Date Published: October 5, 2017
Publisher: BioMed Central
Author(s): Ping Li, Zhongjuan Liu, Ziyan Wu, Xiaoting Wen, Liubing Li, Shulan Zhang, Yingchun Xu, Yongzhe Li.
To determine the adult reference intervals for the Siemens IgG subclass reagents.
636 blood samples of healthy adults were analyzed to determine the level of IgG subclass using the reagents of Siemens immunonephelometric assay with molecular biology kits.
IgGSc reference intervals were as follows: IgG1 4.45–9.76 g/L, IgG2 2.07–8.57 g/L, IgG3 0.08–0.80 g/L and IgG4 0.05–1.54 g/L. There was an excellent correlation between the total IgG and the sum of the IgG subclasses. No significant gender and age differences were observed.
Our data provide the missing reference intervals and enable the use of the nephelometric IgG subclass reagents in Chinese. The study can offer reference on clinic diagnose.
Four distinct heavy chain subgroups of human IgG were first demonstrated in the 1960s by using polyclonal antisera prepared in animals immunized with human myeloma proteins [1, 2]. Since then, determination of selective immunoglobulin subclasses (IgGSc) has become an established tool in the diagnosis of many diseases, such as immunologic deficiencies and adult IgG4-related disease (IgG4-RD) [3, 4].
After excluding outliers, IgGSc serum concentrations were determined in 617 IgG1, 631 IgG2, 619 IgG3 and 599 IgG4 groups. IgG1 and IgG2 serum concentrations were normally distributed, and IgG3 and IgG4 serum concentrations were non-normally distributed, whereas square-root transformed serum concentrations were approximately normally distributed (Fig. 1).Fig. 1Histogram of square-root transformed IgG subclasses serum concentrations in 636 healthy adults
Due to the fact that appropriate reference intervals are important for clinical application of diagnostic markers, it was necessary to produce reliable reference intervals for the newly developed commercial assays, especially as nephelometric data are scarce in Chinese populations.