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)-α 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-α 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-α levels, nitrite levels, and IL-8 levels increased progressively as the stage of the disease progressed. IL-8 levels, but not TNF-α and nitrite levels, were statistically different among the groups. IL-8, TNF-α, and nitrite levels all correlated positively with each other (all p ≤ 0.001), and pH correlated negatively with these markers (all p ≤ 0.001). At a cutoff value of 76.6 pg/mL, TNF-α 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.