Anti-HLA class I IgG subclasses skew platelet activation mechanisms in transfusion refractoriness.

ABSTRACT: Patients requiring recurrent platelet transfusions are subject to platelet transfusion refractoriness (PTR), a therapeutic failure due to rapid clearance of transfused platelets from the circulation. One major cause of PTR is the presence in the recipient of multiple immunoglobulin (Ig)G directed against allogeneic HLA class-I (HLA-I) molecules expressed by the donor platelets. Strikingly, the presence of anti-HLA-I IgG does not necessarily correlate with PTR, thus questioning the role of the antibody properties themselves. Using blood of HLA-I allo-immunized patients with or without PTR, we identified the subclasses of their anti-HLA-I IgG. We found the distribution of these subclasses to be different in patients, with IgG1 being predominant in non-PTR patients while IgG1 in combination w

SUBMITTER: Couvidou A 

PROVIDER: S-EPMC12862294 | biostudies-literature | 2026 Feb

REPOSITORIES: biostudies-literature