The overall incidence of IgA nephropathy is estimated at 3.2 cases per 100 000 population per year, with a higher rate among Caucasians than African Americans. Data from a recent study may be helpful in predicting the risk for IgA nephropathy in a specific patient group.
IgA nephropathy is characterized by glomerulopathy, but also considerable tubulointerstitial damage; the incidence of renal failure is relatively low. However, many patients develop chronic kidney disease, which may lead to end-stage renal failure or even death.
In the last few years, the number of prospective controlled studies on IgAN has increased, as well as the number of randomized controlled trials. It seems that further research is needed to explore the potential role of IgAN in influencing the course of the disease. However, it seems that despite some promising results, our knowledge about the pathogenesis of IgAN remains severely limited. The lack of a single and accurate diagnostic test raises questions regarding the usefulness of renal biopsy in the diagnosis of IgAN. To date, only a handful of strategies have demonstrated efficacy in treatment of IgAN. The use of rituximab and other immunosuppressive drugs remain the mainstay of therapy for IgAN.
This article describes recent advances in the treatment of IgAN. Although clinical trials provide important information, they can not be considered sufficient evidence to support or reject the efficiency of certain treatments. Potential bias can produce misleading results when these trials are analysed. Thus, additional large cohort studies are required to investigate the true efficacy of various therapies for IgAN.
The two major causes of IgA nephropathy are an underlying systemic autoimmune disorder (usually vasculitis or granulomatosis with polyangiitis), and infection with human herpesvirus 8. It is important to remember that the urinary sediment found in patients with IgA nephropathy does not necessarily indicate active inflammation. Also, the presence of hepatitis B surface antigen has been shown to correlate well with IgA nephropathy. When patients present with renal failure, the cause must be looked for.
A cure has not been found in this study; however, at least 50% of patients had a spontaneous remission. Therefore, our findings suggest that some patients with IgAN have a more favorable outcome than previously suspected and may be managed successfully without costly immunosuppression.
Patients with a family history of IgA nephropathy are at higher risk for further development of disease than patients without a family history of IgA nephropathy. Therefore, early recognition and treatment of IgA nephropathy in patients with a positive family history may prevent progression from minimal change disease to end stage renal failure.
The presence of IgAN is associated with severe renal disease and mortality. Currently there is no evidence that IgAN is reversible. Results from a recent paper have important implications for patients as well as clinicians who are working in the rheumatology clinic.
IFNalpha induces the production of IgG1 autoantibodies against GBM in patients with primary renal disease possibly through the activation of B cells, and such antibodies are associated with the development of renal lesions.
In SLE patients, the presence of anti-dsDNA was significantly associated with the development of NGA. Findings from a recent study suggest that anti-dsDNA may play an important role in the development of NGA in SLE patients.
Immunosuppression was associated with rapid deterioration of renal function in patients with IgAN. The biochemical markers of glomerular injury were closely related to the level of immunosuppression.
IgAN is a chronic glomerulonephritis (or 'progressive' GN) characterized by deposits of IgA in the mesangium, capillaries, and tubules. The prognosis of IgAN is poor with progression in approximately 50% of patients after two years and long-term renal survival is rare.