Treatment Options for Idiopathic Thrombocytopenic Purpura When Splenectomy Is Ineffective

Summaries for Patients are a service provided by Annals to help patients better understand the complicated and often mystifying language of modern medicine.

Summaries for Patients are presented for informational purposes only. These summaries are not a substitute for advice from your own medical provider. If you have questions about this material, or need medical advice about your own health or situation, please contact your physician. The summaries may be reproduced for not-for-profit educational purposes only. Any other uses must be approved by the American College of Physicians.

The summary below is from the full report titled "Management of Adult Patients with Persistent Idiopathic Thrombocytopenic Purpura Following Splenectomy. A Systematic Review." It is in the 20 January 2004 issue of Annals of Internal Medicine (volume 140, pages 112-120). The authors are S.K. Vesely, J.J. Perdue, M.A. Rizvi, D.R. Terrell, and J.N. George.

What is the problem and what is known about it so far?

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.

Why did the authors do this review?

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

How did the authors do this review?

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.

What did the authors find?

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.

What are the implications of the review?

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.