Reference Intervals for Serum Immunoglobulin (IGA, IGG, IGM) and IGG Subclasses in Healthy Subjects

Aim: Regional reference values of immunoglobulin and immunoglobulin subgroups are necessary for clinical research and diagnosis. A main problem in determining the reference intervals, reference values show variability depending on laboratory and technical conditions against interregional and reference populations. In clinical laboratories mainly test kit's reference intervals are used according to the manufacturer. In this study it is aimed to determine reference interval values of regional immunoglobulin and IgG subgroups. Method: Healthy reference individuals were designated according to "CLSI-C28-A3" standard's suggestions (n:255). Serum IgG, IgM, IgA, and IgG1, IgG2, IgG3, IgG4 values were determined nephelometrically. The reference values determined were compared with the references intervals given by manufacturer and reported from other studies. Results: Reference intervals of serum IgA, IgG, IgM, and IgG subgroups (IgG1, IgG2, IgG3, IgG4) were 75-100, 816-959, 97-118 mg/dL; 5.34-6.26,1.48-197, 0.46-0.58, 0.18-0.29 g/L, respectively. Out of IgA, serum reference values of males and females were statistically different. Values were higher in females (p<0. 05). Out of IgG, reference intervals were different statistically between age groups. Discussion: When compared with other studies in literature and manufacturer values, our study values were different. This difference was found to be associated with regional diversity. As a result, our study provided useful, regional data about serum immunoglobulin and IgG subgroups normal values and varieties depending on age and gender.