Antiphospholipid SyndromeICAS_APSNCT05583305
Prevalence and Etiologies of Intracranial Stenosis in Patients With Antiphospholipid Syndrome
An observational study of Antiphospholipid Syndrome and Stenosis, run by Chinese University of Hong Kong at 1 site in Hong Kong.
Trial summary
Antiphospholipid syndrome (APS) is an important cause of young stroke which could result in major disability. Cohort studies suggested that 17% of young ischemic stroke were accountable by APS (1). Read more about this study
- Who is it for?
- Ages 18 years and older
- Conditions the study is for
- Antiphospholipid Syndrome, Stenosis, Intracranial Stenosis
- What is being tested?
- Imaging assessment, Neurosonology assessment and Blood Test
- How many people
- 60 participants
- Where
- 1 siteHong Kong
- Study dates
- 12 Oct 2022to 17 Jul 2027
- 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
- No healthy volunteers
- Adult, Older adult
Study population: Adults with or without APS
Who may be able to join
- Patients diagnosed with APS who fulfilled the modified Sapporo criteria:
- at least one clinical criterion (vascular thrombosis or pregnancy morbidity); and
- laboratory criteria (aPL positivity twice, 12 weeks apart):
- Lupus anticoagulant positivity requires screening, mixing, and confirmation test as per International Society of Thrombosis and Hemostasis guidelines (11). ii. Anticardiolipin antibodies positivity requires a medium to high titer IgG and/or IgM level by ELISA assays. iii. Anti-β2 glycoprotein antibodies positivity requires a >99th titer IgG and/or IgM level by ELISA assays.
- Patients age ≥18 years
- Patients who are able to provide an informed consent to study procedures
Who cannot join
- Patient with established neurological disease, such as stroke, cerebral venous thrombosis, vasculitis of the central nervous system, cerebral lupus, etc.
- Patient contraindicated to contrast MRI scans. E.g. claustrophobia, allergy to gadolinium contrast, MRI incompatible implants, estimated glomerular filtration rate of < 30mL/min/1.73m2.
Trial locations and contacts
1 site in 1 country. Contact the study team or a site near you to ask about taking part.
About this study
Official title: Prevalence and Etiologies of Intracranial Stenosis in Patients With Antiphospholipid Syndrome: a Cross Sectional Study (ICAS_APS)
Antiphospholipid syndrome (APS) is an important cause of young stroke which could result in major disability. Cohort studies suggested that 17% of young ischemic stroke were accountable by APS (1). Although warfarin has been the mainstay of treatment in APS for the past decades, recurrent thromboembolism occurred up to 10% of warfarinized patients with APS (2, 3). These observations call for an in-depth understanding of disease mechanisms secondary to antiphospholipid antibodies (aPL). Contrary to traditional understanding, recent evidence suggested mechanisms of cerebrovascular ischemia in APS are far more complex than hypercoagulability alone.
In the proposed cross-sectional study, we aim to determine the prevalence of intracranial stenosis, and to explore the correlations between the neuroimaging findings and the immunological as well as clinical features in patients with APS.
In the proposed cross-sectional study, we aim to determine the prevalence of intracranial stenosis, and to explore the correlations between the neuroimaging findings and the immunological as well as clinical features in patients with APS.
Read the detailed description
In the proposed cross-sectional study, we aim to determine the prevalence of intracranial stenosis, and to explore the correlations between the neuroimaging findings and the immunological as well as clinical features in patients with APS.
Upon reviewing the clinical and laboratory information in the medical specialist out-patient clinics, electronic patient record and/or through the Clinical Data Analysis And Reporting System (CDARS), investigators shall identify and recruit on-site APS patients who fulfilled the modified Sapporo criteria, currently aged ≥18 years, and receive care from the Prince of Wales Hospital.
Investigators shall then arrange a study clinic visit for eligible patients. After obtaining an informed consent, patients will be subjected to cognitive assessment (Hong Kong Version of Montreal Cognitive Assessment (HK-MoCA)), blood pressure, pulse, body mass index measurement, urinalysis, and contrast MRI brain (see imaging assessment below). Demographic data (age, gender, smoking, drinking, ambulatory status), medical comorbidities (concurrent autoimmune diseases and their organ involvement, history of catastrophic APS, hypertension, hyperlipidemia, diabetes mellitus, congestive heart failure, number and type of previous arterial or venous thromboembolism), laboratory parameters (complete blood count, liver and renal function test, C-reactive protein, erythrocyte sediment rate, high sensitive C-reaction protein, plasminogen activator inhibitor-1, neurofilament light chain, titers of autoimmune markers including anti-nuclear antibodies, extractable nuclear antigen antibodies, aPLs, rheumatoid factor, anti-cyclic citrullinated peptide antibody, etc.), concurrent medications (aspirin, warfarin, direct oral anticoagulants, antihypertensives, statins, steroid, immunosuppressants, etc.). In another ongoing prospective Brain Health Longitudinal study which contained stroke- and dementia free participants (CREC Ref. No: 2018.148), investigators shall identify age- and gender-matched individuals without aPLs as controls. They will be assessed in the same manner as the APS patients.
- Conditions
- Antiphospholipid Syndrome, Stenosis, Intracranial Stenosis
- Being tested
- Imaging assessment, Neurosonology assessment, Blood Test
- Medical subject headings
- Antiphospholipid Syndrome, Constriction, Pathologic
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Imaging assessmentDiagnostic test
Investigators shall perform cranial MRI examinations. The scanning protocol will employ an MRI scan protocol with T1-weighted, T2-weighted, FLAIR, susceptibility weighted imaging, diffusion weighted imaging, and time-of-flight magnetic resonance angiography (MRA) sequences. In addition, high-resolution magnetic resonance vessel wall imaging (HRMRI) allows assessment of the vessel wall using specific the SPACE sequence and the MATCH sequence. Assessors of the HRMRI images shall be blinded to the group allocation and clinical information.
Neurosonology assessmentDiagnostic test
Investigators shall perform carotid duplex ultrasonography (CD) assessment, focusing on the peak systolic (PSV) and end diastolic velocity (EDV) of bilateral extracranial internal carotid arteries (ICA) Brightness mode imaging shall gauge the intimal thickness and plaque characteristics (if any) of bilateral ICAs.
Blood TestDiagnostic test
Nine milliliters of EDTA blood will be drawn during the research clinic visit for evaluation of the degree of neurovascular inflammation. Serum plasminogen activator inhibitor-1 (PAI-1) and high-sensitive C-reactive protein (hsCRP) are markers of vascular inflammation, atherosclerosis, and thrombotic risk. Serum neurofilament light chain (NfL) is a biomarker for neuroaxonal injury that correlates with small vessel disease.
| Study group | Role | What they receive |
|---|---|---|
| Patients diagnosed with APS | Investigators shall recruit patients with the following criteria:
1. Diagnosed with APS who fulfilled the modified Sapporo criteria:
1. at least one clinical criterion (vascular thrombosis or pregnancy morbidity); and
2. laboratory criteria (aPL positivity twice, 12 weeks apart):
i. Lupus anticoagulant positivity requires screening, mixing, and confirmation test as per International Society of Thrombosis and Hemostasis guidelines (11).
ii. Anticardiolipin antibodies positivity requires a medium to high titer IgG and/or IgM level by ELISA assays.
iii. Anti-β2 glycoprotein antibodies positivity requires a >99th titer IgG and/or IgM level by ELISA assays.
2. Patients age ≥18 years
3. Patients who are able to provide an informed consent to study procedures Receives: Diagnostic Test: Imaging assessment; Diagnostic Test: Neurosonology assessment; Diagnostic Test: Blood Test | |
| Controls | From the ongoing prospective Brain Health Longitudinal study which contained stroke- and dementia free participants (CREC Ref. No: 2018.148), investigators shall identify age- and gender-matched individuals without aPLs as controls Receives: Diagnostic Test: Imaging assessment; Diagnostic Test: Neurosonology assessment; Diagnostic Test: Blood Test |
What is being measured
The primary outcome is the main question the study is designed to answer.
Radiological evidence of intracranial arterial stenosis
Defined as the presence of >50% stenosis of any intracranial arteries (ICA, MCA, anterior cerebral arteries, posterior cerebral arteries, basilar artery, or vertebral arteries) or presence of arterial plaques in vessel wall imaging.
Measured: 31／01／2026
Secondary outcomes (1)
Other radiological outcomes
Including the presence and pattern of enhancing intracranial plaques (concentric vs eccentric), Age-related White Matter Change Scale ≥ 2, white matter hyperintensity volume, presence of lacunes, cerebral microbleeds, extracranial ICA plaques, normalized total brain volume. Secondary biochemical outcomes include level of hs-CRP and PAI-1. The relationship between the neuroimaging outcomes and the clinical characteristics of patients with APS will be evaluated.
Measured: 31／01／2026
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted17 Oct 2022
- Study start12 Oct 2022
- Primary completion31 Jan 2027 (estimated)
- Study completion17 Jul 2027 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Antiphospholipid SyndromeStudies of the same condition, open and under way.
- More trials run by Chinese University of Hong KongThe 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
- Cohort
- Time perspective
- Cross-sectional
- Enrolment
- 60 participants (estimated)
Sponsor and investigators
- Lead sponsor
- Chinese University of Hong Kong
- Sponsor type
- University, hospital or other
- Responsible party
- Principal investigator, Dr. IP Yiu Ming Bonaventure, Chinese University of Hong Kong
- Investigators
- Bonaventure Yiu Ming IP, MB ChB, Principal investigator, Chinese University of Hong Kong
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT05583305
- Sponsor's protocol ID
- CREC 2022.352
- Acronym
- ICAS_APS
- Status last verified
- May 2026
- First submitted
- 13 Oct 2022
- Last updated
- 26 May 2026
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- No
Study at a glance
From the registry record, last updated by the sponsor on 26 May 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Prevalence and Etiologies of Intracranial Stenosis in Patients With Antiphospholipid Syndrome: a Cross Sectional Study (ICAS_APS)
- ClinicalTrials.gov ID
- NCT05583305
- Acronym / sponsor ID
- ICAS_APS / CREC 2022.352
- Conditions
- Antiphospholipid Syndrome, Stenosis, Intracranial Stenosis
- Study type
- Observational
- Recruitment status
- Enrolling by invitation
- Enrolment
- 60 participants (estimated)
- Lead sponsor
- Chinese University of Hong KongUniversity, hospital or other
- Study start
- 12 Oct 2022 (actual)
- Primary completion
- 31 Jan 2027 (estimated)
- Study completion
- 17 Jul 2027 (estimated)
- First posted
- 17 Oct 2022 (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.
Antiphospholipid syndrome (APS) is an important cause of young stroke which could result in major disability. Cohort studies suggested that 17% of young ischemic stroke were accountable by APS (1). Although warfarin has been the mainstay of treatment in APS for the past decades, recurrent thromboembolism occurred up to 10% of warfarinized patients with APS (2, 3). These observations call for an in-depth understanding of disease mechanisms secondary to antiphospholipid antibodies (aPL). Contrary to traditional understanding, recent evidence suggested mechanisms of cerebrovascular ischemia in APS are far more complex than hypercoagulability alone.
In the proposed cross-sectional study, we aim to determine the prevalence of intracranial stenosis, and to explore the correlations between the neuroimaging findings and the immunological as well as clinical features in patients with APS.
In the proposed cross-sectional study, we aim to determine the prevalence of intracranial stenosis, and to explore the correlations between the neuroimaging findings and the immunological as well as clinical features in patients with APS.
Detailed description
In the proposed cross-sectional study, we aim to determine the prevalence of intracranial stenosis, and to explore the correlations between the neuroimaging findings and the immunological as well as clinical features in patients with APS.
Upon reviewing the clinical and laboratory information in the medical specialist out-patient clinics, electronic patient record and/or through the Clinical Data Analysis And Reporting System (CDARS), investigators shall identify and recruit on-site APS patients who fulfilled the modified Sapporo criteria, currently aged ≥18 years, and receive care from the Prince of Wales Hospital.
Investigators shall then arrange a study clinic visit for eligible patients. After obtaining an informed consent, patients will be subjected to cognitive assessment (Hong Kong Version of Montreal Cognitive Assessment (HK-MoCA)), blood pressure, pulse, body mass index measurement, urinalysis, and contrast MRI brain (see imaging assessment below). Demographic data (age, gender, smoking, drinking, ambulatory status), medical comorbidities (concurrent autoimmune diseases and their organ involvement, history of catastrophic APS, hypertension, hyperlipidemia, diabetes mellitus, congestive heart failure, number and type of previous arterial or venous thromboembolism), laboratory parameters (complete blood count, liver and renal function test, C-reactive protein, erythrocyte sediment rate, high sensitive C-reaction protein, plasminogen activator inhibitor-1, neurofilament light chain, titers of autoimmune markers including anti-nuclear antibodies, extractable nuclear antigen antibodies, aPLs, rheumatoid factor, anti-cyclic citrullinated peptide antibody, etc.), concurrent medications (aspirin, warfarin, direct oral anticoagulants, antihypertensives, statins, steroid, immunosuppressants, etc.). In another ongoing prospective Brain Health Longitudinal study which contained stroke- and dementia free participants (CREC Ref. No: 2018.148), investigators shall identify age- and gender-matched individuals without aPLs as controls. They will be assessed in the same manner as the APS patients.
Study design
- Observational model
- Cohort
- Time perspective
- Cross-sectional
- Number of arms
- 2
| Arm | Type | Receives |
|---|---|---|
| Patients diagnosed with APS | – | Diagnostic Test: Imaging assessment, Diagnostic Test: Neurosonology assessment, Diagnostic Test: Blood TestInvestigators shall recruit patients with the following criteria: 1. Diagnosed with APS who fulfilled the modified Sapporo criteria: 1. at least one clinical criterion (vascular thrombosis or pregnancy morbidity); and 2. laboratory criteria (aPL positivity twice, 12 weeks apart): i. Lupus anticoagulant positivity requires screening, mixing, and confirmation test as per International Society of Thrombosis and Hemostasis guidelines (11). ii. Anticardiolipin antibodies positivity requires a medium to high titer IgG and/or IgM level by ELISA assays. iii. Anti-β2 glycoprotein antibodies positivity requires a >99th titer IgG and/or IgM level by ELISA assays. 2. Patients age ≥18 years 3. Patients who are able to provide an informed consent to study procedures |
| Controls | – | Diagnostic Test: Imaging assessment, Diagnostic Test: Neurosonology assessment, Diagnostic Test: Blood TestFrom the ongoing prospective Brain Health Longitudinal study which contained stroke- and dementia free participants (CREC Ref. No: 2018.148), investigators shall identify age- and gender-matched individuals without aPLs as controls |
Who may qualify
- Ages
- 18 years and older
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Adult, Older adult
- Study population
- Adults with or without APS
Key inclusion criteria (6 listed)
- Patients diagnosed with APS who fulfilled the modified Sapporo criteria:
- Patients age ≥18 years
- Patients who are able to provide an informed consent to study procedures
Key exclusion criteria (2 listed)
- Patient with established neurological disease, such as stroke, cerebral venous thrombosis, vasculitis of the central nervous system, cerebral lupus, etc.
- Patient contraindicated to contrast MRI scans. E.g. claustrophobia, allergy to gadolinium contrast, MRI incompatible implants, estimated glomerular filtration rate of < 30mL/min/1.73m2.
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| Imaging assessmentInvestigators shall perform cranial MRI examinations. The scanning protocol will employ an MRI scan protocol with T1-weighted, T2-weighted, FLAIR, susceptibility weighted imaging, diffusion weighted imaging, and time-of-flight magnetic resonance angiography (MRA) sequences. In addition, high-resolution magnetic resonance vessel wall imaging (HRMRI) allows assessment of the vessel wall using specific the SPACE sequence and the MATCH sequence. Assessors of the HRMRI images shall be blinded to the group allocation and clinical information. | Diagnostic test | Controls, Patients diagnosed with APS |
| Neurosonology assessmentInvestigators shall perform carotid duplex ultrasonography (CD) assessment, focusing on the peak systolic (PSV) and end diastolic velocity (EDV) of bilateral extracranial internal carotid arteries (ICA) Brightness mode imaging shall gauge the intimal thickness and plaque characteristics (if any) of bilateral ICAs. | Diagnostic test | Controls, Patients diagnosed with APS |
| Blood TestNine milliliters of EDTA blood will be drawn during the research clinic visit for evaluation of the degree of neurovascular inflammation. Serum plasminogen activator inhibitor-1 (PAI-1) and high-sensitive C-reactive protein (hsCRP) are markers of vascular inflammation, atherosclerosis, and thrombotic risk. Serum neurofilament light chain (NfL) is a biomarker for neuroaxonal injury that correlates with small vessel disease. | Diagnostic test | Controls, Patients diagnosed with APS |
Primary outcome
Radiological evidence of intracranial arterial stenosis
Time frame: 31／01／2026
Defined as the presence of >50% stenosis of any intracranial arteries (ICA, MCA, anterior cerebral arteries, posterior cerebral arteries, basilar artery, or vertebral arteries) or presence of arterial plaques in vessel wall imaging.
1 secondary outcome
Other radiological outcomes
Time frame: 31／01／2026
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 26 May 2026.
- Individual participant dataSharing planned: No
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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.
Bonaventure Yiu Ming IP, MB ChB principal investigator
Chinese University of Hong Kong
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 Antiphospholipid Syndrome and Stenosis, run by Chinese University of Hong Kong at 1 site in Hong Kong.
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 6 inclusion and 2 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: enrolling by invitation, as of the sponsor's last update on 26 May 2026. 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 Hong Kong. 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?
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?
Radiological evidence of intracranial arterial stenosis (time frame: 31／01／2026). It is what the study was designed to measure, not a finding.
Where can I read the original study information?
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 26 May 2026.