Abstract:

ABSTRACT Objective: To explore the clinical and pathological features of proliferative glomerulonephritis with monoclonal IgG deposits （PGNMID） from Chinese patients. Methodology: From Jun 2010 to Aug 2011, nine patients were diagnosed as PGNMID. Their clinical and pathological features were retrospectively analyzed. The diagnosed criteria of PGNMID was proliferative or membranoproliferative glomerulonephritis on LM, monoclonal IgG and staining for a single light-chain isotype on IF, and glomerular electron-dense deposits on EM. Results: Patients were 5 males and 4 females with an average age of 49.8±10.9 years old (ranged from 31～69). The duration of renal disease was 15.9±13.1 months（1～36 months）. All of them had proteinuria with an average 5.60?2.80 g/24h of urine protein excretion (ranged from 2.56~10.1), 7 had microscopic hematuria and 8 had hypoalbuminia with an average serum albumin of 29.0?5.5g/L (23.7~40). The level of urine NAG was 72.3?38.6 U/g.cr (from 16~126.7) (normal?16.5U/g.cr), and RBP was 11.3? 17.1 mg/L (from 0.57~50.4) (normal ?0.5mg/L). 7 patients had elevated serum creatine, 8 hypertension, and 8 had anemia (from 76~102g/L) who had no myeloma by bone marrow biopsy. Serum protein electrophoresis (SPEP) showed that only one patient had monoclonal (M) spikes (IgG?) in serum from 7 patients. 5 patients had decreased serum complement C3, while C4 normal. In histological examinations, alll patients showed proliferative glomerulonephritis, 3 of them had nodular lesions and one presented cellular and fibro-cellular crescents (33.3%). On EM, the granular dense deposits were identified predominately in subendothelial, mesangial and occasional in subepithelial region. 2 had massive crystal lattice in subendothelial, mesangial and ocasional subepithelia regions. By IF, all patients had IgG and C3 glomerular diposits, and 5 had C1q deposits. Subtype IgG and light chain staining showed IgG3? in 3, IgG3? in 3, IgG1? in 2, and IgG1? in one. Conclusion: The clinical features of patients with PGNMID were massive proteinuria, heamaturia, renal dysfunction as well as anemia. There was predominance of IgG3-kappa glomerular deposits associated with granular dense and occasional crystal lattice deposits.

Key words: proliferative glomerulonephritis,  , monoclonal IgG,  , renal pathology