The detection in urine specimens of IgG and IgM antibodies to hepatitis A and hepatitis B core antigens.

The use of urine as a noninvasive specimen for the diagnosis of hepatitis A (HAV) and hepatitis B (HBV) virus infections was investigated. Specimens of urine were collected at the same time as blood or saliva specimens, or singly in cases of previously serologically confirmed recent infection. The specimens were tested for IgG and IgM anti-HAV and anti-HBc by immunoglobulin class-specific capture radioimmunoassays (GACRIA and MACRIA). On the basis of assays on urine specimens it was possible to distinguish between individuals who were susceptible or immune to HAV or who had recently been infected with HAV. Using assays on 327 corresponding saliva specimens as reference tests, the observed sensitivity and specificity of tests on urine specimens by anti-HAV GACRIA were 98.9% and 99.1%, respectively, and by anti-HAV MACRIA were 95.8% and 99.6%, respectively. IgM and IgG anti-HBc were detected readily in the urine of 35 acute or recent cases of hepatitis B but were not found in the urine of seronegative individuals. Of the urine specimens from 52 individuals who were HBsAg carriers or who had had long past HBV infections, 49 contained detectable IgG anti-HBc. Of urine specimens from 42 HBsAg carriers, 11 contained raised IgM anti-HBc levels. Urine, which is a convenient specimen to collect, can be used to study outbreaks of hepatitis A, to ascertain the HAV immune status of individuals, to differentiate hepatitis A from hepatitis B, and to identify individuals who have been naturally exposed to HBV.