The Variety Of Mannose Binding Protein Level In Sera From Children With Recurrent Respiratory Tract Infection

Objection To investigate the relationship between deficiency of mannose binding protein (MBP) in sera and recurrent respiratory tract infection (RRTI ) of children/To provide theoretical basis of pathogenesis of RRTI.Methods Take 23 cases health children as control group.MBP level in sera of 57 cases RRTI were analyzed with ABC-ELISA. The T-cell subset function of 57 cases of RRTI were analyzed by immunoflurescence meanwhile to test the sera IFN-r and IL-2 level by ELISA. Immunoglobulin A, G, M level in sera were analyzed by immnodiffusion.Resulte MBP level in sera of RRTI children were (28.36 ± 16.76)ng/ml. It was significantly lower than that of control group [(36.76 ± 9.08)ng/ml] (t=2.26,P<0.01).MBP level in sera of 18 cases of RRTI were lower than x-2S (18. 6ng /ml) of control group (account of 31.58%) Among of them under age 6 were made up of 32.56%.RRTI cases with only lower MBP level in sera were 12 cases in addition other 6 cases were not only lower MBP level in sera but also lower T-cell subset function and immunoglobulin level in sera .The percentage of CD⁺₃,CD⁺₄, CD⁺₈ and ratio of CD⁺₄/CD⁺₈ in RRTI children were significantly lower than that of control group (t=2.55 5.39, P<0.01);The sera level of IgA, IgG, IgM, C₃, C₄ of two group were not significant t=0.60 1.23,P>0.05 ).IFN-r and IL-2 level in sera suffering from RRTI children were significantly lower (t=2.36,3.11 ,P<0.01).Relative analyze were showed that in RRTI children MBP level in sera were not related to T-cell subset function , IFN-r level, IL-2 level and immunoglobulin level in sera.Conclusion Besides the lower T-cell subset function(most partly Th1) the deficiency of MBP is one of the most important pathogeny of RRTI in children (especially under age 6).