OBJECTIVETo investigate changes in serum complement, immunoglobulins and lymphocyte subsets in children with common and severe bronchial pneumonia, and the role of immune function testing in bronchial pneumonia.

METHODSTwenty children with common bronchial pneumonia, 20 with severe bronchial pneumonia and 20 healthy children (as controls) were enrolled in this study. Immunization rate scattering turbidimetry and six-color flow cytometry were used to detect changes in serum levels of IgA, IgG and IgM, complement C3 and C4 and CD3(+), CD4(+), CD8(+), CD16(+), CD56(+) and CD19(+) cells.

RESULTSThe IgA levels of children with common and severe pneumonia were significantly lower than in the control group (P<0.05). The IgG level of children with severe pneumonia was significantly lower than in the control group (P<0.05). There were no significant differences in the levels of IgM and complement C3 and C4 between the two pneumonia groups and the control group (P>0.05). Compared with the controls, the children with severe pneumonia showed significantly lower CD4(+) and CD3(+) counts (P<0.05) and a significantly higher CD19(+) count (P<0.05), and the CD16(+) and CD56(+) counts of children with severe pneumonia were significantly lower than in the controls and in children with common pneumonia (P<0.05). There were no differences in CD8(+) count and CD4(+)/CD8(+) ratio between the two pneumonia groups and the control group (P>0.05).

CONCLUSIONSImmune dysfunction exists in children with bronchial pneumonia, especially those with severe pneumonia. Changes in immune function are correlated with the severity of pneumonia. Immune function testing in children with pneumonia has important clinical significance.