HLA-matched platelet transfusions proved more effective than random or cross-matched platelet units in patients with immunized platelet transfusion refractoriness (PTR), a condition commonly linked to HLA alloimmunization and involved in fetal and neonatal alloimmune thrombocytopenia (FNAIT), according to a study published recently in Transfusion Clinique et Biologique.
A cohort study involving nine patients with hematological disorders assessed 113 platelet transfusions and demonstrated that HLA-matched platelets yielded the best results for platelet count recovery. This research provided valuable insights into optimizing care for patients with PTR.
“IPTR [immune PTR] is mostly caused by antibodies to HLA (HLA-I) (80%), and the risk of IPTR is increased in patients with previous pregnancies and transfusion with blood products,” this study’s authors explained. They continued, “The exact biological mechanisms that explain HLA-induced platelet refractoriness are unclear.”
This study, conducted at the First Affiliated Hospital of Soochow University, evaluated transfusion outcomes using the 14-hour corrected count increment (14h-CCI), a measure of transfusion success. A 14h-CCI greater than 5000 indicated a successful outcome. Of the 113 platelet units transfused, 50 were random, 34 were cross-matched, and 29 were HLA-matched. HLA-matched transfusions achieved the highest median 14h-CCI value of 5643, compared to 5246 for cross-matched and 1683 for random transfusions (P = 0.02).
Read more about FNAIT signs and symptoms
Success rates were also significantly higher for HLA-matched platelets (43.8%) than for cross-matched (25%) or random platelets (10%) in the presence of non-immune factors such as infection, splenomegaly, and bleeding (P = 0.013). These results highlighted the role of both immune and non-immune factors in PTR and the superiority of HLA-matched platelets in overcoming immune-related barriers.
Non-immune factors were frequently observed in patients with PTR, emphasizing the complexity of managing this condition. Random platelet transfusions, infections, and bleeding were identified as significant contributors to lower platelet count recovery (P < 0.05). This underscores the importance of addressing these variables alongside immune-related challenges to improve transfusion outcomes.
The cohort consisted of nine patients, predominantly female, with a median age of 43 years. Most participants had acute myeloid leukemia (66.7%), while others were treated for myelodysplastic syndromes, hemophagocytic syndrome, or lymphoma. None of the patients had antibodies against human platelet antigens, further affirming the central role of HLA alloimmunization in immunized PTR.
