The clinical presentation of primary membranoproliferative glomerulonephritis (MPGN) has not been thoroughly investigated among patients of different ages. We therefore compared the features of primary MPGN and impact of blood pressure on decreased estimated glomerular filtration rates (eGFR) based on data from the Japan Renal Biopsy Registry (J-RBR).Design and Method:
This cross-sectional study analyzed data from patients who were registered in the J-RBR between 2007 and 2015. Clinical findings at diagnosis were compared among children (aged ≤ 20 years), adult (aged 20–64 years) and elderly (aged ≥ 65 years) patients with primary MPGN (type I and III, n = 332).Results:
Mean age was 51.6 ± 24.6 years, mean systolic blood pressure 137.9 ± 22.4 mmHg, mean proteinuria 3.8 ± 3.4 g/day, mean serum albumin 2.97 ± 0.80 g/dL and mean eGFR 49.9 ± 26.1 ml/min/1.73m2. The clinical features were significantly more severe in elderly patients, especially systolic blood pressure (children, 112.8 ± 15.8; adult, 136.0 ± 18.1; elderly patients, 148.2 ± 20.3 mmHg), proteinuria (children, 1.8 ± 2.2; adult, 4.0 ± 3.2; elderly patients, 4.2 ± 3.6 g/day), low albumin levels (children, 3.5 ± 0.9; adults, 3.0 ± 0.8 g/day; elderly patients, 2.8 ± 0.7 g/dL), and low eGFR (adults, 59.6 ± 28.7; elderly patients, 40.2 ± 18.6 ml/min/1.73m2). The rate of clinically classified nephrotic syndrome was higher in adults and elderly patients than children patients, whereas the rate of chronic glomerulonephritis was higher in children than adults and elderly patients. Multiple regression analysis revealed that high systolic blood pressure and high proteinuria were independent factors associated with decreased eGFR in adult and elderly patients with primary MPGN.Conclusions:
Systolic blood pressure was independent determinants of decreased eGFR, suggesting that the management of blood pressure is important for retarding the progression of renal function in patients with primary MPGN.