Immune thrombocytopenia (ITP)
This project, which attempts to develop new treatments for immune thrombocytopenia, has been funded by a grant from the National Heart, Lung, and Blood Institute of the National Institutes of Health (project: HL67347).
Immune thrombocytopenia is a common autoimmune disease. Afflicted patients develop autoantibodies that bind to epitopes on the platelet membrane, opsonizing platelets for destruction by cells of the reticuloendothelial system (e.g., macrophages). The increased rate of platelet destruction leads to thrombocytopenia (i.e., reduced quantities of platelets in blood), which places patients at risk for spontaneous hemorrhage. New therapies are needed to treat patients with ITP.
The main aims of the initial project were: (a) to develop relevant animal models of ITP, (b) to investigate mechanisms of IVIG therapy, (c) to develop a liposomal therapy (opsisomes) that would inhibit pathways of platelet destruction in ITP, and (d) to develop a bioreactor capable of removing pathogenic antibodies from the blood of patients afflicted with ITP.
Based on work conducted during the initial grant period, two additional therapies have been proposed. Macro-Block is a novel therapy that utilizes endogenous antibodies to decrease the rate of platelet elimination in ITP patients. We believe Macro-Block will evolve into a convenient, effective, and economical alternative to IVIG therapy. Additionally, work conducted on HL67347 has led to the hypothesis that specific FcRn inhibitors may be used to accelerate the elimination of pathogenic antibodies in patients afflicted with ITP and other humoral immune diseases.