Circulating profile of Th1 and Th2 cytokines in tuberculosis patients with different degrees of pulmonary involvement.

To investigate whether differences in the degree of pulmonary tuberculosis lesions could be accompanied by changes in the pattern of circulating cytokines, 29 untreated tuberculosis patients showing mild (n = 10), moderate (n = 5) or advanced (n = 14) pulmonary disease, and 12 age-matched healthy controls (mean +/- S.D., 36 +/- 15 years) were studied. ELISA methods for the evaluation of interferon-gamma, interleukin-2, interleukin-4, and interleukin-10 indicated that all patients had increased serum levels of the four cytokines in relation to controls. Mean titers of interferon-gamma and interleukin-2 in mild and moderate patients appeared higher than in those with advanced disease, whereas moderate and advanced patients showed the higher levels of IL-4 in comparison to mild cases. Raised levels of interleukin-10 were more prevalent in advanced disease, and statistically different from those in mild patients. This cytokine pattern may help to explain findings wherein mild tuberculosis is characterized by preserved cellular immune responses while advanced disease is accompanied by an impairment of such parameters.