Childhood parapneumonic effusions: biochemical and inflammatory markers.

STUDY OBJECTIVES Biochemical and inflammatory markers in pleural inflammation were evaluated in pediatric cases of parapneumonic effusions, and interleukin (IL)-8 and tumor necrosis factor (TNF)-alpha concentrations were tested for possible differentiation of the complicated nature of effusions. PATIENTS Twenty-eight patients (12 female) who were admitted to Hacettepe University Childrens' Hospital over a 2-year period were included in the study. MEASUREMENTS Patients were grouped according to the stage of effusion. Pleural fluid leukocyte count, neutrophil ratio, pH, protein, glucose levels, lactate dehydrogenase (LDH) levels, TNF-alpha levels, IL-8 levels, and nitrite levels were obtained. RESULTS Of these patients, 13 had empyema, 10 had complicated parapneumonic effusions (CPEs), and 5 had uncomplicated parapneumonic effusions (UPEs). Protein and glucose levels decreased, leukocyte count, neutrophil ratio, TNF-alpha levels, nitrite levels, and IL-8 levels increased progressively as the stage of the disease progressed. IL-8 levels, but not TNF-alpha and nitrite levels, were statistically different among the groups. IL-8, TNF-alpha, and nitrite levels all correlated positively with each other (all p < or = 0.001), and pH correlated negatively with these markers (all p < or = 0.001). At a cutoff value of 76.6 pg/mL, TNF-alpha discriminated between CPEs and UPEs with a sensitivity of 50%, a specificity of 100%, and an accuracy of 78%. At a cutoff value of 701.6 pg/mL, IL-8 differentiated CPE and UPE with a sensitivity of 80%, a specificity of 80%, and an accuracy of 86%. CONCLUSIONS Progressive changes in common biochemical markers (ie, pH, and protein, glucose, and LDH levels) are interrelated during stages of pleural inflammation. IL-8 may be used as an alternative marker for discriminating between CPEs and UPEs in pediatric parapneumonic effusions.