Diagnostic significance of anti-HBcIgM prevalence related to symptoms in Canadian patients acutely or chronically infected with hepatitis B virus.

A total of 362 sera from 295 Canadian patients were examined for HBsAg, anti-HBs, anti-HBc, anti-HBcIgM, HBeAg, and anti-HBe using commercial immunoassays. Serial samples from 70 acutely infected patients demonstrated that anti-HBcIgM may detect 10% more positives than HBsAg within 4 months after the onset of clinical symptoms, and all except two were negative for anti-HBcIgM after the fourth month. None of 66 asymptomatic (HBeAg rate 18.2%) and two of 14 (14.3%) symptomatic (HBeAg rate 64.3%) carriers of HBsAg were positive for anti-HBcIgM (P = 0.029). Elevated marker responses were measured in two symptomatic carriers for a 20-month period. Anti-HBcIgM was not detected in either 100 asymptomatic patients positive for total anti-HBc, negative for HBsAg and negative for or possessing low levels of anti-HBs, 25 patients with liver disorders not caused by HBV, or 20 healthy milk donors. In diagnostic laboratory practice this anti-HBcIgM test may be useful in the following situations: to supplement HBsAg testing, providing a theoretical 10% increase in positives within 4 months following onset of acute viral hepatitis; to replace testing for anti-HBc and anti-HBs in symptomatic HBsAg-negative patients; to confirm whether a patient is experiencing acute or chronic HBV infection or symptoms superimposed upon asymptomatic HBsAg carriage by another cause, such as nonA-nonB viral hepatitis.