Alloreactive Lymphoid Infiltrates in Human Heart Transplants Loss of Class H-Directed Cytotoxicity More Than 3 Months After Transplantation

ABSTRACT: From 535 endomyocardial biopsies (87 heart transplant recipients) 283 cell cultures could be generated. All cultures tested contained T lymphocyte, and it ~ most cases CD4 was the predominant phenotype at any time postrransplant. A significantly higher propor-tion of CD8-dominated cultures was found among cul-tureS from biopsies without myocytolysis. In the first 3 months post transplant 57 % of cultures showed cytotoxicity against both class I and class II mis-matched onor major histocorupatibility complex (MHC) antigens, changing to an incidence of 33 ~ at> 90 day:. This proved to be due to a significant decrease in the number of cultures with human leukocyte antigen class]]-directed cytotoxicity. This study shows that early after transplantation a heart ransplant is infiItrated with activated onor-specific cytotoxic T cells which recogr.ize a broad spectrum of mismatched donor MHL antigens, and that in time this spectrum becomes more restricted. Human lmmunolog~ 30.50-9 ¢79911 ABBREVIATIONS B-LCL B-lymphoblastoid cell line CML cell-mediated lFmpholysis CTL cytolytic T]ymphucytes t/MB endomyocardial biopsy EBV Epstein-Barr virus FACScan fluorescence-activated cell scan HLA human leukocym antigen IL-2 interleukin-2 MHC major histocompatibility complex NK natural killer PBMC peripheral blood mononuclear cells PHA phytohemaggtutinin TCR T-cell recepto