Aetiology of membranous glomerulonephritis: a prospective study of 82 adult patients.

Eighty-two consecutive Caucasian adults (52 males, 30 females, aged 17-86 years) with membranous glomerulonephritis were prospectively evaluated for possible aetiological factors 1-4 weeks after renal biopsy. Presumed causes were identified in 17 patients (21%) as follows: drugs in five (D-penicillamine 3, captopril 1, fenoprofen 1); malignancy in four; chronic thyroiditis in three; systemic lupus erythematosus (SLE) in two; secondary syphilis in one; hepatitis B virus (HBV) infection in one and non-insulin-dependent diabetes mellitus in one patient. Except for age (patients with secondary membranous glomerulonephritis were older), clinical presentation and histological stage distribution did not differ between the secondary and the primary groups. Ten out of the 17 patients with secondary membranous glomerulonephritis (59%) achieved complete clinical remission within 12 months. The incidence of associated conditions in adults with membranous glomerulonephritis in this study corresponds with that reported in the few previous series. Although membranous glomerulonephritis is deemed to be idiopathic in most cases, it seems warranted to search for medication, malignancy, SLE, HBV infection, syphilis and thyroiditis as possible aetiological factors. Further evaluation should be orientated by the clinical context. An improved outcome of membranous glomerulonephritis may be expected insofar as the underlying condition is controlled.