IgA NEPHROPATHY IN CHILDREN AND THE LIMITED OPTIONS FOR THE IMMUNOSUPPRESSIVE THERAPY

It is believed that IgA nephropathy (IgAN) in childhood is predominantly manifested by hematuria with episodes of macrohematuria and has a relatively favorable course. The purpose of this research was to analyze the frequency of the use of mycophenolate mofetil (MMF) in children with IgAN in the Nephrology Department of the National Medical Research Center for Children’s Health (Moscow, Russia) and to evaluate the results of treatment in terms of the severity of proteinuria and the presence of a decrease in renal function by glomerular filtration. Materials and methods used: to assess the clinical course, histological features and kidney function during therapy, Authors analyzed the results of 737 biopsies performed in 2018-2022. Results: 126 biopsy specimens with predominant IgA deposition and mesangial proliferation and/or crescents were identified, 20 of them were excluded from further analysis due to the clinical picture of IgA vasculitis. 17 (16% of the remaining 106) patients had nephrotic-level of proteinuria prior to the biopsy, 11 had a history of acute kidney injury and 9 had a persistent decrease in glomerular filtration renal function. Steroid therapy with prednisolone at a dose of 0.5 to 1 mg/kg was carried out in 21 children, 14 (66.7%; CI 45.4-84.1%) of them had relapse or resistance. MMF therapy was started in 16 (11 boys and 5 girls) patients, median age of the therapy initiation was 13.4 [7.9; 15.3] y/o, 6 had a decrease in glomerular filtration rate (GFR) in the range of 64 to 85 ml/min. Kidney biopsy specimens were ere scored according to the Oxford classification MEST-C criteria. During the follow-up period (median 27.6 [20.0; 49.4] months), 14 (88% CI; 66-98) of 16 achieved complete (10) or partial remission, 2 patients had proteinuria of more than 1 g/l. Of 56 patients (median age 13.3 [9.6; 14.9] months) with a follow-up period of more than 6 months, a decrease in GFR was recorded in 5 (31.3%; CI 12.5-55.5) patients on MMF therapy and 4 (22.2%; CI 7.5-44.3) patients who received only a course of steroids and a single one (4.5%; CI 0.3-18.5) who received ACE inhibitor only. Analysis of biopsy results showed an increased risk of reduced GFR in patients with tubular atrophy. Conclusion: MMF therapy may have limited efficacy for proteinuria in IgAN though it does not prevent the GFR decline.