A comparison of the clinical and laboratory features of thin basement membrane disease (TBMD) and IgA glomerulonephritis (IgA GN)

Abstract

Aim: The aim of this study was to determine the clinical and laboratory characteristics that distinguished thin basement membrane disease (TBMD) from IgA glomerulonephritis (IgA GN) at presentation and at follow-up.

Patients and methods: Seventy-one patients with TBMD and 31 with IgA GN were studied. Males accounted for 11/71 (15%) patients with TBMD, and 20/31 (65%) of those with IgA GN (p < 0.001).

Results: At presentation, patients with TBMD had hematuria (42%) or proteinuria (42%), and sometimes both (24%), while those with IgA GN usually had both hematuria and proteinuria (71%, p < 0.0001). Furthermore, patients with IgA GN were more likely to have higher urinary RBC counts (p < 0.001), and more proteinuria (p < 0.001) than those with TBMD. An elevated serum creatinine or blood pressure did not distinguish between TBMD and IgA GN at presentation. At review, fewer individuals with IgA GN had elevated levels of urinary RBC and protein, and the proportions were not different from those in patients with TBMD. This was presumably because the acute episode had resolved.

Conclusion: The outcome was worse in patients with IgA GN, with 8/31 (26%) having an elevated serum creatinine and 3/31 (10%) with end-stage renal failure, compared with an elevated serum creatinine in 3/61 (5%) patients with TBMD (p < 0.02) and no patients with renal failure (p < 0.05).