Sjögren Syndrome without Focal Lymphocytic Infiltration of the Salivary Glands

J Rheumatol. 2020 Mar;47(3):394-399. doi: 10.3899/jrheum.181443. Epub 2019 May 15.

Abstract

Objective: Primary Sjögren syndrome (SS) is characterized by a focal lymphocytic infiltrate in exocrine glands. We describe patients who lacked this key feature.

Methods: We evaluated patients with sicca in a comprehensive clinic at which medical, dental, and ophthalmological examinations were performed. All subjects underwent a minor salivary gland biopsy with focus score calculation. Extraglandular manifestations were also determined. We categorized subjects as high, intermediate, or low in terms of expression of interferon (IFN)-regulated genes.

Results: About 20% (51 of 229, 22%) of those classified as having primary SS had a focus score of zero. Compared to those with anti-Ro positivity and a focus score > 1.0, the patients with focus score of zero (who by classification criteria must be anti-Ro-positive) were statistically less likely to have anti-La (or SSB) and elevated immunoglobulin, as well as less severe corneal staining. The focus score zero patients were less likely to have elevated expression of IFN-regulated genes in peripheral blood mononuclear cells than anti-Ro-positive SS patients with a focal salivary infiltrate.

Conclusion: There are only a few clinical differences between patients with primary SS with focus score zero and those with both anti-Ro and a focus score > 1.0. The small subset of focus score zero patients tested did not have elevated expression of IFN-regulated genes, but did have systemic disease. Thus, extraglandular manifestations are perhaps more related to the presence of anti-Ro than increased IFN. This may have relevance to pathogenesis of SS.

Keywords: AUTOANTIBODIES; INTERFERON; PRIMARY SJÖGREN SYNDROME.

Publication types

  • Research Support, U.S. Gov't, Non-P.H.S.
  • Research Support, N.I.H., Extramural