Is it necessary to test patients with immune thrombocytopenic purpura (ITP) for seropositivity to HTLV-1?

HTLV-111 (HIV-1) has been shown to be associated with thrombocytopenia of a type resembling immune thrombocytopenic purpura (ITP), HTLV-1 is a retrovi rus similar to HIV-I (HTLV-III) in a number of features, such as CD4 tropis m. It is responsible for several clinical entities, including adult T-cell leukemia/lymphoma. The relationship, if any, of HTLV-1 and thrombocytopenia has not been systematically studied. To determine how frequently ITP patie nts are commonly infected with HTLV-1, the following study was performed, F rozen serum samples from 123 randomly selected patients with ITP were thawe d and tested for antibodies to HTLV-1 by enzyme-linked immunoabsorbent assa y. Positives were confirmed by Western blot. Three patients were initially found to be positive for HTLV-1, One was a female of Caribbean ancestry, on e was a male HIV-1+ patient, and one was an adolescent female with no known risk factors for HIV-1, The two females later tested negative for HTLV-I, As a screening program for HTLV-1 antibodies was not introduced into blood banks until November 1988, there may have been passive transfer of the viru s from intravenous immunoglobulin that these patients had received. This st udy of a large number of ITP patients shows that it is extremely unlikely t hat they are infected with HTLV-I, and, therefore, it is unnecessary to scr een ITP patients for seropositivity to HTLV-1, Am, J, Hematol. 61:94-97, 19 99, (C) 1999 Wiley-Liss, Inc.