Existence and significance of anti-HLA-C autoantibodies to primary and persistent platelet transfusion refractoriness in patients with hematologic disorders: a retrospective study from a single centre.

OBJECTIVES

Platelet transfusion refractoriness (PTR) is a frustrating clinical problem, and primary and persistent (P/P) PTR who experienced persistent PTR since the first transfusion was failed to be well recognized. This study aims to investigate the incidence and risk factors for P/P PTR.

METHODS

Patients with hematologic disorders who underwent HLA high-resolution genotyping and donor-specific HLA antibody or panel reactive antibody (PRA) testing between January 2019 and March 2023 were reviewed. Clinical data including infection history, splenomegaly, frequency and quantity of blood transfusions, and transfusions response were delineated and subsequently analyzed.

RESULTS

114 patients were included retrospectively, and 1071 transfusions were recorded. The overall incidence of PTR was 28.95% (33/114), with 63.63% (21/33) being P/P PTR. Anti class I HLA (anti-HLA-I) antibody was identified as an independent risk factor for ineffective platelet transfusion through multivariate logistic regression analysis (p = .034). Interestingly, anti-HLA-C autoantibodies were first found in six patients, and both anti-HLA-A and C autoantibodies were detected in one case, comprising a total of 10.71% (6/56) of HLA-I antibody-positive patients. Further analysis revealed that anti-HLA-C autoantibody was identified as an independent risk factor for P/P PTR (p = .039). Among patients with positive anti-HLA-C antibodies, significant differences in the effectiveness of ABO, D-matched and cross-matching transfusions were observed between patients with or without anti-HLA-C autoantibodies (p < .001 and p = .017). Notably, platelet transfusions independence was achieved by two of the four patients who received rituximab.

CONCLUSIONS

This work emphasized the significance of anti-HLA-C autoantibody for P/P PTR in hematological patients, and rituximab may therapeutic.