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Transplantation InfectionTxL-FNNCT02811835

TransplantLines Food and Nutrition Biobank and Cohort Study (TxL-FN)

An observational study of Transplantation Infection and Renal Transplant Donor of Left Kidney, run by University Medical Center Groningen.

Active, not recruiting

Under way, not looking for participants. Everyone needed has enrolled. The study is still running.

Official record
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Trial summary

Short-term (1-year) results of renal transplantation are now excellent (over 95%). Long-term (10-year and longer) results are, however, still disappointing. Where most research has focused on immunosuppression and infections, the investigators hypothesize that due to poor homeostatic capacity and necessary use of… Read more about this study

Who is it for?
Ages 18 years and olderHealthy volunteers can take part
How many people
1,007 participants
Where
No sites listed yet
Study dates
Nov 2008to Nov 2028
How long will I take part?
20 Years
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 18 years and older
  • All sexes
  • Healthy volunteers accepted
  • Adult, Older adult

Study population: Renal Transplant Recipients and Healthy Potential Kidney Donors

Inclusion Criteria: More than one year after transplantation, prognosis > 1 year, stable outpatients situation -

Exclusion Criteria: Acute illnesses, fever, current hospitalisation

-

About this study

Official title: Renal Sensing of the Acidifying Effect of Sulphur-containing Amino Acids: Consequences for the Relation Between Protein Intake and Blood Pressure in Renal Transplant Recipients

Short-term (1-year) results of renal transplantation are now excellent (over 95%). Long-term (10-year and longer) results are, however, still disappointing. Where most research has focused on immunosuppression and infections, the investigators hypothesize that due to poor homeostatic capacity and necessary use of immunosuppressive and other drugs, renal transplant recipients are much more susceptible to poor dietary habits and exposure to potentially toxic contaminants than people of the general population, and that this contributes to accelerated function loss of the graft and excess risk of premature mortality, both contributing to poor long-term results. This study is a biobank and cohort study which investigates this hypothesis.

Read the detailed description

Short-term (1-year) results of renal transplantation are now excellent (over 95%). Long-term (10-year and longer) results are, however, still disappointing. Where most research has focused on immunosuppression and infections, the investigators hypothesize that due to poor homeostatic capacity and necessary use of immunosuppressive and other drugs, renal transplant recipients are much more susceptible to poor dietary habits and exposure to potentially toxic contaminants than people of the general population, and that this contributes to accelerated function loss of the graft and excess risk of premature mortality, both contributing to poor long-term results.

To investigate one part of this overarching hypothesis, the investigators wrote a project on around the specific topic of the relation between dietary acid load, ammoniagenesis and its potential influence on blood pressure. The investigators used this project to build a biobank and cohort in which they can test additional hypotheses on the relation between diet, contaminants and development of graft failure and the occurrence of mortality.

The investigators also included 300 healthy controls to compare diet, contaminant exposure and biomarkers with the renal transplant recipients.

What participants receive

What participants receive. In a randomised study each person is assigned to one group by chance.

Study groups in NCT02811835
Study groupRoleWhat they receive
Renal Transplant RecipientsRenal Transplant Recipients that were more than 1 year post-transplantation
Healthy ControlsHealthy subjects being evaluated as potential living kidney donors

What is being measured

The primary outcome is the main question the study is designed to answer.

  1. Graft failure

    Return to dialysis or re-transplantation

    Measured: 20 years

  2. All-cause mortality

    Death

    Measured: 20 years

Secondary outcomes (3)

  1. Cardiovascular mortality

    Cause specific mortality

    Measured: 20 years

  2. Cancer mortality

    Cause specific mortality

    Measured: 20 years

  3. Infectious disease mortality

    Cause specific mortality

    Measured: 20 years

Timeline

From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.

  1. First posted23 Jun 2016 (estimated)
  2. Study startNov 2008
  3. Primary completionMay 2011
  4. Study completionNov 2028 (estimated)

Resources

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
Cohort
Time perspective
Prospective
Enrolment
1,007 participants (actual)
Target duration
20 Years
IDs, dates and publications
ClinicalTrials.gov ID
NCT02811835
Sponsor's protocol ID
METc2008/186
Acronym
TxL-FN
Status last verified
Aug 2017
First submitted
21 Jun 2016
Last updated
22 Aug 2017
Results posted
No
Data monitoring committee
No
Individual data sharing
Yes: Each participant has a study number which is not traceable to the patient in the study

Publications

  • van der Veen Y, Doorenbos CS, Kremer D, Touw DJ, Corpeleijn E, Rimbach G, Annema C, Franssen CF, Bakker SJ, Post A. Low Dietary Bromide Intake and Sex-Specific Mortality in Kidney Transplant Recipients. Curr Dev Nutr. 2026 Sep 25;10(10):109543. doi: 10.1016/j.cdnut.2026.109543. eCollection 2026 Oct.

    PubMed 42935991

  • Kremer D, Groothof D, Salamah S, Post A, Knobbe TJ, Peterson S, van Londen M, Yerramilli M, Berger SP, Alkaff FF, Bakker SJL. Plasma Symmetric Dimethylarginine and Mortality in Kidney Transplant Recipients: A Cohort Study. Kidney360. 2026 Aug 1;7(8):1873-1879. doi: 10.34067/KID.0000001204. Epub 2026 May 4.

    PubMed 42081278

  • van der Veen Y, Post A, Kremer D, Hao J, Doorenbos CSE, Knobbe TJ, de Borst MH, Touw DJ, Franssen CFM, Corpeleijn E, Annema C, Bakker SJL. Low Dietary Iodine Intake and Sex-Specific Mortality in Kidney Transplant Recipients. Clin J Am Soc Nephrol. 2026 Jun 1;21(6):1036-1047. doi: 10.2215/CJN.0000001048. Epub 2026 Mar 30.

    PubMed 41911029

  • Kremer D, Rawee P, Knobbe TJ, Vinke JSJ, Luersen K, Leaf DE, Swinkels DW, de Borst MH, Rimbach G, Bakker SJL, Eisenga MF. Higher Urinary Iron Levels Are Associated with Kidney Dysfunction, Tubular Damage, and Increased Mortality in Kidney Transplant Recipients. Kidney360. 2025 Nov 1;6(11):1970-1980. doi: 10.34067/KID.0000000878. Epub 2025 Jun 26.

    PubMed 40569672

  • Heddema WA, Hof MAJ, Sosnowski P, Bakker SJL, Hopfgartner G, Klont F; TransplantLines Investigators. Pharmacometabolomics Detects Various Unreported Metoprolol Metabolites in Urine of (Potential) Living Kidney Donors and Kidney Transplant Recipients. Clin Pharmacokinet. 2025 May;64(5):779-789. doi: 10.1007/s40262-025-01502-7. Epub 2025 Apr 26.

    PubMed 40285825

  • Post A, Groothof D, Kremer D, Knobbe TJ, Abma W, Koops CA, Tsikas D, Wallimann T, Dullaart RPF, Franssen CFM, Kema IP, Heiner-Fokkema MR, Bakker SJL. Creatine homeostasis and the kidney: comparison between kidney transplant recipients and healthy controls. Amino Acids. 2024 Jun 13;56(1):42. doi: 10.1007/s00726-024-03401-w.

    PubMed 38869518

  • Post A, Kremer D, Groothof D, Seidel U, Huebbe P, Franssen CFM, Kema IP, Luersen K, Rimbach G, Bakker SJL. Dietary lithium intake, graft failure and mortality in kidney transplant recipients. Nephrol Dial Transplant. 2023 Jul 31;38(8):1867-1879. doi: 10.1093/ndt/gfac340.

    PubMed 36564033

  • Kremer D, Alkaff FF, Post A, Knobbe TJ, Tepel M, Thaunat O, Berger SP, van den Born J, Genovese F, Karsdal MA, Rasmussen DGK, Bakker SJL. Plasma endotrophin, reflecting tissue fibrosis, is associated with graft failure and mortality in KTRs: results from two prospective cohort studies. Nephrol Dial Transplant. 2023 Mar 31;38(4):1041-1052. doi: 10.1093/ndt/gfac332.

    PubMed 36535643

  • Oste MCJ, Duan MJ, Gomes-Neto AW, Vinke PC, Carrero JJ, Avesani C, Cai Q, Dekker LH, Navis GJ, Bakker SJL, Corpeleijn E. Ultra-processed foods and risk of all-cause mortality in renal transplant recipients. Am J Clin Nutr. 2022 Jun 7;115(6):1646-1657. doi: 10.1093/ajcn/nqac053.

    PubMed 35470855

  • Kremer D, Post A, Gomes-Neto AW, Groothof D, Kunutsor SK, Nilsen T, Hidden C, Sundrehagen E, Eisenga MF, Navis G, Bakker SJL; TransplantLines Investigators. Plasma neutrophil gelatinase-associated lipocalin and kidney graft outcome. Clin Kidney J. 2021 Nov 8;15(2):235-243. doi: 10.1093/ckj/sfab219. eCollection 2022 Feb.

    PubMed 35145638

  • Stam SP, Sokooti S, Eisenga MF, van der Veen A, Gomes-Neto AW, van Dijk PR, van Zanden JJ, Vos MJ, Kema IP, van Beek AP, Bakker SJL; TransplantLines Investigators. Androgens and Development of Posttransplantation Diabetes Mellitus in Male Kidney Transplant Recipients: A Post Hoc Analysis of a Prospective Study. Diabetes Care. 2021 Dec;44(12):2683-2690. doi: 10.2337/dc21-0237. Epub 2021 Oct 5.

    PubMed 34610923

  • Yeung SMH, Gomes-Neto AW, Oste MCJ, van den Berg E, Kootstra-Ros JE, Sanders JSF, Berger SP, Carrero JJ, De Borst MH, Navis GJ, Bakker SJL. Net Endogenous Acid Excretion and Kidney Allograft Outcomes. Clin J Am Soc Nephrol. 2021 Sep;16(9):1398-1406. doi: 10.2215/CJN.00780121. Epub 2021 Jun 16.

    PubMed 34135022

  • Cai Q, Oste MCJ, Gomes-Neto AW, Dekker LH, Borgonjen-van den Berg KJ, Geleijnse JM, Bakker SJL, de Borst MH, Navis GJ. Metabolic syndrome-related dietary pattern and risk of mortality in kidney transplant recipients. Nutr Metab Cardiovasc Dis. 2021 Apr 9;31(4):1129-1136. doi: 10.1016/j.numecd.2021.01.005. Epub 2021 Jan 19.

    PubMed 33618925

  • Klont F, Kremer D, Gomes Neto AW, Berger SP, Touw DJ, Hak E, Bonner R, Bakker SJL, Hopfgartner G. Metabolomics data complemented drug use information in epidemiological databases: pilot study of potential kidney donors. J Clin Epidemiol. 2021 Jul;135:10-16. doi: 10.1016/j.jclinepi.2021.02.008. Epub 2021 Feb 9.

    PubMed 33577985

  • Sotomayor CG, Oskooei SS, Bustos NI, Nolte IM, Gomes-Neto AW, Erazo M, Gormaz JG, Berger SP, Navis GJ, Rodrigo R, Dullaart RPF, Bakker SJL. Serum uric acid is associated with increased risk of posttransplantation diabetes in kidney transplant recipients: a prospective cohort study. Metabolism. 2021 Mar;116:154465. doi: 10.1016/j.metabol.2020.154465. Epub 2020 Dec 13.

    PubMed 33316268

Questions about this trial

What is this clinical trial studying?

An observational study of Transplantation Infection and Renal Transplant Donor of Left Kidney, run by University Medical Center Groningen.

The full registered description is in the About this study section and the official record.

Who may be eligible to take part?

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: under way, not looking for participants, as of the sponsor's last update on 22 Aug 2017. Status can change between updates, so confirm with the study contact before making plans.

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?

The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.

What does the primary outcome measure?

Graft failure (time frame: 20 years). The study lists 2 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 NCT02811835, which also lists 25 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 22 Aug 2017.

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