%0 Journal Article
%T Establishment of a serum IgG4 cut-off value for the differential diagnosis of IgG4-related disease in Chinese population.
%A Li P
%A Chen H
%A Deng C
%A Wu Z
%A Lin W
%A Zeng X
%A Zhang W
%A Zhang F
%A Li Y
%J Mod Rheumatol
%V 26
%N 4
%D Jul 2016
%M 26565780
%F 2.862
%R 10.3109/14397595.2015.1117171
%X <B>OBJECTIVE: </B>This study was performed to better know diagnosis associated with serum IgG4 concentration, and to explore the possibility for development of a serum IgG4 for IgG4-related disease (IgG4-RD) in Chinese populations.<BR><B>METHODS: </B>We studied retrospectively 497 IgG4 serum subclass measurements from Peking Union Medical College Hospital during the four-year period, including 242 IgG4-RD, 130 other diseases and 125 healthy individuals.<BR><B>RESULTS: </B>Serum IgG4 concentrations were significantly higher in IgG4-RD than in other pathologies (1662.9 ± 3760.9 mg/L, p < 0.001) and healthy individuals (538.2 ± 458.6 mg/L, p < 0.001). There were no significant differences in serum IgG4 level between other pathologies group and healthy individuals (p = 0.075). Among the 242 IgG4-RD patients analyzed, serum IgG4 concentrations were normal in 46 patients (19.0%). We found 32 patients (24.6%) with elevated serum IgG4 levels among the 130 patients who suffered from other pathologies. There were seven (5.6%) with serum IgG4 over 1350 mg/L in healthy individuals. The ROC curve analysis revealed that the optimal sensitivity and specificity were 80.0% and 88.2%, respectively, at the concentration of 1575 mg/L for Chinese patients.<BR><B>CONCLUSIONS: </B>Our study demonstrated that serum IgG4 elevation was not specific of IgG4-RD. Further studies are needed to define the sensibility and specificity of IgG4 values for the diagnosis of IgG4-RD.