Comparison of local and systemic production of Interleukin-8 in smoking and non smoking patients with infectious lung disease

In the pathogenesis of human lung diseases, much of the experimental evidence has indicated involvement of the neutrophil chemotactic factor interleukin-8 [IL-8]. Since IL-8 is secreted by alveolar capillary wall macrophages, local production of IL-8 may act a mechanism for polymorphonuclear cell migration into lung tissues. In this study, the concentrations of IL-8 were measured by ELISA in plasma and broncho-alveolar lavage [BAL] fluid of 49 patients. The study was divided into three patient groups: group A, 17 with bacterial pneumonia [7 non-smokers and 10 smokers]; group B, 23 with pulmonary tuberculosis [9 non-smokers and 14 smokers], and control group, 9 non-smokers. The concentration of IL-8 in BAL fluids was increased significantly in groups A and B [non-smokers and smokers] in comparison to the control group. In addition, there were significant differences between non-smokers versus smokers in IL-8 concentration n group A [non-smokers = 170.6 +/- 32 versus smokers = 350 +/- 89 pg/ml, p<0.001] and group B [non-smokers = 146.6 +/- 31 versus smokers = 305.5 +/- 54 pg/ml, p<0.001]. No significant differences in plasma IL-8 concentration were observed in different patient groups [smokers and non-smokers]. The present study suggests that the increased local production [BAL] of IL-8 is a associated with lung diseases, such as bacterial pneumonia and pulmonary tuberculosis, and that smoking can increase IL-8 production