COMBINATION CHEMOTHERAPY IN REFRACTORY IMMUNE THROMBOCYTOPENIC PURPURA

Background. Chronic idiopathic thrombocytopenic purpura is a destructi ve thrombocytopenia caused by an autoantibody. About 80 percent of pat ients with chronic idiopathic thrombocytopenic purpura have remissions after either corticosteroid therapy or splenectomy. Some patients wit h resistant disease respond to other agents, but a substantial group a re refractory to therapy. Methods. We used combination chemotherapy to treat 10 patients with refractory immune thrombocytopenia. An average of 6.8 (range, 3 to 10) previous therapies, including corticosteroids and splenectomy, had been unsuccessful in these patients. The patient s received from three to eight cycles of therapy consisting of cycloph osphamide and prednisone combined with either vincristine (one patient ), vincristine and procarbazine (four patients), or etoposide (six pat ients, including one patient who received four cycles each containing procarbazine and etoposide) Results. Among the 10 patients, 6 had comp lete responses (platelet count, >180,000 per cubic millimeter); of the se, 4 patients had responses that persisted for more than 11, 30, 54, or 126 months, 1 had a relapse 9 months after therapy but had a remiss ion with further therapy and remained in remission for 48 months befor e dying of an unrelated illness, and another relapsed just before her fifth course of therapy. Two patients had partial responses (platelet count, >50,000 per cubic millimeter); the platelet counts in one remai ned stable for more than nine months after the end of therapy, and the other patient relapsed. The remaining two patients had no response. C omplete responses were associated with a disappearance or marked decre ase in the level of platelet-associated auto-antibody. Conclusions. Co mbination chemotherapy is beneficial in some patients in whom immune t hrombocytopenia is refractory to corticosteroids and splenectomy.