Complement (C1q) Binding to HLA Antibodies in a Solid-phase Immunoassay and Clinical Effect on Platelet Transfusion
| Status: | Completed |
|---|---|
| Conditions: | Hematology |
| Therapuetic Areas: | Hematology |
| Healthy: | No |
| Age Range: | 3 - 80 |
| Updated: | 8/11/2018 |
| Start Date: | July 27, 2016 |
| End Date: | June 20, 2017 |
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.
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.
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.
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.
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.
- INCLUSION CRITERIA:
1. Class I HLA antibodies detected by the IgG solid phase immunoassay method
2. > 1 episode of platelet transfusion at NIH after the first positive HLA IgG
antibody result
EXCLUSION CRITERIA:
1) Hyperproliferative thrombocytopenia
We found this trial at
1
site
9000 Rockville Pike
Bethesda, Maryland 20892
Bethesda, Maryland 20892
301-496-2563
National Institutes of Health Clinical Center The National Institutes of Health (NIH) Clinical Center in...
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