Urine samples as a possible alternative to serum for human immunodeficiency virus antibody screening

The detection of specific antibodies against human immunodeficiency virus (HIV) was tested by dot blot enzyme immunoassay in 95 urine samples from 72 individuals infected with HIV and 23 seronegative individuals. Western blot of paired serum samples from these same individuals was used as the gold standard. The dot blot tested had a sensitivity of 97.2% and a specificity of 100%; only two samples from HIV-infected individuals at Centers for Disease Control (CDC) stages II and IV were non-reactive. Reactive and discrepant samples (serum/urine) were confirmed by Western blot, which had a sensitivity of 98.6% and a specificity of 100%. The most commonly observed Western blot reactivity pattern in urine samples included bands against three groups of HIV structural proteins (ENV, POL, and GAG). The results indicate that urine can be used in screening for HIV antibodies in epidemiological studies of high-prevalence populations, though it is not recommended for individualized diagnostic purposes.