Hepatitis D General Clinical Tests


Test Name Method	Hepatitis Delta Antigen and Antibody (HDAg; anti-HD) Solid-phase EIA
Specimen Requirements	Serum. Stable for 7 d at RT and indefinately at 4°
Ref. Range Conventional International Recommended Units	Negative
Chemical Interfaces In Vivo Effects	None found
Diagnostic Information	Hepatitis Delta is a generate RNA virus or nirusoid that requires the surface coat of Hepatitis B (HBsAg) in order to become an infectious virus. After transcription of the RNA into mRNA, the virus produces a protein, HDAg, which might interfere with translation of other mRNA’s and produce cell damage. When Hepatitis D infection occurs simultaneously with Hepatitis B, the course of infections tends to be self-limited. However, in the case of acute Hepatitis D superinfection of an established Hepatitis B infection, there is much more Hepatitis D replication, and a more severe clinical hepatitis occurs. In this situation, the Hepatitis D infection usually becomes chronic. Anti-HD does not necessarily indicate active infection, but the ;presence of HDAg does.
Remarks	The role of testing for either HDAg or anti-HD is currently controversial. Genereally one tests for Hepatitis D only patients with markers for Hepatitis B. It has been suggested, for prognostic reasons, that all patients with chronic Hepatitis B be tested for anti-HD, especially if there is exacerbation of a stable hepatitis.

References:
Clinical Guide to Laboratory Tests, third edition.