Characterization, quantification, and localization of passenger T lymphocytes and NK cells in human liver before transplantation.

Quantification and localization of the main lymphocyte populations were studied in the livers of normal (n = 8) and brain dead (n = 8) subjects. Cytometric analysis performed on mononuclear cell suspensions obtained from liver biopsies was compared to an automatic image analysis of immunostained sections. The overall number of liver associated lymphocytes was in the usual range of peripheral blood content (2 to 9x10(9) cells). Phenotypic analysis showed predominant NK and CD8+ cells that highly expressed class II antigen and CD25 and CD69 activation markers. Quantitative mapping of these activated lymphocytes revealed their preferential localization in the portal tract and the perisinusoidal area as compared to the pericentrolobular zone, especially in donor livers. This strategic localization could suggest a possible early cooperation between donor lymphocytes and initial infiltrating cells from the recipient and could explain the special immunological status of allografted livers.