national laws regulating clinical trials.
Study design
- Observational model
- Case-control
- Time perspective
- Prospective
- Number of arms
- 2
| Arm | Type | Receives |
|---|---|---|
| Lumbar Spinal Stenosis Surgery Group | – | –This cohort consists of patients undergoing decompression surgery for lumbar spinal stenosis. Tissue and biological fluid samples will be collected intraoperatively to analyze molecular and histological characteristics associated with ligamentum flavum hypertrophy (LFH). |
| Other Degenerative Spinal Disease Surgery Group | – | –This cohort includes patients undergoing surgery for other degenerative spinal conditions of the spine such as lumbar disk herniation. Ligamentum flavum samples from this group will serve as a comparative control to assess differences in molecular, histological, and proteomic profiles between non-LFH and LFH tissues. |
Who may qualify
- Ages
- 50 to 85 years
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Adult, Older adult
- Study population
- The study population will consist of adult patients (aged 50-85 years) undergoing spinal surgery at the Fondazione Policlinico A. Gemelli IRCCS, a tertiary referral center specializing in neurosurgical care. Patients will be evaluated, assessed for surgical indication, and enrolled in the study at the Neurosurgery Department of the Institution.
Key inclusion criteria (3 listed)
- Radiological (CT and/or MRI) and clinical evidence of lumbar spinal stenosis (LSS).
- Age range: 50-85 years.
- Signed informed consent, medical records release form, and HIPAA authorization form (or equivalent according to local regulations), reviewed and signed by the patient or legally authorized representatives.
Key exclusion criteria (5 listed)
- Pediatric population and individuals under 50 years of age.
- Concomitant genetic musculoskeletal disorders.
- History of trauma.
- Spinal infections (spondylodiscitis, osteomyelitis, abscess, etc.).
- Presence of spinal tumors or other neoplasms.
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Primary outcome
Histological Modifications in the Ligamentum Flavum in Lumbar Spinal Stenosis and Other Degenerative Spinal Diseases
Time frame: Intraoperative sample collection and subsequent laboratory analysis within 12 months post-surgery
This outcome measures the relative abundance and structural organization of collagen and elastin fibers in ligamentum flavum tissue from patients with lumbar spinal stenosis and other degenerative spinal diseases, using histological staining. Unit of Measure: Histological score or percentage composition
Cellularity of Ligamentum Flavum Tissue
Time frame: Intraoperative sample collection; analysis completed within 12 months post-surgery
This outcome measures the number and density of fibroblasts and other resident cells in the ligamentum flavum. Unit of Measure: Cells per high power field (HPF)
Presence of Inflammatory Markers in Ligamentum Flavum
Time frame: Intraoperative sample collection; analysis completed within 12 months post-surgery
This outcome evaluates the expression of inflammatory markers (e.g., TNF-α, IL-6, CD68) in ligamentum flavum tissue using immunohistochemistry or immunofluorescence. Unit of Measure: Semi-quantitative histological score or intensity of staining
5 secondary outcomes
Expression of Matrix Metalloproteinases (MMPs) in Ligamentum Flavum Tissue
Time frame: Within 12 months post-surgery, based on sample processing and analysis.
Expression of Transforming Growth Factor-beta (TGF-β) in Ligamentum Flavum Tissue
Time frame: Intraoperative tissue collection; laboratory analysis within 12 months post-surgery
Expression of Bone Morphogenetic Proteins (BMPs) in Ligamentum Flavum Tissue
Time frame: Intraoperative tissue collection; laboratory analysis within 12 months post-surgery
Correlation Between Histological and Molecular Findings and Preoperative Clinical Presentation
Time frame: Preoperative clinical data and intraoperative sample analysis; correlation analysis within 12 months
Correlation Between Histological and Molecular Findings and Postoperative Surgical Outcomes
Time frame: Intraoperative sample collection and postoperative follow-up at 3, 6, and 12 months
Results and safety
This study is still under way. Results are not available in the source record yet.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 7 Aug 2025.
- Background: PubMed 33072735Zheng Z, Ao X, Li P, Lian Z, Jiang T, Zhang Z, Wang L. CRLF1 Is a Key Regulator in the Ligamentum Flavum Hypertrophy. Front Cell Dev Biol. 2020 Sep 18;8:858. doi: 10.3389/fcell.2020.00858. eCollection 2020.
- Background: PubMed 36131026Liu C, Li P, Ao X, Lian Z, Liu J, Li C, Huang M, Wang L, Zhang Z. Clusterin negatively modulates mechanical stress-mediated ligamentum flavum hypertrophy through TGF-beta1 signaling. Exp Mol Med. 2022 Sep;54(9):1549-1562. doi: 10.1038/s12276-022-00849-2. Epub 2022 Sep 21.
- Background: PubMed 35398327Wang AY, Saini H, Tingen JN, Sharma V, Flores A, Liu D, Olmos M, McPhail ED, Safain MG, Kryzanski J, Arkun K, Riesenburger RI. The Relationship Between Wild-Type Transthyretin Amyloid Load and Ligamentum Flavum Thickness in Lumbar Stenosis Patients. World Neurosurg. 2022 Aug;164:e113-e118. doi: 10.1016/j.wneu.2022.04.008. Epub 2022 Apr 6.
- Background: PubMed 38281553Zhao R, Dong J, Liu C, Li M, Tan R, Fei C, Chen Y, Yang X, Shi J, Xu J, Wang L, Li P, Zhang Z. Thrombospondin-1 promotes mechanical stress-mediated ligamentum flavum hypertrophy through the TGFbeta1/Smad3 signaling pathway. Matrix Biol. 2024 Mar;127:8-22. doi: 10.1016/j.matbio.2024.01.005. Epub 2024 Jan 26.
- Background: PubMed 22236525Troyer KL, Puttlitz CM. Nonlinear viscoelasticty plays an essential role in the functional behavior of spinal ligaments. J Biomech. 2012 Feb 23;45(4):684-91. doi: 10.1016/j.jbiomech.2011.12.009. Epub 2012 Jan 10.
- Background: PubMed 27635416Cheung PWH, Tam V, Leung VYL, Samartzis D, Cheung KM, Luk KD, Cheung JPY. The paradoxical relationship between ligamentum flavum hypertrophy and developmental lumbar spinal stenosis. Scoliosis Spinal Disord. 2016 Sep 5;11(1):26. doi: 10.1186/s13013-016-0088-5. eCollection 2016.
- Background: PubMed 31996548Lu QL, Wang XZ, Xie W, Chen XW, Zhu YL, Li XG. Macrophage migration inhibitory factor may contribute to hypertrophy of lumbar ligamentum flavum in type 2 diabetes mellitus. Chin Med J (Engl). 2020 Mar 5;133(5):623-625. doi: 10.1097/CM9.0000000000000680. No abstract available.
- Background: PubMed 24284271Tomkins-Lane CC, Battie MC, Hu R, Macedo L. Pathoanatomical characteristics of clinical lumbar spinal stenosis. J Back Musculoskelet Rehabil. 2014;27(2):223-9. doi: 10.3233/BMR-130440.
- Background: PubMed 35503342Katz JN, Zimmerman ZE, Mass H, Makhni MC. Diagnosis and Management of Lumbar Spinal Stenosis: A Review. JAMA. 2022 May 3;327(17):1688-1699. doi: 10.1001/jama.2022.5921.
- Background: PubMed 36814366Sobanski D, Staszkiewicz R, Stachura M, Gadzielinski M, Grabarek BO. Presentation, Diagnosis, and Management of Lower Back Pain Associated with Spinal Stenosis: A Narrative Review. Med Sci Monit. 2023 Feb 23;29:e939237. doi: 10.12659/MSM.939237.
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part.
Giuseppe La Rocca principal investigator
Fondazione Policlinico Agostino Gemelli IRCSS
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
An observational study of Spinal Stenosis of Lumbar Region and Spine Degeneration, run by Fondazione Policlinico Universitario Agostino Gemelli IRCCS at 1 site in Italy.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 3 inclusion and 5 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: looking for participants now, as of the sponsor's last update on 7 Aug 2025. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in Italy. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
Are results available for this study?
This study is still under way. Results are not available in the source record yet.
How can a doctor refer a patient or contact the research team?
Contact Giuseppe La Rocca (+ 39 3283776263, giuseppe.larocca@policlinicogemelli.it), or a site near the patient. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Histological Modifications in the Ligamentum Flavum in Lumbar Spinal Stenosis and Other Degenerative Spinal Diseases (time frame: Intraoperative sample collection and subsequent laboratory analysis within 12 months post-surgery). The study lists 3 primary outcomes in all. It is what the study was designed to measure, not a finding.
Where can I read the original study information?
On the ClinicalTrials.gov record for NCT07026552, which also lists 10 linked publications.
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 7 Aug 2025.