Renal involvement in patients with chronic hepatitis C virus infection

There is an increasing recognition of the association between chronic hepatitis C virus (HCV) infection and glomerular diseases. Renal complications may be the presenting manifestation of HCV infection. Patients may present with systemic vasculitis secondary to cryoglobulinemia, or they may present with proteinuria, microscopic hematuria, acute renal failure, or nephrotic syndrome. The pathogenesis of HCV-associated renal disease remains incompletely understood; however, deposition of HCV-containing circulating immune complexes in the glomeruli (ie, subendothelial space and mesangium) seems to play an important role. The most common renal pathology associated with HCV infection is type I membranoproliferative glomerulonephritis with or without cryoglobulinemia. In patients who do not have significant renal impairment, combination therapy with interferon-á and ribavirin is the treatment of choice. The experience with this combination therapy is quite limited in patients with renal impairment. Prolonged courses of high-dose interferon-á therapy have been successfully used for these patients; however, relapse of HCV viremia and recurrence of renal disease is common after discontinuation of therapy.