Establishment and performance evaluation of a quantitative detection method for immunoglobulin G4 based on fluorescence immunochromatography / 中华胰腺病杂志

ABSTRACT

Objective:To establish a rapid and quantitative method for the determination of immunoglobulin G4 (IgG4) by fluorescence immunochromatography and to analyze its clinical application value.Methods:Fluorescence immunoassay for quantitative detection of IgG4 was obtained by means of preparation of kits in a competitive reaction mode and combining immunoassay with fluorescence quantitative assay. The linearity, precision, accuracy, anti-interference ability and stability of the method were evaluated, and compared with immune-scattering turbidimetry, receiver operating characteristic curve (ROC) was plotted, area under the curve (AUC) was calculated, and the critical value for the diagnosis of pancreatitis related diseases was determined, and sensitivity and specificity were calculated.Results:The linear range of fluorescence immunoassay for IgG4 was 0.2-10.0 g/L. The accuracy coefficient of variation was less than 15%, and the accuracy deviation was within ±15%. Bilirubin (2.5 g/L), triglyceride (10 g/L) and hemoglobin (10 g/L) had no significant effect on the quantitative determination. Within 14 months, 1.20 g/L and 2.65 g/L reference samples were detected with concentration deviations within ±15%. The kit validity period was >12 months. Serum samples of 200 healthy people were detected by fluorescence immunochromatography, and the normal reference value of IgG4 was <2.03 g/L. fluorescence immunochromatography and Immunoturbidimetry were used to detect IgG4 concentrations in 383 clinical serum samples. The results showed that the two methods were consistent ( P>0.05). Using 2.01g/L IgG4 as the critical value, the sensitivity and specificity of fluorescence immunochromatography were 96.3% and 95.5% by ROC curve analysis, respectively. Conclusions:Fluorescence immunochromatography was a simple, rapid and accurate method for the quantitative detection of IgG4, and had high sensitivity and specificity for the diagnosis of pancreatitis related diseases. It was suitable for quantitative detection of bulk samples in outpatient and emergency departments.