Background: The current 3rd edition of the Italian Society of Nephrology guidelines has been drawn up to summarize evidence of key intervention issues on the basis of systematic reviews (SR) of randomized trials (RCT) or RCT data only. In the present guideline, evidence of the use of immunosuppressive and non-immunosuppressive treatments in IgA nephropathy (IgAN) is presented.
Methods: SR of RCT and RCT on treatment in patients with IgAN were identified referring to a Cochrane Library and Renal Health Library search (2005 update). Quality of SR and RCT was assessed according to current methodological standards.
Results: Two SR of RCT (13 and 3 RCT, respectively), and 18 further RCT were available to address this issue. Methodological quality of available trials was suboptimal. In patients with IgAN and normal or mildly impaired renal function, steroids significantly delay the progression to end stage kidney disease (evidence from SR) and improve proteinuria. Associating steroids and cytotoxic agents (cyclophosphamide followed by oral azathioprine) proves effective in patients with rapidly progressive renal disease (evidence from RCT). Angiotensin converting enzyme inhibitors and angiotensin II receptor blockers significantly improve proteinuria (evidence from RCT), but there are no conclusive data on efficacy on hard patient level endpoints. There are no conclusive data available on the use of a therapy combining these agents.
Conclusion: In IgAN patients current evidence supports the hypothesis that immunosuppressive agents delay the progression to end stage renal disease. Further studies are necessary to test this hypothesis in selected patient populations.