Prevalence of human immunodeficiency virus antibodies and hepatitis B markers among patients having hemodialysis

Cohort study of human immunodeficiency virus (HIV) antibody testing among patients receiving long-term dialysis at a university hospital

In a longitudinal study to determine the seroprevalence of antibody to the human immunodeficiency virus (HIV) and the natural history of a positive enzyme immunoassay (EIA) result we followed a cohort of 98 patients receiving long-term dialysis. Eight patients (8.2%) in the cohort had a positive EIA and a negative Western blot test result. The EIA-positive results of all patients seroconverted to negative during follow-up. No illness suggestive of HIV infection developed in any of the patients. Significantly associated with a false positive EIA were prior renal transplantation, transfusions during the months just before the positive EIA result, and a greater number of lifetime transfusions before the positive test result. We confirm that routine HIV screening of patients receiving long-term dialysis is associated with a high rate of false positive EIA results and conclude that such testing is unnecessary in the absence of established risk factors for HIV infection.

False-positive results of screening for antibodies to human immunodeficiency virus in chronic hemodialysis patients

Eighty-three chronic hemodialysis patients were tested for human immunodeficiency virus (HIV) infection. Testing included screening enzyme immunoassay (EIA) for HIV antibodies, competitive EIA for envelope and core antibodies, EIA for HIV antigen, and lymphocyte culture. Five (6%) of the patients had positive screening EIA at low reactivity. Four of these five had antibodies to H-9 cellular antigens. Comparison of the five seropositive patients to matched controls showed no significant differences in number of lymphocytes or helper/suppressor ratio. Six months later, the five patients had negative screening EIA results using a kit with a manufacturing change approved by the Food and Drug Administration that provided improved specificity. In addition, their Western blot analysis was negative. We conclude that (1) false-positive screening EIA results are more common in chronic hemodialysis patients than other populations; (2) evaluation of chronic hemodialysis patients for HIV infection requires confirmatory tests; and (3) newer EIA screening kits appear to have improved specificity.