IMPLICATIONS OF HUMAN T-LYMPHOTROPIC VIRUS TYPE-I AND TYPE-II TESTINGIN DONORS AND PATIENTS

The retroviruses known as Human T-Lymphotropic Virus Types I and II (H TLV-I and -II) were recognized before the human immunodeficiency virus (HIV-1). Associated diseases of HTLV-I infection, including a particu lar kind of leukemia or the development of a specific demyelinating di sease, have also been observed. Screening of blood donors for antibodi es to HTLV was mandated in November of 1988. This paper examines the b iology of HTLV-I and HTLV-II and reviews the testing methods for HTLV- I/II. Data from 39,908 blood donations of volunteer donors at The Univ ersity of Texas M. D. Anderson Cancer Center (UTMDACC), Division of La boratory Medicine, Section of Transfusion Medicine are presented, Init ially reactive specimens for HTLV antibodies were 158 (0.4 percent), O f these 0.26 percent or 105 of 39,908 were repeatedly reactive. Eight hundred and sixty-seven cancer patients were also tested for HTLV anti bodies. Eight or 0.9 percent were repeatedly reactive for HTLV antibod ies by enzyme immunoassays (EIA), but only one could be confirmed as p ositive. HTLV-I/II has a very low incidence in the ambulatory populati on. The relationship of clinical sequelae and the rate of transmission of these viruses remain unclear. A readily applicable confirmatory te st is not yet available. Even significant improvements in the sensitiv ity and specificity of testing will present ongoing problems for ident ification of true HTLV carriers. The clinical decision-making process related to the meaning of these results continues to be difficult.