Reference Intervals for Serum Immunoglobulins IgG, IgA, IgM and Complements C3 and C4 in Iranian Healthy Children

Background: Determination of reference ranges of each serum protein in normal population of each country is required for studies and clinical interpretation. The aim of this study was defining reference range values of immunoglobulins and complement components in Iranian healthy children. Methods: This study was conducted from June 2003 to June 2006 in Immunology, Asthma and Allergy Research Institute, Tehran University of Medical Sciences. Serum levels of IgG, IgM, IgA, C3 and C4 in 800 Iranian healthy children from newborn to 18 years of age in four population were measured by nephelometry. Kolmogrov-Smirnov tests and Pearson correlation tests were used for analysis. Results: Our results mainly agree with previous reports, except for some discrepancy that might be due to the ethnic and geographic variety. There was a significant difference between two sexes only with IgA in the group of 1-3 months old, which was higher in male group and IgM in groups of 3-5, 6-8 and 9-11 years old that were higher in female groups. Mean of other serum immunoglobulins and complements was not significantly different between male and female groups. Conclusion: These results can be considered as a local reference for use in laboratories, clinical interpretations, and research for Iranian children.