[Thin membrane nephropathy: 27 cases]

To disclose the prevalence of thin membrane nephropathy (TMN) in China and its clinical and pathological features, we prospectively studied TMN cases including 722 cases of renal biopsies in 2 years. 27 cases (male 7 cases, female 20) were diagnosed as primary glomerulonephritis. The GBM thicknesses of TMN group (n = 27) and control group (n = 32) was 207 +/- 36 nm and 382 +/- 34 nm (P < 0.01) respectively. IF of TMN was negative or trace, near normal morphology or mild mesangial proliferative glomerulo nephritis was observed by LM. A few of them had global glomerular sclerosis or single crescent formation. All TMN patients had microscopic hematuria. About one third (9/27 cases) patients with TMN presented isolated persistent microscopic hemataria, 44.4% (12/27 cases) and 22.2% (6/27 cases) patients with TMN were accompanied with mildmoderate proteinuria and heavy proteinuria (> or = 3.5 g/24 h) or nephrotic syndrome. The patients with heavy proteinuria or nephrotic syndrome had good response to corticosteroid therapy. All patients with TMN had normal renal function, only a few of them had transient hypertension. The results showed that the prognosis of TMN would be regarded as good. The familial history of 15 patients with TMN was investigated, and 47% (7/15 cases) of them had > or = two members with microscopic hematuria in their families. TMN was found in 3.7% (27/722 cases) in total renal biopsies and 11.5% (9/78 cases) in the patients with isolated microscopic hematuria. It suggests that TMN isn't a rare kidney disease in China. Careful EM is a critical method for the correct diagnosis of TMN.