Renal disease in patients infected with hepatitis B virus

Infection with hepatitis B virus (HBV) can result in hepatic diseases which may include an asymptomatic non-replicative carrier state, immunotolerant phase characterized by high DNA levels without significant hepatic injury, immune-reactive phase characterized by occurrence of chronic hepatitis and fibrosis in the liver, or complications like cirrhosis or hepatocellular carcinoma. Extrahepatic manifestations may also accompany HBV infection. These may include serum sickness syndrome, polyarthralgia, polyarthritis, dermatologic manifestations like pitted keratolysis, urticaria, purpura, oral lichen planus or Gianotti-Crosti syndrome-a childhood papular eruption. Renal involvement may occur with HBV infection and usually involves glomerular or vascular injury. Various morphologic forms of renal injury have been reported with HBV infection, the commonest being membranous glomerulonephritis. The manifestations may include swelling over face and body, pedal edema, and urinary abnormalities. Evaluation may detect proteinuria, hematuria and reduction in estimated glomerular filtration rate (GFR). The management options include use of antiviral drugs targeting HBV infection with or without concomitant immunosuppressive medication. With availability of newer drugs like entecavir and tenofovir, these have become the first line agents as they have a high barrier to resistance. Sole use of immunosuppression is not recommended for lack of clear benefit and the possible risk of HBV reactivation or flare.