title: Elevation of cytotoxic lymphocyte gene expression is predictive of islet allograft rejection in nonhuman primates.
abstract: Hyperglycemia and increased insulin requirements are indicators of ongoing islet allograft rejection, but there are no methods to predict or confirm rejection. Elevation of cytotoxic lymphocyte (CL) gene expression in peripheral blood (PB) has been correlated with renal allograft rejection in humans, but no published study has assessed the utility of monitoring these markers as predictors of rejection before the onset of clinical symptoms. We have established quantitative real-time PCR methods to determine the levels of mRNA transcripts for the CL genes granzyme B (GB), perforin, and fas ligand in blood samples from rhesus and cynomolgus monkeys. Four rhesus monkeys with long-term islet allograft function were studied. Antirejection (anti-CD154) therapy was discontinued, and weekly PB samples were obtained to determine whether the levels of mRNA transcripts for CL genes correlated with and/or were predictive of islet allograft rejection, defined as a loss of C-peptide production. For all monkeys, elevation of CL gene expression preceded rejection by 83--197 days, with GB as the best predictor. Elevated mRNA levels were sustained for 2--2.5 months in three of four animals and 1 month in the other, thus suggesting that the testing of these parameters may have practical applications in clinical islet cell transplantation.
authors.affiliation: Diabetes Research Institute, University of Miami School of Medicine, Miami, Florida 33136, USA. dhan@med.miami.edu
authors.forename: Dongmei
authors.initials: D
authors.lastname: Han
authors.forename: Xiumin
authors.initials: X
authors.lastname: Xu
authors.forename: Ricardo L
authors.initials: RL
authors.lastname: Pastori
authors.forename: Camillo
authors.initials: C
authors.lastname: Ricordi
authors.forename: Norma S
authors.initials: NS
authors.lastname: Kenyon
mesh_terms: D000818:Animals; D000911:Antibodies, Monoclonal / Q000627:therapeutic use; D023201:CD40 Ligand / Q000276:immunology; D053222:Fas Ligand Protein; D015870:Gene Expression; D006084:Graft Rejection / Q000276:immunology* / Q000517:prevention & control; D053804:Granzymes; D016381:Islets of Langerhans Transplantation; D008253:Macaca mulatta; D008562:Membrane Glycoproteins / Q000235:genetics; D054353:Perforin; D016133:Polymerase Chain Reaction / Q000379:methods; D052899:Pore Forming Cytotoxic Proteins; D012333:RNA, Messenger / Q000032:analysis; D012697:Serine Endopeptidases / Q000235:genetics; D013602:T-Lymphocytes, Cytotoxic / Q000378:metabolism*; D013997:Time Factors
chemical_list: D000911:Antibodies, Monoclonal; D053222:Fas Ligand Protein; D008562:Membrane Glycoproteins; D052899:Pore Forming Cytotoxic Proteins; D012333:RNA, Messenger; D054353:Perforin; D023201:CD40 Ligand; D053804:Granzymes; D012697:Serine Endopeptidases