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Biomedical subjects

A R Moss

Publications and source records attributed to A R Moss.

At least 19 recordsLinked to original sources
PubMed1992

Differences in laboratory values in HIV infection by sex, race, and risk group.

OBJECTIVES: To determine differences in CD4+ and CD8+ lymphocyte values, beta 2-microglobulin (beta 2M), and HIV p24 antigenemia by sex and race among HIV-seropositive and HIV-seronegative injecting drug users (IDU), and to compare these values with those in homosexual men of equivalent status. DESIGN: Baseline values from a cohort of 206 HIV-seropositive and 173 HIV-seronegative IDU were compared with values from a cohort of 288 HIV-seropositive homosexual men and 176 HIV-seronegative controls, who were prospectively followed at 6-month intervals, to examine differences in laboratory values in HIV-infected individuals by sex, race, and risk group. METHODS: Among HIV-seropositives, we compared white and black IDU only (n = 167), and white male IDU (n = 38) with white homosexual men (n = 256). Laboratory values from the cohort of homosexual men at 24, 36 and 48 months of follow-up were compared with IDU values. RESULTS: HIV-infected female IDU had significantly higher CD4+ lymphocyte counts (P < 0.03) and percentages of CD4+ lymphocytes (P < 0.004) than male IDU, resulting in higher CD4:CD8 ratios (P < 0.002). White IDU had significantly higher serum beta 2M levels than black IDU (P < 0.02). Black female IDU were much less likely to be HIV p24-antigenemic (1%) than all other groups (P < 0.005). Compared with homosexual men, male IDU had significantly elevated beta 2M levels (0.58 mg/l higher). When controlled for CD4+ lymphocyte values as a surrogate for length of time HIV-infected, beta 2M and HIV p24 antigenemia differences persisted. CONCLUSIONS: These differences should be considered when HIV p24 antigen, CD4+ lymphocyte counts and beta 2M levels are used as surrogate markers in clinical trials and management of HIV disease.

Adult↗
PubMed1992

Charting the epidemic: the case study of HIV screening of injecting drug users in San Francisco, 1985-1990.

HIV screening for drug users in treatment began in San Francisco in 1985, and was followed by street screening, community outreach, bleach distribution and other intervention programs. The HIV seroconversion rate fell from 4.5% per year in 1985-86 to 1.7% per year in 1987-88 and has remained stable at about 2% per year since 1988. While this decline cannot be attributed to specific programs, the broad spectrum of interventions in San Francisco appears to be keeping the new infection rate low. Future programs should aim at reducing heterosexual HIV transmission, at intervening with multiply-diagnosed drug users, and at providing service to homeless and other very poor drug-using groups.

HIV Infections↗
PubMed1992

Early predictors of survival in symptomatic HIV-infected persons treated with high-dose zidovudine.

The survival times of 246 patients treated with high-dose zidovudine beginning in 1986 were obtained through November 1988. We analyzed clinical and laboratory predictors of survival as measured before initiation of therapy and during the first 32 weeks of therapy. In a multivariate proportional-hazards model, we found significant independent predictive abilities for four pretherapy measurements (AIDS versus ARC diagnosis, Karnofsky performance score, age, and hemoglobin) and four measurements made during therapy (change in log CD4 lymphocyte count from pretherapy to week 24, CD8 lymphocyte count at week 24, rate of decline of hemoglobin over the first 3 months of therapy, and rate of decline in white blood count over the first 6 months of therapy). The presence of three predictors measured during therapy that are statistically significant when controlled for changes in CD4 count suggests that the use of other measures in addition to CD4 counts may substantially improve the prediction of long-term survival based on early response of surrogate markers to therapy.

Drug Administration Schedule↗
PubMed1991

Immune activation markers and AIDS prognosis.

Four assays for serum levels of cellular products of immune activation were examined as prognostic markers for AIDS in a prospective study of asymptomatic HIV-seropositive homosexual men. Baseline serum values of beta 2-microglobulin (beta 2M), neopterin, soluble CD8 (sCD8), and soluble interleukin-2 receptor (sIL-2R) for 185 men were examined univariately and multivariately as predictors of AIDS during 36 months of follow-up. Thirty-three cases of AIDS (18%) were diagnosed during the follow-up period. All four assays correlated highly with each other (r = 0.48-0.63), and all four were good univariate predictors of AIDS and comparable to CD4 lymphocyte count. beta 2M, neopterin, and sCD8 predicted AIDS independently of both CD4 count and HIV p24 antigen or p24 antibody in multivariate analysis. Within the range of CD4 count 200-499 x 10(6) cells/l, an immune activation marker used in combination with an assay for p24 antigen identifies those at 3-6% risk of AIDS over 36 months (low risk on both assays) and those at 63-86% risk (high risk on both assays). These results can be used to guide physicians and patients making decisions about treating asymptomatic HIV infection with zidovudine in individuals with CD4 lymphocyte count of 200-499 x 10(6) cells/l.

Acquired Immunodeficiency Syndrome↗
PubMed1991

Absence of HIV-1 DNA in high-risk seronegative individuals using high-input polymerase chain reaction.

Evidence of frequent HIV-1 infections in antibody-negative, high-risk individuals (so-called 'silent' infections) remains controversial. To evaluate whether these discrepant results may be the consequence of intermittent detection of rare infected cells (low viral load) preceding seroconversion, we developed a modification of the polymerase chain reaction (PCR) technique which enabled analysis of 10-fold greater amounts of cellular DNA per reaction than standard PCR (2 x 10(6) rather than 0.2 x 10(6) input cells). This technique allowed consistent detection of HIV-1 provirus in two seropositive individuals who had repeatedly tested negative by standard-input PCR. However, results were negative when high-input PCR was applied to 51 specimens from 39 selected high-risk seronegative individuals. These results suggest that variations in viral load preceding or in the absence of seroconversion probably do not explain discrepant evidence regarding silent HIV-1 infection.

Cohort Studies↗
PubMed1991

Does the NART hold after head injury? A case report.

The NART is frequently used to estimate the premorbid intellectual ability of subjects undergoing neuropsychological assessment for a variety of reasons. Although the NART has been shown to hold in dementia, depression and head injury, reports to date have inferred premorbid IQs with no actual data on premorbid functioning. This is a case report of a man who sustained a severe head injury on whom an intelligence test had been administered in childhood. The NART produced a very accurate estimate of his pre-injury IQ.

Adult↗
PubMed1991

Results of a one year longitudinal study of HIV antibody test notification from the San Francisco General Hospital cohort.

We examined the psychological impact of HIV antibody testing in 107 homosexual men in San Francisco. Seventy-eight percent of the seropositives but only 43% of the seronegatives correctly anticipated their results. Twelve months after notification (but not earlier), notified seropositives reported significantly greater increases in total distress than nonnotified controls. However, notified seronegatives demonstrated significantly lower levels of hopelessness than nonnotified controls at every follow-up assessment. Thus, knowledge of HIV antibody status appears to dispel a sense of gloom in persons who incorrectly believe themselves to be infected with HIV, but does not appear to induce significant distress in those whose expectation of a positive result is confirmed. Both groups reported lower distress than men with ARC or AIDS, suggesting that distress was related more to symptomatology than knowing antibody status. These results suggest the benefits of HIV testing for the considerable proportion of seronegative subjects believing themselves to be seropositive and should be weighted against the more limited induction of distress in seropositives who receive confirmation of their test result expectation. The benefits of testing are also supported by increasing knowledge of the usefulness of early intervention in HIV disease.

AIDS Serodiagnosis↗
PubMed1990

Projections of AIDS morbidity and mortality in San Francisco.

To develop a model for predicting acquired immunodeficiency syndrome (AIDS) morbidity in San Francisco, Calif, through June 1993, we combined annual human immunodeficiency virus seroconversion rates for homosexual and bisexual men and for heterosexual intravenous drug users with estimates of the cumulative proportion of the population with AIDS by duration of human immunodeficiency virus infection and with estimates of the size of the at-risk populations. We projected AIDS mortality by applying Kaplan-Meier estimates of survival time following diagnosis to the projected number of cases. The median incubation period for AIDS among homosexual and bisexual men infected with the human immunodeficiency virus was estimated to be 11.0 years (mean, 11.8 years; 95% confidence interval, 10.6 to 13.0 years). The model projects 12,349 to 17,022 cumulative cases of AIDS in San Francisco through June 1993, with 9,966 to 12,767 cumulative deaths.

Acquired Immunodeficiency Syndrome↗
PubMed1990

Sensitivity of treponemal tests for detecting prior treated syphilis during human immunodeficiency virus infection.

To evaluate the sensitivity of treponemal tests as a marker of prior syphilis in individuals with human immunodeficiency virus (HIV) infection, the syphilis serology of 109 homosexual men with a documented history of treated syphilis was compared with records of prior results and confirmed on stored serum samples. None of the HIV-seronegative individuals lost reactivity to a treponemal test, whereas 7% of the seropositive asymptomatic individuals and 38% of those with symptomatic HIV infection had loss of reactivity. Symptomatic HIV infection was associated with loss of reactivity, as a T4 lymphocyte count less than 200 X 10(6)/1, a T4-to-T8 ratio less than 0.6, a single prior episode of syphilis, and a low VDRL titer at the time of the last documented episode of syphilis. Although no conclusions can be drawn about the sensitivity of treponemal tests in patients with active syphilis and HIV infection, these data suggest that treponemal tests may not identify those previously infected with Treponema pallidum.

Adult↗
PubMed1989

Incubation period of AIDS in San Francisco.

In a closed population, the distribution of AIDS diagnoses over time is the convolution of the distributions of human immunodeficiency virus (HIV) infections and the incubation period. This has motivated estimates of the infection distribution, assuming known diagnosis and incubation distributions, but the usefulness of this method is limited by uncertainty about incubation. The large amount of information on the distribution of HIV infections in San Francisco's gay community suggests the opposite approach--estimating the incubation distribution, assuming known infection and diagnosis distributions. A non-parametric implementation of this strategy produced an estimate with a median at 9.8 years, increasing hazard rates, and less uncertainty than previous estimates.

Acquired Immunodeficiency Syndrome↗
PubMed1989

Cocaine use and HIV infection in intravenous drug users in San Francisco.

We assessed risk factors for human immunodeficiency virus (HIV) infection in 633 heterosexual intravenous drug users. The HIV seroprevalence was 26% in blacks, 10% in Hispanics, and 6% in whites. Intravenous cocaine use significantly increased the risk of HIV infection, with a seroprevalence of 35% in daily cocaine users (odds ratio, 6.4; 95% confidence interval, 3.0 to 13.3). Black subjects were more likely to use cocaine regularly. Drug use in shooting galleries and sharing of drug injection equipment were also associated with HIV infection and were more common in cocaine users. By multivariate analysis, black race, daily cocaine injection by blacks and Hispanics, all other cocaine injection, heavy use prior to entry into methadone treatment by blacks, and use of drugs in shooting galleries were independent predictors of HIV infection. Methadone therapy was associated with substantial reductions in heroin use and some reduction in cocaine use, but 24% of cocaine users receiving methadone began or increased cocaine injection after entry into treatment.

Black or African American↗
PubMed1989

Lymphocyte subset analysis to predict progression to AIDS in a cohort of homosexual men in San Francisco.

A group of 10 leukocyte and lymphocyte subsets were measured by simultaneous dual immunofluorescence and flow cytometry in a group of homosexual men from the San Francisco General cohort. Absolute numbers and percentages of lymphocytes were determined in 30 individuals who progressed to AIDS and 29 who did not over a 44-month period at annual intervals. At entry into the study, all subjects were asymptomatic, HIV seropositive, and had multiple changes in lymphocyte subsets compared to HIV-negative controls. In progressors, large changes occurred from the first visit to the last visit before progression in both absolute numbers and percentages of CD4 cells. The percentage of HLA-DR-bearing CD8 cells also increased. We utilized a proportional hazards model to assign a predictive value for progression to AIDS to lymphocyte subsets in both univariate and multivariate tests. Increased DR-positive CD8 cells, decreased CD4 cells, and increased CD8-positive, Leu 7-positive cells independently predicted progression to AIDS at P less than 0.006 (relative hazard 5.8-4.0). In a multivariate model, the most useful tests were either increased numbers or percentages of DR-positive CD8 cells. These data suggest parsimonious approaches to following HIV-positive individuals and further support the possibility of autoreactive T cells in the pathogenesis of HIV-associated diseases.

Acquired Immunodeficiency Syndrome↗
PubMed1989

Lymphocyte proliferative responses to human immunodeficiency virus antigens in vitro.

All HIV seronegative (HIV Ab-) and most HIV seropositive (HIV Ab+) individuals' lymphocytes failed to proliferate in primary cultures in response to purified HIV or to recombinant envelope and core antigens of HIV, even in the presence of recombinant interleukin 2 (rIL-2). Most HIV Ab- and HIV Ab+ individuals' lymphocytes, however, could proliferate or be induced by rIL-2 to proliferate in response to lysates of Escherichia coli or Saccharomyces cerevisiae. These findings indicate selective defects in lymphocyte proliferative responses to HIV antigens before the development of AIDS in which lymphocytes are unable to proliferate in response to any antigens. These defects in cell-mediated immune responses to HIV antigens are likely to play an important role in the pathobiology of HIV infections. Although intact HIV or glycosylated gp120 envelope protein of HIV are involved in these defects, a non-glycosylated recombinant form of the HIV gp120 envelope (ENV2-3) and p25 core proteins did not inhibit antigen- or mitogen-driven lymphocyte proliferation.

AIDS-Related Complex↗
PubMed1988

Seropositivity for HIV and the development of AIDS or AIDS related condition: three year follow up of the San Francisco General Hospital cohort.

The three year actuarial progression rate to the acquired immune deficiency syndrome (AIDS) in a cohort of men in San Francisco who were seropositive for the human immunodeficiency virus (HIV) was 22%. An additional 26 (19%) developed AIDS related conditions. Beta 2 Microglobulin concentration, packed cell volume, HIV p24 antigenaemia, and the proportion and number of T4 lymphocytes each independently predicted progression to AIDS. Beta 2 Microglobulin was the most powerful predictor. The 111 subjects tested who were normal by all predictors (40%) had a three year progression of 7%, and the 68 subjects who were abnormal by two or more predictors (24%) had a progression rate of 57%. Two thirds of all men who progressed to AIDS were in the last group. The median T4 lymphocyte count in subjects who did not progress to AIDS fell from 626 x 10(6) to 327 x 10(6)/l. HIV p24 antigenaemia developed in 7% of the subjects per year. The proportion who were abnormal by two or more predictive variables rose to 41%. At three years an estimated two thirds of the seropositive subjects showed clinical AIDS, an AIDS related condition, or laboratory results that were highly predictive of AIDS. It is concluded from the observed rates and the distribution of predictive variables at three years that half of the men who were seropositive for HIV will develop AIDS by six years after the start of the study, and three quarters will develop AIDS or an AIDS related condition.

AIDS-Related Complex↗