In this meta-analysis, results from 18 retrospective cross-sectional studies including 15135 patients hospitalized with COVID-19 from January 1, 2020 to June 1, 2020 demonstrated that AKI was not rare in COVID-19. The incidence of AKI is associated with the age, disease severity and race of patients in our subgroup study. And we also proved that using Remdesivir for treatment did not increase the risk of AKI.
COVID-19 infection is primarily a respiratory disease, but other organs including the kidneys are often involved. Renal abnormalities, such as proteinuria, hematuria, and AKI occurred in patients with COVID-1934. AKI is characterized by a rapid increase in serum creatinine, decrease in urine output, or both35. The currently widespread AKI definition was developed by the Kidney Disease Improving Global Outcomes (KDIGO) group in 201236. The most common causes of AKI were septic shock, post major surgery, cardiogenic shock, drug toxicity and hypovolemia37. The cause of AKI in COVID-19 is likely to be multifactorial, including hemodynamic instability, microcirculatory dysfunction, tubular cell injury, renal congestion, microvascular thrombi and endothelial dysfunction38. Pathology from autopsies of patients with COVID-19 with renal failure revealed that the kidneys had varying degrees of acute tubular necrosis, diffuse proximal tubule injury with the loss of brush border, non-isometric vacuolar degeneration, hemosiderin granules and pigmented casts39,40 .We found out that incidence of AKI in all hospitalized COVID-19 patients was 12.0%. The diversity of patients included in our meta-analysis cause the heterogeneity. According to the subgroup analysis, the estimated AKI incidence of patients with averaged age more than 60 years old is higher than patients averaged age less than 60 years old (13% vs 8%). Many reports on COVID-19 have highlighted age-related differences in health outcomes, mortality of COVID-19 is particularly high among older patients41,42. Age is also an important risk factor for AKI43. The pooled estimated AKI incidences in the Asian subgroup was lower than Western subgroup (8% vs 28%). Black race is a risk factor for AKI44. In a large cohort study of hospitalization COVID-19 patients among black patients and white patients with COVID-19, 76.9% of the patients who were hospitalized with COVID-19 and 70.6% of those who died were black, whereas blacks comprise only 31% of the population45. The incidence of AKI in ICU patients with the COVID-19 was particularly high range from 8%-62%15,18,23–25,28,29. Critical ill patients hospitalized with COVID-19, requiring ventilator is more likely to develop AKI4. In our subgroup study, patients were divided into two groups according to the proportion of using ventilator or ICU. The incidence of AKI is higher in more severe patients (24% vs 6%).
As the ongoing pandemic of COVID-19, there is an urgent need to identify safe and effective treatment options, such as antiviral drug. Introduction of antiviral drugs is a common cause of drug-induced AKI46,47. In the clinical experiment of Remdesivir, AKI as the most frequent adverse event lead to drug discontinuation11,12. Antiviral drugs cause AKI by many mechanisms including direct renal tubular toxicity, allergic interstitial nephritis, and crystal nephropathy48,49. But in animal models, Remdesivir treatment was effective against MERS-CoV and did not show any side effect of AKI50. As shown in Figs. 2 and 3, the incidence of AKI in hospitalized COVID-19 patients using Remdesivir is lower than all hospitalized COVID-19 patients whether using Remdesivir or not. The meta-analysis of RCTs also proved that Remdesivir did not increase the risk of AKI in hospitalized COVID-19 patients. Similar to the results of our study, a RCT study of Ebola virus disease (EVD) therapeutics also showed that Remdesivir reduced mortality from EVD without increase the risk of AKI7. Our meta-analysis may provide an evidence for future study that AKI is associated with the natural cause of COVID-19, not the adverse event after the usage of the drug.
Our meta-analysis had some limitations. First, most of the studies included in were retrospective cross-sectional study, although most of them (72%) were high quality. The RCTs included in our study were high quality but with limited amount. Sensitivity analysis which performed using one by one exclusion got similar results in our study. Second, there was a statistically significant heterogeneity in the meta-analysis of AKI incidence. The diversity of included studies involving different disease stage or activity, age, race and sex might be associated with the heterogeneity. Although we did subgroup study, the results still had significant heterogeneity. Third, the limited original studies (n༜10) for the meta-analysis of the incidence of AKI in hospitalized COVID-19 patients using Remdesivir. No begger’s test is needed. Finally, since the clinical experiments for Remdesivir are ongoing now, the extra clinical data should be considered after their publications.