Elevated Concentrations of Interleukins and Leukotriene in Response to Mycobacterium Tuberculosis Infection

There is significant research in the role of interleukins in lung disease, as the cytokines are important mediators in the host response to mycobacterium tuberculosis infection. Plasma from patients with pulmonary tuberculosis (TB) and healthy controls were investigated for their content of granulocyte-macrophage colony stimulating factor (GM-CSF), interleukin-6 (IL-6) and leukotriene B4 (LTB4). LTB4 and IL-6 were measured by enzyme immunoassay after lipid extraction in the case of LTB4 while GM-CSF was measured by enzyme amplified sensitive immunoassay. Significantly elevated concentrations of IL-6 were found in far-advanced lesions of pulmonary tuberculosis patients, P < 0·05. However, nonsignificant increases of IL-6 were obtained in moderate lesions and minimal lesions compared to normal healthy subjects. Marked elevations of LTB4 were found in TB patients, the highest values being shown in patients with far-advanced lesions followed by moderately advanced and minimal lesions in relation to the mean value for normal healthy controls, P < 0·001 for all groups. 93% of the tuberculosis patients showed a higher level of LTB4 above the upper limit of the control group. In contrast there was no significant increase of GM-CSF in any of the TB subgroups. These results suggest that LTB4 and the interleukins may play a role in the pathogenesis of mycobacterium tuberculosis infection.