Complement (C1q) Binding to HLA Antibodies in a Solid-phase Immunoassay and Clinical Effect on Platelet Transfusion

NCT ID: NCT02858323

Last Updated: 2025-11-20

Study Results

Results pending

The study team has not published outcome measurements, participant flow, or safety data for this trial yet. Check back later for updates.

Basic Information

Get a concise snapshot of the trial, including recruitment status, study phase, enrollment targets, and key timeline milestones.

Recruitment Status

COMPLETED

Total Enrollment

68 participants

Study Classification

OBSERVATIONAL

Study Start Date

2016-07-27

Study Completion Date

2017-06-20

Brief Summary

Review the sponsor-provided synopsis that highlights what the study is about and why it is being conducted.

Background:

Platelets are blood cells that help blood clot. Some people have what is called thrombocytopenia. This means they have a low blood platelet count. They need platelet transfusions very often. Human leukocyte antigen (HLA) alloimmunization occurs for a lot of these people. They become refractory. This means their platelet levels no longer increase after transfusions. Researchers want to study a procedure that detects HLA antibodies. They want to test how well it predicts how a person will respond to a transfusion. They want to see if it does this better than the procedure that is usually used.

Objective:

To study the effect of C1q-binding of Class I HLA antibodies on platelet refractoriness in people who get platelet transfusions. To test if this method better predicts response to platelet transfusion than the IgG solid phase immunoassay method.

Eligibility:

People enrolled on protocols 11-C-0136, 08-H-0156, 03-C-0277, 01-C-0157, or 01-C-0129 who:

Agreed to have their specimens and data used for future research

Had Class I HLA antibodies detected by the IgG method

Had one or more platelet transfusions at NIH after the first positive HLA IgG antibody result

Design:

For each participant, researchers will look at a small portion of their archived plasma sample. The samples were left over from prior HLA antibody tests.

Participants samples will be analyzed. They will be tested to see if C1q-binding HLA antibodies are present. This will be done by solid phase immunoassay. Results will be compared with the past results of the IgG method.

Participants data will be stored in database that s protected by password.

Detailed Description

Dive into the extended narrative that explains the scientific background, objectives, and procedures in greater depth.

Human leukocyte antigen (HLA) alloimmunization is common in patients undergoing frequent platelet transfusion, and is the most important cause of immune platelet refractoriness. Management strategies in HLA alloimmune platelet-refractory patients include transfusion with HLA-matched or crossmatched platelets; however, in broadly-sensitized patients, or in patients with uncommon HLA types, antigen-negative or epitope compatible donors may be difficult to find.

The Luminex immunoglobulin (Ig)G single-antigen-bead (SAB) solid phase immunoassay is now commonly used to detect HLA antibodies. However, an assay that specifically detects C1qbinding to HLA antibodies has been reported to identify a clinically relevant subset of HLA antibodies in solid organ transplantation; one group has studied the utility of this assay in platelet transfusion of HLA-alloimmunized platelet refractory patients. We intend to evaluate the ability of this C1-binding immunoassay to predict response to platelet transfusion in HLA alloimmune patients.

Conditions

See the medical conditions and disease areas that this research is targeting or investigating.

Thrombocytopenia Platelet Transfusion Refractoriness

Study Design

Understand how the trial is structured, including allocation methods, masking strategies, primary purpose, and other design elements.

Observational Model Type

COHORT

Study Time Perspective

RETROSPECTIVE

Study Groups

Review each arm or cohort in the study, along with the interventions and objectives associated with them.

1

Previously selected HLA-alloimmunized platelet refractory, clinical, patients.

No interventions assigned to this group

Eligibility Criteria

Check the participation requirements, including inclusion and exclusion rules, age limits, and whether healthy volunteers are accepted.

Inclusion Criteria

1. Class I HLA antibodies detected by the IgG solid phase immunoassay method
2. Greater than or equal to 1 episode of platelet transfusion at NIH after the first positive HLA IgG antibody result

Exclusion Criteria

1\) Hyperproliferative thrombocytopenia
Minimum Eligible Age

3 Years

Maximum Eligible Age

80 Years

Eligible Sex

ALL

Accepts Healthy Volunteers

No

Sponsors

Meet the organizations funding or collaborating on the study and learn about their roles.

National Institutes of Health Clinical Center (CC)

NIH

Sponsor Role lead

Responsible Party

Identify the individual or organization who holds primary responsibility for the study information submitted to regulators.

Responsibility Role SPONSOR

Principal Investigators

Learn about the lead researchers overseeing the trial and their institutional affiliations.

Willy A Flegel, M.D.

Role: PRINCIPAL_INVESTIGATOR

National Institutes of Health Clinical Center (CC)

Locations

Explore where the study is taking place and check the recruitment status at each participating site.

National Institutes of Health Clinical Center

Bethesda, Maryland, United States

Site Status

Countries

Review the countries where the study has at least one active or historical site.

United States

References

Explore related publications, articles, or registry entries linked to this study.

Chen G, Sequeira F, Tyan DB. Novel C1q assay reveals a clinically relevant subset of human leukocyte antigen antibodies independent of immunoglobulin G strength on single antigen beads. Hum Immunol. 2011 Oct;72(10):849-58. doi: 10.1016/j.humimm.2011.07.001. Epub 2011 Jul 18.

Reference Type BACKGROUND
PMID: 21791230 (View on PubMed)

Fontaine MJ, Kuo J, Chen G, Galel SA, Miller E, Sequeira F, Viele M, Goodnough LT, Tyan DB. Complement (C1q) fixing solid-phase screening for HLA antibodies increases the availability of compatible platelet components for refractory patients. Transfusion. 2011 Dec;51(12):2611-8. doi: 10.1111/j.1537-2995.2011.03194.x. Epub 2011 May 26.

Reference Type BACKGROUND
PMID: 21615749 (View on PubMed)

Loupy A, Lefaucheur C, Vernerey D, Prugger C, Duong van Huyen JP, Mooney N, Suberbielle C, Fremeaux-Bacchi V, Mejean A, Desgrandchamps F, Anglicheau D, Nochy D, Charron D, Empana JP, Delahousse M, Legendre C, Glotz D, Hill GS, Zeevi A, Jouven X. Complement-binding anti-HLA antibodies and kidney-allograft survival. N Engl J Med. 2013 Sep 26;369(13):1215-26. doi: 10.1056/NEJMoa1302506.

Reference Type BACKGROUND
PMID: 24066742 (View on PubMed)

Other Identifiers

Review additional registry numbers or institutional identifiers associated with this trial.

16-CC-N155

Identifier Type: -

Identifier Source: secondary_id

999916155

Identifier Type: -

Identifier Source: org_study_id

More Related Trials

Additional clinical trials that may be relevant based on similarity analysis.

FolateScan in Autoimmune Disease
NCT00588393 COMPLETED PHASE2