[Effects of lead exposure on thymic output naive T cells function].

ABSTRACT

OBJECTIVE: To investigate the levels of T cell receptor rearrangement excision DNA circles (TRECs) within peripheral blood from workers exposed to lead, and thereby to evaluate the number of naive T cells and recent thymic output function. METHODS: Quantitative detection of TRECs in peripheral blood mononuclear cells (PBMNC) from 10 cases of workers exposed to lead was performed by real time PCR analysis. 11 workers without exposure to lead served as unexposed controls. In addition, the relationship between TRECs, age, length of service, blood lead, urea lead, blood ZPP and urea delta-ALA was investigated. RESULTS: The mean value of TRECs in workers exposed to lead was (2.44 +/- 1.87)/1000 PBMC, significantly under (5.60 +/- 3.96)/1000 PBMC in unexposed controls. A significant negative correlation was found between the TRECs and urea-ALA. But there was no significant correlation between them after controlling for blood lead, urea lead. CONCLUSION: Lead exposure may damage thymic output naive T cells function. Furthermore, low-level exposure to lead may damage immune system and earlier than expected.