Needle biopsy specimens of the liver, obtained from 30 persons with circulating hepatitis B antigen and from 25 seronegative persons, were examined by the indirect immunofluorescent antibody technique for the antigen. Paraffin sections were prepared from the same cryostat block and examined histologically under code.

Hepatitis B antigen was demonstrated by immunofluorescence in all 30 liver specimens obtained from seropositive individuals. No fluorescence was seen in the group of seronegative young men with essentially normal livers but who had a history of acute hepatitis 6 or more months before biopsy. Two patterns of fluorescent staining were seen: many hepatocytes with bright cytoplasmic fluorescence, often arranged in clusters, were found in 19 out of 21 antigen carriers with an essentially normal liver. The second type of pattern consisted of a few scattered hepatocytes containing antigen in their cytoplasm, usually associated with antigen in Kupffer cells. This pattern was observed in 9 biopsy specimens showing acute or chronic hepatitis and in 2 without evidence of liver cell injury. Weak nuclear fluorescence was seen in addition in 2 patients with chronic hepatitis.