[Rhesus(D)-IgG-antibodies in the treatment of autoimmune thrombocytopenia].

25 patients with confirmed chronic autoimmune thrombocytopenia (AITP) (20 women, 5 men; mean age 42 [17-75] years) were treated with anti-erythrocytic rhesus (D) antibodies. In the course of 5 days they each received three doses of 1200 micrograms of anti-D IgG antiserum by short-duration infusion. No adverse effects were noted. In 19 out of 25 (76%) the platelet counts (determined on the 6th day after the last infusion) rose by more than 30,000/microliters, in some by over 200,000/microliters. In 6 patients the maximal rise in platelets was below 30,000/microliters. There was little or no fall in haemoglobin concentration in 24 of the patients, although the direct antiglobulin test was clearly positive in all cases. Moderate transitory anaemia occurred in one case only (haemoglobin fell from 12.4 to 8.4 g/dl). The platelet counts gradually declined after treatment, taking several weeks or months to reach their original levels. The mechanism of anti-D therapy in AITP is not fully understood, but it probably depends on competitive inhibition of Fc receptors on phagocytic cells in the reticuloendothelial system.