Immunohistologic pattern of the portal T-lymphocyte infiltration in hepatic allograft rejection

Monoclonal antibodies were used to identify helper T cells (TH) and suppressor/cytotoxic T cells (TS/C) in liver allograft biopsy specimens obtained 7,21,90,180, and 365 days postoperatively and then annually or during episodes of graft dysfunction and after treatment of rejection episodes. Biopsy specimens were obtained from 70 hepatic allografts from patients treated with cyclosporine and corticosteroids. Rejection was diagnosed by the presence of appropriate laboratory and light microscopic findings and at least 16 weeks of follow-up to exclude other causes of graft dysfunction. Three immunohistologic patterns were noted: no or only a trace of T lymphocytes, predominantly TH infiltrate with or without a small amount of TS/C cells (portal TH), and a mixture of TH with an equal or greater number of TS/C infiltrate (portal mix). Of 68 biopsy specimens obtained during quiescent periods, only 3 had a portal tract T-lymphocyte infiltrate. Of 30 protocol biopsy specimens, 24 contained such an infiltrate a mean of 12.4 days before biochemical and routine histologic indications of rejection in the allograft. At the time of the rejection episode, 33 biopsy specimens were immunohistologically labeled; portal tract T-lymphocyte infiltrate was predominantly TH in 8 and a mixture of TH and TS/C in 25. All rejection episodes with a predominantly TH pattern responded to methylprednisolone. Of the 25 rejection episodes with a portal mix pattern, only 3 responded to methylprednisolone. Eighty-seven biopsy specimens were obtained more than 10 days after treatment of rejection.(ABSTRACT TRUNCATED AT 250 WORDS)