regulatory t cell subtypes and tgf-β1 gene expression in chronic allograft dysfunction

background: regulatory t cells have been suggested to have a protective role against acute rejection in allograft recipients. however, there is little information available about their contribution to chronic rejection process. the role of transforming growth factor-beta 1 (tgf- β1) as a profibrogenic and/or immunoregulatory cytokine in renal allografts is also controversial. objectives: to evaluate the frequency of cd4+cd25+cd127- and cd3+cd8+cd28- regulatory t cells in chronic allograft dysfunction (cad) and to investigate the expression of tgf- β1 in renal allografts. methods: thirty biopsy-proven cad patients were pair-matched with 30 stable graft function patients and a third group of healthy volunteers. flowcytometry was performed on pbmcs to determine the frequency of cd3+cd8+cd28- and cd4+cd25+cd127- regulatory t cells in lymphocyt population. tgf- β1 gene expression was assessed by real time pcr. results: the percentage of cd3+cd8+cd28- tregs among renal allograft recipients was higher than healthy controls (p