The Effect of COVID-19 Pandemic on Distribution of Biopsy-Proven Glomerular Disease: A Single Center Experience

Introduction: This study aims to examine the patients who underwent kidney biopsies due to urinary abnormalities and/or kidney failure in our unit and whether there was a change in the distribution of glomerular diseases before and after the coronavirus disease-2019 pandemic. Materials and Methods: The patients were divided into pre-pandemic (group-1) and post-pandemic (group-2). The frequency of renal pathology results and the representative clinical syndrome were compared between groups. Results: 452 patients [median age: 48 years (IQR: 36.25-58), 54.8% male], (group-1, n:215; 47.57%), (group-2, n:237; 52,43%)) were included in the study. Non-nephrotic proteinuria was the most common indication in both two groups. The frequency of nephrotic syndrome was significantly higher in group-1 (19.5%, p:0.007). The acute or rapidly progressive renal failure frequency was significantly higher in group-2 (p:0.021). The median 24-hour urine protein level was 1354 (IQR:521-3000) mg/ day, significantly lower in group-2 (p: 0,001). Primary glomerular disease was the most common category (42.19%), followed by secondary glomerular diseases (35.02%) and tubulointerstitial nephropathies (6.32%) in group-2. The frequency of primary glomerular disease was significantly higher in group-1 (p:0.022). Hypertensive nephrosclerosis (6.80%) was common in group-2 compared to group-1 (p:0,026). Conclusion: We did not detect an increase in the prevalence of primary glomerular disease; on the contrary, there was a decrease in the prevalence of primary glomerular disease in the post-pandemic period. The acute or rapidly progressive renal failure frequency was significantly higher in the post pandemic period. Further multicenter studies are needed to determine the effect of the COVID-19 pandemic on glomerular diseases.