Fc Receptor Blockade in Patients with Refractory Chronic Immune Thrombocytopenic Purpura with Anti-D IgG

Background s an evaluation of the treatment of 63 patients with chronic immune thrombocytopenic purpura (54 splenectomized and nine nonsplenectomized) with weekly doses of anti-D (IgG)-coated red blood cells (RBCs). s tients were given one 5–15 μg/kg/dose of intravenous (i.v.) anti-D (IgG)-coated RBCs per week (average of 300 μg/dose/week) for a median 3-month period (3–6 months). Treatment modality was evaluated on a weekly basis by platelet counts, measuring of hemoglobin levels, and performance of Coombs tests. s tients presented a clinical response. Fifty-two patients (82.5%) increased their platelet count (PC) and 45 (69.8%) increased their PC >50 × 109/L. In 34 cases, response was sustained. Six of nine nonsplenectomized patients (67%) increased PC, thus avoiding splenectomy; four patients attained a stable complete response (CR). Similar platelet responses were observed in homozygous and heterozygous Rh (D)-positive patients (Rh/Hr phenotypes). Currently, after >10 years, 43 patients present a now permanent complete response with platelet count >50 × 109/L. Ten patients subsequently decreased their platelet count, although they were able to attain CR after receiving six doses of anti-D (IgG)-coated RBCs. sions on our study of Fc receptor blockade treatment with anti-D (IgG)-coated RBCs with the most difficult cases of ITP, which resulted in a 69.8% successful response rate, we concluded that weekly prescription of anti-D (IgG)-coated RBCs is an effective approach to treating chronic refractory ITP.