Clinical and immunological characteristics of patients with Sjogren's syndrome in relation to -fodrin antibodies

Abstract

Objectives . To analyse the prevalence of α-fodrin antibodies in patients with primary (pSS) and secondary Sjögren's syndrome (sSS) and the relation to clinical, serological and immunological features. Methods . Serum IgA and IgG antibodies to the 120 kDa α-fodrin were determined by ELISA technique in 62 pSS patients and 28 sSS patients. Results were correlated with clinical symptoms and laboratory findings as well as with the HLA-DR genotype. Additionally, antibody concentrations were correlated with the numbers of peripheral blood mononuclear cells (PBMCs) secreting interleukin (IL)-6, IL-10, interferon-γ (INF)-γ, and tumour necrosis factor-α determined by ELISPOT analysis. Lymphocytes and monocytes were examined flow-cytometrically for the expression of activation markers. Healthy age- and sex-matched volunteers served as controls. Results . The sensitivity of IgA and IgG α-fodrin antibodies was 35 and 31%, respectively, in pSS patients. In sSS patients, the sensitivity was 29 and 21%, respectively. In pSS patients with IgG antibodies, recurrent parotid swelling was significantly more prevalent. Also the number of INF-γ secreting PBMCs and the percentage of CD4/CD71+ lymphocytes as well as CD14/HLA-DR+ monocytes were significantly increased in this group compared with α-fodrin-negative patients or with controls. Interestingly, these patients also had a shorter disease duration. No association of α-fodrin antibodies with the HLA-DR genotype was found. Conclusion . Due to the low prevalence, serum antibodies to α-fodrin turned out to be of limited diagnostic value in our study. However, our data suggest that IgG antibodies to α-fodrin are indicative of clinical and immunological activity in pSS especially in patients with shorter disease duration and may thus serve as a marker of disease activity.