DIAGNOSTIC-VALUE OF BLOOD CYTOKINE CONCENTRATIONS IN ACUTE PNEUMONIA

Background - The role of cytokines in the pathogenesis of pneumonia is still poorly understood. In a previous study the diagnostic value of measuring blood concentrations of interleukin 6 and interferon gamma w as established. In the present study the value of blood concentrations of interleukin 8, granulocyte-colony stimulating factor, and lactofer rin as markers of bacteraemic pneumonia is evaluated. Methods - The ci rculating concentrations of interleukin 8 (IL-8), granulocyte-colony s timulating factor (G-CSF), and lactoferrin were measured in 14 patient s with bacteraemic pneumococcal pneumonia and 49 patients with atypica l pneumonia or influenza A infection using enzyme immunoassays. Result s - Serum G-CSF concentrations were higher in the group with bacteraem ic pneumococcal pneumonia, and G-CSF values correlated with the white blood cell count and levels of C-reactive protein (CRP). The levels of IL-8 were higher in the group with bacteraemic pneumococcal pneumonia than the groups with Chlamydia pneumonia, Legionella pneumonia, or in fluenza A infection, but there was no difference when compared with th e group with Mycoplasma pneumonia. A white blood cell count of > 15 x 10(9)/l was highly suggestive of bacteraemic pneumonia. The concentrat ions of lactoferrin were raised in all groups except those with influe nza A infection, but no difference was found between the different aet iological groups. A correlation was found between lactoferrin and whit e blood cell counts. Conclusions - Serum G-CSF and IL-8 concentrations are potential markers of bacteraemic pneumonia.