Diagnostic and management algorithm for severe alloimmune platelet refractoriness. Key factors involved in the identification, diagnosis, management, and prevention of alloimmune platelet refractoriness. The corrected count increment (CCI) may be calculated using the following formula: [Posttransfusion platelet count – Pretransfusion platelet count (/L)] ×  body surface area (m²)/platelets transfused (10¹¹). The number of platelets transfused may be assumed to be 3 × 10¹¹ when this information is unavailable. In clinical practice, refractoriness may be suspected when the posttransfusion platelet increment is less than 10 × 10⁹/L. IVIG, intravenous immune globulin.