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

NCT02858323 | Completed

• 2 other identifiers: 99991615516-CC-N155
• Study Type: observational
• Target: 68
• Locations: 1 country
• Sites: 1

Brief Summary

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.

Conditions

Platelet Transfusion Refractoriness; Thrombocytopenia

Keywords

Alloimmunization; Refractoriness; Corrected Count Increment; HLA-Compatible; Natural History

Outcome Measures

Primary Outcomes (1)

• Corrected count increment after platelet transfusion

  Corrected Count Increment

  Retrospective

Study Arms (1)

1

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

Eligibility Criteria

• Age: 3 Years - 80 Years
• Sex: all
• Healthy Volunteers: No
• Age Groups: Child (0-17), Adult (18-64), Older Adult (65+)
• Sampling Method: Non-Probability Sample

You may qualify if:

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

You may not qualify if:

• \) Hyperproliferative thrombocytopenia

Sponsors & Collaborators

• National Institutes of Health Clinical Center (CC): lead

Study Sites (1)

National Institutes of Health Clinical Center

Bethesda, Maryland, 20892, United States

Location

Related Publications (3)

• 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.

  PMID: 21791230 BACKGROUND

• 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.

  PMID: 21615749 BACKGROUND

• 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.

  PMID: 24066742 BACKGROUND

MeSH Terms

Conditions

Thrombocytopenia

Condition Hierarchy (Ancestors)

Blood Platelet Disorders; Hematologic Diseases; Hemic and Lymphatic Diseases; Cytopenia

Study Officials

• Willy A Flegel, M.D.

  National Institutes of Health Clinical Center (CC)

  PRINCIPAL INVESTIGATOR

Study Design

• Study Type: observational
• Observational Model: COHORT
• Time Perspective: RETROSPECTIVE
• Sponsor Type: NIH
• Responsible Party: SPONSOR

Study Record Dates

• First Submitted: August 4, 2016
• First Posted: August 8, 2016
• Study Start: July 27, 2016
• Primary Completion: June 20, 2017
• Study Completion: June 20, 2017
• Last Updated: April 20, 2026

Record last verified: 2025-09-10

Locations

US (1)