AIM. The analysis of incidence, clinical and morphological manifestations, and the prognosis of IgA nephropathy in the Russian population.PATIENTS AND METHODS. Six hundred cases with primary IgA nephropathy (IgAN) from 1999 to 2019 were enrolled in the single-center retrospective study. Demographic and clinical parameters, morphrology data, and the treatment were analyzed. Three hundred forty seven patients were included in follow-up study. The following outcomes were evaluated: the occurrence of complete (PR) or partial remission (CR), death from all causes, the need for renal replacement therapy (RRT). The composite endpoint (RRT or eGFR decrease ≥ 50 % from the time of biopsy) was used to evaluate the risk of IgAN progression and associated factors.RESULTS. The period-average incidence of IgAN cases was 20.5 % of all indication biopsies and 31.7 % of primary immune glomerulopathies (with gradual increase to 41,5 % in last 5 years). At the time of the kidney biopsy, the proteinuria was 2.20 (1.10; 4.40) g/24h, eGFR – 69 ± 32 ml / min / 1.73 m2. Proportions of cases with arterial hypertension and with eGFR <60 ml / min / 1.73 m2 were 75 % and 36 %, respectively. The prevalence of histological changes in accordance with the MEST-C classification was as follows: M1 – 40.5 %, E1 -22.9 %, S1-70.2 %, T1-22 %, T2 – 9 %, C1-16.7 %, C2 – 4.4 %. Combined deposits of IgA and IgM (71.1 % of cases) were more frequent compared to IgA and IgG (9,6 %). In the followup period (27 (11; 61) month), 6 deaths from all causes were registered (1.7 %). The 10-year cumulative renal survival was 75 % (by dialysis) and 55 % (by composite endpoint). PR registered in 26 % of cases, CR – 24 %. PR / CR was more frequent in patients who received immunosuppression compared with patients on renin-angiotensin system blockers only (60 % vs. 40 %, p = 0.001). In multivariable Cox regression the independent factors associated with the risk of IgAN progression were: male gender, a younger age, higher blood pressure and hematuria, lower eGFR, interstitial fibrosis/ tubular atrophy (≥50 %), peritubular capillaritis and the presence of any crescents. Compared to the cohorts of other ethnic or geographical affiliation, analyzed IgAN cases were found to have more severe clinical and morphological presentations and faster progression rate.CONCLUSION. While being the most common glomerulopathy, IgAN in the Russian population has more pronounced clinical and morphological presentations and an unfavorable prognosis.

Aim. То evaluate the effectiveness of a novel multi-targeted treatment approach including rituximab (RTX), cyclophosphamide (CPH) and steroids (S) to the induction of remission in patients with primary membranous nephropathy (PMN) compared to standard immunosuppression (IST). Materials and methods. An open-label prospective comparative study included 56 PMN patients (pts) with nephrotic syndrome (NS) and high serum level of antibodies to the phospholipase A2 receptor anti-PLA2R (mean age 5112 years, men 70%). We recorded demographic and clinical parameters at the time of kidney biopsy, data from light-optical and immunomorphological studies. All pts were on stable doses of the renin-angiotensin systems blockers. We compared the effectiveness of different treatments in the inductions of clinical and immunological remissions in pts who received experimental treatment with RTX, CPH and S (RTX+CPH+S group, n=14) and two control groups: high-dose RTX therapy (group RTX, n=12), cyclosporine and steroids (group CsA+S, n=30). Results. In the RTX+CPH+S group, remission was achieved in 100% of cases (of which complete remissions CR in 21.4%). The median time-to-remission (2.5 [1.0; 3.5] months) was significantly lower compared to both control groups: RTX (8.7 [6.6; 14.0] months, p=0.005) and CsA+S (12.4 [6.5; 19.9] months, p0.001). The cumulative incidence of clinical and immunological remissions was also significantly higher in the RTX+CPH+S group than in the control groups. These results were confirmed in comparative analyzes in the same treatment groups after propensity score matching. The cumulative incidence of clinical and immunological remissions in the RTX+CPH+S group was higher than in the combined group of patients who received other therapies (p0.001). The incidence of serious adverse events was low and did not differ between groups. Conclusion. The use of multi-targeted therapy with rituximab, cyclophosphamide, and steroids seems to be an effective approach for the rapid induction of PMN remission and prevention of NS complications.

Aim. An evaluation of the effectiveness of immunosuppressive therapy (IST) and tonsillectomy (TE) in patients with IgA nephropathy (IgAN). Materials and methods. A retrospective cohort of the study included cases with biopsy proven primary IgAN (n=367, age 3412 years, men 55%). We used demographic and clinical and morphological parameters at the time of biopsy. Median followup period was 26 (10; 61) months. Outcomes were remission (complete or partial) and the progression of IgAN (defined as the start of dialysis or a decrease in glomerular filtration rate 50% from baseline). All patients received treatment with renin angiotensin system blockers. Evaluation of the effectiveness of therapy was carried out using propensity score (PS) methods matching, conventional double robust regression models with PS as independent covariate, and inverse probability weighting. Following patient subgroups were used for comparative analyses: with IST (n=176) and without IST (n=191); with TE (n=63) and without TE (n=304); without IST and without TE (IST-TE-; n=162); with TE and without IST (IST-TE+; n=29); with IST and without TE (IST+TE-; n=142); with IST and with TE (IST+ TE+; n=34). Results. All PS methods used gave close estimates of the comparative effectiveness of treatment in different subgroups: 1) patients on monotherapy with corticosteroids (CS) and combination of CS with other immunosuppressants did not have significant differences in probabilities of IgAN progression (hazard ratio 0.919; 95% CI 0.3332.950) and remission (odds ratio 0.919; 95% CI 0.3792.344) and were further combined into a group of IST; 2) IST was significantly associated with the lower risk of disease progression and increased odds ratio for remission; 3) the positive effects of IST were limited to cases with proteinuria 2 g/24 h; 4) the likelihood of IgAN remission and progression did not differ significantly between TE+ and TE-, IST-TE+ and IST-TE- groups. There were no cases of disease progression in the IST+TE+ group. The cumulative renal survival was higher in the IST+TE+ group compared to IST+ TE- group (p=0.010), while the probability of remission did not differ. Conclusion. IST was associated with a lower risk of IgAN progression and increased probability of remission, while these effects of IST were limited to patients with proteinuria 2 g/24 h. TE in combination with IST is associated with an additional reduction in the risk of disease progression.

Primary membranous nephropathy (PMN) typical cause of nephrotic syndrome in adults. The key point in its pathogenesis is the production of IgG4 subclass autoantibodies (IgG4) against podocytic transmembrane phospholipase A2 M-type receptor (anti-PLA2R), followed by the deposition of subepithelial immune complexes (IC) in situ. We present a case of a 37-year-old young man with PMN associated with demyelinating polyneuropathy and idiopathic inflammatory lesions of skeletal muscles demonstrating a possible variant of extrarenal effects of IgG4-anti-PLA2R with an extended analysis of diagnostics and probable mechanisms of imbalance of secreted and intracellular phospholipases.