ABSTRACT
BACKGROUND AND AIMS: Renal involvement in COVID-19 under vigilant public health surveillance, including mass screening and early hospitalization is less wellcharacterized. We assessed renal involvement of COVID-19 patients in Hong Kong, including the association with risk factors, length of hospitalization, critical presentation and mortality. METHOD: Linked electronic records of all confirmed patients from 5 major designated hospitals were extracted. Primary outcome was the incidence of in-hospital AKI. Secondary outcomes were AKI-associated mortality, incident RRT, intensive care admission, prolonged hospitalization and disease course (defined as >90th percentile of hospitalization duration and duration from symptom onset to discharge, respectively), and change of eGFR. Patients were further stratified into being symptomatic or asymptomatic. RESULTS: Patients were characterized by young age (median:38.4, IQR:28.4-55.8 years old) and short time (Median:5, IQR:2-9 days) from symptom onset to admission. Among the 591 patients, 22 (3.72%) developed AKI and 4 (0.68%) required RRT. AKI increased the odds of prolonged hospitalization and disease course by 2.0 and 3.5 folds, respectively. Estimated GFR 24 weeks post-discharge reduced by 7.51 and 1.06 ml/min/ 1.73m2 versus baseline (at admission) in the AKI and non-AKI groups, respectively. The incidence of AKI was comparable between asymptomatic (4.8%) and symptomatic (3.7%) patients. CONCLUSION: The overall rate of AKI among COVID-19 patients in Hong Kong is low, which could be attributable to a vigilant screening program and early hospitalization. Among patients who developed in-hospital AKI, the duration of hospitalization is prolonged and kidney function impairment can persist for up to 6 months post-discharge. Mass surveillance for COVID-19 is warranted in identifying asymptomatic subjects for earlier AKI management.
ABSTRACT
Background: COVID-19 caused substantial casualty worldwide. As the reported renal involvement varied across regions, we sought to review the global prevalence of renal manifestations among COVID-19 patients and determine the risk factors associated with AKI. Methods: We systematically searched 6 databases for peer-reviewed reports and 7 data portals for grey literature for all trials, cohorts, case-control studies and case-series that reported the prevalence of renal manifestations including AKI, RRT, proteinuria and hematuria, and their associated risk factors. All papers were screened, assessed and extracted by at least 2 researchers independently. Quality was assessed according to NIH assessment tools. To avoid duplicate of patient data, we matched the location, institution and time period, and only included the largest data source if studies overlapped. Prevalence of renal manifestations was pooled from studies that consecutively recruited patients from the general population, and with clear definition of outcome. This review was prospectively registered at PROSPERO (CRD42020184621). Results: 36 studies from 8 countries and over 50 cities with a total of 14,712 patients were identified. 34 and 2 were cohorts and case-control studies respectively. 24, 7 and 5 studies reported COVID-19 patients from the general population, severe / critical patients and patients with history of RRT. AKI occurred in 14.3% of all COVID-19 cases and was highest in New York City. 4.7% of hospitalized COVID-19 patients underwent RRT. Proteinuria and hematuria were present in 42.5% and 26.7% of all COVID-19 cases. The odds of mortality among COVID-19 patients who developed AKI was 15 times higher than non-AKI COVID-19 patients (pooled OR=16.85, 95% CI: 10.06 to 28.23, 2 cities, 6 studies, 9,297 patients) and was higher in Hubei. Such effect was not observed among kidney transplant patients (pooled OR=0.95, 95% CI: 0.12 to 7.22, 2 studies, 30 patients). Higher C-reactive protein, leukocyte count, serum lactate dehydrogenase and creatinine levels on admission were associated with AKI. Conclusions: AKI was prevalent among COVID-19 patients and significantly associated with mortality. The odds of mortality among AKI patients varied significantly between cities, which could be associated with differences in healthcare infrastructure and delayed hospitalization and treatment initiation.