P0369MINOR GLOMERULAR ABNORMALITIES ARE ASSOCIATED WITH DETERIORATION OF LONG-TERM KIDNEY FUNCTION AND MITOCHONDRIAL INJURY

Abstract Background and Aims Minor glomerular abnormalities (MGAs) are unclassified glomerular lesions indicated by the presence of minor structural abnormalities that are insufficient for a specific pathological diagnosis. The long-term clinical outcomes and pathogenesis have not been examined. We hypothesized that MGAs would be associated with the deterioration of long-term kidney function and increased urinary mitochondrial DNA (mtDNA) copy numbers. Method We retrospectively enrolled patients with MGAs, age-/sex-/estimated glomerular filtration rate (eGFR)-matched patients with IgA nephropathy (IgAN), and similarly matched healthy controls (MHCs; n = 49 each). We analyzed the time×group interaction effects of the eGFR and compared mean annual eGFR decline rates between the groups. We prospectively enrolled patients with MGAs, age- and sex-matched patients with IgAN, and MHCs (n = 15 each) and compared their urinary mtDNA copy numbers. Results Compared to the MHC group, the MGA and IgAN groups displayed differences in the time×group effects of eGFR (Figure 1), higher mean annual rates of eGFR decline (Table), and higher urinary mtDNA copy numbers (Figure 2); however, these groups did not significantly differ from each other. Figure 1. Changes in the estimated glomerular filtration rate (eGFR) in the minor glomerular abnormality (MGA), matched healthy control (MHC), and immunoglobulin A nephropathy (IgAN) groups in the 10 years after kidney biopsy. Time effects were tested using a linear mixed model. aMGA and MHC groups; bMHC and IgAN groups; cMGA and IgAN groups. Figure 2. Urinary mitochondrial DNA copy numbers in the matched healthy control (MHC), minor glomerular abnormality (MGA), and immunoglobulin A nephropathy (IgAN) groups. Data were analyzed by the Mann-Whitney test. *p < 0.001. MT-ND1, mitochondrially encoded NADH dehydrogenase 1; COX3, cytochrome c oxidase subunit III. Table. C hanges in eGFR in the MGA, MHC, and IgAN groups in the retrospective study. Variable MHC Group (n = 49) MGA Group (n =49) p Valuea IgAN Group (n = 49) p Valueb Mean follow-up duration (months) 110.69 ± 20.82 64.40 ± 44.27