Glomerular diseases in patients with hepatitis C virus infection after renal transplantation.

Currently, it is well known that hepatitis c virus (HCV) represents the major cause of chronic liver disease in renal transplant patients. On the other hand, HCV has been described in association with different types of glomerular diseases, usually type I membranoproliferative glomerulonephritis (MGPN) and less frequently membranous glomerulonephritis (MGN). After renal transplantation two glomerular entities have described in HCV positive patients: MPGN, associated or not with cryoglobulinemia, hypocomplememtemia and rheumatoid factor and another lesion was MGN. All patients had chronic HCV infection and with detectable HCV RNA in the serum, developed proteinuria, nephrotic syndrome and microhematuria. Characteristically MGN occurs without cryoglobulinemia, hypocomplememtemia and rheumatoid factor. The clinical pictures and outcomes of these pathological pictures seem to be similar to those of the novo MPGN or MGN in renal transplant patients. These entities seem to be more frequent in HCV-positive than in HCV-negative patients. Also, a possible relationship between HCV infection and transplant glomerulopathy has been described. Therefore, in renal transplant patients with proteinuria, serology for HCV infection, HCV RNA and immunological tests should be performed as part of the differential diagnosis.