Platelet compatibility and platelet antibodies detection: A step towards resolving dilemma in management of platelet refractoriness in oncology patients

Abstract

Background: Platelet refractoriness complicates the provision of platelet transfusions- a critical and essential part in management of thrombocytopenia in Oncology patients. Platelet refractoriness poses challenge due to alloimmunization to HLA (Class I) and human platelet antigens (HPAs) and is associated with adverse clinical outcomes and increases health care costs. Aim: A prospective, observational study was planned in medical oncology patients having thrombocytopenia to analyse result of platelet compatibility with post-transfusion platelet count increment and to ascertain presence of platelet antibodies as causative factor in platelet refractory patients. Methods: Eighty oncology patients having thrombocytopenia in a tertiary care centre; both solid organ and hematological malignancies, requiring platelet transfusion were included in this study. ABO-compatible, leucoreduced, random donor platelets with less than 72 hours storage and platelet cross matched were transfused. In case of platelet refractoriness and presence of platelet incompatibility, platelet antibody screening test was performed using SPRCA technique. A P-value < 0.05 was considered statistically significant. Results: Study population was 18-85 years with maximum number of cases (31.3 %) in 60-70 years age group with equal number of both genders. 80% cases showed platelet cross-match compatibility, while 20% were platelet cross-match incompatible. Amongst incompatible platelet cross matches, 87.5% cases showed presence of platelet alloantibodies and all cases except one showed platelet refractoriness. Platelet yield in compatible platelet cross match was higher than in patients with incompatible platelet cross match (P-value < 0.001). Previous exposure in the form of Pregnancy (61% cases) and history of transfusion (54% cases) played a vital role in platelet refractoriness and development of platelet alloantibodies. Patients treated with chemotherapy (78.8%) had significant risk of platelet refractoriness and platelet alloimmunization. Conclusion: Platelet cross matching along with testing for anti-platelet antibodies using SPRCA method is an effective, useful tool and rapid, first-line approach for selecting compatible platelets from the local inventory as compared to HLA-matched platelets in the treatment of thrombocytopenic cancer patients. Blood services must be aware of the measures to prevent alloimmunization and correct identification of refractoriness to provide adequate transfusion support for oncology patients reducing hospital length of stay and minimizing health care cost.

Keywords

• oncology
• platelet antibodies
• platelet cross matching
• refractoriness