ThrombocytopeniaNCT02858323
Complement (C1q) Binding to HLA Antibodies in a Solid-phase Immunoassay and Clinical Effect on Platelet Transfusion
An observational study of Thrombocytopenia and Platelet Transfusion Refractoriness, run by National Institutes of Health Clinical Center (CC) at 1 site in United States.
Trial 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. Read more about this study
- Who is it for?
- Ages 3 to 80 years
- Conditions the study is for
- Thrombocytopenia, Platelet Transfusion Refractoriness
- Type of treatment
- Vaccines
- How many people
- 68 participants
- Where
- 1 siteUnited States
- Study dates
- 27 Jul 2016to 20 Jun 2017
- Phase
- Observational
- Are there results?
- None posted in the registry
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 3 to 80 years
- All sexes
- No healthy volunteers
- Child, Adult, Older adult
Who may be able to join
- 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
Who cannot join
- 1) Hyperproliferative thrombocytopenia
Trial locations and contacts
1 site in 1 country.
United States1 site
National Institutes of Health Clinical Center
Bethesda, Maryland, 20892
About this study
Official title: Complement (C1q) Binding to HLA Antibodies in a Solid-Phase Immunoassay and Clinical Effect on Platelet Transfusion
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.
Read more
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.
...
Read the detailed description
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.
- Keywords
- Alloimmunization, Refractoriness, Corrected Count Increment, HLA-Compatible, Natural History
- Medical subject headings
- Thrombocytopenia
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
| Study group | Role | What they receive |
|---|---|---|
| 1 | Previously selected HLA-alloimmunized platelet refractory, clinical, patients. |
What is being measured
The primary outcome is the main question the study is designed to answer.
Corrected count increment after platelet transfusion
Corrected Count Increment
Measured: Retrospective
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted8 Aug 2016 (estimated)
- Study start27 Jul 2016
- Primary completion20 Jun 2017
- Study completion20 Jun 2017
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Publications (3)Papers the sponsor has linked to this study.
- Other trials for ThrombocytopeniaStudies of the same condition, open and under way.
- 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
- Retrospective
- Enrolment
- 68 participants (actual)
Sponsor and investigators
- Lead sponsor
- National Institutes of Health Clinical Center (CC)
- Sponsor type
- US National Institutes of Health
- Responsible party
- Sponsor
- Investigators
- Willy A Flegel, M.D., Principal investigator, National Institutes of Health Clinical Center (CC)
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT02858323
- Sponsor's protocol ID
- 999916155
- Other IDs
- 16-CC-N155
- Status last verified
- 21 Aug 2026
- First submitted
- 4 Aug 2016
- Last updated
- 26 Oct 2026
- Results posted
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
Publications
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.
PubMed 21791230Fontaine 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.
PubMed 21615749Loupy 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.
PubMed 24066742
Study at a glance
From the registry record, last updated by the sponsor on 26 Oct 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Complement (C1q) Binding to HLA Antibodies in a Solid-Phase Immunoassay and Clinical Effect on Platelet Transfusion
- ClinicalTrials.gov ID
- NCT02858323
- Acronym / sponsor ID
- 999916155
- Keywords
- Alloimmunization, Refractoriness, Corrected Count Increment, HLA-Compatible, Natural History
- Study type
- Observational
- Recruitment status
- Completed
- Enrolment
- 68 participants (actual)
- Lead sponsor
- National Institutes of Health Clinical Center (CC)US National Institutes of Health
- Study start
- 27 Jul 2016
- Primary completion
- 20 Jun 2017 (actual)
- Study completion
- 20 Jun 2017 (actual)
- First posted
- 8 Aug 2016 (estimated)
- 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.
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
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.
Study design
- Observational model
- Cohort
- Time perspective
- Retrospective
- Number of arms
- 1
| Arm | Type | Receives |
|---|---|---|
| 1 | – | –Previously selected HLA-alloimmunized platelet refractory, clinical, patients. |
Who may qualify
- Ages
- 3 to 80 years
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Child, Adult, Older adult
Key inclusion criteria (2 listed)
Key exclusion criteria (1 listed)
- 1) Hyperproliferative thrombocytopenia
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Primary outcome
Corrected count increment after platelet transfusion
Time frame: Retrospective
Corrected Count Increment
Results and safety
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 26 Oct 2026.
- Background: PubMed 21791230Chen 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.
- Background: PubMed 21615749Fontaine 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.
- Background: PubMed 24066742Loupy 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.
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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. This study is not recruiting at the moment.
Willy A Flegel, M.D. principal investigator
National Institutes of Health Clinical Center (CC)
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 Thrombocytopenia and Platelet Transfusion Refractoriness, run by National Institutes of Health Clinical Center (CC) at 1 site in United States.
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 2 inclusion and 1 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: finished, as of the sponsor's last update on 26 Oct 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 United States. 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?
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
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?
Corrected count increment after platelet transfusion (time frame: Retrospective). 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 NCT02858323, which also lists 3 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 26 Oct 2026.