Do gender differences in CD4 cell counts matter?

Contribution of Sex Differences to HIV Immunology, Pathogenesis, and Cure Approaches

Approximately 38 million people were living with human immunodeficiency virus (HIV) in 2020 and 53% of those infected were female. A variety of virological and immunological sex-associated differences (sexual dimorphism) in HIV infection have been recognized in males versus females. Social, behavioral, and societal influences play an important role in how the HIV pandemic has affected men and women differently. However, biological factors including anatomical, physiologic, hormonal, and genetic differences in sex chromosomes can each contribute to the distinct characteristics of HIV infection observed in males versus females. One striking example of this is the tendency for women to have lower HIV plasma viral loads than their male counterparts early in infection, though both progress to AIDS at similar rates. Sex differences in acquisition of HIV, innate and adaptive anti-HIV immune responses, efficacy/suitability of specific antiretroviral drugs, and viral pathogenesis have all been identified. Sex differences also have the potential to affect viral persistence, latency, and cure approaches. In this brief review, we summarize the major biological male/female sex differences in HIV infection and their importance to viral acquisition, pathogenesis, treatment, and cure efforts.

Factors associated with prognostic or treatment outcomes in HIV/AIDS patients with and without hypertension in Eswatini

Non-communicable diseases are increasing faster in HIV/AIDS patients than in the general population. We studied the association between hypertension and other possible confounding factors on viral load and CD4-cell counts in hypertensive and non-hypertensive HIV/AIDS patients receiving antiretroviral therapy (ART) at a large hospital in Eswatini over a 4-year period. We performed a retrospective longitudinal review of the medical records of 560 ART patients divided into non-hypertension and hypertension groups (n = 325 and n = 235) from July 27 to September 8, 2018. Generalized Estimated Equation was used to analyze the longitudinal data. Hypertensive patients were more likely to have improved CD4-cell counts than non-hypertensive patients (OR = 1.83, [1.37–2.44]). ART patients with hypertension were more likely to have detectable viral loads, though not significant (OR = 1.37 [0.77–2.43]). In non-hypertensive patients, second line ART was significantly associated with viral load (OR = 8.61 [2.93–25.34]) and adverse side effects (OR = 3.50 [1.06–11.54]), while isoniazid preventive therapy was significantly associated with CD4-cell counts (OR = 1.68 [1.16–2.45]). In hypertensive patients, factors associated with viral load were WHO HIV stage (OR = 2.84 [1.03–7.85]) and adherence (OR = 8.08 [1.33–49.04]). In both groups, CD4-cell counts significantly and steadily increased over time (p-value < 0.001). Results show a significant association between hypertension and CD4 cell counts but not viral load. In ART patients with and without hypertension, the factors associated with prognostic markers were different. More attention may need to be paid to ART patients with well controlled HIV status to monitoring and controlling of hypertension status.

The rapid CD4 + T-lymphocyte decline and human immunodeficiency virus progression in females compared to males

CD4 + T-lymphocyte counts are used to assess CD4 + decline and the stage of human immunodeficiency virus (HIV) progression in HIV-infected patients. Clinical observation suggests that HIV progress more rapid in females than males. Of the original 5000 HIV-infected population of Western New York HIV/AIDS, Referral Center at Erie County Medical Center (ECMC), 1422 participated in the cohort study. We identified 333 HIV-infected patients with CD4 + T-cell-counts ≥ 500/µƖ, among them 178 met the inclusion criteria for the 10-year study. Females had higher mode (600 vs. 540) and mean (741.9 vs. 712.2) CD4 + counts than males at baseline. However, CD4 + declined faster among females in a shorter time than males (234.5 vs. 158.6, P < 0.004), with rapid HIV progression. Univariate analyses determined that females had a 40% higher risk for CD4 + decline than males. The bivariate analyses specified CD4 + decline remained greater in females than males. Multivariate analyses which employed Cox’s proportional Hazard-Model to adjust for numerous variables simultaneously identified women had almost twice the risk for CD4 + decline and rapid HIV progression than males (RR = 1.93; 95%CI 1.24, 2.99). Although the biological mechanism remains unknown, findings suggest gender differences in CD4 + decline, with a higher risk of rapid HIV progression and shorter longevity in females.

Greater Sensorimotor Deficits and Abnormally Lower Globus Pallidus Fractional Anisotropy in HIV+ Women than in HIV+ Men

AIMS

Cognitive impairment may be greater in HIV-positive (HIV+) women than in HIV+ men. Whether sex-specific differences exist in brain microstructure of HIV+ individuals is unknown and was evaluated.

METHOD

39 HIV+ (21 men, 18 women) and 45 seronegative (SN, 20 men, 25 women) participants were assessed with brain diffusion tensor imaging and cognitive assessments (7 neuropsychological domains). Fractional anisotropy (FA) and mean diffusivity (MD) were measured with an automated atlas in selected brain regions. Group comparisons were assessed with linear mixed effects models, with sub-regions and hemisphere (left/right) as repeated factors for each region.

RESULTS

HIV+ women, but not HIV+ men, were slower than sex-matched SN controls on sensorimotor function (Dominant-hand: interaction-p = 0.007; Non-dominant hand: interaction-p = 0.039). Similarly, only HIV+ women had lower FA in the globus pallidus (GP, interaction-p = 0.011). Additionally, regardless of sex, the HIV+ group had poorer Fluency, Speed, and Attention than SN-controls (p = 0.006-0.008), as well as lower FA and higher MD in multiple brain regions (p = <0.001-0.044). Across all participants, performance on Attention was predicted by uncinate-FA (p < 0.001, r = 0.5) and corpus callosum (CC)-FA (p = 0.038, r = 0.23), while the Speed of Information Processing was predicted by CC-FA (p = 0.009, r = 0.3). Furthermore, faster sensorimotor function correlated with higher CC-FA and uncinate-FA in men but not in women (Sex*DTI-interaction-p = 0.03-0.06).

CONCLUSIONS

The relatively poorer sensorimotor function and abnormally lower GP_FA, suggesting lesser neuronal integrity, in HIV+ women demonstrate sex-specific effects from HIV-infection on these measures. These findings may be related to the greater immune activation and neuroinflammation in HIV+ women compared to HIV+ men. Graphical Abstract.

Joint modelling of longitudinal and time-to-event data: an illustration using CD4 count and mortality in a cohort of patients initiated on antiretroviral therapy

Background

Modelling of longitudinal biomarkers and time-to-event data are important to monitor disease progression. However, these two variables are traditionally analyzed separately or time-varying Cox models are used. The former strategy fails to recognize the shared random-effects from the two processes while the latter assumes that longitudinal biomarkers are exogenous covariates, resulting in inefficient or biased estimates for the time-to-event model. Therefore, we used joint modelling for longitudinal and time-to-event data to assess the effect of longitudinal CD4 count on mortality.

Methods

We studied 4014 patients from the Centre for the AIDS Programme of Research in South Africa (CAPRISA) who initiated ART between June 2004 and August 2013. We used proportional hazards regression model to assess the effect of baseline characteristics (excluding CD4 count) on mortality, and linear mixed effect models to evaluate the effect of baseline characteristics on the CD4 count evolution over time. Thereafter, the two analytical approaches were amalgamated to form an advanced joint model for studying the effect of longitudinal CD4 count on mortality. To illustrate the virtues of the joint model, the results from the joint model were compared to those from the time-varying Cox model.

Results

Using joint modelling, we found that lower CD4 count over time was associated with a 1.3-fold increase in the risk of death, (HR: 1.34, 95% CI: 1.27-1.42). Whereas, results from the time-varying Cox model showed lower CD4 count over time was associated with a 1.2-fold increase in the risk of death, (HR: 1.17, 95% CI: 1.12-1.23).

Conclusions

Joint modelling enabled the assessment of the effect of longitudinal CD4 count on mortality while correcting for shared random effects between longitudinal and time-to-event models. In the era of universal test and treat, the evaluation of CD4 count is still crucial for guiding the initiation and discontinuation of opportunistic infections prophylaxis and assessment of late presenting patients. CD4 count can also be used when immunological failure is suspected as we have shown that it is associated with mortality.

Sex Differences, Cocaine Use, and Liver Fibrosis Among African Americans in the Miami Adult Studies on HIV Cohort

Background: HIV infection disproportionally affects African Americans. Liver disease is a major cause of non-HIV morbidity and mortality in this population. Substance abuse accelerates HIV disease and may facilitate progression of liver disease. This study investigated the relationship between sex differences and cocaine use with liver injury, characterized as hepatic fibrosis. Materials and Methods: A cross-sectional study was conducted on 544 African Americans [369 people living with HIV (PLWH) and 175 HIV seronegative] from the Miami Adult Studies on HIV (MASH) cohort. Cocaine use was determined with a validated self-reported questionnaire and confirmed with urine screen. Fasting blood was used to estimate liver fibrosis using the noninvasive fibrosis-4 (FIB-4) index. Results: Men living with HIV had 1.79 times higher odds for liver fibrosis than women living with HIV (p = 0.038). African American women had higher CD4 count (p = 0.001) and lower HIV viral load (p = 0.011) compared to African American men. Fewer women (PLWH and HIV seronegative) smoked cigarettes (p = 0.002), and fewer had hazardous or harmful alcohol use (p < 0.001) than men. Women also had higher body mass index (kg/m²) (p < 0.001) compared to men. No significant association was noted among HIV seronegative participants for liver fibrosis by sex differences or cocaine use. Among African Americans living with HIV, cocaine users were 1.68 times more likely to have liver fibrosis than cocaine nonusers (p = 0.044). Conclusions: Sex differences and cocaine use appear to affect liver disease among African Americans living with HIV pointing to the importance of identifying at-risk individuals to improve outcomes of liver disease.

Mindfulness-Based Interventions for Adults Living with HIV/AIDS: A Systematic Review and Meta-analysis

This meta-analysis examined the effects of mindfulness-based interventions (MBIs) on stress, psychological symptoms, and biomarkers of disease among people living with HIV/AIDS (PLWHA). Comprehensive searches identified 16 studies that met the inclusion criteria (N = 1059; M age = 42 years; 20% women). Participants had been living with HIV for an average of 8 years (range = < 1-20 years); 65% were currently on antiretroviral therapy. Between-group analyses indicated that depressive symptoms were reduced among participants receiving the MBIs compared to controls (d+ = 0.37, 95% CI 0.03, 0.71). Within-group analyses showed reductions in psychological symptoms (i.e., less anxiety, fewer depressive symptoms) and improved quality of life over time among MBI participants (d+s = 0.40-0.85). No significant changes were observed for immunological outcomes (i.e., CD4 counts) between- or within-groups. MBIs may be a promising approach for reducing psychological symptoms and improving quality of life among PLWHA. Studies using stronger designs (i.e., randomized controlled trials) with larger sample sizes and longer follow-ups are needed to clarify the potential benefits of MBIs for PLWHA.

Sexual dimorphism in HIV-1 infection

Sex-specific differences affecting various aspects of HIV-1 infection have been reported, including differences in susceptibility to infection, course of HIV-1 disease, and establishment of viral reservoirs. Once infected, initial plasma levels of HIV-1 viremia in women are lower compared to men while the rates of progression to AIDS are similar. Factors contributing to these sex differences are poorly understood, and range from anatomical differences and differential expression of sex hormones to differences in immune responses, the microbiome and socio-economic discrepancies, all of which may impact HIV-1 acquisition and disease progression. Ongoing research efforts aiming at controlling HIV-1 disease or reducing viral reservoirs need to take these sex-based differences in HIV-1 pathogenesis into account. In this review, we discuss established knowledge and recent findings on immune pathways leading to sex differences in HIV-1 disease manifestations, with focus on HIV-1 latency and the effect of female sex hormones on HIV-1.

Modeling HIV disease progression and transmission at population-level: The potential impact of modifying disease progression in HIV treatment programs

INTRODUCTION

Mathematical models that incorporate HIV disease progression dynamics can estimate the potential impact of strategies that delay HIV disease progression and reduce infectiousness for persons not on antiretroviral therapy (ART). Suppressive treatment of HIV-positive persons co-infected with herpes simplex virus-2 (HSV-2) with valacyclovir, an HSV-2 antiviral, can lower HIV viral load, but the impact of partially-suppressive valacyclovir relative to fully-suppressive ART on population HIV transmission has not been estimated.

METHODS

We modeled HIV disease progression as a function of changes in viral load and CD4 count over time among ART naïve persons. The disease progression Markov model was nested within a dynamic model of HIV transmission at population level. We assumed that valacyclovir reduced HIV viral load by 1.23 log copies/μL, and that persons treated with valacyclovir initiated ART more rapidly when their CD4 fell below 500 due to retention in HIV care. We estimated the potential impact of valacyclovir on onward transmission of HIV in three scenarios of different ART and valacyclovir population coverage.

RESULTS

The average duration of HIV infection was 9.5 years. The duration of disease before reaching CD4 200cells/μL was 2.53 years longer for females than males. Relative to a baseline of ART initiation at CD4≤500cells/μL, the valacyclovir scenario resulted in 167,000 fewer HIV infections over ten years, with an incremental cost-effectiveness ratio (ICER) of $5276 per HIV infection averted. A Test and Treat scenario with 70% ART coverage and no valacyclovir resulted in 350,000 fewer HIV infections at an ICER of $2822 and $812 per HIV infection averted and QALY gained, respectively.

CONCLUSION

Even when compared with valacyclovir suppression, a drug that reduces HIV viral load, universal treatment for HIV is the optimal strategy for averting new infections and increasing public health benefit. Universal HIV treatment would most effectively and efficiently reduce the HIV burden.

Sex and gender differences in HIV-1 infection

The major burden of the human immunodeficiency (HIV) type 1 pandemic is nowadays carried by women from sub-Saharan Africa. Differences in the manifestations of HIV-1 infection between women and men have been long reported, and might be due to both socio-economic (gender) and biological (sex) factors. Several studies have shown that women are more susceptible to HIV-1 acquisition than men. Following HIV-1 infection, women have lower viral loads during acute infection and exhibit stronger antiviral responses than men, which may contribute to differences in the size of viral reservoirs. Oestrogen receptor signalling could represent an important mediator of sex differences in HIV-1 reservoir size and may represent a potential therapeutic target. Furthermore, immune activation, a hallmark of HIV-1 infection, is generally higher in women than in men and could be a central mechanism in the sex difference observed in the speed of HIV-1 disease progression. Here, we review the literature regarding sex-based differences in HIV-1 infection and discuss how a better understanding of the underlying mechanisms could improve preventive and therapeutic strategies.

Joint estimation of CD4+ cell progression and survival in untreated individuals with HIV-1 infection

OBJECTIVE

We compiled the largest dataset of seroconverter cohorts to date from 25 countries across Africa, North America, Europe, and Southeast/East (SE/E) Asia to simultaneously estimate transition rates between CD4 cell stages and death, in antiretroviral therapy (ART)-naive HIV-1-infected individuals.

DESIGN

A hidden Markov model incorporating a misclassification matrix was used to represent natural short-term fluctuations and measurement errors in CD4 cell counts. Covariates were included to estimate the transition rates and survival probabilities for each subgroup.

RESULTS

The median follow-up time for 16 373 eligible individuals was 4.1 years (interquartile range 1.7-7.1), and the mean age at seroconversion was 31.1 years (SD 8.8). A total of 14 525 individuals had recorded CD4 cell counts pre-ART, 1885 died, and 6947 initiated ART. Median (interquartile range) survival for men aged 20 years at seroconversion was 13.0 (12.4-13.4), 11.6 (10.9-12.3), and 8.3 years (7.9-8.9) in Europe/North America, Africa, and SE/E Asia, respectively. Mortality rates increase with age (hazard ratio 2.22, 95% confidence interval 1.84-2.67 for >45 years compared with <25 years) and vary by region (hazard ratio 2.68, 1.75-4.12 for Africa and 1.88, 1.50-2.35 for Asia compared with Europe/North America). CD4 cell decline was significantly faster in Asian cohorts compared with Europe/North America (hazard ratio 1.45, 1.36-1.54).

CONCLUSION

Mortality and CD4 cell progression rates exhibited regional and age-specific differences, with decreased survival in African and SE/E Asian cohorts compared with Europe/North America and in older age groups. This extensive dataset reveals heterogeneities between regions and ages, which should be incorporated into future HIV models.

Response by gender of HIV-1-infected subjects treated with abacavir/lamivudine plus atazanavir, with or without ritonavir, for 144 weeks

Purpose

The 144-week results of the open-label, multicenter Atazanavir/Ritonavir Induction with Epzicom Study (ARIES) were stratified by gender to compare treatment responses.

Methods

A total of 369 HIV-infected, antiretroviral-naïve subjects receiving once-daily abacavir/lamivudine + atazanavir/ritonavir (ATV/r) whose HIV-1 RNA was <50 copies/mL by week 30 were randomized 1:1 at week 36 to maintain or discontinue ritonavir for 108 subsequent weeks. Between- and within-treatment gender-related efficacy and safety differences were analyzed.

Results

Subjects were 85% male; 64% white; and had a mean age of 39 years, baseline median HIV-1 RNA of 114,815 copies/mL, and median CD4+ cell count of 198 cells/mm³. Gender (ATV [n=189]: 29 females/160 males; ATV/r [n=180]: 25 females/155 males) and most other demographics were similar between groups; more females than males were black (65% vs 25%) and fewer females had baseline HIV-1 RNA ≥100,000 copies/mL (41% vs 58%). At week 144, no significant differences between genders were observed in proportion maintaining HIV-1 RNA <50 copies/mL (ATV, 79% vs 77%; ATV/r, 60% vs 75%) or <400 copies/mL (ATV, 83% vs 84%; ATV/r, 68% vs 82%) (intent-to-treat-exposed: time to loss of virologic response analysis); median CD4+ change from baseline (ATV, +365 vs +300 cells/mm³; ATV/r, +344 vs +301 cells/mm³); proportion with treatment-related grade 2–4 adverse events (baseline to week 144: ATV, 41% vs 31%; ATV/r, 36% vs 43%; weeks 36 to 144: ATV, 14% vs 13%; ATV/r, 24% vs 23%); or proportion developing fasting lipid changes. Female and male virologic failure rates (ATV, 0 vs 5; ATV/r, 2 vs 4) and proportions completing the study were similar during the extension phase. Primary withdrawal reasons were loss to follow-up and pregnancy for females and loss to follow-up and other for males.

Conclusion

Over 144 weeks, no significant gender differences were observed in efficacy, safety, or fasting lipid changes with abacavir/lamivudine +ATV or abacavir/lamivudine +ATV/r.

Sex disparities in outcomes among adults on long-term antiretroviral treatment in northern Nigeria

BACKGROUND

There are conflicting reports of sex differences in HIV treatment outcomes in Africa. We investigated sex disparities in treatment outcomes for adults on first line antiretroviral treatment (ART) in Nigeria.

METHODS

We compared clinical and immunologic responses to ART between HIV-infected men (n=205) and women (n=140) enrolled in an ART program between June 2004 and December 2007, with follow-up through June 2014. We employed Kaplan-Meier estimates to examine differences in time to immunologic failure and loss to follow-up (LTFU), and generalized estimating equations to assess changes in CD4+ count by sex.

RESULTS

Men had lower baseline mean CD4+ count compared to women (327.6 cells/µL vs 413.4, respectively, p<0.01). Women had significantly higher rates of increase in CD4+ count than men, even after adjusting for confounders, p<0.0001. There was no significant difference in LTFU by sex: LTFU rate was 2.47/1000 person-months (95% CI 1.6-3.9) in the first five years for men vs 1.98/1000 person-months (95% CI (1.3-3.0) for women. There was no difference in time to LTFU by sex over the study period.

CONCLUSIONS

Women achieved better long-term immune response to ART at baseline and during treatment, but had similar rates of long-term retention in care to men. Targeted efforts are needed to improve immune outcomes in men in our setting.

Sex differences in HIV-1-mediated immunopathology

PURPOSE OF REVIEW

The article reviews our current knowledge regarding the role of sex and sex hormones in regulating innate immune responses to viral infections, which may account for the described sex differences in immunity to HIV-1.

RECENT FINDINGS

Prominent sex differences exist in various infectious and autoimmune diseases. Biological mechanisms underlying these differences include the modulation of immunological pathways by sex hormones and gene dosage effects of immunomodulatory genes encoded by the X chromosome. During HIV-1 infections, women have been shown to present with lower viral load levels in primary infection, although their progression to AIDS is faster in comparison with men when accounting for viral load levels in chronic infection. HIV-1-infected women furthermore tend to have higher levels of immune activation and interferon-stimulated gene expression in comparison with men for the same viral load, which has been associated to innate sensing of HIV-1 by Toll-like receptor 7 and the consequent interferon-α production by plasmacytoid dendritic cells.

SUMMARY

Improvement in understanding the mechanisms associated with sex differences in HIV-1-mediated immunopathology will be critical to take sex differences into consideration when designing experimental and clinical studies in HIV-1-infected populations.

Are there differences in disease progression and mortality among male and female HIV patients on antiretroviral therapy? A meta-analysis of observational cohorts

Studies examining the sex differences in morbidity and mortality among HIV/AIDS patients have yielded inconsistent results. We conducted a meta-analysis of sex differences in disease progression and mortality among HIV/AIDS patients. Medical literature databases from inception to August 2014 were searched for published observational studies assessing sex differences in immunologic and virologic response, disease progression and mortality among HIV-infected patients. Random effects meta-analyses of 115 eligible studies were conducted to obtain pooled estimates of outcomes and heterogeneity was explored in sub-group analyses. Pooled estimates showed an increased risk of progression to AIDS (relative risk [RR]=1.11,95% CI=1.02-1.21) and all-cause mortality (RR=1.23, 95% CI=1.17-1.29) among males compared to females. All-cause mortality differed by sex only in low and middle income countries. The risk of AIDS-related mortality (RR=1.03, 95% CI=0.82-1.30), immunologic failure (RR=1.19,95% CI: 0.97-1.47), virologic suppression (RR=0.98, 95% CI=0.84-1.14), virologic failure (RR=1.26, 95% CI=0.99-1.61) and the change in CD4 cell count (Weighted mean difference [WMD] = -5.15, 95% CI= -13.57 to 3.28) did not differ by sex. These findings were modified by disease severity, adherence and use of highly active antiretroviral therapy. We conclude that HIV-related disease progression and survival outcomes are poorer in males.

Barriers to a cure for HIV in women

Introduction

Distinct biological factors exist that affect the natural history of HIV and the host immune response between women and men. These differences must be addressed to permit the optimal design of effective HIV eradication strategies for much of the HIV-positive population.

Methods and results

Here, we review the literature on sex-based differences in HIV pathogenesis and natural history in tissues and anatomic compartments, HIV latency and transcriptional activity, and host immunity including the role of sex hormones. We then outline the potential effects of these differences on HIV persistence, and on the safety and efficacy of HIV eradication and curative interventions. Finally, we discuss the next steps necessary to elucidate these factors to achieve a cure for HIV, taking in account the complex ethical issues and the regulatory landscape in the hopes of stimulating further research and awareness in these areas.

Conclusions

Targeted enrolment of women in clinical trials and careful sex-based analysis will be crucial to gain further insights into sex-based differences in HIV persistence and to design sex-specific approaches to HIV eradication, if required.

Inferring HIV incidence from case surveillance with CD4+ cell counts

BACKGROUND

In some countries, HIV surveillance is based on case-reporting of newly diagnosed infections. We present a new back-projection method for estimating HIV-incidence trends using individuals' CD4 cell counts at diagnosis.

METHODS

On the basis of a review of CD4 cell count distributions among HIV-uninfected people, CD4 cell count following primary infection, and rates of CD4 cell count decline over time among people with HIV, we simulate the expected distribution in time between infection and diagnosis. Applying this to all diagnosed individuals provides a distribution of likely infection times and estimates for population incidence, level of undiagnosed HIV, and the average time from infection to diagnosis each year. We applied this method to the national HIV case surveillance data of Australia for 1983-2013.

RESULTS

The estimated number of new HIV infections in Australia in 2013 was 912 (95% uncertainty bound 835-1002). We estimate that 2280 (95% uncertainty bound 1900-2830) people were living with undiagnosed HIV at the end of 2013, corresponding to approximately 9.4% (95% uncertainty bound 7.8-10.1%) of all people living with HIV. With increases in the average CD4 count at diagnosis, the inferred HIV testing rate has been increasing over time and the estimated mean and median times between infection and diagnosis have decreased substantially. However, the estimated mean time between infection and diagnosis is considerably greater than the median, indicating that some people remain undiagnosed for long periods. Differences were found between cases attributable to male homosexual exposure versus other cases.

CONCLUSION

This methodology provides a novel way of estimating population incidence by combining diagnosis dates and CD4 cell counts at diagnosis.

Differential Survival for Men and Women with HIV/AIDS-Related Neurologic Diagnoses

OBJECTIVES

Neurologic complications of human immunodeficiency virus (HIV) infection and acquired immune deficiency syndrome (AIDS) frequently lead to disability or death in affected patients. The aim of this study was to determine whether survival patterns differ between men and women with HIV/AIDS-related neurologic disease (neuro-AIDS).

METHODS

Retrospective cohort data from a statewide surveillance database for HIV/AIDS were used to characterize survival following an HIV/AIDS-related neurologic diagnosis for men and women with one or more of the following conditions: cryptococcosis, toxoplasmosis, primary central nervous system lymphoma, progressive multifocal leukoencephalopathy, and HIV-associated dementia. A second, non-independent cohort was formed using university-based cases to confirm and extend the findings from the statewide data. Kaplan-Meier analysis was used to compare the survival experiences for men and women in the cohorts. Cox regression was employed to characterize survival while controlling for potential confounders in the study population.

RESULTS

Women (n=27) had significantly poorer outcomes than men (n=198) in the statewide cohort (adjusted hazard ratio=2.31, 95% CI: 1.22 to 4.35), and a similar, non-significant trend was observed among university-based cases (n=17 women, 154 men). Secondary analyses suggested that this difference persisted over the course of the AIDS epidemic and was not attributable to differential antiretroviral therapy responses among men and women.

CONCLUSIONS

The survival disadvantage of women compared to men should be confirmed and the mechanisms underlying this disparity elucidated. If this relationship is confirmed, targeted clinical and public health efforts might be directed towards screening, treatment, and support for women affected by neuro-AIDS.

Sex, age, race and intervention type in clinical studies of HIV cure: a systematic review

This systematic review was undertaken to determine the extent to which adult subjects representing sex (female), race (nonwhite), and age (>50 years) categories are included in clinical studies of HIV curative interventions and thus, by extension, the potential for data to be analyzed that may shed light on the influence of such demographic variables on safety and/or efficacy. English-language publications retrieved from PubMed and from references of retrieved papers describing clinical studies of curative interventions were read and demographic, recruitment year, and intervention-type details were noted. Variables of interest included participation by sex, age, and race; changes in participation rates by recruitment year; and differences in participation by intervention type. Of 151 publications, 23% reported full demographic data of study enrollees, and only 6% reported conducting efficacy analyses by demographic variables. Included studies recruited participants from 1991 to 2011. No study conducted safety analyses by demographic variables. The representation of women, older people, and nonwhites did not reflect national or international burdens of HIV infection. Participation of demographic subgroups differed by intervention type and study location. Rates of participation of demographic groups of interest did not vary with time. Limited data suggest efficacy, particularly of early therapy initiation followed by treatment interruption, may vary by demographic variables, in this case sex. More data are needed to determine associations between demographic characteristics and safety/efficacy of curative interventions. Studies should be powered to conduct such analyses and cure-relevant measures should be standardized.

Sex-based differences in HIV type 1 pathogenesis

Human immunodeficiency virus (HIV) remains a global infectious diseases threat that disproportionally affects women. Beyond social and political factors, biological and genetic differences have been identified that lead to differential disease courses and outcomes in men and women. Following HIV type 1 (HIV-1) seroconversion, women have up to 40% lower HIV loads and higher CD4(+) T-cell counts than men. However, at the same level of viremia, progression to AIDS is faster in women. After adjustment for viral load, HIV-positive women also display increased levels of generalized immune activation and experience the consequences of elevated inflammatory activity more frequently than men. Part of these observations are linked to sex-based differences in innate immunity, in which the differential ability of plasmacytoid dendritic cells to produce interferon α following stimulation of Toll-like receptor 7 and upregulation of interferon-stimulated genes play a central role. Here, we review the current knowledge and remaining gaps therein regarding sex-based differences in HIV-1 pathogenesis.

Time from human immunodeficiency virus seroconversion to reaching CD4+ cell count thresholds <200, <350, and <500 Cells/mm³: assessment of need following changes in treatment guidelines

BACKGROUND

Recent updates of human immunodeficiency virus (HIV) treatment guidelines have raised the CD4+ cell count thresholds for antiretroviral therapy initiation from 350 to 500 cells/mm(3) in the United States and from 200 to 350 cells/mm³ in mid- and low-income countries. Robust data of time from HIV seroconversion to CD4+ cell counts of 200, 350, and 500 cells/mm³ are lacking but are needed to inform health care planners of the likely impact and cost effectiveness of these and possible future changes in CD4+ cell count initiation threshold.

METHODS

Using Concerted Action on Seroconversion to AIDS and Death in Europe data from individuals with well-estimated dates of HIV seroconversion, we fitted mixed models on the square root of CD4+ cell counts measured before combined antiretroviral therapy (cART) initiation. Restricting analyses to adults (age >16 years), we predicted time between seroconversion and CD4+ cell count <200, <350, and <500 cells/mm³ as well as CD4+ cell count distribution and proportions reaching these thresholds at 1, 2, and 5 years after seroconversion.

RESULTS

Median (interquartile range [IQR]) follow-up for the 18495 eligible individuals from seroconversion while cART-free was 3.7 years (1.5, 7). Most of the subjects were male (78%), had a median age at seroconversion of 30 years (IQR, 25-37 years), and were infected through sex between men (55%). Estimated median times (95% confidence interval [CI]) from seroconversion to CD4+ cell count <500, <350, and <200 cells/mm(3) were 1.19 (95% CI, 1.12-1.26), 4.19 (95% CI, 4.09-4.28), and 7.93 (95% CI, 7.76-8.09) years, respectively. Almost half of infected individuals would require treatment within 1 year of seroconversion for guidelines recommending its initiation at 500 cells/mm³, compared with 26% and 9% for guidelines recommending initiation at 350 and 200 cells/mm³, respectively.

CONCLUSIONS

These data suggest substantial increases in the number of individuals who require treatment and call for early HIV testing.

Cluster of differentiation 4+ cell count mean value, reference range and its influencing factors in Human Immunodeficiency Virus-seronegative pregnant women in Lagos

Background:

Immunity in pregnancy is physiologically compromised and this may affect cluster of differentiation four (CD4) count levels. It is well established that several factors affect CD4 count level in pregnancy. This study aims to determine the effects of maternal age, gestational age, parity and level of education as they influence CD4 count in pregnancy and also to determine the mean and reference range of CD4 count in pregnancy in Lagos, Nigeria.

Materials and Methods:

A descriptive cross-sectional study was carried out at Ante-natal clinics in Lagos State, Nigeria. About 5 mls of blood was collected into Ethylene Diamine Tetracetic Acid (EDTA) bottles from HIV-negative pregnant women in various gestational ages of pregnancy. CD4+ cell count and full blood count of all samples were done within 3 hours of collection. The descriptive data was given as means ± standard deviation (SD). Pearson's chi-squared test and correlation were used for analytical assessment.

Results:

A total of 74 pregnant women were recruited. The age range was 19–41 years and a mean age of 30.42 ± 5.34 years. The CD4+ cell count was not statistically significant when compared with participants ages P = 0.417, neither with gestational ages P = 0.323, nor with parity P = 0.247 nor level of education P = 0.96. An overall mean CD4+ cell count was 771.96 ± 250 cells/μl and the range was 193–1370 cells/μl.

Conclusion:

Maternal age, gestational age, parity and level of education had no significant effects on CD4+ cell count levels in pregnancy. The mean CD4+ cell count of HIV-negative pregnant women in Lagos is 771.96 ± 250 cells/μl.

Sex differences in HIV outcomes in the highly active antiretroviral therapy era: a systematic review

To assess sex disparities in AIDS clinical and laboratory outcomes in the highly active antiretroviral therapy (HAART) era we conducted a systematic review of the published literature on mortality, disease progression, and laboratory outcomes among persons living with HIV and starting HAART. We performed systematic PubMed and targeted bibliographic searches of observational studies published between January, 1998, and November, 2013, that included persons starting HAART and reported analyses of mortality, progression to AIDS, or virologic or immunologic treatment outcomes by sex. Risk ratios (relative risks, odd ratios, and hazard ratios) and 95% confidence intervals were obtained. Sixty-five articles were included in this review. Thirty-nine studies were from North America and Europe and 26 were from Latin America, Asia, and Africa. Forty-four studies (68%) showed no statistically significant difference in risk of mortality, progression to AIDS, or virologic or immunologic treatment outcomes by sex. Decreased risk of death among females compared to males was observed in 24 of the 25 articles that included mortality analyses [pooled risk ratio 0.72 (95% confidence interval=0.69-0.75)], and decreased risk of death or AIDS was observed in 9 of the 13 articles that examined the composite outcome [pooled risk ratio=0.91 (0.84-0.98)]. There was no significant effect of sex on the risk of progression to AIDS [pooled risk ratio=1.15 (0.99-1.31)]. In this systematic review, females starting HAART appeared to have improved survival compared to males. However, this benefit was not associated with decreased progression to either AIDS or to differences in virologic or immunologic treatment outcomes.

CD4 counts and viral loads of newly diagnosed HIV-infected individuals: implications for treatment as prevention

OBJECTIVE

To report the viral load and CD4 count in HIV-infected, antiretroviral naïve, first -time HIV-testers, not immediately eligible for treatment initiation by current South Africa treatment guidelines.

DESIGN

This was a cross-sectional study in a high-volume, free-of-charge HIV testing centre in Soweto, South Africa.

METHODS

We enrolled first time HIV testers and collected demographic and risk-behaviour data and measured CD4 count and viral load.

RESULTS

Between March and October 2011, a total of 4793 adults attended VCT and 1062 (22%) tested positive. Of the 1062, 799 (75%) were ART naïve and 348/799 (44%) were first-time HIV testers. Of this group of 348, 225 (65%) were female. Overall their median age, CD4 count and viral load was 34 years (IQR: 28-41), 364 (IQR: 238-542) cells/mm3 and 13,000 (IQR: 2050-98171) copies/ml, respectively. Female first time HIV testers had higher CD4 counts (419 IQR: 262-582 vs. 303 IQR: 199-418 cells/mm3) and lower viral loads (9,100 vs. 34,000 copies/ml) compared to males. Of 183 participants with CD4 count >350 cells/mm3, 62 (34%) had viral loads > 10,000 copies/ml.

CONCLUSIONS

A large proportion of HIV infected adults not qualifying for immediate ART at the CD4 count threshold of 350 cells/mm3 have high viral loads. HIV-infected men at their first HIV diagnosis are more likely to have lower CD4 counts and higher viral loads than women.

The cost-effectiveness of expanded HIV screening in the United States

OBJECTIVE

The current Centers of Disease Control and Prevention (CDC) guidelines from 2006 recommend a one-time test for low-risk individuals and annual testing for those at high risk. These guidelines may not be aggressive enough, even for those at low risk of infection, due to the earlier initiation of HAART and a movement towards a test-and-treat environment. We evaluated the optimal testing frequencies for various risk groups in comparison to the CDC recommendations.

METHODS

We build a deterministic mathematical model optimizing the tradeoff between the societal cost of testing and the benefits over a patient's lifetime of earlier diagnosis.

RESULTS

Under a test-and-treat scenario with immediate initiation of HAART, the optimal testing frequency is every 2.4 years for low-risk (0.01% annual incidence) individuals; every 9 months for moderate risk (0.1% incidence) individuals; and every 3 months for high-risk (1.0% incidence) individuals. The incremental cost-effectiveness of the optimal policy is $ 36 ,342/quality-adjusted life-years (QALY) for low-risk individuals and $ 45 ,074/QALY for high-risk individuals compared with 20-year and annual testing, respectively.

CONCLUSION

The current CDC guidelines for HIV testing are too conservative, and more frequent testing is cost-effective for all risk groups.

Age-associated changes in monocyte and innate immune activation markers occur more rapidly in HIV infected women

BACKGROUND

Aging is associated with immune dysfunction and the related development of conditions with an inflammatory pathogenesis. Some of these immune changes are also observed in HIV infection, but the interaction between immune changes with aging and HIV infection are unknown. Whilst sex differences in innate immunity are recognized, little research into innate immune aging has been performed on women.

METHODS

This cross-sectional study of HIV positive and negative women used whole blood flow cytometric analysis to characterize monocyte and CD8(+) T cell subsets. Plasma markers of innate immune activation were measured using standard ELISA-based assays.

RESULTS

HIV positive women exhibited elevated plasma levels of the innate immune activation markers CXCL10 (p<0.001), soluble CD163 (sCD163, p = 0.001), sCD14 (p = 0.022), neopterin (p = 0.029) and an increased proportion of CD16(+) monocytes (p = 0.009) compared to uninfected controls. Levels of the innate immune aging biomarkers sCD163 and the proportion of CD16(+) monocytes were equivalent to those observed in HIV negative women aged 14.5 and 10.6 years older, respectively. CXCL10 increased with age at an accelerated rate in HIV positive women (p = 0.002) suggesting a synergistic effect between HIV and aging on innate immune activation. Multivariable modeling indicated that age-related increases in innate immune biomarkers CXCL10 and sCD163 are independent of senescent changes in CD8(+) T lymphocytes.

CONCLUSIONS

Quantifying the impact of HIV on immune aging reveals that HIV infection in women confers the equivalent of a 10-14 year increase in the levels of innate immune aging markers. These changes may contribute to the increased risk of inflammatory age-related diseases in HIV positive women.

CD4 Count Pattern and Demographic Distribution of Treatment-Naïve HIV Patients in Lagos, Nigeria

Background. CD4 count measures the degree of immunosuppression in HIV-positive patients. It is also used in deciding when to commence therapy, in staging the disease, and in determining treatment failure. Using the CD4 count, this study aimed at determining the percentage of HIV-positives who require antiretroviral therapy at enrollment in an HIV treatment and care centre. Methods. The Baseline CD4 count, age and gender of 4,042 HAART-naïve patients, who registered between December 2006 and June 2010, at Lagos State University Teaching Hospital, Ikeja, were retrospectively studied. Data were analyzed using SPSS version 16.0 (Statistical Package for Social Sciences, Inc., Chicago, Ill). Results. Patients consisted of 2507 (62%) female and 1535 (38%) males. The mean age of males was 37.73 ± 9.48 years and that of females 35.01 ± 9.34 years. Overall, the mean CD4 count was of 298.76 ± 246.93  cells/mm³. The mean CD4 count of males was 268.05 ± 230.44  cells/mm³ and that of females 317.55 ± 254.72 cells/mm³. A total of 72.3% males, 64.3% females and 67.4% overall registered patients had CD4 count <350 cells/mm³, while only 15.1% males , 20.3% females, and 18.3% overall registered patients had CD4 count >500 cells/mm³ at registration. Conclusion. Females account for more than half of registered patients in HIV clinic and have a relatively higher CD4 count than males. About three-quarter of HIV positives require antiretroviral therapy at registration.

Impact of gender on the risk of AIDS-defining illnesses and mortality in Danish HIV-1-infected patients: a nationwide cohort study

BACKGROUND

Gender differences in the risk of AIDS-defining illness (ADI) and mortality have been reported in the HIV-1-infected (HIV-positive) population, with conflicting findings. We aimed to assess the impact of gender on the risk of ADI and death in HIV-positive patients infected sexually.

METHODS

This was a population-based, nationwide cohort study of incident Danish HIV-positive individuals infected by sexual contact. Outcomes were progression to AIDS and death. We used Cox proportional hazards models and Poisson regression analyses to calculate the risk of progression to AIDS and mortality rate ratios (MRR) between risk groups and compared these with the general Danish population.

RESULTS

We identified 587 heterosexually infected women, 583 men who have sex with women (MSW), and 1089 men who have sex with men (MSM). The total follow-up time was 13,708 person-y. At the time of HIV diagnosis MSM had a lower prevalence of AIDS compared to MSW. Women and MSW presented more often with tuberculosis and less often with AIDS-defining cancers compared to MSM. In the adjusted analyses we observed no differences in progression to AIDS. In the adjusted analyses of risk of death, there were no differences between the 3 risk groups, although we saw a trend towards a higher risk of death in older MSW. MSM had a lower risk of death compared to the background population than women and MSW.

CONCLUSIONS

In the Danish HIV population, gender has no major impact on progression to AIDS or mortality. Differences in these factors between women, MSW, and MSM are mainly due to confounding from race and CD4 + cell count at diagnosis.

Does discordancy between the CD4 count and CD4 percentage in HIV-positive individuals influence outcomes on highly active antiretroviral therapy?

INTRODUCTION

The CD4 count and CD4 percentage (CD4%) are both strong predictors of clinical disease progression in human immunodeficiency virus (HIV). Although individuals may show discordancy between their CD4 count and CD4%, the clinical relevance of this is unclear.

METHODS

Discordancy was defined where the CD4% was ≤10th percentile for a selected CD4 count range (referred to as low discordancy), within the central 80% range (concordant), or ≥90th percentile (high discordancy). Regression methods identified factors associated with low and high discordancy in untreated individuals and assessed the impact of discordancy on treatment responses to highly active antiretroviral therapy (HAART).

RESULTS

High discordancy was associated with female sex, low viral load, and white ethnicity; low discordancy was associated with black or nonwhite ethnicity, older age, and injection drug use. Clinical event rates were higher in individuals with high discordancy starting HAART, but there was no association with subsequent HIV progression by 6 months after starting HAART. CD4 count increases remained lower, by 20 cells/mm(3), in individuals with low discordancy, and higher, by 27 cells/mm(3), in those with high discordancy.

CONCLUSIONS

Overall discrepancies between the CD4/CD4% are small, confirming the use of absolute CD4 counts as a monitoring tool.

Imputation of the Date of HIV Seroconversion in a Cohort of Seroprevalent Subjects: Implications for Analysis of Late HIV Diagnosis

Objectives. Since subjects may have been diagnosed before cohort entry, analysis of late HIV diagnosis (LD) is usually restricted to the newly diagnosed. We estimate the magnitude and risk factors of LD in a cohort of seroprevalent individuals by imputing seroconversion dates. Methods. Multicenter cohort of HIV-positive subjects who were treatment naive at entry, in Spain, 2004–2008. Multiple-imputation techniques were used. Subjects with times to HIV diagnosis longer than 4.19 years were considered LD. Results. Median time to HIV diagnosis was 2.8 years in the whole cohort of 3,667 subjects. Factors significantly associated with LD were: male sex; Sub-Saharan African, Latin-American origin compared to Spaniards; and older age. In 2,928 newly diagnosed subjects, median time to diagnosis was 3.3 years, and LD was more common in injecting drug users. Conclusions. Estimates of the magnitude and risk factors of LD for the whole cohort differ from those obtained for new HIV diagnoses.

Normal Range of CD4 Cell Counts and Temporal Changes in Two HIVNegative Malawian Populations

Longitudinal studies were carried out to determine trends in CD4 cell counts over a four year period in healthy HIV-negative adults in a rural (134 individuals) and an urban (80 individuals) site in Malawi, using TruCountTM and FACScountTM platforms. At baseline, median counts and 95% ranges were 890 (359-1954) cells per microlitre (μl) and 725 (114-1074) cells/μl respectively. 1.5% and 6% respectively had baseline counts below 350 cells/μl and 1.5% and 2.5% below 250 cells per μl. Transient dips to below 250 cells/μl were observed in seven individuals, with two individuals having persistently low CD4 counts over more than one year. Women and individuals from the urban site were significantly more likely to have "low CD4 count" (< 500 cells/μl) even when adjusted for other factors. In common with neighbouring countries, HIV-negative populations in Malawi have CD4 counts considerably lower than European reference ranges, and healthy individuals may have persistently or transiently low counts. Within Malawi, ranges differ according to the selected population.

Time for gender mainstreaming in editorial policies

The HIV epidemic has been continuously growing among women, and in some parts of the world, HIV-infected women outnumber men. Women's greater vulnerability to HIV, both biologically and socially, influences their health risk and health outcome. This disparity between sexes has been established for other diseases, for example, autoimmune diseases, malignancies and cardiovascular diseases. Differences in drug effects and treatment outcomes have also been demonstrated. Despite proven sex and gender differences, women continue to be underrepresented in clinical trials, and the absence of gender analyses in published literature is striking. There is a growing advocacy for consideration of women in research, in particular in the HIV field, and gender mainstreaming of policies is increasingly called for. However, these efforts have not translated into improved reporting of sex-disaggregated data and provision of gender analysis in published literature; science editors, as well as publishers, lag behind in this effort.Instructions for authors issued by journals contain many guidelines for good standards of reporting, and a policy on sex-disaggregated data and gender analysis should not be amiss here. It is time for editors and publishers to demonstrate leadership in changing the paradigm in the world of scientific publication. We encourage authors, peer reviewers and fellow editors to lend their support by taking necessary measures to substantially improve reporting of gender analysis. Editors' associations could play an essential role in facilitating a transition to improved standard editorial policies.

Sex, race, and geographic region influence clinical outcomes following primary HIV-1 infection

BACKGROUND

It is unknown whether sex and race influence clinical outcomes following primary human immunodeficiency virus type 1 (HIV-1) infection.

METHODS

Data were evaluated from an observational, multicenter, primarily North American cohort of HIV-1 seroconverters.

RESULTS

Of 2277 seroconverters, 5.4% were women. At enrollment, women averaged .40 log₁₀ fewer copies/mL of HIV-1 RNA (P < .001) and 66 more CD4(+) T cells/μL (P = .006) than men, controlling for age and race. Antiretroviral therapy (ART) was less likely to be initiated at any time point by nonwhite women and men compared to white men (P < .005), and by individuals from the southern United States compared to others (P = .047). Sex and race did not affect responses to ART after 6 months (P > .73). Women were 2.17-fold more likely than men to experience >1 HIV/AIDS-related event (P < .001). Nonwhite women were most likely to experience an HIV/AIDS-related event compared to all others (P = .035), after adjusting for intravenous drug use and ART. Eight years after diagnosis, >1 HIV/AIDS-related event had occurred in 78% of nonwhites and 37% of whites from the southern United States, and 24% of whites and 17% of nonwhites from other regions (P < .001).

CONCLUSIONS

Despite more favorable clinical parameters initially, female HIV-1-seroconverters had worse outcomes than did male seroconverters. Elevated morbidity was associated with being nonwhite and residing in the southern United States.

Hematologic Abnormalities in Treatment-naïve HIV Patients

Objectives

Hematologic abnormalities, indicated by a deranged full blood count, are common manifestations and important prognostic tools for human immunodeficiency virus (HIV) infection and AIDS. This study aimed to determine the prevalence of cytopenia and its relationship to the degree of immunosupression in HIV treatment-naïve patients.

Methods

This was a cross-sectional study of treatment-naïve HIV-infected clients who enrolled at the HIV clinic of Lagos State University Teaching Hospital (LASUTH) between December 2009 and June 2010. Participants had samples taken for full blood count and CD4 counts, which are free routine pre-requisite and pre-treatment evaluations done for all registered HIV patients at LASUTH. They were asked to fill the structured questionnaires to obtain demographic data, with assistance if necessary.

Results

A total of 205 cases were reviewed: 24.2% had anemia (PCV < 30%), 26.8% had leucopenia (white blood cell <4,000/L) and 16.1% had thrombocytopenia (platelet count <150,000/L) at enrollment. The degree of cytopenia was directly related to the degree of immunosupression.

Conclusion

About one-fifth of HIV treatment-naïve patients were cytopenic at enrollment and the degree of cytopenia was directly related to the degree of immunosupression. It is necessary to investigate various causes of cytopenia in these patients so as to administer a specific intervention.

HIV infection in women: do sex and gender matter?

At least half of all HIV infections occur in women. Most women are of childbearing potential; therefore, issues encompassing reproduction and mother-to-child transmission are critical in the management of this population. The efficacy of antiretroviral therapy (ART) is similar in men and women, although rates of adverse events or toxicity may be higher in women, which, in turn, may be related to higher antiretroviral drug levels documented in pharmacokinetic studies. A substantial proportion of women may not derive the benefit of highly active ART because nonsuppressive regimens are commonly used, especially in resource-limited settings, to decrease mother-to-child transmission. The likely emergence of resistant virus can have long-term sequelae for the mother, child, and other exposed individuals. Additional studies are needed of sex/gender-related issues including antiretroviral toxicities, pharmacokinetic profiles of approved and novel agents, ART strategies during pregnancy to minimize HIV resistance, and determination of optimal antiretroviral regimens for women.

Decrease of initial CD4+ T-cell counts at the time of diagnosis of HIV infection in Korea; 1988-2006

The aim of the study was to evaluate the trends of initial CD4+ T-cell counts (CD4+) at HIV diagnoses and to identify the factors influencing the annual changes of CD4+ cell counts in Korea during 1988-2006. As a retrospective study, 2613 individuals (>/=15 years at diagnosis, their CD4+ counts were measured within six months) were selected from all 4580 HIV-infected Koreans diagnosed between 1985 and 2006. The mean CD4+ cell counts in all the selected individuals was 312 cells/mm(3), and this value decreased significantly by 20.3 cells/mm(3)/year over the 19 year study period. Men had lower CD4+ cell count than women by 22.7 cells/mm(3), and age at HIV diagnosis had an inverse relationship with CD4+ cell counts of 23.5 cells/mm(3) lower per 10 years advancing age. Cases diagnosed in hospitals showed CD4+ cell count levels 33.9 cells/mm(3) lower than public institutions by 33.9 cells/mm(3). Gender and age seemed to affect trends of CD4+ count; however the institution where cases were diagnosed had the strongest effect on decreasing CD4+ cell counts. The results suggest that HIV diagnoses in recent years are being made in later stages of HIV infection and that it is imperative to develop more efficient programmes for early HIV diagnosis to prevent transmission.

Predictors of death and survival duration among a sample of persons living With HIV/AIDS

A follow-up study was conducted on a sample of 120 ethnically diverse HIV-positive men and women first interviewed in 2000. Participant survival and death rates were ascertained from death records and analyses were performed to identify demographic and psychosocial predictors of survival from the original data. Consistent with past studies, factors associated with survival were age, CD4 count, years HIV positive, and lower alcohol use. Two analyses identified use of professional counseling as a unique factor associated with reduced risk of death. Contrary to our hypotheses, the results from these analyses did not suggest that social groups with fewer economic and institutional resources or those with limited access to highly active retroviral therapy (HAART) therapies were at reduced risk of survival.

Cell-mediated immunity to HIV in the female reproductive tract

The majority of HIV infections occur via sexual transmission across a mucosal barrier. In the case of male-to-female transmission, HIV-susceptible target cells are abundant in the ectocervix and vagina but are also present in the upper reproductive tract (endocervix and uterus). While the mechanisms of HIV transmission in the female reproductive tract are an active area of investigation, cell-mediated immune responses in reproductive tissues have not been thoroughly characterized. HIV-specific CD8+ T cells are present in reproductive tissues, to some extent mirroring populations present in the blood and gastrointestinal mucosa. Innate natural killer (NK) cells and regulatory T cells are also present in the genital tract. Furthermore, there is mounting evidence that the female reproductive tract may be uniquely susceptible to infection at specific times during the menstrual cycle, due to hormonal regulation of both innate and adaptive immune responses. This review provides an overview of recent findings on cell-mediated immunity to HIV in the female reproductive tract.

Causes of death in HIV-infected women: persistent role of AIDS. The 'Mortalité 2000 & 2005' Surveys (ANRS EN19)

BACKGROUND

Little is known about the causes of death in human immunodeficiency virus (HIV)-infected women in the era of combination antiretroviral therapy (ART).

METHODS

In the French nationwide Mortalité 2000 and 2005 surveys, physicians reported causes of deaths in HIV-infected adults in 2000 and 2005, using a standardized questionnaire. We used multivariate logistic regression models to study the association between gender and AIDS-defining causes of death, adjusting for other characteristics.

RESULTS

Of the 1013 HIV-infected adults who died in 2005, 247 (24%) were women. Half of women were infected through heterosexual contacts, compared with 25% men. In 2005, the proportion of AIDS-defining causes of death was higher in women than in men (43 vs 34%; P = 0.01), whereas it had been the same in 2000 (47% in women and men). In 2005, women died less frequently than men from respiratory malignancies (lung, ear/nose/throat) and cardiovascular disease (9% of all causes of death in women compared with 16% in men; P = 0.004), and suicides or accidents (4 vs 9%; P = 0.02). Socio-economic precariousness, younger age, less alcohol and tobacco consumption and lack of prior ART explained the higher proportion of deaths from AIDS in women compared with men.

CONCLUSIONS

The higher proportion of AIDS-related deaths in women is probably explained by two factors: (i) some HIV-infected women, especially migrants in poor socio-economic conditions, may not have access to optimal care; and (ii) a lower prevalence of risk factors for respiratory, cardiovascular and violent deaths means that the risk of dying from non-AIDS causes may be lower in women.

Establishment of reference values of CD4 and CD8 lymphocyte subsets in healthy Nigerian adults

A total of 2,570 apparently healthy human immunodeficiency virus-negative adults from the six geopolitical zones in the country were enrolled in our study in 2006. The samples were assayed using the Cyflow technique. Data were analyzed using the Statistical Package for Social Scientists (SPSS). The majority (64%) of the participants had CD4 counts within the range of 501 to 1,000 cells/microl. The reference range for CD4 was 365 to 1,571 cells/microl, while the reference range for CD8 was 145 to 884 cells/microl.

County-level socioeconomic status and survival after HIV diagnosis, United States

PURPOSE

To estimate relative survival (RS) after human immunodeficiency virus (HIV) diagnosis, by race/ethnicity and county-level socioeconomic status (SES).

METHODS

We estimated 5-year RS by age, race/ethnicity, transmission category, sex, diagnosis year, CD4 count, and by county-level SES variables from the U.S. Census. Data, from the national HIV/AIDS Reporting System, were for HIV-infected persons ages > or =13 years (diagnosis during 1996-2003 and follow-up through 2005). We calculated RS proportions by using a maximum likelihood algorithm and modeled the relative risk of excess death (RR) using generalized linear models, with poverty as a random effect.

RESULTS

For men, RS was worse in counties with larger proportions of people living below the 2000 U.S. poverty level (87.7% for poverty of > or =20% vs. 90.1% for poverty of <5.0%) and where unemployment was greater (87.8% where unemployment > 7.1% vs. 90.5% where unemployment < 4.0%). The effects of county-level SES on RS of women were similar. In multilevel multivariate models, RR for men and women within 5 years after an HIV diagnosis was significantly worse in counties where 10.0-19.9% (compared with <5.0%) lived below the poverty level (RR = 1.3 [95% CI 1.2-1.5] and RR = 1.8 [95% CI 1.4-2.2], respectively).

CONCLUSIONS

RS was worse in lower SES areas. To help address the impact of county-level SES, resources for HIV testing, care, and proven economic interventions should be directed to areas with concentrations of economically disadvantaged people.

Immunohaematological reference values in human immunodeficiency virus-negative adolescent and adults in rural northern Tanzania

Background

The amount of CD4 T cells is used for monitoring HIV progression and improvement, and to make decisions to start antiretroviral therapy and prophylactic drugs for opportunistic infections. The aim of this study was to determine normal reference values for CD4 T cells, lymphocytes, leucocytes and haemoglobin level in healthy, HIV negative adolescents and adults in rural northern Tanzania.

Methods

A cross sectional study was conducted from September 2006 to March 2007 in rural northern Tanzania. Participants were recruited from voluntary HIV counselling and testing clinics. Patients were counselled for HIV test and those who consented were tested for HIV. Clinical screening was done, and blood samples were collected for CD4 T cell counts and complete blood cell counts.

Results

We enrolled 102 participants, forty two (41.2%) males and 60 (58.8%) females. The mean age was 32.6 ± 95% CI 30.2–35.0. The mean absolute CD4 T cell count was 745.8 ± 95% CI 695.5–796.3, absolute CD8 T cells 504.6 ± 95% CI 461.7–547.5, absolute leukocyte count 5.1 ± 95% CI 4.8–5.4, absolute lymphocyte count 1.8 ± 95% CI 1.7–1.9, and haemoglobin level 13.2 ± 95% CI 12.7–13.7. Females had significantly higher mean absolute CD4 T cell count (p = 0.008), mean absolute CD8 T cell count (p = 0.009) and significantly lower mean haemoglobin level than males (p = 0.003)

Conclusion

Immunohaematological values found in this study were different from standard values for western countries. Females had significantly higher mean CD4 T cell counts and lower mean haemoglobin levels than males. This raises the issue of the appropriateness of the present reference values and guidelines for monitoring HIV/AIDS patients in Tanzania.

Gender differences in HIV progression to AIDS and death in industrialized countries: slower disease progression following HIV seroconversion in women

To evaluate sex differences in human immunodeficiency virus (HIV) disease progression before (pre-1997) and after (1997-2006) introduction of highly active antiretroviral therapy, the authors used data from a collaboration of 23 HIV seroconverter cohort studies from Europe, Australia, and Canada restricted to the 6,923 seroconverters infected through injecting drug use and sex between men and women. Within a competing risk framework, they used Cox proportional hazards models allowing for late entry to evaluate sex differences in time from HIV seroconversion to death, to acquired immunodeficiency syndrome (AIDS), and to each first AIDS-defining disease and death without AIDS. While no significant sex differences were found before 1997, from 1997 onward, women had a lower risk of AIDS (adjusted cumulative relative risk (aCRR) = 0.76, 95% confidence interval (CI): 0.63, 0.90) and death (adjusted hazard ratio = 0.68, 95% CI: 0.56, 0.82) than men did. Compared with men, women also had lower risks of AIDS dementia complex (aCRR = 0.23, 95% CI: 0.07, 0.74), tuberculosis (aCRR = 0.60, 95% CI: 0.39, 0.92), Kaposi's sarcoma (aCRR = 0.27, 95% CI: 0.07, 0.99), lymphomas (aCRR = 0.47, 95% CI: 0.23, 0.96), and death without AIDS (aCRR = 0.74, 95% CI: 0.56, 0.98). Sex differences in HIV disease progression have become larger and statistically significant in the era of highly active antiretroviral therapy, supporting a stronger impact of health interventions among women.

Increased mortality of male adults with AIDS related to poor compliance to antiretroviral therapy in Malawi

OBJECTIVE

To investigate the effect of gender on mortality of HIV-infected adults receiving antiretroviral therapy (ART) and its possible reasons.

METHODS

A retrospective study to review the records for outcomes of adult cases receiving ART at Mzuzu Central Hospital, Malawi, between July 2004 and December 2006.

RESULTS

Over the study period, 2838 adult AIDS patients received ART. Of these, 2029 (71.5%) were alive and still on ART, 376 (13.2%) were dead and 433 (15.3%) were lost to follow-up. Survival analysis with Kaplan-Meier estimator showed significantly higher survival rates among females than males in WHO stage 1, 2 and 3 (both P < 0.0001) and borderline in stage 4 (P = 0.076). The Cox model revealed a death hazard ratio (males vs. females) of 1.70 (95% confidence interval 1.35-2.15) after controlling for WHO clinical stages, body mass index and age. More men than women were lost to follow-up in all occupations except health workers.

CONCLUSIONS

The most important reasons for a higher mortality in male patients starting ART may relate to their seeking medical care at a more advanced stage of immunodeficiency and poorer compliance with therapy. The issue needs to be addressed in scaling up ART programmes in Africa.

Factors associated with CD4 lymphocyte counts in HIV-negative Senegalese individuals

CD4+ lymphocytes are a primary target of the human immunodeficiency virus (HIV), and CD4 counts are one of the factors used to measure disease progression in HIV-positive individuals. CD4 counts vary in uninfected individuals and across populations due to a variety of demographic, environmental, immunological and genetic factors that probably persist throughout the course of HIV infection. This study sought to determine reference levels and identify factors that influence lymphocyte counts in 681 HIV-uninfected adults in Senegal, where residents are exposed to a variety of infectious diseases and other conditions that may affect CD4 counts. Lymphocyte counts were assessed in commercial sex workers, symptomatic men and women presenting to the University of Dakar infectious disease clinic for out-patient care and women seeking family planning services. CD4 and CD3 lymphocyte counts differed between the four study groups (P < 0.01). Men had the lowest mean CD4 count (711.6 cells/microl), while commercial sex workers had the highest levels (966.0 cells/microl). After adjustment for age and other behavioural and clinical factors, the difference in CD4 counts between the three groups of women did not remain. However, both gender and smoking were associated independently with CD4 counts, as men maintained lower mean CD4 counts (beta = -156.4 cells/microl, P < 0.01) and smokers had higher mean CD4 counts (beta = 124.0 cells/microl, P < 0.01) than non-smokers in multivariable analyses. This study is the first to explore factors that may influence CD4 levels in Senegal and to estimate baseline CD4 levels among HIV-negatives, information that may guide clinicians in interpreting CD4 counts.

Progression to AIDS and death and response to HAART in men and women from a multicenter hospital-based cohort

OBJECTIVE

To study if progression to AIDS and death, as well as clinical and virological response to highly active antiretroviral therapy (HAART), differs between men and women.

METHODS

We studied a multicenter, hospital-based cohort of HIV-infected patients attending 10 hospitals in Spain from January 1997 to December 2003. Kaplan-Meier and Cox regression were used to assess the effect of sex on time to AIDS, survival from AIDS, onset of a new AIDS event or death, and viral suppression from HAART.

RESULTS

Of 4643 patients, 27% were women. Women had statistically significant lower viral loads (VL) of 3.9 vs. 4.1 log10/mL (p = 0.02) and higher median CD4 counts of 339 vs. 288 cells/mm3 (p < 0.001) at entry and were more likely to be AIDS free at entry. In univariate analysis, women seemed to show a nonsignificant lower progression to AIDS (HR 0.88) (95 CI% 0.73-1.07), which disappeared in multivariate analyses (HR 1.03) (95% CI 0.82-1.29). Survival from AIDS seemed to be higher in women (HR 0.65) (95% CI 0.40-1.05), but differences became clearly nonsignificant after adjustments (HR 0.71) (95% CI 0.42-1.23). No differences were seen in time to new AIDS condition or death after HAART (HR 1.08) (95% CI 0.80-1.46) in multivariate analyses. No differences were seen for time to VL suppression after initiation of HAART (HR 1.07) (95% CI 0.92-1.24).

CONCLUSIONS

We have found no differences in HIV progression and response to HAART attributable to gender among patients accessing the Spanish hospital network.

HIV progression and predictors of mortality in a community-based cohort of Zambian adults

This article describes immunological HIV progression, mortality, and its predictors in 974 Zambian adults. During 3138 person-years of follow-up, 281 deaths occurred, and the overall mortality rate was 9.0 per 100 person-years. Thirty-six percent of patients were dead within 5 years of enrollment. The median survival in patients with baseline CD4 count ≥500 cells/mm³ was 5.62 years, with CD4 count between 200 and 499 cells/mm³ 5.46 years, and with CD4 count <200 cells/mm³ 3.89 years. The mortality rate increased significantly with older age (6.9 in patients <25 years, 9.3 in individuals aged 25-39 years, 10.2 in patients ≥40 years) and was higher in women (rate ratio 1.29). The median annual change of progression markers was -29.6 cells/mm³ for CD4 count, -3.0% for CD4 count percentage, 1.2 nmol/L for neopterin, -1.9 g/L for hemoglobin, and -70 cells/mm³ for total lymphocyte count. Hemoglobin and neopterin were as accurate as CD4 count to predict mortality.

Effects of age and sex on immunological and virological responses to initial highly active antiretroviral therapy

BACKGROUND

Highly active antiretroviral therapy (HAART) has increased longevity. Currently, women comprise >50% of HIV-infected individuals worldwide. It is not known if there are differences between the sexes in the immunological and virological responses to HAART across the age strata.

METHODS

Immunological reconstitution and virological response in the first 6 months of a first HAART regimen in two observational clinical HIV-infected cohorts were compared by both sex and age (>or=50 vs. <50 years old).

RESULTS

A total of 246 individuals (28% women) were included in the study; 63 cases (>or=50 years old) and 183 controls (<50 years old). Over two-thirds of patients had HIV RNA levels <400 HIV-1 RNA copies/mL and CD4 count increases >or=50 cells/microL at 6 months from therapy initiation. There were no differences in immunological reconstitution across age and sex strata (P=0.81) and no differences in virological suppression, even after adjusting for type of HAART (P=0.68) or restricting the analysis to women only (P=0.81). These results suggest that younger and older women and men may have similar short-term initial HAART outcomes.

CONCLUSIONS

Further evaluation of longer term clinical response to initial HAART regimen based on sex and age is indicated, especially with more efficacious and simplified antiretroviral regimens and the associated decrease in mortality.