Anti-D treatment for chronic immune thrombocytopenic purpura: clinical and laboratory aspects

We used low-dose anti-D immunoglobulins for home treatment of Rh+ adult patients with chronic immune thrombocytopenic purpura (ITP). After informed consent, 15 unselected outpatients (ten males and five females, aged 22 to 72), affected by chronic ITP with negative HIV test, were given intramuscular injection of 900–1500 μg of anti-RhO (D) IgG over 3 days every month for 2 or 3 consecutive months. Platelet count (mean ±SD) significantly increased from basal value of 17,000 ±9,000/μL to 72,000 ±55,000/μL at the end of treatment. Eight patients achieved a rise in platelet count above 50,000/μL (five above 100,000/μL) and two of them maintained the increase longer than 6 months without further anti-D administration. Three patients responsive to the first cycle responded to further treatment with substantially identical results. Seven patients had no response. Four of them had not responded to previous glucocorticoid and intravenous IgG therapy. Direct antiglobulin test became strongly positive in all patients and mean serum haptoglobin decreased from a basal value of 118 ±59 to 61 ±43 mg/dL; nevertheless no clinically overt hemolysis was observed in any patient, there was no rise of serum indirect bilirubin and hemoglobin level was unchanged (mean ±SD basal level 13.6 ±2.2 g/dL; after anti-D 13.9 ±1.2 g/dL). No hematoma developed at the injection site, and no other side effects occurred. Our results show that anti-D therapy is effective in the majority of patients well tolerated, and feasible as home treatment: thus it can be recommended as a cheap and safe alternative treatment in ITP Rh+ patients