Age-related leukocyte and cytokine patterns in community-acquired bronchopneumonia

Community-acquired bronchopneumonia in children is frequently accompanied by extreme leukocytosis, whereas in adults with the same diagnosis a high leukocyte count is uncommon. Data regarding differences in the serum levels of inflammatory cytokines between children and adults are limited.To compare leukocyte counts and blood levels of various inflammatory cytokines in children and adults diagnosed with community-acquired bronchopneumonia.We prospectively evaluated all pediatric and adult patients admitted for bronchopneumonia based on clinical and chest X-ray findings. Blood was drawn for complete blood count and serum concentration of the following cytokines: granulocyte colony-stimulating factor, interleukins-6, 8 and 10, interferon-gamma, tumor necrosis factor, as well as matrix metalloproteinase-9 and intercellular adhesion molecule-1.There were 31 children and 32 adults. The patients in both groups had similar parameters of infection severity. None of them required admission to the Intensive Care Unit. Mean (+/- SD) leukocyte counts in the pediatric and adult groups were 21,018/mm3 (+/- 10,420) and 12,628/mm3 (+/- 6735) respectively (P = 0.02). Age was inversely correlated with leukocytes in the pediatric group (P = 0.0001). A significant inverse correlation was also found between age and platelet counts. Although cytokine levels in both groups were not significantly different, age was directly correlated with MMP-9 (P= 0.03), IL-8 (P= 0.03) and G-CSF (P= 0.014).The immune response in community-acquired bronchopneumonia is, at least partly, age-dependent.