Determination of total antibodies to HBcAg of hepatitis B virus in blood serum by ELISA method (anti-HBcAg total)
An indicator of the presence of protective immunity against the hepatitis B virus. Anti-HBs antibodies appear in the recovery phase after acute hepatitis B, usually 3 to 4 months after HBsAg elimination (the so-called "window" phase). The duration of the window phase can vary from 1 month to 1 year, depending on the state of the patient's immune system. During this window period, it is important to examine the patient for anti-HBcIgM.
Anti-HBs antibodies are especially important in providing immune protection against this virus, so the quantification of anti-HBs antibodies is usually used to monitor the effectiveness of immunity in hepatitis B vaccination. Over time, the antibody titer decreases to the point of being undetectable. Sometimes lifelong circulation of anti-HBs antibodies is possible.
The appearance of anti-HBs against the background of clinical improvement in hepatitis B patient and the disappearance of HBsAg is a good prognostic sign and indicator of recovery. In the chronic course of hepatitis B, parallel determination of surface antigen and antibodies to it is possible. Detection of anti-HBs in the acute phase of hepatitis B in parallel with HBsAg indicates an unfavorable prognosis.
The surface (HBsAg) and core (HBcAg) proteins of the virus are antigens, driving the production of anti-HBs and anti-HBc, respectively. The core antigen, entering the blood, splits into more stable components, one of which HBe-Ag also carries antigenic properties. Anti-HBe antibodies are produced on it.
The genetic variability of HBV contributes to the "escape" of the virus from the immune response. This is associated with difficulties in laboratory diagnosis (seronegative hepatitis B), as well as the chronization of the disease. The appearance of atypical DNA regions in the virus genome leads to the fulminant course of hepatitis B.