Impact of public health strategies on reducing AIDS mortality in southern Brazil

Early mortality in a cohort of people living with HIV in Rio de Janeiro, Brazil, 2004-2015: a persisting problem

BACKGROUND

Global mortality from AIDS-related diseases has been declining since 2005, resulting primarily from the widespread use and early initiation of combination antiretroviral therapy. Despite the significant improvements, high rates of early mortality, usually defined as that occurring within the 1st year of entry to care, have been observed, especially in resource-limited settings. This analysis draws upon data from an observational cohort of people with HIV (PWH) followed at a reference center for HIV/AIDS care and research in the city of Rio de Janeiro, Brazil, to identify the pattern and factors associated with early mortality.

METHODS

The study population includes PWH aged 18 or older followed at the National Institute of Infectious Diseases Evandro Chagas who were enrolled between 2004 and 2015. The primary outcome was early mortality, defined as deaths occurring within 1 year of inclusion in the cohort, considering two follow-up periods: 0 to 90 days (very early mortality) and 91 to 365 days (early mortality). Cox proportional hazards models were used to identify the variables associated with the hazard of very early and early mortality.

RESULTS

Overall, 3879 participants contributed with 3616.4 person-years of follow-up. Of 220 deaths, 132 happened in the first 90 days and 88 between 91 and 365 days. Very early mortality rate ratios (MRR) show no statistically significant temporal differences between the periods 2004-2006 to 2013-2015. In contrast, for early mortality, a statistically significant decreasing trend was observed: mortality rates in the periods 2004-2006 (MR = 5.5; 95% CI 3.9-7.8) and 2007-2009 (MR = 3.9; 95% CI 2.7-5.7) were approximately four and three-fold higher when compared to 2013-2015 (MR = 1.4; 95% CI 0.7-2.7). Low CD4 count and prior AIDS-defining illness were strongly associated with higher hazard ratios of death, especially when considering very early mortality.

CONCLUSIONS

The present study shows an excess of mortality in the 1st year of follow-up with no changes in the mortality rates within 90 days among PWH from Rio de Janeiro. We note the significant impact of initiating treatment with immunosuppression, as evidenced by the increased risk of death among those with low CD4 cell count and with AIDS-defining illnesses.

Blood amyloid-β protein isoforms are affected by HIV-1 in a subtype-dependent pattern

This study aimed to compare serum amyloid processing biomarkers among HIV subtype B (n = 25), HIV subtype C (n = 26), healthy HIV-negative controls (n = 18), and patients with Alzheimer's disease (AD; n = 24). Immunoassays were used to measure main soluble Aβ isoforms Aβ38, Aβ40, Aβ42, and Aβ-total in serum and cerebrospinal fluid (CSF). People living with HIV (PLWH) and HIV(-) samples, including AD samples, were compared for gender and age, while HIV subtypes were compared for nadir CD4 and plasma viral load suppression. CSF/serum ratios of Aβ40, Aβ42, and Aβ-total were lower in HIV-1C group than in HIV-1B group (p = 0.020, 0.025, and 0.050, respectively). In serum, these biomarkers were comparable. Serum Aβ isoforms were significantly lower in PLWH than in AD. Serum Aβ42 levels in PLWH were decreased compared to those in control group, thus similar to Aβ42 alterations in CSF; these results were different from those observed in AD. Impaired cellular immunity, low CD4 cell count (nadir or current) influences serum Aβ metabolism in HIV-1B but not HIV-1C. However, in PLWH overall, but not in individual HIV subtype groups, greater CD4 recovery, calculated as the difference between current and nadir CD4, correlated with Aβ42/Aβ40 ratio in serum (rs 0.246; p = 0.0479). No significant correlation was found with global deficit score (GDS), an index of neurocognitive performance, age, or duration of infection. These findings are consistent with those of subtype-dependent amyloid processing in blood in chronic HIV disease.

Biomarkers of neuronal injury and amyloid metabolism in the cerebrospinal fluid of patients infected with HIV-1 subtypes B and C

Based on prior reports that the HIV-1 Tat protein modulates amyloid-beta (Aβ) metabolism, this study aimed to compare CSF neural injury biomarkers between 27 patients with HIV subtype B, 26 patients with HIV subtype C, 18 healthy HIV-negative controls, and 24 patients with Alzheimer's disease (AD). Immunoassays were used to measure soluble amyloid precursor protein α and β (sAPPα, sAPPβ), Aβ oligomers 38, 40, 42, and Aβ-total; phosphorylated tau (P-tau181), and total tau (T-tau). Comparisons between HIV(+) and HIV(-) (including AD) were adjusted by linear regression for gender and age; HIV subtype comparisons were adjusted for nadir CD4 and plasma viral load suppression. The p values were corrected for multiple testing with the Benjamini-Hochberg procedure. CSF Aβ-42 and Hulstaert (P-tau181) index were lower in HIV1-C than B (p = 0.03, and 0.049 respectively); subtypes did not differ on other CSF biomarkers or ratios. Compared to AD, HIV(+) had lower CSF levels of T-tau, P-tau181 (p < 0.001), and sAPPα (p = 0.041); HIV(+) had higher CSF Aβ-42 (p = 0.002) and higher CSF indexes: [Aß-42/(240 + 1.18 T-tau)], P-tau181/Aβ-42, T-tau/Aβ-42, P-tau181/T-tau, sAPPα/β (all p ≤ 0.01) than AD. Compared to HIV(-), HIV(+) had lower CSF Aβ-42, and T-tau (all p ≤ 0.004). As conclusion, amyloid metabolism was influenced by HIV infection in a subtype-dependent manner. Aß-42 levels were lower in HIV1-C than B, suggesting that there may be greater deposition of Aß-42 in HIV1-C. These findings are supported by CSF Hulstaert (P-tau181) index. Differences between HIV and AD in the patterns of Aß and Tau biomarkers suggest that CNS HIV infection and AD may not share some of same mechanisms of neuronal injury.