Urinary HIV-1 antibody patterns by western blot assay

Diagnosis of human immunodeficiency virus infection (HIV-1) is normally carried out by serum testing for HIV-1 antibody. Recently, antibody testing in other body fluids such as saliva and urine have been attempted. In this study, we examined HIV-1 antibody patterns in urine by Western blot assay as compared to that found in serum. Out of 44 sero-positive samples by Western blot assay we found 43 to be HIV-1 antibody positive in the urine, whereas all 40 sero-negative samples were negative in urine. Thus the sensitivity of urine testing was 97.7% with 100% specificity when compared to serum testing by the Western blot assay. In the analysis of the antibody pattern in urine, we found 6.8% of p17, 68% of p24, and 47.7% of p39 in the core proteins; 72.7% of p31, 61.4% of p51, and 68.2% of p66 in the polymerase; and 63.6% of gp41, 75% of gp120, and 97.7% of gp160 in the envelope proteins. The data obtained supports the selection of the HIV-1 antigen subtype-E to develop a home test kit using urine. Urine testing for HIV-1 antibody is convenient, non-invasive, safe, and easily performed at home. However, if the urine is positive, the confirmation test on serum is needed.