[Hepatitis serology: use and interpretation]

Presently five viruses causing hepatitis are known, the hepatitis viruses A (HAV), B (HBV), C (HCV), D (HDV) and E (HEV). The genomic structure is known of most of all these viruses as well as some of their structural and regulatory gene products. Using radio- and enzyme immunoassays viral antigens can be detected for HBV and HDV as well as specific antibodies against all the five viruses. The results of these tests are the basis for the diagnosis and the follow-up of these infections but differ in their accuracy for each given virus. Concerning HIV one can differentiate between an ongoing or recently passed infection and immunity. Concerning HBV (and HDV), an ongoing infection at various stages can be distinguished from immunity. Such distinctions are not possible with respect to HCV except when also applying the expensive and cumbersome method of the polymerase chain reaction. In this paper the most important characteristics of the hepatitis viruses are given and the behaviour of the various viral markers during the infections and their consequences are described.