Delayed-type hypersensitivity skin reaction to HBsAg and immunohistopathologic study of liver in patients with acute type B viral hepatitis.

In an attempt to clarify the role of cellular immunity in the pathogenesis of acute type B viral hepatitis (AHB, we studied delayed-type hypersensitivity (DTH) skin reaction to hepatitis B surface antigen (HBsAg) and immunohistopathology of livers in patients with AHB. DTH skin reaction to HBsAg developed early in the convalescent phase in all 14 patients with AHB. In contrast, the production of anti-HBs was significantly delayed in these patients, compared with healthy controls immunized with HB vaccine intradermally (P less than 0.001). These observations suggest that DTH to HBsAg but not anti-HBs may be associated with recovery from AHB. In the biopsied livers obtained from patients with AHB, the proliferation of Kupffer cells was extensive and immunohistopathologic studies revealed an accumulation of CD-4 positive lymphocytes in the portal area, a finding which suggested a DTH reaction in the liver with AHB. CD-8 positive cells had infiltrated the lobule and made contact with affected hepatocytes, thereby indicating that a cytotoxic T cell response is involved in damaging of the infected cells. All these observations taken together, we propose that not only a cytotoxic T cell response but also a DTH reaction may be involved in the pathogenesis of AHB.