The aims of the study were to describe the clinical, pathological and biological features of membranous GN and to prospectively evaluate the relationships between individual negative prognostic factors--type of therapy and outcome. Between 1993-1998, 13/150 (8.7%) consecutive patients with renal biopsy had membranous GN (M = 62%, age = 42.5 +/- 14.5 years). Main (major) findings in these patients were: asymptomatic proteinuria--23.1%, heavy proteinuria (> 10 g/day)--33.3%, microscopic hematuria--53.8%, increased plasma creatinine levels--33.3%, hypertension--23.1% cases. 60% of the patients with nephrotic proteinuria had an underlying cause (infection, malignancy, immune-mediated systemic diseases). 40% of the patients with nephrotic proteinuria had 0 or less than 2 negative prognostic factors (without any of the recognized severe morphological changes). The following differentiated treatment protocols were applied: no treatment for asymptomatic proteinuria (group A), i.v. methyl-prednisolone boluses + prednisone 1 mg/kgc/day 3 months for those patients with few negative prognostic factors (group B), and steroids (as above) + cyclophosphamide (2 mg/kgc/day 3 months) or the Ponticelli regime in patients with important risk factors (group C). Outcome after a median follow-up period of 24 months was: complete remission in all cases from groups A + B (with only one exception were the underlying cause was breast malignancy); in group C in 75% of the subjects a complete or partial remission (proteinuria < 1 g/day) was obtained. Only one case progressed to chronic renal failure. There were no secondary effects from corticoids or immunosuppressive therapy.
Conclusions: In membranous GN treatment should be tailored to the presence and type of negative prognostic factors. Even in high-risk patients combined steroids and immunosuppressive therapy determines a favorable outcome in 75% of the cases, without severe adverse effects.