“…The causes of indeterminate patterns on Western blot include technical artifact, laboratory error, irrelevant cross-reactions, nonspecific binding, infection with a related retrovirus such as HIV-2, the presence of an antigenic variant of HIV-1, early HIV-1 infection, or late-stage disease (3,6,7,17,32,40). Antiretroviral therapy reduces viral load and has been reported to reduce HIV-specific antibody (11,16,22,23,28). Presumably, patients on antiretroviral therapy would be diagnosed before the initiation of therapy.…”