Clinical Usefulness of ImmuneCheck™ IgG for Rapid Semiquantitation of Total IgG

ABSTRACT

BACKGROUND: Conventional IgG assays require costly equipment and skilled experts. Semiquantitative measurement of total IgG using point-of-care testing devices may be the solution for these limitations. This study evaluated the reproducibility of the ImmuneCheck™ IgG assay (ProteomeTech Inc., Korea) and the correlation of its results with conventional laboratory IgG results in the serum and whole blood. METHODS: Both the serum and whole blood samples from 120 patients were used. To evaluate the intra-test reproducibility and inter-test correlation, intraclass correlation coefficient (ICC) analysis was used. RESULTS: The concentration of serum total IgG measured by cobas® 6000 (Roche Diagnostics, Switzland) ranged from 690.4 to 2,756.4 mg/dL. The intra-test reproducibility of ImmuneCheck™ IgG was high (Serum ICC=0.724, P < 0.001; Whole blood ICC=0.843, P < 0.001). The inter-test correlation between the ImmuneCheck™ IgG and cobas® 6000 results was very good (Serum ICC=0.805, P < 0.001; Whole blood ICC=0.842, P < 0.001). Because there were no samples with a total IgG level lower than 600 mg/dL, the pre-existing serum samples were diluted and then the linearity tests were conducted. The intra-test reproducibility for the diluted serum samples was almost perfect (ICC=0.995, P < 0.001), and the inter-test correlation between the ImmuneCheck™ IgG and cobas® 6000 results was also strong (ICC=0.992, P < 0.001). CONCLUSIONS: The ImmuneCheck™ IgG assay is reproducible and highly correlated with the conventional IgG assay for the serum and whole blood. It could be applied for the rapid detection of total IgG.