Background: Treatment of adults with autoimmune thrombocytopenic purpura (AITP) is based more on individual experience than on results of controlled studies. We compared intravenous immunoglobulin with high-dose methylprednisolone in untreated adults with severe AITP and assessed efficacy of subsequent oral steroids compared with placebo. Primary outcome was number of days with platelet count greater than 50 x 10(9)/L within the first 21 days.
Methods: We did a randomised multicentre trial based on a 232 design. 122 adults with severe AITP (platelet count < or =20 x 10(9)/L) were randomly assigned to receive either intravenous immunoglobulin or high-dose methylprednisolone on days 1-3 (randomisation A), and then to receive either oral prednisone or placebo (randomisation B) on days 4-21. Analysis was by intention to treat.
Findings: Six patients were excluded from the analysis. The number of days on which platelet counts were above 50 x 10(9)/L was 18 in 56 patients receiving intravenous immunoglobulin and 14 in 60 receiving high-dose methylprednisolone (p=0.02). Percentage of patients who had platelet counts over 50 x 10(9)/L on days 2 and 5 was 7% and 79%, respectively, in the intravenous immunoglobulin group compared with 2% and 60%, respectively, in the high-dose methylprednisolone group (p=0.04). During the second treatment period, prednisone was more effective than placebo for all short-term endpoints. Patients who received intravenous immunoglobulin and prednisone had platelet count greater than 50 x 10(9)/L for 18.5 days (p=0.005), and those treated with high-dose methylprednisolone and prednisone had this count for 17.5 days.
Interpretation: Intravenous immunoglobulin and oral prednisone seems to be more effective than high-dose methylprednisolone and oral prednisone in adults with severe AITP, although the latter treatment is effective and well tolerated.