Adrenal Autoimmunity in Primary Sjogren's Syndrome

Objective. To evaluate the prevalence of anti- bodies to 21-hydroxylase (anti-21(OH)), a marker of autoimmune adrenal disease, in a cohort of patients with primary Sjogren's syndrome (SS) and to investi- gate whether the presence of anti-21(OH) correlates with clinical, serologic, and salivary gland features of the disease. Methods. Sera from 63 consecutive patients with primary SS, 32 patients with autoimmune thyroid dis- ease (AITD), and 20 healthy controls were obtained and anti-21(OH) levels were determined by radioimmuno- assay. Clinical, serologic, and histopathologic features were recorded, and a short Synacthen test was used to assess adrenal function reserve. Seven available minor salivary gland (MSG) tissue specimens from patients in the primary SS cohort were also assessed for interferon- (IFN), BAFF, and interleukin-21 (IL-21) cytokine transcripts, which are all implicated in B cell activation. Results. Anti-21(OH) positivity was detected in 17.5% and 28.1% of primary SS and AITD patients, respectively, and in none of the healthy controls. While no evidence of adrenal insufficiency was detected in any of the patients studied, a blunted rate of increase in cortisol levels was observed in patients with detectable serum autoantibodies against 21(OH), compared to their anti-21(OH)-negative counterparts. A strong cor- relation between the serum titer of anti-21(OH) anti- bodies and expression of IFN, BAFF, and IL-21 mes- senger RNA in MSG tissues was also detected. Conclusion. Adrenal autoimmunity occurs in al- most 20% of patients with primary SS in association with markers of B cell activation. Although the presence of adrenal autoantibodies was not associated with adre- nal insufficiency in the present study, there was a blunted adrenal response, suggesting the need for fur- ther followup and monitoring of adrenal function in patients with primary SS who are positive for the autoantibodies.