The link between moderate COVID-19 and delayed manifestation of glomerulonephritis: Insights from cluster analysis of TGF-β1 and VEGF levels

Abstract

Recent data reveal delayed pathological kidney changes occurring 8-12 months post-moderate COVID-19, often detected for the first time. While severe COVID-19 leads to interstitial and subsequent glomerular lesions, the predominant changes in moderate cases remain elusive. This study aimed to investigate the potential association between moderate COVID-19 and the manifestation of glomerulonephritis (GN).
 Methods. This cross-sectional study included 25 patients with stage 1-2 GN and a history of moderate COVID-19 8-12 months before the onset of GN, 27 individuals without GN who experienced COVID-19, and 20 healthy subjects without a history of COVID-19. Transforming growth factor-β1 (TGF-β1) and vascular endothelial growth factor (VEGF) levels in blood and urine were measured using enzyme-linked immunosorbent assay. Cluster and classification data mining methods were utilized for these markers to assess potential relationships between moderate COVID-19 and GN manifestation.
 Results. A significant increase in blood and urine TGF-β1 and VEGF levels was found in GN patients with a history of moderate COVID-19 (p<0.05), while elevated blood VEGF was observed in those without GN (p<0.05). Cluster analysis affirmed the correlation, emphasizing that urinary TGF-β1 within the range of 1.352 to 5.693 pg/ml and urinary VEGF < 214.12 pg/ml serve as classification rules for predicting GN.
 Conclusions. The cluster and classification analysis method for TGF-β1 and VEGF levels can be utilized in clinical practice to predict the development of GN in the long-term post-COVID period.