Analysis of platelet-reactive alloantibodies and evaluation of cross-match-compatible platelets for the management of patients with transfusion refractoriness

Abstract

Background: Cross-match-compatible platelets can improve corrected count increments (CCIs) in alloimmunised patients with transfusion refractoriness. However, only a few studies mentioned that the specificities of platelet-reactive alloantibodies can predict high reactivity in cross-match assays among these patients.

Methods: A total of 204 medical records of patients who were refractory to random single-donor apheresis platelets between January 2014 and December 2014 were enrolled. Platelet-reactive antibodies in patients' serum were screened by an enzyme-linked immunosorbent assay (ELISA).The platelet cross-match assays were performed by a solid-phase adherence assay. The specificities of human leukocyte antigen (HLA) class I and human platelet antigens (HPAs) alloantibodies were determined by Luminex Single Antigen and Monoclonal Antibody-specific Immobilization of Platelet Antigens (MAIPA) assays, respectively.

Results: Anti-HLA and anti-HPA alloantibodies were found in 114 of 204 (55.88%) patients, including 110 (96.49%) with anti-HLA alloantibodies only, 2 (1.75%) with anti-HPA alloantibodies (anti-GPIIb/IIIa) only and 2 (1.75%) with both anti-HLA and anti-HPA alloantibodies (anti-HPA-3a and anti-HPA-5b). The most common HLA class I alloantibody phenotypes in cross-match-incompatible patients were HLA-A23 (59.38%), -A24 (50.00%), -A02 (43.75%), -B27 (65.63%), -B40 (50.00%), -B18 (46.88%) and -B07 (43.75%). A total of 480 cross-matched platelet units were administered in 82 of 114 alloimmunised patients with a mean CCI of 7800 ± 5200, a significant improvement over random platelet units (P < 0.001).

Conclusions: No development of additional platelet alloantibodies was observed during this platelet transfusion regiment. This study showed that transfusion of cross-match-compatible platelet units offers effective and safe management of platelet transfusion refractoriness (PTR). The finding of alloantibodies among cross-match-incompatible cases can be used as predictors for platelet donor selection.

Keywords: HLA class I antibody; cross-match-compatible platelet; platelet transfusion refractoriness; platelet-specific antibody.