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Membranoproliferative glomerulonephritis associated with HCV infection in native kidneys and renal allograft
H J Jeong1, K H Choi, C Y Chon
1Department of Pathology, Yonsei University College of Medicine, Seoul, Korea. jeong10@yumc.yonsei.ac.kr
Insights
Hepatitis C virus (HCV) can cause kidney disease, specifically membranoproliferative glomerulonephritis, even without cryoglobulinemia. Active HCV infection correlates with more severe kidney immune deposits.
Area of Science:
- Nephrology
- Virology
- Immunology
Background:
- Hepatitis C virus (HCV) infection is less common in Korea than Hepatitis B but has a higher progression rate to chronic hepatitis and cirrhosis.
- HCV infection is linked to kidney diseases like cryoglobulinemia and glomerulonephritis in both native and transplanted kidneys.
Observation:
- This study presents three cases of membranoproliferative glomerulonephritis type I in anti-HCV positive patients who were cryoglobulin-negative.
- Two cases involved native kidneys, and one involved a kidney allograft, all presenting with massive proteinuria.
- Two patients had positive HCV-RNA, two had cirrhosis, and two showed mildly elevated ALT levels. Two native kidneys also exhibited features overlapping with diabetic nephropathy.
Findings:
- Immunofluorescence revealed predominantly IgM and C3 deposits along peripheral capillary walls.
- Electron microscopy showed subendothelial electron-dense deposits in all cases, with additional subepithelial and intramembranous deposits in two.
- Active HCV infection (positive HCV-RNA) was linked to increased immune deposit quantity and the presence of subepithelial and intramembranous deposits.
Implications:
- Hepatitis C virus infection is a significant cause of glomerulonephritis, even in the absence of cryoglobulinemia.
- Active viral replication plays a role in the severity and type of immune deposits in the glomeruli.
- These findings highlight the importance of considering HCV in the differential diagnosis of glomerulonephritis, particularly in endemic areas.
Abstract:
Hepatitis C viral infection occurs relatively low in Korea compared to hepatitis B. However, it progresses into chronic hepatitis and cirrhosis more frequently than HBV. It may be associated with cryoglobulinemia and glomerulonephritis, both in native and transplanted kidneys. We report three cases of membrano-proliferative glomerulonephritis type I in anti-HCV positive, but cryoglobulin-negative patients, presenting massive proteinuria, two in native kidneys and one in an allograft. HCV-RNA was positive in sera of two patients. Two were cirrhotic and ALT was mildly elevated in two. In addition to the characteristic membranoproliferative feature, two native kidneys overlapped with features of diabetic nephropathy. Immunofluorescence demonstrated mainly IgM and C3 deposits along the peripheral capillary walls. Subendothelial electron dense deposits were present in the glomeruli of all three cases with subepithelial and intramembranous deposits in two. HCV-RNA was associated not only with a greater amount of immune deposits but also with subepithelial and intramembranous deposits, indicating the role of active infection.