Clinical features of thin basement membrane disease and associated glomerulopathies

Background: Thin basement membrane disease (TBMD) occurs in 5-11% of renal biopsy series, and can be associated with other glomerulopathies (GNs). Data on the prevalence, clinical features, and prognosis of TBMD with other GNs are limited. Methods and Results: From June 1990 to May 2001, findings from 658 native kidney biopsies were retrospectively studied. The overall prevalence of TBMD was 7.9% (52 of 658). The mean glomerular basement membrane (GBM) thickness was 206 ± 30 nm. Clinicopathological features were compared for patients with TBMD only (n = 14) and in those with TBMD and GN (n = 38). Focal segmental glomerulosclerosis, mesangial proliferative GN, and minimal change disease were the most common GNs associated with TBMD. After a mean follow-up period of 44.9 ± 42.5 months, the group who only had TBMD revealed a relatively benign disease with microscopic haematuria and trivial proteinuria, a low prevalence of hypertension, and no renal progression. In the group who had both TBMD and GN, heavy proteinuria (6.1 ± 5.2 g/day), hypoalbuminaemia (26 ± 12 g/L) and renal insufficiency (76 ± 25 mL/min) might develop. Conclusion: We suggested that the TBMD is a developmental abnormality of little or no significance and that it is the underlying associated GN rather than TBMD, which has the relevance to the outcome of renal disease.