Defective interferon-gamma production by T-lymphocytes from patients with acute brucellosis.

The authors investigated the production of interleukin-2 (IL-2) and interferon-gamma (IFN-gamma) by phytohaemagglutinin (PHA)-stimulated T-lymphocytes from 21 untreated patients with acute brucellosis. PHA-stimulated T-lymphocytes from acute brucellosis patients showed normal IL-2 production but defective IFN-gamma production (brucellosis patients 531 +/- 103 pg mL-1 vs. healthy controls 1024 +/- 212 pg mL-1) after 72 h of culture. This altered pattern of IL-2 and IFN-gamma production by T-lymphocytes was observed in seven brucellosis patients whose T-lymphocytes exhibited a normal proliferative response to PHA (61 612 +/- 18 422 cpm) as well as in the 14 patients with a defective T-lymphocyte proliferative response to the PHA after 5 days of culture (19 479 +/- 4409 cpm). After antibiotic therapy, production of the two lymphokines by the PHA-stimulated T-lymphocytes from acute brucellosis patients was similar to that of T-lymphocytes from healthy control subjects. The authors conclude that PHA-stimulated T-lymphocytes from untreated patients with acute brucellosis have defective INF-gamma production but normal IL-2 production.