Persistently negative HIV-1 antibody enzyme immunoassay screening results for patients with HIV-1 infection and AIDS: serologic, clinical, and virologic results

Objective: To describe persons with HIV infection and AIDS but with persist ently negative HIV antibody enzyme immunoassay (EIA) results. Design: Surveillance for persons meeting a case definition for HIV-1-serone gative AIDS. Setting: United States and Canada. Patients: A total of eight patients with seronegative AIDS identified from July 1995 through September 1997. Main outcome measures: Clinical history of HIV disease, history of HIV test results, and CD4 cell counts from medical record review; results of testin g with a panel of EIA for antibodies to HIV-1, and HIV-1 p24 antigen; and v iral subtype. Results: Negative HIV EIA results occurred at CD4 cell counts of 0-230 x 10 (6)/l, and at HIV RNA concentrations of 105 000-7 943 000 copies/ml. Using a panel of HIV EIA on sera from three patients, none of the HIV EIA detecte d infection with HIV-1, and signal-to-cut-off ratios were less than or equa l to 0.8 for all test kits evaluated. Sera from five patients showed weak r eactivity in some HIV EIA, but were non-reactive in other HIV EIA. All pati ents were infected with HIV-1 subtype B. Conclusions: Rarely, results of EIA tests for antibodies to HIV-1 may be pe rsistently negative in some HIV-1 subtype B-infected persons with AIDS. Phy sicians treating patients with illnesses or CD4 cell counts suggestive of H IV infection, but for whom results of HIV EIA are negative, should consider p25 antigen, nucleic acid amplification, or viral culture testing to docum ent the presence of HIV. (C) 1999 Lippincott Williams & Wilkins.