[Diagnostic value of anti-alpha-fodrin antibody testing for Sjögren's syndrome: a meta-analysis]

To evaluate the diagnostic accuracy of anti-alpha-fodrin antibody for Sjögren's syndrome (SS).

Qualified literatures on evaluation of anti-alpha-fodrin antibody in diagnosis of SS in English and Chinese published between January 1997 and December 2007 were retrieved from the Cochrane Library, Medline, Embase, and China National Knowledge Infrastructure (CNKI) databases, etc. Two reviewers independently assessed the methodological quality of each study with the tool QUADAS (quality assessment of diagnostic accuracy studies). Statistical analysis was performed by employing MATLAB, Review Manager 4.2 and Meta-Disc1.4. A meta-analysis of the reported sensitivity and specificity of each study and Summary Receiver Operating Characteristic (SROC) curve was performed.

Eighteen literatures were included at last. After testing the heterogeneity of the included articles, proper effect model was selected to calculate the pooled weighted sensitivity and specificity with 95% confidence interval: for anti-alpha-fodrin antibody IgG, the sensitivity was 0.40 [95%CI (0.37-0.43)] and the specificity was 0.82 [95%CI (0.79-0.84)], the area under the curve (AUC) of SROC was 0.8029 (SE=0.0580). Eight studies tested anti-alpha-fodrin antibody IgA, the pooled weighted sensitivity and specificity with 95% confidence interval were 0.34 [95%CI (0.30-0.38)] and 0.83 [95%CI (0.79-0.86)] respectively, the AUC of SROC was 0.6374 (SE=0.1841), the synthesis data all showed heterogeneity. The subgroups were analyzed to identify the sources of heterogeneity according to age, race, assay method, agent source, diagnostic criteria, and country. There was homogeneity among the 4 studies from China, and the 6 studies from Japan, the AUC of SROC were 0.7343 (SE=0.0448) and 0.9273 (SE=0.0394), respectively.

Diagnostic criteria, agent source, assay method, age, race, and country are the important sources of heterogeneity. Anti-alpha-fodrin antibodies IgG and IgA have relatively low pooled sensitivity and relatively high pooled specificity. Negative anti-alpha-fodrin antibody has not important value in excluding SS, but positive anti-alpha-fodrin antibody may be a useful parameter in clinical diagnosis of SS.