Idiopathic thrombocytopenic purpura (ITP) is a common autoimmune disorder managed by hematologists often outside of tertiary care centers. Yet despite its relative commonness, its natural history has not been studied systematically. Ironically, the paucity of studies of ITP subtly supports the concept of its benign nature. In contrast to patients with acute leukemia, patients with ITP are often managed in the community, where data collection is difficult. Portielje and colleagues (page 2549) follow 152 patients with ITP who were managed in a consistent fashion. Their analysis of the outcome at 2 and 10 years after diagnosis should give us comfort. Most patients (85%) achieved a safe platelet count (above 30 000/μL) off all therapy, and these patients had the same 10-year mortality as the general population. Nine percent of the patients had severe and refractory disease, and their overall mortality was 4.2%, with death caused equally by bleeding (the disease itself) and by infection (often secondary to the treatment). A further 6 percent of patients maintained a safe platelet count on maintenance therapy. These investigators concluded that most patients with ITP have a good outcome without excess morbidity or mortality. Their study further supports the growing practice of avoiding aggressive therapy in ITP patients with mild to moderate thrombocytopenia.
The study answers some questions but raises others. What is the explanation of the surprisingly high rate (26%) of postoperative complications of splenectomy? I suspect that laparoscopy splenectomy will prove to have a lower morbidity. The study also confirms the centrality of splenectomy as the current definitive treatment for ITP. Portielje and colleagues demonstrate that 75% of splenectomy patients were in remission at 2 years and 66% remained in remission at 10 years.