Allergic hepatitis in guinea pigs induced by 2,4,6-trinitrophenyl liver protein conjugate

Experimental drug-induced allergic hepatitis was induced in guinea pigs which had been immunized to the 2,4,6-trinitrophenyl (TNP)-conjugated liver protein first peak (TNP-LP1) emulsified in complete Freund's adjuvant (CFA). Delayed-type hypersensitivity (DTH) was elicited in the immunized animals by intradermal challenge with TNP-LP1. When TNP-LP1 was introduced into the liver via the mesenteric vein, allergic hepatitis was provoked. Histological examination of the liver revealed massive monocytic infiltration and focal hepatic necrosis in the periportal areas. Blood biochemical analysis showed increased levels of glutamate oxalacetate transaminase (GOT) and total bilirubin. TNP-modified hepatocytes were found to be effective as a challenge elicitor to the immunized animals to induce both DTH skin reaction and allergic hepatitis. In the latter case, the severity of the lesion was stronger than that observed by the challenge with TNP-LP1.