TOPLINE:
Both labial and parotid salivary glands can be used for the diagnosis of Sjögren syndrome (SjS), as their biopsies show largely similar histopathologic features in patients with sicca complaints suspected of having SjS.
METHODOLOGY:
- While a labial gland biopsy is the conventional method for diagnosing SjS, a biopsy of the parotid gland is preferable, as it allows for repeat measurements and increases the possibility of finding a mucosa-associated lymphoid tissue lymphoma.
- In this prospective study, researchers compared the focus score (FS) and other histopathologic features of SjS between paired labial and parotid salivary gland biopsies in a diagnostic cohort of patients with sicca suspected of having SjS.
- Labial and parotid gland biopsies were simultaneously obtained under local infiltration anesthesia in 99 patients with oral and/or ocular sicca complaints at the University Medical Center Groningen, Groningen, the Netherlands, between 2014 and 2017.
- FS is defined as the number of foci per 4 mm2 of salivary gland tissue. An FS ≥ 1 indicates a positive diagnosis of SjS.
- On the basis of an expert opinion of three experienced rheumatologists, 36 patients were diagnosed with SjS, and 63 were diagnosed with non-SjS sicca.
TAKEAWAY:
- The absolute agreement of various histopathologic features was high between labial and parotid biopsies, with values being 80% for FS, 89% for germinal centers, 84% for the immunoglobulin (Ig) A/IgG plasma cell shift, and 93% for pre-lymphoepithelial lesions.
- However, an FS ≥ 1 was more frequently seen in labial glands than in parotid glands (P = .012) in both the SjS and non-SjS sicca populations, indicating that labial gland biopsies show more inflammation irrespective of the presence of SjS.
- In patients with SjS, the absolute B-lymphocyte count, the number of germinal centers per mm2, and the severity of pre-lymphoepithelial lesions were higher in parotid glands than in labial glands, revealing evident histopathologic signs of B-lymphocyte hyperactivity.
IN PRACTICE:
“The results of this study offer novel insights into the pathophysiology of pSS [primary Sjögren syndrome] and can be incorporated into guidelines for the histopathological analysis of salivary gland biopsies,” the authors wrote.
SOURCE:
This study, led by Uzma Nakshbandi, MD, Department of Reumatology & Clinical Immunology, University Medical Center Groningen, Groningen, the Netherlands, was published online in Rheumatology (Oxford).
LIMITATIONS:
This study did not discuss any limitations.
DISCLOSURES:
This study was funded by the National Institutes of Health. One of the authors disclosed serving as a consultant and scientific advisory board member for several pharmaceutical companies, as well as receiving speaker’s fees from some of them.
A version of this article appeared on Medscape.com.