Diagnostic performances of serum IgG4 concentration and IgG4/IgG ratio in IgG4-related disease

Abstract

Patients with IgG4-related disease (IgG4-RD) often have elevated serum IgG4 levels. Here, we aimed to evaluate the diagnostic performances of elevated serum IgG4 concentration and IgG4/IgG ratio for IgG4-RD. We retrospectively analyzed 1381 patients subjected to serum IgG subclass testing to differentiate IgG4-RD from other diseases at Peking University People's Hospital from 2012 to 2016. This sample included 133 IgG4-RD patients and 1248 non-IgG4-RD patients. Serum IgG subclass concentrations were measured using Siemens reagents. The median values (25th-75th percentile) for serum IgG4 concentration and IgG4/IgG ratio, respectively, were 8640 (3970-17750) mg/L and 0.339 (0.229-0.517) in IgG4-RD patients and 450 (220-920) mg/L and 0.032 (0.014-0.061) in non-IgG4-RD patients (p < 0.001). For distinguishing IgG4-RD from non-IgG4-RD, the optimal cut-off values of IgG4 and IgG4/IgG were 2100 mg/L and 0.114, respectively. The corresponding area under the curve (AUC) values were 0.964 and 0.970, respectively. Comparison of the receiver operating characteristic curves revealed a significant difference between these AUC values (p = 0.002). The sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV), respectively, were 94.7, 91.6, 54.5, and 99.4% for the IgG4 optimal cut-off value and 96.2, 92.1, 56.4, and 99.6% for the IgG4/IgG optimal cut-off value. Our results confirmed that elevated serum IgG4 concentration and IgG4/IgG ratio were of great value for IgG4-RD diagnosis.

IgG4-related disease in a patient with HIV infection

“…Seric IgG4/IgG ratio is also a useful biomarker. Values over 0.11 have high sensibility and specificity for diagnosis as seen in some series 15. Our patient ratio was 0.13.…”

A disclosed diagnosis for 24 year’s unknown illness

“…Its diagnosis basically requires histopathological evidence of infiltration of IgG4-positive plasma cells. Recently, Xia et al suggested the diagnostic value of elevated serum IgG4 concentration and IgG4/IgG ratio for IgG4-RD 4. Serum level of IgG4 in our patient was 732 mg/dL, and IgG4/IgG ratio of the patient was 0.36.…”

IgG4-Related orbital disease in patients with diabetic retinopathy: Effects of glucan and vitamin D supplementation

“…Criteria for IgG4-RD are changing and different authors use limits from 1.35 mg/ml to 2.48 mg/ml [7,14,15,[17][18][19][20]31,33]. Many authors now agree that the IgG4/IgG ratio is a better marker and levels above 10% are usually considered to be significant [14,[16][17][18]22]. We believe that it would be better to use individual IgG subclasses rather than IgG only.…”

“…Hamano and colleaguesnot only described elevated levels of IgG4 in autoimmune pancreatitis, but also prepared the basis for diagnostic and inspired health professionals from various doi: 10.7243/2052-7896-6-1 disciplines to follow complications of diseases connected with IgG4 levels, which are now defined as IgG4-RD [15]. A high level of IgG4 alone does not indicate a diagnosis of IgG4-RD and should be evaluated together with additional laboratory and clinical results [16][17][18][19][20][21][22]. IgG4-ROD (IgG4-related ophthalmic disease) is a recently recognizedfibroinflammatory disorder characterized by lymphoplasmacytic infiltrates with large numbers of IgG4-positive plasma cells, eosinophil infiltration, and storiform fibrosis [7,14,23].…”