Levels of TNF-alpha in culture supernatants.

<p>TNF-alpha was assayed by ELISA in supernatants of PBMC cultured for 48 h in the absence of any stimulus and in the presence of <i>T. cruzi</i> antigen, LPS and PHA. <b>A.</b> Subjects with positive serology and negative serology were grouped according to the presence or absence of the TNF-238A allele; *p = 0.045 (Mann-Whitney test). <b>B.</b> Only subjects with positive serology were grouped according to the presence or absence of the TNF-238A allele; * p = 0.04 compared to medium, p = 0.004 compared to <i>T. cruzi</i> antigen, and p = 0.007 compared to LPS (Mann-Whitney test). Results are expressed as pg/mL. The horizontal line indicates the median, bars the 25% and 75% percentiles, and vertical lines the 10% and 90% percentiles.