How can Hepatitis C (HCV) affect renal function, specifically causing Impaired renal function?

From the Guidelines

Hepatitis C can significantly impair renal function through direct infection of kidney cells, cryoglobulinemia, and chronic inflammation, leading to glomerular diseases, chronic kidney disease, and end-stage renal disease. The virus can cause glomerular diseases like membranoproliferative glomerulonephritis and membranous nephropathy, damaging the kidney's filtering units and leading to protein leakage in urine and reduced filtration capacity 1. Additionally, hepatitis C often triggers cryoglobulinemia, where abnormal proteins deposit in small blood vessels, including those in the kidneys, causing inflammation and damage. The chronic inflammation associated with hepatitis C infection can also lead to systemic effects that indirectly harm the kidneys, including increased insulin resistance and oxidative stress. Key points to consider in the management of hepatitis C-related renal impairment include:

• The use of direct-acting antivirals like glecaprevir/pibrentasvir, which has been shown to be effective in patients with stage 4 or 5 CKD, including those on haemodialysis, with an SVR12 rate of 98% 1.
• The safety of sofosbuvir-based regimens in patients with severe renal dysfunction, which has been questioned due to the renal elimination of sofosbuvir, but has been reported to be safe and effective in several studies 1.
• The importance of regular monitoring of renal function through blood tests for creatinine, estimated glomerular filtration rate (eGFR), and urine protein levels, particularly for patients with existing kidney issues 1.
• The consideration of the optimal timing of treatment for patients on dialysis, including pre- or post-renal transplantation, and the potential benefits and risks of antiviral therapy in this population 1.

From the Research

Hepatitis C and Renal Function

Hepatitis C virus (HCV) infection has been associated with various renal diseases, including:

• Membranoproliferative glomerulonephritis (MPGN) 2, 3, 4, 5
• Membranous glomerulonephritis 2, 5
• Cryoglobulinemic glomerulonephritis 2, 6, 4
• Focal segmental glomerulosclerosis 6
• IgA nephropathy 6
• Fibrillary and immunotactoid glomerulopathies 6
• Hepatorenal syndrome 6, 5

Pathogenesis of HCV-Related Renal Disease

The pathogenesis of HCV-related renal disease is thought to be related to the deposition of immune complexes in the glomeruli 2, 4. Toll-like receptor 3 may also play a pathogenic role in establishing a link between viral infection and glomerulonephritis 2.

Clinical Manifestations

Patients with HCV-related renal disease may present with:

• Proteinuria 2, 6, 4
• Hematuria 6, 4
• Nephrotic syndrome 2, 6, 4
• Impaired renal function 2, 6, 4
• Renal insufficiency 4
• End-stage renal disease 6, 4, 5

Treatment

Treatment of HCV-related renal disease may include:

• Angiotensin-converting enzyme inhibitors 2
• Angiotensin receptor blockers 2
• Anti-HCV therapy, such as combined antiviral therapy with standard or pegylated interferon-α and ribavirin 2
• Direct-acting antivirals (DAAs) 3, 5
• Immunosuppression, such as cyclophosphamide or rituximab with steroids 2, 3