Effect of COVID-19 Infection on Kidney Function in IgAN

Previous studies have suggested that COVID-19 infection may trigger immunoglobulin A nephropathy (IgAN), but little research has examined the impact of COVID-19 in patients already diagnosed with IgAN. Therefore, Miao Hui and colleagues conducted a single-center cohort study to determine whether COVID-19 independently affects the subsequent trajectory of kidney function in individuals with IgAN. Their results were published in the Clinical Kidney Journal.

The study included 199 patients with IgAN, of whom 90 (45.23%) were male and 81 (44.75%) had COVID-19. Participants’ kidney function trajectory was assessed by eGFR, calculated based on serum creatinine levels measured during follow-up outpatient visits. The primary endpoint was the eGFR trajectory.

Of the 199 patients, 181 (75%) had a SARS-CoV-2 infection confirmed via antigen or polymerase chain reaction tests. This accounted for 143 (79%) of the infected participants. Most patients with COVID-19 (98%) had mild or moderate symptoms.

During a median follow-up of 10.7 months post-COVID-19 infection, gross hematuria occurred in 30 (16.6%) patients, normalizing within three days on average, and 10 (5.5%) patients experienced a twofold increase in proteinuria or progression to the nephrotic range. There were no cases of acute kidney injury.

COVID-19 infection was associated with an absolute change in eGFR of 2.98 mL/min/1.73 m² per month (95% CI, 0.46 to 5.50). However, in a fully adjusted model, the estimated changes in eGFR slope post-COVID-19 were –0.39 mL/min/ 1.73 m² per month (95% CI, –0.83 to 0.06; P=.088) and included the possibility of no significant effect. Patients with a baseline eGFR less than 45 mL/min/1.73 m²  (–0.56 mL/min/1.73 m² [–1.11 to –0.01]; P=.048) had a higher rate of kidney function. The study was limited by the absence of long-term follow-up outcomes.

In summary, the authors wrote, “Our findings suggest that mild to moderate COVID- 19 infection does not appear to significantly exacerbate subsequent kidney function decline in IgA nephropathy patients, particularly those with preserved baseline kidney function.”

Source: Clinical Kidney Journal