Comparative analysis of autoantibodies against a-fodrin in serum, tear fluid, and saliva from patients with Sjögren's syndrome.
OBJECTIVE
To evaluate levels of IgA and IgG antibodies against a-fodrin in serum, tear fluid, and saliva and compare them with anti-Ro and anti-La antibody levels in the same samples of patients with Sjögren's syndrome (SS).


METHODS
Samples from 25 patients with SS (17 primary and 8 secondary), 8 patients with systemic lupus erythematosus (SLE), and 7 patients with rheumatoid arthritis (RA) as well as 20 healthy blood donor controls were collected. Antibodies were measured using ELISA.


RESULTS
Although 40% of patients with primary SS had IgG anti-a-fodrin in their sera, it was also found in 36% and 32% of samples of their tear fluid and saliva, respectively. IgA a-fodrin antibodies were detected in 32% of SS sera, 20% of tear fluid samples, and 32% of saliva samples. Although the level of IgG anti-a-fodrin was significantly greater in serum, tear fluid, and saliva of SS patients compared to controls (p < 0.001), a significant difference was observed only in serum and saliva. While anti-Ro was detected in 48%, 56%, and 24% of serum, tear fluid, and saliva samples, respectively, anti-La was found in 40%, 44%, and 28%. Significant association was observed between serum IgG antibodies against a-fodrin and dry eye symptom score and rose bengal staining score. A negative association was also noted between tear IgA antibodies against a-fodrin and Schirmer I test.


CONCLUSIONS
Correlation of IgG and IgA antibodies against a-fodrin with the severity of eye involvement suggests that these autoantibodies may be considered activation markers of SS.
Yavuz
Sule
S
Department of Rheumatology, and the Faculties of Health Education, University of Marmara Medical School, Istanbul, Turkey. suleyavuz@gmail.com
Toker
Ebru
E
Bicakcigil
Muge
M
Mumcu
Gonca
G
Cakir
Sezen
S
D000974:Antibodies, Antinuclear / Q000032:analysis*; D015415:Biomarkers / Q000032:analysis; D002352:Carrier Proteins / Q000276:immunology*; D006801:Humans; D007070:Immunoglobulin A / Q000032:analysis; D007074:Immunoglobulin G / Q000032:analysis; D007231:Infant, Newborn; D008840:Microfilament Proteins / Q000276:immunology*; D012463:Saliva / Q000276:immunology*; D012859:Sjogren's Syndrome / Q000276:immunology*; D013666:Tears / Q000276:immunology*; D013049:Spectrin
D000974:Antibodies, Antinuclear; D015415:Biomarkers; D002352:Carrier Proteins; D007070:Immunoglobulin A; D007074:Immunoglobulin G; D008840:Microfilament Proteins; D013049:Spectrin; C035356:SS-A antibodies; C035357:SS-B antibodies