Serum and effector-cell antibody-dependent cellular cytotoxicity (ADCC) activity remains high during human immunodeficiency virus (HIV) disease progression.

The activity of both serum and effector cell antibody-dependent cellular cytotoxicity (ADCC) against human immunodeficiency virus (HIV-1, HIV) was assessed in HIV-infected individuals. The goal was to relate ADCC levels with the stage or progression of HIV disease. Serial serum samples, usually collected at 6-month intervals, from individuals at defined stages of HIV disease (seroconversion, the HIV-seropositive period before AIDS, and around the time of clinical AIDS diagnosis) were tested. HIV-coated CEM tumor cells were used as targets. Effector-cell ADCC activity was evaluated using fresh peripheral blood mononuclear cells (PBMC) from HIV-infected individuals at different stages of HIV disease. Samples were obtained from male homosexual participants in the Multicenter AIDS Cohort Study (MACS). In seroconverters, ADCC-inducing HIV-specific antibodies were detected at the time that the ELISA antibody test was first positive. Within several months, serum ADCC activity stabilized in each individual. In 29 HIV-seroprevalent individuals (HIV seropositive on their first visit), serum ADCC activity remained constant regardless of whether the individual's HIV disease was stable (high stable CD4; n = 9) or rapidly deteriorating (sharply declining CD4, n = 10; AIDS progressors, n = 10). With respect to effector-cell activity, PBMC from HIV-infected individuals with or without AIDS were capable of mediating ADCC with heterologous and usually with autologous sera. Although the level of NK cytotoxic activity and the level of antibody-armed effector cell activity have been reported to decline as disease progresses, our results support previous observations that ADCC effector-cell activity against antibody-coated targets does not decline in HIV infection.(ABSTRACT TRUNCATED AT 250 WORDS)

Significance of quantitative enzyme-linked immunosorbent assay (ELISA) results in evaluation of three ELISAs and Western blot tests for detection of antibodies to human immunodeficiency virus in a high-risk population.

The characteristics of primary (first) tests with three enzyme-linked immunosorbent assay (ELISA) kits for human immunodeficiency virus (HIV) antibody were determined. The three ELISAs were performed on 3,229, 3,130, and 685 specimens from high-risk individuals using the Litton (LT; Litton Bionetics Laboratory Products, Charleston, S.C.), Dupont (DP; E. I. du Pont de Nemours & Co., Inc., Wilmington, Del.), and Genetic Systems (GS; Genetic Systems, Seattle, Wash.) kits, respectively. Evaluation was based on the distribution of quantitative test results (such as optical densities), a comparison with Western blot (WB) results, reproducibility of the tests, and identification of seroconverters. The performances of the GS and the DP kits were good by all four criteria and exceeded that of the LT kit. Primary ELISA-negative results were not always confirmed with repeat ELISA and by WB testing. The largest percentage of these unconfirmed negative test results came from samples with quantitative results in the fifth percentile nearest the cutoff. Thus, supplementary testing was indicated for samples with test results in this borderline negative range. Similarly, borderline positive primary ELISA results that were quantitatively nearest (fifth percentile) the cutoff value were more likely to be antibody negative on supplementary testing than samples with high antibody values. In this study, results of repeated tests by GS ELISA showed the least change from first test results. DP ELISA showed more unconfirmed primary positive test results, and LT ELISA showed more unconfirmed primary negative test results. Designation of a specimen with a single ELISA quantitative level near the cutoff value as positive or negative should be viewed with skepticism. A higher than normal proportion of specimens with high negative optical densities by GS ELISA (fifth percentile nearest the cutoff) and also negative by WB were found to be from individuals in the process of seroconversion.

Prognostically significant classification of immune changes in AIDS with Kaposi's sarcoma.

Sixteen immunological parameters were assessed quantitatively for their value in providing an immunologically-based and prognostically significant classification of the immune alteration in 97 patients with AIDS and Kaposi's sarcoma (AIDS-KS). The dimensions of reductions in the T4 (T helper-inducer cells) subpopulation of lymphoid cells in the T4-T8 ratio were found to correlate most closely with prognosis. Most other immunological changes did not relate to clinical course. T4 lymphocyte levels greater than 300/microL and a T4-T8 ratio greater than 0.5 indicated a relatively good prognosis, eg, 85% to 95% survival at 12 months. T4 levels less than 100/microL and/or a T4-T8 ratio less than 0.2 had a very poor prognosis, eg, less than 25% survival at 12 months. Intermediate T4 levels and T4-T8 ratios had intermediate prognosis. These immunological findings were found to have independent prognostic value for survival when compared with disease classifications based on tumor stage (I through IV) or on clinical status A (without) or B (with fever, night sweats, or weight loss). Reduced proliferative capacity, increased OKT10 antigen expression, elevated levels of serum IgA, and immune complexes also correlated with prognosis. Elevated levels of serum IgG, cellular HLA-DR expression, and skin test anergy occurred frequently in AIDS-KS but did not have prognostic significance. Variations in level of total lymphocyte, T8 (T suppressor/cytotoxic) cell, gamma FcR receptor-positive cell number, NK activity, or level of serum IgM were less common in AIDS-KS and did not correlate with prognosis.