Treatment Options for Idiopathic Thrombocytopenic Purpura When Splenectomy Is Ineffective FREE

Idiopathic thrombocytopenic purpura (ITP) is a bleeding disorder. Thrombocytopenia is a deficiency of platelets (thrombocytes), the cells needed for blood to clot normally. Bleeding beneath the skin or mucous membranes gives rise to small red spots or purple blotches (purpura). The term idiopathic applies when the underlying cause of the disorder is unknown. It is possible that, in ITP, antibodies produced in the spleen destroy the body's own platelets. When an adult with ITP does not respond to medicines such as cortisone-like hormones (corticoids), removing the spleen is effective about two thirds of the time. Doctors often try different drug treatments in the patients who do not get better after spleen removal. A summary of the known effects of the different treatments for these patients might help doctors and their patients make better choices about which drugs to try first.

To learn what treatments lead to lasting responses in adults with ITP whose platelet counts remain low after splenectomy.

Rather than doing a new study, the researchers looked at 90 previous studies published between 1966 and 2003. Each study had involved at least 5 patients older than 16 years of age who had had ITP for longer than 3 months. All of the 656 patients in the studies had had splenectomy, and all had persistent low platelet counts. In total, the studies assessed responses to 22 different treatments. The researchers summarized results of the studies and identified treatments that were associated with a “complete response.” They defined a complete response as having a normal platelet count for at least 3 months after stopping the treatment.

Only 14% of the patients in the studies had a complete response to treatment. Nearly half (46%) had no response at all. Complete responses were most frequent with the drugs azathioprine, cyclophosphamide, and rituximab. Between 17% to 27% of the patients who were given one of these drugs had a complete response, but 36% to 42% had no response. The studies had many limitations. Few reported bleeding or other clinical outcomes. Most were small. Many did not have comparison groups. Patients sometimes took multiple medicines, which made it difficult to sort out effects of specific therapies.

No one treatment has emerged as especially effective for patients with ITP who do not respond to splenectomy. We need prospective trials that compare different therapies and assess clinical outcomes to learn how to best manage these patients.