Frequency and Predictors of HIV-Related Cognitive Impairment in East Africa: The Africa Cohort Study (AFRICOS)

Prevalence and variability of HIV/AIDS-associated neurocognitive impairments in Africa: a systematic review and meta-analysis

BACKGROUND

HIV/AIDS-associated neurocognitive impairments negatively affect treatment adherence, viral load suppression, CD4 count, functionality, and the overall quality of life of people with seropositive status. However, huge variability is observed across primary studies regarding the prevalence and determinants of neurocognitive impairment in people with HIV/AIDS. This systematic review and meta-analysis sought to determine the pooled prevalence of neurocognitive impairment and identify factors contributing to variations in its estimate among people living with HIV/AIDS in Africa.

METHODS

A comprehensive literature search of scientific databases (Medline/PubMed, SCOPUS, Web of Science, PsycINFO, and EMBASE) was performed from inception onward. Google and Google Scholar were also searched for grey literature. Research articles available until July 15, 2022 were included. We used STATA-version 14 statistical software for analysis. A random effect model was executed to pool the reported prevalence of neurocognitive impairments. Subgroup analysis was done to show variations in the prevalence of neurocognitive impairments and factors that might contribute to these variations.

RESULTS

A literature search resulted in 8,047 articles. After the removal of duplications and thorough evaluation, a total of 49 studies were included in the meta-analysis. The prevalence of HIV/AIDS-associated neurocognitive impairments was highly variable across studies, ranging from 14% to 88%, yielding the pooled prevalence of HIV/AIDS-associated neurocognitive impairment to be 46.34% [95% CI (40.32, 52.36)] and I² = 98.5% with a P-value of 0.001.

CONCLUSIONS

A large proportion of people living with HIV/AIDS in Africa have HIV/AIDS-associated neurocognitive impairment. This illustrates the need to establish practical approaches to early identification and effective control of HIV/AIDS-associated neurocognitive impairments. However, there were variabilities in the reported prevalence of HIV/AIDS-associated neurocognitive impairments across studies. This further demonstrates the need to have consistent measurement approaches.

TRIAL REGISTRATION

PROSPERO 2022, "CRD42020166572".

Twelve-year neurocognitive decline in HIV is associated with comorbidities, not age: a CHARTER study

Modern antiretroviral therapy (ART) has increased longevity of people with HIV and shifted the age distribution of the HIV pandemic upward toward that of the general population. This positive development has also led to concerns about premature and/or accelerated neurocognitive and physical ageing due to the combined effects of chronic HIV, accumulating comorbidities, adverse effects or possible toxicities of ART and biological ageing. Here we present results of comprehensive assessments over 12 years of 402 people with HIV in the CNS HIV ART Effects Research (CHARTER) programme, who at follow-up were composed of younger (<60 years) and older (≥60 years) subgroups. Over the 12 years, ART use and viral suppression increased in both subgroups as did systemic and psychiatric comorbidities; participants in both subgroups also evidenced neurocognitive decline beyond what is expected in typical ageing. Contrary to expectations, all these adverse effects were comparable in the younger and older CHARTER subgroups, and unrelated to chronological age. Neurocognitive decline was unrelated to HIV disease or treatment characteristics but was significantly predicted by the presence of comorbid conditions, specifically diabetes, hypertension, chronic pulmonary disease, frailty, neuropathic pain, depression and lifetime history of cannabis use disorder. These results are not consistent with premature or accelerated neurocognitive ageing due to HIV itself but suggest important indirect effects of multiple, potentially treatable comorbidities that are more common among people with HIV than in the general population. Good medical management of HIV disease did not prevent these adverse outcomes, and increased attention to a range of comorbid conditions in people with HIV may be warranted in their care.

The Need to Revise Frascati Criteria for HIV-associated Neurocognitive Disorders to Improve Relevance for Diverse Global Populations

Abstract:

Worldwide, cognitive impairment is a frequent complication of HIV and few treatments are available. Existing diagnostic criteria for cognitive disorders associated with HIV have limited diagnostic accuracy, hampering biomarker and therapeutic development. Further, these criteria are not linked to clinically meaningful outcomes, limiting utility in clinical settings. Limitations in diagnostic accuracy is most pronounced in resource-limited settings where the burden of HIV is greatest, largely due to heavy reliance on neuropsychological testing with limited cross-cultural validity. Accurate and clinically meaningful diagnostic criteria validated in diverse populations will improve research and clinical care for cognitively impaired people living with HIV globally.

Neuroimmunology of CNS HIV Infection: A Narrative Review

This short review provides an overview of the interactions of human immunodeficiency virus type 1 (HIV), immune and inflammatory reactions, and CNS injury over the course of infection. Systemic infection is the overall driver of disease and serves as the “platform” for eventual CNS injury, setting the level of immune dysfunction and providing both the HIV seeding and immune-inflammatory responses to the CNS. These systemic processes determine the timing of and vulnerability to HIV-related neuronal injury which occurs in a separate “compartment” with features that parallel their systemic counterparts but also evolve independently. Direct CNS HIV infection, along with opportunistic infections, can have profound neurological consequences for the infected individual. HIV-related CNS morbidities are of worldwide importance but are enhanced by the particular epidemiological, socioeconomic and environmental factors that heighten the impact of HIV infection in Africa.

Long-term HIV treatment outcomes and associated factors in sub-Saharan Africa: multi-country longitudinal cohort analysis

OBJECTIVE

In a multicountry prospective cohort of persons with HIV from six countries between 2007 and 2015, we evaluated long-term outcomes of first-line non-nucleoside reverse-transcriptase inhibitor-based antiretroviral therapy (ART), and risk factors for loss-to-follow-up, mortality, virological failure, and incomplete CD4+ T-cell recovery.

METHODS

We calculated cumulative incidence of lost-to-follow-up, death, virological failure (VL ≥ 1000 cps/ml) and incomplete CD4+ T-cell recovery (<500 cells/μl) at successive years, using Kaplan-Meier and Cox regression.

RESULTS

Of 2735 participants, 58.0% were female, median age was 37 (interquartile range [IQR] 32-43) years, and median pre-ART CD4+ T-cell count was 135 (IQR 63-205)/μl. Total follow-up time was 7208 person-years (median 24.3 months, IQR 18.7-58.3). Deaths by any cause and loss to follow-up occurred mostly during the first year of ART (84%, 201/240 and 56%, 199/353, respectively). During their first 6 years of ART, 71% (95% confidence interval [CI] 69.0-73.7) were retained on first-line, and among those 90-93% sustained viral suppression (<1000 cps/ml); CD4+ T-cell recovery was incomplete in 60% (220/363) of participants. The risk factors associated with poor outcomes during long-term ART were: for loss-to-follow-up, recent VL ≥1000 cps/ml, recent CD4+ T-cell count ≤50 cells/μl, age <30 years, being underweight; for mortality, recent CD4+ T-cell count ≤50 cells/μl; and, for virological failure, age <40 years, recent CD4+ T-cell count ≤200 cells/μl, poor adherence, male sex, and low-level viremia.

CONCLUSION

To achieve long-term ART success towards the UNAIDS targets, early ART initiation is crucial, coupled with careful monitoring and retention support, particularly in the first year of ART. Male and youth-centred care delivery models are needed to improve outcomes for those vulnerable groups.

A Meta-Analytic Review of the Effect of Antiretroviral Therapy on Neurocognitive Outcomes in Adults Living with HIV-1 in Low-and Middle-Income Countries

HIV-associated neurocognitive impairment remains a challenge even in the era of antiretroviral therapy (ART). Over 90% of people living with HIV are in low- and middle-income countries. Hence, it is not surprising that such countries bear a considerable burden of comorbidities like HIV-associated neurocognitive impairment despite an overall increase in life expectancy. The literature suggests differences in patient characteristics, clinical profile, prevalent HIV subtypes, treatment choices, pharmacogenetics, and socioeconomic factors between low- and middle-income countries compared with high-income countries. Therefore, we aimed to evaluate the effect of ART on neurocognitive outcomes in low- and middle-income countries. A comprehensive search of five databases (PubMed, CINAHL, CENTRAL, PsychInfo, Google scholar) for studies published between 1996 to 2020 was performed to identify studies that reported neurocognitive outcomes in ART-treated and ART naïve HIV positive individuals. Two independent reviewers conducted study screening, data extraction, and evaluation of the risk of bias. Pooled effect size estimates (Hedges' g) and 95% CI were computed using random-effects models. Sensitivity analysis, subgroup analysis, meta-regression, and evaluation of publication bias were also conducted. Forty studies (24 cross-sectional, 13 longitudinal studies, and two randomized controlled trials) contributed to a series of meta-analyses. We found significant small to moderate effects of antiretroviral therapy for global cognition (Hedges' g observed = 0.30; 95% CI: 0.15, 0.44; k = 25; p = 0.0003; I² = 92.1%; tau = 0.32; Q = 305.1), executive function (Hedges' g = 0.24, 95%CI: 0.02,0.46; p-0.04; k = 8; I² = 37.5%; tau = 0.23; Q = 11.2), and speed of information processing (Hedges' g = 0.25, 95% CI: 0.05, 0.45; k = 9; p = 0.02; I² = 86.4%; tau = 0.21; Q = 58.9). We found no significant ART effect on attention-working memory, learning and memory, motor function, and verbal fluency. No significant effect was seen with the duration of therapy, efavirenz use, and Central Penetrating Effectiveness (CPE) of antiretroviral therapy. Subgroup analyses identified study design (between-group and within-group; cross-sectional and longitudinal) and normative scores as significant sources of heterogeneity. Meta-regression analysis indicated that nadir CD4 modified the magnitude of ART's effect on cognitive outcomes. Age, gender, and country income-group were not significant moderators. Our findings provide systematic evidence that antiretroviral therapy improves neurocognitive outcomes in the domains of global cognition, executive function and speed of information processing, of people living with HIV in low- and middle-income countries, especially those with advanced immunosuppression. However, these findings are not definitive as they are limited by the probability of publication bias, high heterogeneity, and exclusion of significant confounders. Prospero registration number: CRD42020203791.

Prevalence and risk factors associated with HIV and syphilis co-infection in the African Cohort Study: a cross-sectional study

Background

Each year, 5.6 million new syphilis cases are diagnosed globally. Guidelines for people living with HIV (PLWH) in low-income countries (LIC) recommend STI testing for symptomatic persons and those newly diagnosed with HIV; routine STI testing is less clear. Here we provide updated syphilis prevalence and identify co-infection risk factors in PLWH in the African Cohort Study (AFRICOS) to understand these rates as they relate to syndromic treatment.

Methods

AFRICOS is a study enrolling PLWH and HIV-uninfected individuals in four African countries. Participant study enrollment information was used to determine syphilis prevalence and co-infection risk factors. Inclusion criteria consisted of adults 18 years or older receiving care at a participating clinic as a long-term resident who consented to data and specimen collection. Exclusion criteria consisted of pregnancy and/or imprisonment. Screen-positive syphilis was defined as a reactive rapid plasma regain (RPR) upon study enrollment whereas confirmed syphilis included a reactive RPR followed by reactive treponemal test. Multivariate analyses was performed to determine HIV and syphilis co-infection risk factors.

Results

Between 2013 and March 1, 2020, 2939 PLWH enrolled and 2818 were included for analysis. Screen-positive and confirmed syphilis prevalence were 5.3% (151/2818) and 3.1% (87/2818), respectively. When the analysis was restricted to PLWH with an RPR titer of greater than, or equal to, 1:8, 11/87 (12.6%) participants were included. No PLWH and confirmed syphilis had documented genital ulcers. In the multivariate model, participants with confirmed syphilis co-infection were more likely to have none or some primary education [aOR 3.29 (1.60, 6.74)] and consume alcohol [aOR 1.87 (1.16, 3.03)] compared to those without syphilis. Antiretroviral therapy (ART) with suppressed viral load (VL) was protective in the unadjusted model but not adjusted multivariate model.

Conclusions

Our findings show that syphilis rates in sub-Saharan Africa remain elevated where diagnosis remains challenging, and that both lower education level and alcohol consumption are significantly associated with HIV/syphilis co-infection in AFRICOS. Based on our analysis, current STI guidelines targeting testing for African individuals with either new HIV diagnosis or syndromic symptoms may be inadequate, highlighting the need for increased testing and treatment strategies in resource-limited settings.

Meta-analysis of factors affecting prevalence estimates of HIV-associated neurocognitive disorder in sub-Saharan Africa

Successful treatment of HIV with anti-retroviral therapy (ART) is resulting in more people living with HIV-associated neurocognitive disorder (HAND). In sub-Saharan Africa, this calls for strategic planning and judicious allocation of scarce resources, which requires an accurate estimate of the prevalence of HAND. Estimates of the prevalence of HAND in sub-Saharan Africa vary greatly, between 18.8% and 88.3%. This variability may be explained by factors such as different diagnostic approach, neuromedical examination, ART status, sampling method, substance abuse, assessors’ qualification, depression and outcome measure. Different methods of diagnosing HAND, different outcome measures and non-random sampling techniques make it almost impossible to accurately estimate the prevalence of HAND in sub- Saharan Africa, often resulting in overestimation of the burden of disease. Consumers of health research should consider certain study characteristics and exercise appropriate caution when interpreting burden of disease in sub-Saharan Africa, especially when pursuing policy shift. Underestimating the prevalence of HAND will certainly affect the capacity and speed of containment, while overestimating will draw unnecessary attention and result in the misallocation of scarce resources.

Sex-specific associations between cerebrospinal fluid inflammatory marker levels and cognitive function in antiretroviral treated people living with HIV in rural Uganda

People with HIV (PWH) taking antiretroviral therapy (ART) have persistent cognitive impairment. The prevalence of cognitive impairment is higher in women with HIV (WWH) compared to men with HIV (MWH), possibly due to sex differences in immune function. Here we report sex differences in cerebrospinal fluid (CSF) immune markers in relation to cognitive performance. A subset of 83 PWH on ART (52% WWH; mean age = 37.6 years, SD = 7.9) from the Rakai community cohort study Cohort and Rakai Health Sciences Program supported clinics in rural Uganda completed a neuropsychological (NP) assessment and a lumbar puncture. CSF was used to measure 16 cytokines/chemokines. Individual NP test z-scores were generated based on local normative data. A series of least absolute shrinkage and selection operator (lasso) regressions examined associations between CSF inflammatory markers and NP outcomes. Overall, there were no sex differences in CSF inflammatory marker levels. However, MWH displayed more associations between inflammatory markers and cognitive performance than WWH. Among MWH, inflammatory markers were associated with a number of cognitive domains, including attention, processing speed, fluency, executive function, learning and memory. MIP-1β, INF-γ, GM-CSF, IL-7 and IL-12p70 were associated with multiple domains. Among WWH, few inflammatory markers were associated cognition. Degree of associations between CSF inflammatory biomarkers and cognitive performance varied by sex in this young, ART-treated, Ugandan cohort. Further investigation into sex-specific inflammatory mechanisms of cognitive impairment among PWH is warranted to inform sex-specific management strategies.