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Biomedical subjects

D R Hoover

Publications and source records attributed to D R Hoover.

At least 109 records · Page 6Linked to original sources
PubMed1994

Factors influencing survival after AIDS: report from the Multicenter AIDS Cohort Study (MACS).

The objective of this study was to determine if clinical signs, symptoms, laboratory variables, and use of therapeutic or prophylactic agents have prognostic associations with survival after diagnosis of clinical AIDS. A total of 2,168 homosexual men, seropositive for human immunodeficiency virus type 1 (HIV-1) participated in a longitudinal cohort study of the greater metropolitan areas of Baltimore, Maryland, Washington, D.C., Chicago, Illinois, Pittsburgh, Pennsylvania, and Los Angeles, California, U.S.A.--the Multicenter AIDS Cohort Study (MACS). Variables within 6 months prior to AIDS diagnosis included age, CD4+ lymphocyte counts, hemoglobin, and self-reported thrush, fever, anti-retroviral therapy (ART) beginning prior to AIDS onset, and ART beginning after AIDS (as a time-dependent covariate) were analyzed as mutually exclusive categories, as was prophylaxis for Pneumocystis carinii pneumonia (PCP). Univariate and multivariate survival models of time from AIDS to death were fit. In univariate analysis, younger age, higher counts of CD4+ lymphocytes, hemoglobin, and absence of thrush or fever prior to AIDS onset were associated with longer survival after AIDS. Those who began ART within 3 months after AIDS onset had longer median survival (1.75 years), from 3 months after AIDS, when compared with those who began ART prior to AIDS (1.18 years). This comparison is not influenced by the bias that those who survive longer have a greater likelihood to subsequently receive ART. Prophylaxis for PCP beginning after AIDS onset was also associated with longer post-AIDS survival when compared with beginning prophylaxis prior to AIDS or never using prophylaxis.(ABSTRACT TRUNCATED AT 250 WORDS)

Acquired Immunodeficiency Syndrome↗
PubMed1993

Clinical manifestations of AIDS in the era of pneumocystis prophylaxis. Multicenter AIDS Cohort Study.

BACKGROUND: Among patients infected with human immunodeficiency virus type 1 (HIV-1), early and widespread use of prophylactic regimens against Pneumocystis carinii is changing the pattern of illnesses related to the acquired immunodeficiency syndrome (AIDS). METHODS: We conducted a subcohort analysis of 844 men with AIDS (87 percent of whom have since died) from a prospectively followed cohort of 2592 HIV-1-infected homosexual men. RESULTS: A total of 138 men received prophylaxis before the diagnosis of AIDS, but 39 (28 percent) nevertheless had P. carinii pneumonia at some time. Only four illnesses occurred more frequently in men who received P. carinii prophylaxis before the onset of AIDS: Mycobacterium avium complex disease, which developed in 33.4 percent, as compared with 17.3 percent of the 706 men who did not receive early prophylaxis; wasting syndrome (18.4 percent vs. 6.4 percent); cytomegalovirus disease (44.9 percent vs. 24.8 percent); and esophageal candidiasis (21.3 percent vs. 12.8 percent). Collectively, these four diseases accounted for the initial AIDS-related illness in 42.7 percent of those who received prophylaxis before the onset of AIDS, as compared with 10.7 percent of those who did not. During the three six-month periods before the diagnosis of AIDS (0 to 6, > 6 to 12, and > 12 to 18 months), the geometric mean CD4+ cell counts were 48, 87, and 147 per cubic millimeter, respectively, in men who received prophylaxis against P. carinii, as compared with 118, 211, and 279 per cubic millimeter in those who did not. CONCLUSIONS: M. avium complex disease, esophageal candidiasis, wasting syndrome, and cytomegalovirus disease are more common in HIV-infected patients who have received prophylaxis against P. carinii than in those who have not. Prophylaxis may delay the first AIDS illness for 6 to 12 months.

AIDS-Related Opportunistic Infections↗
PubMed1993

Depressive symptoms as predictors of medical outcomes in HIV infection. Multicenter AIDS Cohort Study.

OBJECTIVE: To ascertain whether depressive symptoms as determined by the Center for Epidemiologic Studies-Depression scale (CES-D) predict accelerated mortality and worse medical outcomes in patients infected with human immunodeficiency virus (HIV). DESIGN: Eight-year cohort study with semiannual follow-up. SETTING: Community volunteers. PARTICIPANTS: A total of 1809 HIV-seropositive homosexual men without the acquired immunodeficiency syndrome (AIDS) who entered the Multicenter AIDS Cohort Study in 1984 or 1985. Eight-year follow-up data were available on 75% of eligible participants. OUTCOME MEASURES: Times to AIDS, death, and prophylactic treatment, and slopes describing the decline in CD4 count for each individual participant. RESULTS: Using a conventional definition of depression (CES-D > or = 16 at the first study visit), 21.3% of participants were classified as depressed. Depressed participants had lower CD4 counts and reported more AIDS-related symptoms. There were no significant differences between depressed and nondepressed participants on any of the outcome measures (P > .05 in all cases). In contrast, men reporting AIDS-related symptoms had shorter times to AIDS and to death even after adjusting for CD4 counts (P < .01). The analyses were repeated, with similar results, using different definitions of depression based on the CES-D. CONCLUSIONS: We find no evidence that depressive symptoms independently prognosticate worse outcomes in HIV infection. Because of associations of depression with symptom reports, CD4 counts, and indicators of socioeconomic status, future studies of the relationship between depression and HIV outcome should consider these variables as confounders.

Adult↗
PubMed1993

Racial and ethnic differences in human immunodeficiency virus type 1 (HIV-1) seroprevalence among homosexual and bisexual men. The Multicenter AIDS Cohort Study.

To determine whether the excess prevalence of human immunodeficiency virus type 1 (HIV-1) infection in US black and Hispanic homosexual men relative to white men can be explained by differences in sociodemographic factors, history of sexually transmitted diseases, or sexual and drug-use behaviors, the authors conducted a cross-sectional analysis of baseline HIV-1 seroprevalence and HIV-1 risk factors among 4,475 non-Hispanic white, 234 Hispanic white, and 194 black homosexual men from four centers in the United States (Baltimore/Washington, DC, Pittsburgh, Chicago, and Los Angeles). HIV-1 seroprevalence was significantly higher in Hispanic men (50%; odds ratio (OR) = 1.83, 95% confidence interval (CI) 1.41-2.39) and black men (47%; OR = 1.62, 95% CI 1.21-2.16) compared with white men (35%). Both Hispanic and black men more frequently reported a history of sexually transmitted diseases. Overall, Hispanics had the highest risk profile and blacks the lowest risk profile with respect to certain high-risk sexual behaviors (e.g., receptive anal intercourse and use of anonymous sexual partners) and recreational drug use. After multivariate adjustment, black race remained a significant independent risk factor for HIV-1 seropositivity (OR = 1.60, 95% CI 1.13-2.26), but Hispanic ethnicity was no longer statistically significant (OR = 1.17, 95% CI 0.82-1.69). Most of the excess HIV-1 prevalent infection among Hispanics was explained by their predominant recruitment from Los Angeles--the study center with the highest HIV-1 seroprevalence--and their greater prevalence of a history of sexually transmitted diseases and certain high-risk sexual practices. By contrast, adjustment for these same risk behaviors failed to explain the observed black-white differences in HIV-1 seroprevalence, and further studies are needed to elucidate the reasons for these unexplained racial differences. HIV-1 educational programs for homosexual men should take into account the behavioral differences that exist between white and minority racial/ethnic groups.

Black or African American↗
PubMed1993

Composite risk score for Kaposi's sarcoma based on a case-control and longitudinal study in the Multicenter AIDS Cohort Study (MACS) population.

The possibility that an agent in addition to human immunodeficiency virus type 1 may be involved in the etiology of Kaposi's sarcoma in acquired immunodeficiency syndrome (AIDS) patients was investigated between 1984 and 1992 in this nested case-control analysis from the Multicenter AIDS Cohort Study (MACS) of homosexual and bisexual men. A total of 316 cases of Kaposi's sarcoma were identified and compared with 510 participants with AIDS and no evidence of cancer. More of the Kaposi's sarcoma cases were from Los Angeles and used a higher number of recreational drugs. The Kaposi's sarcoma cases were also more active sexually. There was a dose-response relation between Kaposi's sarcoma and the number of sexual partners, with an odds ratio of 2 between the most and least sexually active subgroups. The odds ratio for Kaposi's sarcoma increased to 4.18 (95% confidence interval 1.29-14.1) in the presence of a history of five infections. Hepatitis and gonorrhea contributed the most to this relation. The various observed odds ratios did not change after multivariate adjustment for the other risk factors. A model was developed combining all predictive associations into a composite risk score ranging from one to 12 and based on history of infections, sexual activity, use of poppers/nitrites, and having had sexual partners from the West Coast of the United States. The subgroup with the highest scores, compared to the subgroup with the lowest score, had an odds ratio of 8.93 (95% confidence interval 3.21-30.44) for Kaposi's sarcoma. A longitudinal proportional hazards analysis among all 2,190 human immunodeficiency virus type 1-seroprevalent men at study entry, based on this risk score and CD4 cells at baseline, confirmed these findings. Identifying these specific subgroups that are at high and low risk for Kaposi's sarcoma will help future investigations to be more focused in their search for an additional etiologic factor for Kaposi's sarcoma in AIDS.

Acquired Immunodeficiency Syndrome↗
PubMed1993

Epidemiologic analysis of Kaposi's sarcoma as an early and later AIDS outcome in homosexual men.

The authors separately studied the epidemiology (risk and risk factors) of Kaposi's sarcoma occurring as an initial acquired immunodeficiency syndrome (AIDS) outcome (early Kaposi's sarcoma) and later after a different initial AIDS outcome (later Kaposi's sarcoma) in a cohort of 2,591 human immunodeficiency virus type 1-infected gay men of the Multicenter AIDS Cohort Study between 1984 and 1992. Among 844 AIDS cases, 202 presented with early Kaposi's sarcoma, 101 subsequently developed later Kaposi's sarcoma, and 541 were not diagnosed with Kaposi's sarcoma. Overall, 37.4% of AIDS cases were diagnosed with Kaposi's sarcoma prior to death. Kaposi's sarcoma diagnosed on the skin was significantly more common with early Kaposi's sarcoma (77.3%) than with later Kaposi's sarcoma (65.1%). Men presenting with an AIDS outcome other than Kaposi's sarcoma were at high risk for later Kaposi's sarcoma. Later Kaposi's sarcoma onset in men with a previous AIDS outcome was associated with the following characteristics: 1) lower immune status prior to AIDS and 2) longer post-AIDS survival. A Kaposi's sarcoma diagnosis in a man with a previous AIDS illness approximately doubled the risk (hazard) for death. Histories of urethral gonorrhea and scabies prior to study entry were more common in early Kaposi's sarcoma cases than in later Kaposi's sarcoma cases. However, self-reported sexual activity at study entry and prior to AIDS onset was highest in the later Kaposi's sarcoma group. In this cohort, cigarette smoking had a protective association against all Kaposi's sarcoma in univariate and multivariate models. Only 21.0% of the later Kaposi's sarcoma and 25.0% of the early Kaposi's sarcoma men smoked at least one-half pack of cigarettes daily at study entry compared with 33.8% of non-Kaposi's sarcoma and 35.5% of seroprevalent men still AIDS free. The reasons for this surprising association are unclear. However, other evidence which documents that habitual smoking alters the immune system (and possibly cytokine levels) in ways that could perhaps influence Kaposi's sarcoma pathogenesis should be considered.

Acquired Immunodeficiency Syndrome↗
PubMed1993

A method to test for a recent increase in HIV-1 seroconversion incidence: results from the Multicenter AIDS Cohort Study (MACS).

We have formulated the problem of determining whether there has been an upturn in HIV-1 seroconversion incidence over the first five years of follow-up in the Multicenter AIDS Cohort Study (MACS) as that of locating the minimum of a quadratic regression or examination of two-knot piecewise spline models. Under a quadratic model, we propose a method to obtain a direct estimate and a bootstrap estimate for the location of the temporal turning point (local minimum) for HIV-1 seroconversion incidence and three methods to estimate confidence intervals for the location of the turning point for HIV seroconversion incidence: (1) Wald confidence interval estimate with or without log transformation assuming the asymptotic normality and applying the Delta method; (2) asymmetric confidence intervals using Fieller's Theorem and its modification; and (3) bootstrapping confidence intervals. Inferences for the temporal turning point based on Wald tests for a single regression term in a non-linear regression model were not reliable compared to inferences based on confidence intervals placed on calendar time. We present results using these different methods applied to the MACS data and we obtain power estimates to illustrate the performances of different methods.

Cohort Studies↗
PubMed1993

Assessment of the antibody response to the immunosuppressive/immunodominant region of HIV gp41 in a 5-year longitudinal study.

The antibody response of HIV-infected individuals to the 581-609 amino acid (aa) region of HIV-1 gp41 containing the putative immunosuppressive and immunodominant sequences was examined. Sera collected every 5 to 6 months over a period of 5 years from 50 HIV-1-infected homosexual and bisexual men, 25 of whom progressed to AIDS during the collection period, were monitored for changes in ELISA reactivity against synthetic peptides encompassing aa581-609 of gp41. The data obtained in this blinded, historical prospective study were analyzed with respect to changes in mean ELISA absorbance over time and differences in absorbance between patient groups (those who progressed to AIDS and those who did not). No correlation was found between time or disease state and the presence of antibodies to the aa581-597 immunosuppressive sequence. In contrast, ELISA absorbance against the aa598-609 immunodominant sequence continued to increase over time in both the AIDS and non-AIDS groups. The rate of increase in absorbance was similar for both groups; however, the AIDS group had a significantly higher mean absorbance level at the outset of the study and maintained this difference throughout the study. This region of gp41 has been proposed to play a role in complement-mediated antibody-dependent enhancement of infection.

Acquired Immunodeficiency Syndrome↗
PubMed1993

High socioeconomic status is a risk factor for human immunodeficiency virus type 1 (HIV-1) infection but not for sexually transmitted diseases in women in Malawi: implications for HIV-1 control.

A total of 6600 pregnant urban women attending an antenatal clinic of a major hospital in Malawi were evaluated for risk factors for human immunodeficiency virus type 1 (HIV-1) infection. HIV-1 seroprevalence was 23% and significantly (P < .001) associated with markers of heterosexual activity (history of sexually transmitted diseases [STDs], more than one sexual partner, reports of husbands with other partners, and all prevalent STDs except chlamydial infection) and higher socioeconomic status (as measured by husband's education). History of injections, scarification, and transfusions were not associated with HIV-1 infection. In two logistic regression models, higher socioeconomic status was a risk factor for HIV-1 infection (odds ratio [OR] = 2.69, P < .001) but not for STDs (OR = 0.94, P = .30). The opposite associations between HIV-1 and socioeconomic status and STDs and socioeconomic status suggest that HIV prevention strategies, in addition to STD diagnosis and treatment, should include interventions to reduce high-risk sexual activity and promote condom use.

Acquired Immunodeficiency Syndrome↗
PubMed1993

Dementia in AIDS patients: incidence and risk factors. Multicenter AIDS Cohort Study.

We determined incidence and future projections of dementia after AIDS onset in 492 homosexual men with AIDS in the Baltimore/Los Angeles sites of the Multicenter AIDS Cohort Study, 64 of whom developed dementia. We studied various risk factors for dementia, including demographic and clinical features, medical history, markers of immune status before AIDS, and zidovudine use. During the first 2 years after AIDS, HIV dementia developed at an annual rate of 7%. Overall, 15% of the cohort followed through death developed dementia. The median survival after dementia was 6.0 months. Using a proportional hazards model, risk factors for more rapid development of dementia were lower hemoglobin (relative hazard, 0.59 per additional 2 g/dl; p = 0.0005) and body mass index (relative hazard, 0.64 per additional 5 kg/m2; p = 0.05) 1 to 6 months before AIDS, more constitutional symptoms 7 to 12 months before AIDS (relative hazard, 1.68 per additional symptom, p = 0.005), and older age at AIDS onset (relative hazard, 1.60 per decade older; p = 0.009). In a multivariate model, pre-AIDS hemoglobin remained the most significant predictor of dementia. There were no significant risks defined from demographic characteristics, specific AIDS-defining illnesses, zidovudine use before AIDS, or CD4+ lymphocyte count before AIDS. We project that 12 months after the first AIDS diagnosis, 7.1% of survivors will have dementia. The observed association between anemia, low weight, constitutional symptoms, and dementia suggests a role for cytokines inducing both systemic and neurologic disease.

AIDS Dementia Complex↗
PubMed1993

Signs and symptoms of "asymptomatic" HIV-1 infection in homosexual men. Multicenter AIDS Cohort Study.

We investigated the long-term health effects of HIV-1 infection in homosexual men not close to developing AIDS by comparing 916 HIV-1-seropositive (SP) men at least 1.67-3.67 years prior to a clinical AIDS diagnosis to 2,161 HIV-1-seronegative (SN) controls. The SP group reported a higher total of 12 distinct symptoms (fatigue, shortness of breath, night sweats, rash, cough, diarrhea, headache, thrush, skin discoloration, fever, weight loss, and sore throat/mouth) than did the SN group (p < 0.0001), corresponding to at least 5.6 more days/year of such symptoms. The SP group had lower body mass index (p < 0.0001) and lower hemoglobin (p < 0.0001). The SP group was more depressed, as measured by CES-D score (p = 0.047), before knowledge of one's serostatus was likely, and became even further depressed (p = 0.038 for increase in depression) after the HIV-1 serostatus test was accessible to high-risk groups. These associations remained unchanged in multivariate models, incorporating other covariates.

Analysis of Variance↗
PubMed1992

Estimation of time since exposure for a prevalent cohort.

In natural history studies of human immunodeficiency virus type 1 (HIV-1) infection a substantial proportion of participants are seropositive at time of enrollment in the study. These participants form a prevalent subcohort. Estimation of the unknown times since exposure to HIV-1 in the prevalent subcohort is of primary importance for estimation of the incubation time of AIDS. The subset of the cohort that tested negative for antibody to HIV-1 at study entry and was observed to seroconvert forms the incident subcohort that provides longitudinal data on markers of maturity (that is, duration) of infection. We use parametric life table regression models incorporating truncation to describe the conditional distribution (imputing model) of the times since seroconversion given a vector of the markers of maturity. Using the fitted model and the values of the markers of maturity of infection provided by the seroprevalent subcohort at entry into the study, we can impute the unknown times since seroconversion for the prevalent subcohort. We implement multiple imputation based on a model-robust estimate of the covariance matrix of parameters of the imputing model to provide confidence intervals for the geometric mean of the time since seroconversion in the prevalent subcohort, and to compare maturity of infection of cohorts recruited in different cities. The accuracy of imputation is further validated by comparisons of imputation-based estimates of AIDS incubation distribution in the seroprevalent subcohort with more direct estimates obtained from the seroincident subcohort.

Acquired Immunodeficiency Syndrome↗
PubMed1992

T lymphocyte subsets during and after pregnancy: analysis in human immunodeficiency virus type 1-infected and -uninfected Malawian mothers.

Flow cytometric studies were done in Malawi on 229 women in their third trimester and 128 women 6 weeks postpartum; both human immunodeficiency virus type 1 (HIV-1)-seropositive and -seronegative women demonstrated an increase in the absolute number of CD4 and CD8 lymphocytes between late pregnancy and early postpartum, while percentages of CD4 and CD8 cells remained virtually unchanged. Subsequent measurement of CD4 and CD8 cells 6 weeks after delivery in 89 women tested in the third trimester showed an increase in absolute numbers in both HIV-1-seropositive and -seronegative women, without a parallel increase in CD4 or CD8 percentage. Regardless of HIV-1 infection status, Malawian women are no more immunosuppressed, as measured by T cells, in their third trimester of pregnancy than in the nonpregnant state. Percentage, rather than absolute number, should be used when monitoring CD4 and CD8 cell levels in pregnant women to avoid the effect of higher volume of distribution on absolute numbers of T cells.

Analysis of Variance↗