Longitudinal kidney outcomes in surviving COVID-19 patients in Africa: a prospective Congolese single-center cohort study

The aim of this study was to determine kidney outcomes and associated factors in COVID-19 patients discharged from intensive care unit (ICU) in an African setting. In a prospective observational single-center cohort study, we compared the rate of decline in eGFRcr and the incidence of CKD between COVID-19 patients with and without AKI after discharge from ICU. Kidney function decline (KFD) and chronic kidney disease (CKD) during 2 years of follow-up were defined as eGFR decline ≥ 30% and eGFR less than 60 mL/min/1.73 m² and/or the presence of proteinuria, respectively. The association between COVID-19-associated AKI (COVID-AKI) and eGFR decline after hospital discharge was assessed using mixed-effects models. Logistic regression and Cox regression were used to define factors associated with KFD and CKD. The incidence of KFD and CKD at two years of follow-up was 23% and 0.73 per 100 patient months (P-M), respectively. Patients with COVID-AKI had a greater decline in eGFR (-11.09 mL/min/1.73 m²/year [95% CI, −3.65 to-1.02]; <i>p</i> ˂0.001) and CKD incidence (3.11 per 100 P-M vs 0.18 per 100 P-M, <i>p</i> = 0.003) in the fully adjusted model controlling for comorbidities and peak creatinine level. AKI was associated with KFD (aOR: 3.46 [2.40-5.24], <i>p</i> = 0.001) and CKD (aHR: 3.37 [2.35-5.41], <i>p</i> = 0.003). KFD and CKD are common in COVID-19 survivors. AKI was associated with both KFD and CKD after ICU discharge. Kidney care after COVID-19 needs to be organized in the context of AKI.