Diagnostic value of serum IgG and IgG4 in antineutrophil cytoplasmic antibody associated vasculitis

• Main Authors: QIN Chenhao, GU Aiping, ZHAN Fuqin, FENG Ping, GU Haoyu
• Format: Article
• Language: zho
• Published: Editorial Office of Journal of Third Military Medical University 2019-08-01
• Series: Di-san junyi daxue xuebao
• Subjects: igg4; igg4-related diseasse; antineutrophil cytoplasmic antibody-associated vasculitis; anti-mpo antibody; anti-pr3 antibody
• Online Access: http://aammt.tmmu.edu.cn/Upload/rhtml/201902006.htm

Objective To investigate the expression of serum IgG and IgG4 in the patients with antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV), and explore the diagnostic value of IgG4 in AAV patients. Methods A total of 48 patients with AAV admitted in our hospital from July 2016 to June 2018 were recruited as patient group, and 25 healthy persons during the same period were subjected as control group. Their serum samples were collected for concentration of IgG4 by ELISA, that of IgG by immunoturbidimetric assay, and those of anti-MPO and anti-PR3 antibodies by ship type ELISA. Student's t test was used to make data comparison between the 2 groups, one-way ANOVA was employed for comparison among the multiple groups, and LSD-t test was applied for intragroup comparison. Pearson correlation analysis was used to analyze the correlation between the 2 groups, and P < 0.05 was considered statistically. Results The serum IgG4 concentration was 1.17±0.58 g/L, and the percentage of IgG4 to IgG was (10.12±6.64)% in the AAV patients, which were significantly higher than those of healthy individuals (P < 0.01). So were the concentrations in the MPO-ANCA-associated and PR3-ANCA-associated AAV patients (P < 0.01). But there was no difference in the expression of IgG4 between the 2 subtypes (P>0.05), and there was no significant correlation between ANCA concentration and IgG4 concentration (P>0.05). Conclusion IgG4 concentration and IgG4/IgG percentage are significantly increased in the patients with AAV or its subtypes. But there is no significant correlation with the types and ANCA concentration. Detection of IgG4 combined with ANCA is helpful in the diagnosis of AAV.