DANE PARTICLES AND ASSOCIATED DNA-POLYMERASE ACTIVITY IN SALIVA OF CHRONIC HEPATITIS-B CARRIERS

To investigate further the problem of salivary transmission of type B hepatitis, salivas free of blood contamination from three HBsAg‐positive carriers with chronic active hepatitis were examined by CsCl equilibrium density gradients and electron microscopy (EM). In the CsCl gradient HBsAg of whole salivas distributed in a band centered at 1.19 gm/cm3 with a clearly defined shoulder at 1.24 gm/cm3; the HBsAg was found mainly in the mucous component. On EM examination, fractions from the 1.19 gm/cm3 peak contained spherical HBsAg particles of 22+mn3 nm diameter, whereas in the 1.24 gm/cm3 shoulder Dane particles 43 nm in diameter with 28 nm cores were found. Specific hepatitis B virus associated DNA‐polymerase activity also was found in the 1.24 gm/cm3 shoulder where the Dane particles occurred and was absent from the saliva of healthy controls. When salivas were incubated for three hours at 37°C the total amount of HBsAg diminished and the 1.24 gm/cm3 shoulder disappeared, probably as a result of endogenous degradation of the Dane particles and the free HBsAg. These findings clearly indicate that the hepatitis B viral particle is present in the saliva of chronic HBsAg carriers with active disease and further confirm that saliva is an important vehicle of infection. Copyright © 1979 Wiley‐Liss, Inc., A Wiley Company