Immunohistologic labeling as an indicator of liver allograft rejection.

Monoclonal antibodies were used to identify T-helper cells (TH) and T-suppressor/cytotoxic cells (TS/C) in biopsy specimens obtained 7, 21, 90, 180, and 365 days postoperatively, and during episodes of graft dysfunction, from 34 consecutive liver transplant patients treated with cyclosporine and steroids. Rejection was diagnosed by the presence of appropriate laboratory and light microscopic findings and at least 8 weeks of follow-up to exclude other causes of graft dysfunction. Four immunohistologic patterns were seen--no labeled cells (No), only lobular TS/C, only portal TH, and a portal mixture of TH and TS/C (mix). Of 36 specimens with the No or only lobular TS/C pattern, 29 were not associated with rejection. Of the 39 specimens with the portal TH or portal Mix pattern, 33 were associated with a rejection episode. In addition, in nine specimens from patients with no biochemical or routine histologic evidence of rejection, the presence of portal TH or a portal mix indicated immunologic rejection 5 days to 5 weeks before biochemical and routine histologic evidence of it was manifested. Immunohistologic labeling appears to be an early indicator of liver allograft rejection.