RESUMO
PURPOSE: Toll-like receptor 2 (TLR2) is critical in the immune response to mycobacterial infections. The purpose of this study was to analyze TLR2 surface expressions and TLR2-mediated tumor necrosis factor-alpha (TNF-alpha) and interleukin-6 (IL-6) production in patients with BCG vaccine-associated suppurative lymphadenitis. METHODS: Peripheral monocytes were separated from 16 patients with BCG vaccine-associated suppurative lymphadenitis and 10 healthy controls using a magnet cell isolation kit. Monocytes (1x10(6) cells/well) were incubated with a constant amount of Pam(3)CSK(4) (100 microgram/mL) for 24 hours. TLR2 surface expression on monocytes was analyzed by FACS analysis and TLR-2 mRNA expression was determined by RT-PCR. TLR2-mediated TNF-alpha and IL-6 production were measured by ELISA. RESULTS: In patients with BCG vaccine-associated suppurative lymphadenitis, low TLR2 expression on monocytes (3.39+/-1.2% versus 4.64+/-2.6%) together with significantly lower TLR2 mRNA expression than in the healthy controls was seen after Pam(3)CSK(4) stimulation. TLR2-mediated TNF-alpha and IL-6 production in patients with BCG vaccine-associated suppurative lymphadenitis (TNF-alpha, 775.5+/-60.8 pg/mL; IL-6, 4,645.8+/-583.9 pg/mL) were also lesser than that in healthy controls (TNF-alpha, 1,098.5+/-94.3 pg/mL; IL-6, 6,696.3+/-544.3 pg/mL). CONCLUSION: These findings suggest that low TLR2 expression on monocytes might be associated with increased susceptibility to BCG vaccine-associated suppurative lymphadenitis.