Membranoproliferative glomerulonephritis in Russian population

Abstract

Aim: Analysis of etiology, clinical and morphological manifestations, approaches to therapy and prognosis of membranoproliferative glomerulonephritis (MPGN).

Materials and methods: Cases of MPGN were retrospectively identified in the period 2000-2017 with subsequent analysis of etiology, clinical data and morphology (including deposits of immunoglobulins (Ig) and C3 complement fractions). The achievement of complete and partial remissions (PR, CR), overall survival, progression (by composite endpoint: decrease in the estimated GFR (eGFR) ≥50% from the baseline or eGFR <15 ml/min/1.73 m2 or the onset of dialysis).

Results: 214 cases of MPGN entered the study with the average age of 44±16 years. Most patients had nephrotic syndrome and significant hematuria. In 58.4% of cases, eGFR was <60 mL/min/1.73 m2, and every fifth patient had CKD 4 or 5 stages. The prevalence of MPGN among all biopsy-confirmed glomerulopathies was 9.3%. Idiopathic MPGN (iMPGN) was detected in 30.4% of cases, secondary MSGN (sMPGN) - in 69.6% (autoimmune diseases - 34.1%, infectious diseases - 16.4%, monoclonal gammopathies - 9.3%, complement-mediated damage - 9.8%). Ig+C3+MPGN was mainly associated with autoimmune diseases and infections; C3-glomerulopathy or thrombotic microangiopathy were most often causes of Ig-C3+MPGN; Ig-C3-/Ig+C3-MPGN had heterogeneous etiology. The median follow-up period was 28 [7; 37] months. The 10-year total cumulative patient and renal survival rates were 71 and 50%, respectively (without differences between sMPGN and iMPGN). The frequency of the PR/CR was 50% (iMPGN - 46.2%, sMPGN - 51.3%) depending on the etiology of the MPGN (p=0.049). The cumulative 10-year progression-free renal survival was nearly 100% in cases with PR/CR and 0% in non-responders.

Conclusion: MPGN is a severe variant of glomerular damage with a heterogeneous etiological structure and an unfavorable prognosis. Targeted clinical and morphological diagnostics of MPGN allows to identify the cause of the disease in most cases. This approach is reliable for the adequate treatment choice and improvement of outcomes in MPGN.

Keywords: clinical manifestations; complete ­remissions; etiology; immunomorphology; membranoproliferative glomerulonephritis; morphology; partial remissions; prognosis; survival; therapy.