Negative Antiphospholipid Syndrome: a Multicentric Study (SNAPSITA)

May 9, 2025 updated by: Italian Society for Rheumatology

Multicentre no-profit, national, (cross-sectional diagnostic) retrospective study, promoted by the Italian Society for Rheumatology.

The main objective of the study is to assess the diagnostic accuracy of non-criteria aPL (anti-vimentin/cardiolipin and anti-phosphatidylserine/prothrombin) in identifying APS in patients with thrombosis/recurrent adverse pregnancy outcomes.

Study Overview

Status

Status

Indicates the current recruitment status or the expanded access status.
Recruiting

Conditions

Conditions

The disease, disorder, syndrome, illness, or injury that is being studied. On ClinicalTrials.gov, conditions may also include other health-related issues, such as lifespan, quality of life, and health risks.

Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.

Detailed Description

BACKGROUND Antiphospholipid syndrome (APS) is an autoimmune disorder leading to arterial and/or venous thrombotic events, and pregnancy morbidity. Seronegative antiphospholipid syndrome (SN-APS) occurs in case of clinical manifestations highly suggestive of APS but with negative test for circulating conventional antiphospholipid antibodies (anticardiolipin antibodies, anti-beta-I-glycoprotein antibodies, lupus anticoagulant). Recent studies have shown that most SN-APS patients present circulating (non-criteria) antibodies potentially explaining the clinical manifestations. In a smaller proportion of SN-APS patients, no antibody has been detected so far. Available knowledge on the clinical presentation and disease course of SN-APS is limited, and the causal relationship between non-criteria antibodies and recurrent thrombosis deserves further research to be confirmed. To date, no difference between APS and SN-APS groups has been highlighted in terms of thrombotic events or pregnancy morbidity, but this could be in part explained by small samples not sufficiently powered to detect a difference. Moreover, it is still to determine whether the detection of "non-criteria" antibodies in addition to conventional aPL may help stratify patients according to their risk of clinical manifestation.A multicentre study involving Italian centres could allow to investigate the diagnostic accuracy of no-criteria aPL and elucidate the prognostic impact of such antibodies alone or in combination with criteria aPL. In addition, a multicentre study could allow to study a larger sample of patients and better quantify poorly investigated aspects in SN-APS

MAIN OBJECTIVE To assess the diagnostic accuracy of non-criteria aPL (anti-vimentin/cardiolipin and anti-phosphatidylserine/prothrombin) in identifying APS in patients with thrombosis/recurrent adverse pregnancy outcomes (group 1 vs group 3, see below).

SECONDARY OBJECTIVES

  • To assess the diagnostic accuracy of non-criteria aPL in identifying SN-APS in patients with thrombosis/recurrent adverse pregnancy outcomes (group 2 vs group 3).
  • To compare the clinical characteristics of APS vs SN-APS in patients with and without non-criteria aPL.
  • To estimate the association between different aPL status on the recurrence of thrombosis/adverse pregnancy outcomes.

EXPLORATORY OBJECTIVE To assess the prevalence of: anti-cardiolipin antibodies (aCL) by thin-layer chromatography (TLC)-immunostaining, anti-carbamylated-β2-glycoprotein I antibodies and Anti-glucose-modified β2 glycoprotein I antibodies in APS and SN-APS groups (group 1 and group 2).

SAMPLE SIZE AND STUDY PROCEDURES A minimum sample size of 35 patients for each group is planned for this study

LABORATORY PROCEDURES Blood samples will be collected and analysed in each recruiting centre, as routine practice at 12 weeks apart. The laboratory tests for the non-criteria aPL will be centrally performed at the Department of "Experimental Medicine', Umberto I Polyclinic in Rome.

STUDY DURATION Enrolment: 24 months starting from the first patient recruited Analysis and reporting: 12 months starting from the end of the enrollment

STUDY SCHEME The study can be divided into three phases: i) the collection of all clinical data at the onset of the thrombotic or obstetric event; ii) the collection of all the clinical data between the first clinical event and the patient recruitment; iii) the detection of non-criteria aPL from the patient's blood samples. The first two phases characterise the retrospective part of the study, while the third phase characterises the cross-sectional part of the study.

In phase 1, the following data associated with the clinical event will be collected: relevant demographic data, the history of all criteria events, the history of all non-criteria events, all relevant risk factors, the history of pharmacological treatments before or in progress at the clinical event and the collection of laboratory data available at the diagnosis. Phase 1 data will be collected by all participating centres.

In phase 2, new criteria events, non-criteria manifestations related to the clinical events and risk factors developed between the first clinical event and the date of recruitment of a patient will be assessed. Phase 2 data will be collected by all participating centres.

In phase 3, patients' blood samples will be tested at the coordinating centre to evaluate the presence of non-criteria aPL. Two blood samples will be collected by each patient recruited by a centre; such samples should be primarily retrieved from those previously collected by a centre at the time of diagnosis(herein "serum library") and stored at the centre itself; in case of their absence, blood samples can be collected from a recruited patient upon enrolment. In case only one sample can be retrieved from the hospital serum library, the remaining one will be collected from the recruited patient. Blood samples taken from deceased patients will be excluded.

STATISTICAL ANALYSIS Baseline characteristics will be summarized by descriptive statistics. The accuracy of non-criteria aPL (index test) in discriminating between cases and controls (reference standard) will be estimated as sensitivity and specificity.

A first analysis will use APS criteria cases (group 1) and controls(group 3) as non-cases; a second analysis will use SN-APS (group 2) as cases and controls (group 3) as non-cases.

The following groups [APS (group 1), SN-APS (group 2 subdivided into positive for non-criteria aPL and negative for non-criteria) and controls (group 3)] will be compared for clinical characteristics treatment variables.

A logistic regression model, considering the recurrent event as outcome and the APS status (groups 1, 2 and 3) as predictor, adjusted for demographic, event type and treatment will be performed

Study Type

Study Type

Describes the nature of a clinical study. Study types include interventional studies (also called clinical trials), observational studies (including patient registries), and expanded access.
Observational

Enrollment (Estimated)

Enrollment

The number of participants in a clinical study. The "anticipated" enrollment is the target number of participants that the researchers need for the study.
105

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Contact

Study Contact

The name and contact information for the person who can answer enrollment questions for a clinical study. Each location where the study is being conducted may also have a specific contact, who may be better able to answer those questions.

Study Contact Backup

Study Locations

  • Italy
    • Rome
      • Roma, Rome, Italy, 00185
        • Recruiting
        • Umberto I Polyclinic, Rome- Department of Rheumatology
        • Contact:

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Eligibility Criteria

The key requirements that people who want to participate in a clinical study must meet or the characteristics they must have. Eligibility criteria consist of both inclusion criteria (which are required for a person to participate in the study) and exclusion criteria (which prevent a person from participating). Types of eligibility criteria include whether a study accepts healthy volunteers, has age or age group requirements, or is limited by sex.

Ages Eligible for Study

  • Adult
  • Older Adult

Accepts Healthy Volunteers

No

Sampling Method

Non-Probability Sample

Study Population

Investigators plan to include a minimum sample size of 35 patients for each group; all patients will have the following features:

  • patients affected by Antiphospholipid syndrome (APS) or Seronegative antiphospholipid syndrome (SN-APS) or patients with clinical criteria (thrombotic or obstetric) for APS, negative for aPL, but without clinical features highly suggestive of APS
  • Age <65 years (at the event time)
  • Less than 5 years from the first event to the beginning of the study

Description

INCLUSION CRITERIA:

  1. Group 1 [APS]: Patients fulfilling the classification criteria for antiphospholipid syndrome (seropositive APS, SP-APS)
  2. Group 2 [SN-APS]: patients with seronegative APS (SN-APS): with clinical criteria (thrombotic or obstetric) for APS, persistently negative for aPL, and with clinical features highly suggestive of APS (recurrent events, thrombotic + obstetrical events, extra-criteria manifestations, other autoimmune diseases)
  3. Group 3: patients with clinical criteria (thrombotic or obstetric) for APS, negative for aPL, but without clinical features highly suggestive of APS (recurrent events, thrombotic + obstetrical events, extra-criteria manifestations, other autoimmune diseases).
  4. Age < 65 years (at event time)
  5. Less than 5 years from the first even

EXCLUSION CRITERIA

  1. Group 2 and 3: patients with a known cause of thrombosis or obstetrical manifestations
  2. Deceased patients
  3. Less than 5 years from the first event

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

Cohorts and Interventions

Group / Cohort

Group / Cohort

A group or subgroup of participants in an observational study that is assessed for biomedical or health outcomes.
Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.
Group 1 [APS]
Patients fulfilling the classification criteria for antiphospholipid syndrome (seropositive APS, SN-APS)
Other: Diagnostic accuracy
To assess the diagnostic accuracy of non-criteria aPL (anti-vimentin/cardiolipin and anti-phosphatidylserine/prothrombin) in identifying APS in patients with thrombosis/ recurrent adverse pregnancy outcomes
Group 2 [SN-APS]
Patients with seronegative APS (SN-APS): with clinical criteria (thrombotic or obstetric) for APS, persistently negative for aPL, and with clinical features highly suggestive of APS (recurrent events, thrombotic + obstetrical events, extra-criteria manifestations, other autoimmune diseases)
Other: Diagnostic accuracy
To assess the diagnostic accuracy of non-criteria aPL (anti-vimentin/cardiolipin and anti-phosphatidylserine/prothrombin) in identifying APS in patients with thrombosis/ recurrent adverse pregnancy outcomes
Group 3 [Control Group]
Patients with clinical criteria (thrombotic or obstetric) for APS, negative for aPL, but without clinical features highly suggestive of APS (recurrent events, thrombotic + obstetrical events, extra-criteria manifestations, other autoimmune diseases)

What is the study measuring?

Primary Outcome Measures

Primary Outcome Measures

In a clinical study's protocol, the planned outcome measure that is the most important for evaluating the effect of an intervention/treatment. Most clinical studies have one primary outcome measure, but some have more than one.
Outcome Measure
Measure Description
Time Frame
Diagnostic accuracy of non-criteria aPL
Time Frame: 0 months
Evaluation of the sensitivity and specificity of non-criteria aPL (anti-vimentin/cardiolipin and anti-phosphatidylserine/prothrombin) in identifying APS in patients with thrombosis/recurrent adverse pregnancy outcomes
0 months

Secondary Outcome Measures

Secondary Outcome Measures

In a clinical study's protocol, a planned outcome measure that is not as important as the primary outcome measure for evaluating the effect of an intervention but is still of interest. Most clinical studies have more than one secondary outcome measure.
Outcome Measure
Measure Description
Time Frame
Frequency of clinical characteristics in the aPL groups
Time Frame: 0 months
Assessment of the frequency of clinical characteristics in the four different aPL status groups, including APS and SN-APS with and without non-criteria aPL
0 months
Incidence of recurrent thrombosis and pregnancy complications
Time Frame: 0 months
Aestimation of the association between different aPL status on the recurrence of thrombosis/adverse pregnancy outcomes.
0 months

Other Outcome Measures

Other Outcome Measures

For clinical trials, a planned measurement described in the protocol that is used to determine the effect of an intervention/treatment on participants. For observational studies, a measurement or observation that is used to describe patterns of diseases or traits, or associations with exposures, risk factors, or treatment. Types of outcome measures include primary outcome measure and secondary outcome measure.
Outcome Measure
Measure Description
Time Frame
Prevalence of APS- and SN-APS-related antibodies in study groups
Time Frame: 0 months
Prevalence of aCL by TLC-immunostaining, anti-carbamylated-β2-glycoprotein I antibodies and Anti-glucose-modified β2 glycoprotein I antibodies in APS and SN-APS groups
0 months

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Sponsor

The organization or person who initiates the study and who has authority and control over the study.
Italian Society for Rheumatology

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Actual)

Study Start

The actual date on which the first participant was enrolled in a clinical study. The "anticipated" study start date is the date that the researchers think will be the study start date.
September 21, 2024

Primary Completion (Estimated)

Primary Completion

The date on which the last participant in a clinical study was examined or received an intervention to collect final data for the primary outcome measure. Whether the clinical study ended according to the protocol or was terminated does not affect this date. For clinical studies with more than one primary outcome measure with different completion dates, this term refers to the date on which data collection is completed for all the primary outcome measures. The "anticipated" primary completion date is the date that the researchers think will be the primary completion date for the study.
September 1, 2026

Study Completion (Estimated)

Study Completion

The date on which the last participant in a clinical study was examined or received an intervention/treatment to collect final data for the primary outcome measures, secondary outcome measures, and adverse events (that is, the last participant's last visit). The "anticipated" study completion date is the date that the researchers think will be the study completion date.
September 1, 2026

Study Registration Dates

First Submitted

First Submitted

The date on which the study sponsor or investigator first submitted a study record to ClinicalTrials.gov. There is typically a delay of a few days between the first submitted date and the record's availability on ClinicalTrials.gov (the first posted date).
April 15, 2024

First Submitted That Met QC Criteria

First Submitted That Met QC Criteria

The date on which the study sponsor or investigator first submits a study record that is consistent with National Library of Medicine (NLM) quality control (QC) review criteria. The sponsor or investigator may need to revise and submit a study record one or more times before NLM's QC review criteria are met. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
April 15, 2024

First Posted (Actual)

First Posted

The date on which the study record was first available on ClinicalTrials.gov after National Library of Medicine (NLM) quality control (QC) review has concluded. There is typically a delay of a few days between the date the study sponsor or investigator submitted the study record and the first posted date.
April 18, 2024

Study Record Updates

Last Update Posted (Actual)

Last Update Posted

The most recent date on which changes to a study record were made available on ClinicalTrials.gov. There may be a delay between when the changes were submitted to ClinicalTrials.gov by the study's sponsor or investigator (the last update submitted date) and the last update posted date.
May 14, 2025

Last Update Submitted That Met QC Criteria

Last Update Submitted That Met QC Criteria

The most recent date on which the study sponsor or investigator submitted changes to a study record that are consistent with National Library of Medicine (NLM) quality control (QC) review criteria. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
May 9, 2025

Last Verified

Last Verified

The most recent date on which the study sponsor or investigator confirmed the information about a clinical study on ClinicalTrials.gov as accurate and current. If a study with a recruitment status of recruiting; not yet recruiting; or active, not recruiting has not been confirmed within the past 2 years, the study's recruitment status is shown as unknown.
May 1, 2025

More Information

Terms related to this study

Additional Relevant MeSH Terms

Other Study ID Numbers

Other Study ID Numbers

Identifiers or ID numbers other than the NCT number that are assigned to a clinical study by the study's sponsor, funders, or others. These numbers may include unique identifiers from other trial registries and National Institutes of Health grant numbers.
  • SNAPSITA

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

NO

IPD Plan Description

The Italian Society of Rheumatology (SIR) is the only data controller of the study and only reports containing aggregated analysed data will be shared.

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

Clinical Trials on Antiphospholipid Syndrome

Clinical Trials on Diagnostic accuracy

Search Similar Trials

Sponsors and Collaborators

Medical Conditions

Drug Interventions

Conditions

Rare Diseases

Drug Interventions

Dietary Supplements

Sponsor/Collaborators

Locations

Cookie Settings

We use cookies to ensure that we give you the best experience on our website. For more details carefully read our Privacy and Cookies Policy. ...>>>You can change your preferences or withdraw your consent at any time by deleting the cookies from your website or computer as described in the policy. Please accept it and choose your preferences by ticking the corresponding boxes in the "Manage Settings" section below. Please carefully read our Terms of Service before you proceed with using any part of this website.
«Manage Settings