Diagnostic accuracy of anti-alpha-fodrin antibodies for primary Sjögren's syndrome

Abstract

Objectives. To estimate the diagnostic accuracy of anti-alpha-fodrin antibodies for primary Sjögren's syndrome (pSS).

Methods. Sixty-four pSS subjects and 108 non-pSS patients were prospectively enrolled in this study. Serum anti-alpha-fodrin IgA and IgG were detected by ELISA in a blind fashion. The diagnostic accuracy of anti-alpha-fodrin antibodies was assessed by receiver operating characteristic (ROC) curve analysis. Logistic regression was used to investigate whether anti-alpha-fodrin antibodies could improve the accuracy of pSS diagnosis if used in addition to anti-SSA and anti-SSB.

Results. The areas under the ROC curves for anti-alpha-fodrin IgG and IgA were 0.69 (95% confidence interval (CI): 0.60–0.77) and 0.63 (95% CI: 0.54–0.72), respectively (P < 0.01 for both). The optimal diagnostic thresholds for anti-fodrin IgG and IgA were 11.75 U/ml and 9.75 U/ml, respectively, with a sensitivity of 0.59 and 0.55, and a specificity of 0.75 and 0.73, respectively. Anti-alpha-fodrin IgG and IgA antibodies were associated with pSS after adjustment for anti-SSA and anti-SSB.

Conclusions. Anti-alpha-fodrin IgG and IgA antibodies are useful diagnostic markers which may improve the accuracy of pSS diagnosis.

Keywords:

• Anti-alpha-fodrin antibody
• Diagnosis
• Primary Sjögren's syndrome
• Sensitivity
• Specificity

Acknowledgement

We thank Medjaden Bioscience Limited for assisting in the preparation of the manuscript.

Conflict of interest

None.

This research was supported by grants from 973 Foundation (2013CB531606), National Science Foundation of China (81273282, 81202353), Shanghai Municipal Commission for Science and Technology (11JC1410902) and Changhai Hospital Foundation (CH125530300).