We wanted to determine the prevalence of IgA and IgG antibodies against alpha-fodrin in the patients with primary and secondary Sjögren's syndrome (SS) and also to compare with anti-Ro and anti-La antibodies in the diagnosis of SS.
We tested the prevalence of anti-alpha-fodrin IgA, IgG, anti-Ro, anti-La antibodies, anti-nuclear antibodies (ANA) and rheumatoid factor (RF) in naive patients with primary (n = 20) and secondary SS (n = 20) (Rheumatoid Arthritis [RA]+SS, n = 10; Systemic Lupus Erythematosus [SLE] + SS, n = 10), RA (n = 10), SLE (n = 10) and in healthy controls (n = 20). Salivary gland biopsies were performed in the patients with primary and secondary SS.
In primary SS, anti-alpha-fodrin IgA, IgG, anti-Ro and anti-La antibodies were detected as 20, 10, 55 and 20% respectively. In RA + SS, anti-alpha-fodrin IgA was detected to be 10% and IgG was negative; however, anti-Ro antibodies and anti-La antibodies were found to be 40% and 20% respectively. In SLE + SS, anti-alpha-fodrin IgA was found to be 20% and IgG was found to be 10%, but anti-Ro and anti-La antibodies were found to be 90% and 20% respectively. Alpha-fodrin antibodies were not detected in RA, SLE and healthy controls.
The detection of anti-alpha-fodrin antibodies by used ELISA does not give much contribution to the diagnosis of SS, and anti-Ro and anti-La are still useful serological markers in the diagnosis of SS.