COVID-19 severity and in-hospital mortality in an area with high HIV prevalence

Background: HIV is moderate risk factor for developing severe COVID-19 and is associated with increased risk of COVID-19 mortality. HIV infection causes immune dysregulation characterised by progressive lymphopenia, chronic immune activation, immunological senescence, and T cell exhaustion. These changes are partly reversed by effective antiretroviral therapy (ART), which reduces morbidity and mortality in people living with HIV (PWH). We investigated the associations among clinical phenotypes, laboratory biomarkers, and hospitalisation outcomes in a cohort of people hospitalised with COVID-19 in a high HIV prevalence area.Methods: We conducted a prospective observational cohort study in the Tshwane District Hospital complex in Pretoria, South Africa. We analysed data for patients admitted from April to November 2020, before the SARS-CoV-2 Beta variant-driven second wave. Respiratory disease severity was quantified using the respiratory oxygenation (ROX) score. Analysed biomarkers included full blood counts, differential white cell counts, C-reactive protein (CRP), ferritin, procalcitonin (PCT), D-dimer (DDIM), creatinine, alanine aminotransferase (ALT), CD4 T cell counts, and HIV-1 viral loads (HIVVL).Results: The analysis included 558 patients, of whom 112 (21.7%) died during admission. The mean age of the cohort was 54 (SD ±16) years, and numbers of males (50.5%) and females (49.5%) were equivalent. A total of 82 (15%) were HIV-positive. PWH were younger (mean age 46 years) than HIV-negative people; most were on ART with a suppressed HIVVL (72%) and the median CD4 count was 159 (IQR 66-397) cells/µL at the time of admission. After adjusting for age, HIV was not associated with significantly increased risk of mortality during hospitalisation (aHR=1.1, 95% CI: 0.6-2.0). Levels of supportive care were similar in HIV-negative patients and PWH. Inflammatory biomarker levels were equivalent in PWH and HIV-negative patients. A total of 15 PWH had detectable HIVVLs (>1000 copies/mL). Detectable HIVVL was associated with higher ROX scores - indicating less severe respiratory disease. In PWH, mortality was associated with higher levels of CRP, ferritin, PCT and DDIM. When compared to HIV-negative patients who died, PWH who died were younger, had higher DDIM levels, and were more likely to have tuberculosis.Conclusions: HIV per se was not associated with substantively increased risk of severe disease, or in-hospital mortality from COVID-19. Respiratory disease was less severe in PWH with detectable HIVVL. Inflammatory biomarker levels were equivalent in PWH and HIV-negative people, regardless of HIVVL. Increased levels of inflammatory biomarkers and DDIM were associated with in-hospital mortality irrespective of HIV status.