Use of vincristine and cyclosporine in childhood thrombotic thrombocytopenic purpura. Jayabose S, Levendoglu-Tugal O, Ozkayanak MF, Chao CP, Cuccovia B, Sandoval C. Journal of Pediatric Hematology/Oncology 2003;25(5):421-425.

Thrombotic thrombocytopenic purpura (TTP) is a rare but life-threatening hematologic disorder in children. Plasmapheresis, the standard therapy for TTP, is effective in achieving remission in most patients. However, some patients become either refractory to or dependent upon plasmapheresis. The authors report three such patients in whom the use of vincristine or vincristine plus cyclosporine resulted in permanent remission. A 12-year-old girl presented with vomiting and diarrhea and laboratory tests consistent with hemolytic uremic syndrome. Her diagnosis was revised to TTP after two weeks, following normalization of her kidney function tests, persistence of thrombocytopenia and anemia, and the development of low grade fevers and headaches. She was dependent on plasmapheresis for more than 5 months and then responded to vincristine with a decrease in the required frequency of plasmapheresis, but the addition of cyclosporine abrogated the need for further plasmapheresis. She developed serologic evidence of systemic lupus erythematosus twice but she subsequently tested negative after each episode. Two 15-year-old boys with TTP (one of them with underlying mixed connective tissue disease and the other with only transient dizziness, palor, and central nervous system symptoms without underlying disease) became refractory to plasmapheresis after a brief initial response. The addition of vincristine in one patient and vincristine and cyclosporine in the second patient (with mixed connective tissue disease) led to complete remission. The authors' experience in this case study of three patients suggests that vincristine and cyclosporine are effective agents in the management of patients with TTP who do not achieve complete remission with plasmapheresis alone.