6 Interesting Facts of Viral hepatitis associated glomerulonephritis
1. The typical serum creatinine is usually 0.5 to 0.6 mg/dL in patients with cirrhosis, which is well below the normal expected maximum range for the general population: 1.2 mg/dL for women and 1.5 mg/dL for men. Patients with liver disease can have a significant loss of GFR with a serum creatinine level within “the normal range” for the general population.
2. The most common lesion seen worldwide with chronic HBV is MN. This lesion is a result of the formation of immune complexes in the sub-epithelial space of the basement membrane of the glomerulus forming “spikes” on electron microscopy like idiopathic MN, and demonstrates the classic “granular” immunofluorescence pattern with IgG and C3.
3. For those patients who are carriers of hepatitis B but are only HbsAg positive and negative for HbeAg, the kidney lesion is usually not MN but MPGN. This is because the HbsAg-antibody immune complex is too large to filter through the basement membrane, so it lodges in the inner surface of the capillary wall (sub-endothelial space).
4. The most common histologic change in the glomerulus of patients with chronic HCV infection is type I MPGN due to type II cryoglobulinemia. These patients may also develop MN, fibrillary glomerulonephritis, IgA nephropathy, and diabetic nephropathy.
5. Hepatitis C-induced MPGN should be primarily treated with anti-viral therapy. In some cases patients may need additional treatments targeted at reducing antibodies, such as rituximab and plasmapheresis.
6. Not all patients with viral hepatitis and new onset kidney disease have viral-induced glomerulonephritis. HRS is not uncommon in this population.
