Specific laboratory diagnosis of viral hepatitis

Abstract

During the last years, the incidence of chronic forms of viral hepatitis has increased. This necessitates the need for a reliable and timely means of diagnosis, which have been improved progressively. The list of markers of infection has been expanding, and the appropriate interpretation of this data would allow doctors to make the choice of treatment required for each particular case. The following methods are used for diagnosis of viral hepatitis: immunno-electron microscopy (IEM), enzyme-linked immunosorbent assay (ELISA), polymerase chain reaction (PCR). The markers of acute hepatitis A are: anti-HAV Ig M and the viral RNA. The presence of anti-HAV Ig G is indicative of a past history of disease. Diagnosis of viral hepatitis B is based on detection of virus antigens - HBsAg, HBeAg and antibodies (Ig M and G to the НВсAg, Ig G to the HВeAg and Ig G to the HBsAg). In addition, viral DNA detected by PCR is indicative for viral presence. Serological blood testing for markers of hepatitis D is informative only in patients with the presence of HBsAg in the blood. Important are the hepatitis D viral RNA and Ig M/G to the virus. Specific laboratory diagnosis of hepatitis C is based on the detection of antibodies to viral proteins, although detection of viral RNA is considered the «golden standard» in diagnosing of this disease. Laboratory diagnosis of hepatitis E is based on exclusion of specific markers of acute hepatitis A, B, C, as well as by the method of IEM, which relies on the detection of the virus in the feces.