Objective To assess whether ultrasonographic scoring of (i) both parotid and submandibular salivary glands and (ii) all individual components of the Hocevar scoring system, is needed for classifying patients as primary Sjögren’s syndrome (pSS).
Methods Ultrasound examination of the major salivary glands (sUS) was performed in 204 consecutive patients clinically suspected (n=171) or diagnosed (n=33) with pSS.
Parenchymal echogenicity, homogeneity, hypoechogenic areas, hyperechogenic reflections and salivary gland posterior border were scored in left and right parotid and submandibular glands. Logistic regression analyses were performed to assess which glands and sUS components contributed significantly to classification as pSS or non-pSS according to the 2016 American College of Rheumatology-European League Against Rheumatism (ACR-EULAR) criteria.
Results 116 (57%) patients were classified as pSS, the remaining as non-pSS. Instead of scoring both sides (area under the curve; AUC=0.856, Nagelkerke R2=0.526), multivariate analysis showed that sUS scoring of only right (AUC=0.850; R2=0.518) or left (AUC=0.852; R2=0.511) parotid and submandibular glands is sufficient to predict ACR-EULAR classification. Moreover, all individual components of the Hocevar scoring system significantly predicted classification. Multivariate analysis showed that parenchymal echogenicity and hypoechogenic areas contributed independently to ACR-EULAR classification (AUC=0.857; R2=0.539). Scoring these components in one parotid and one submandibular gland highly predicted ACR-EULAR classification (AUC=0.855; R2=0.539). Scoring only hypoechogenic areas on one side showed almost similar results (AUC=0.846; R2=0.498).
Conclusion sUS examination of parotid and submandibular glands on one side is sufficient to predict classification of patients according to the ACR-EULAR criteria. To further increase feasibility of sUS in outpatient clinics worldwide, only hypoechogenic areas can be scored.
- sjøgren’s syndrome
- autoimmune diseases
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Part of this study has been presented at the ACR 2017 in San Diego and the corresponding abstract has been published as a conference abstract.
Handling editor Tore K Kvien
Contributors EM, designed the study, collected, analysed and interpreted data, drafted the article and approved the version to be published; SA, designed the study, analysed and interpreted the data, critically revised the article and approved the version to be published; JFvN, KD and AJS, collected data, critically revised the article and approved the version to be published; FGMK and FKLS, critically revised the article and approved the version to be published and AV and HB, designed the study, critically revised the article and approved the version to be published.
Funding The Dutch Arthritis Foundation, research grant for the REgistry of Sjögren syndrome in Umcg—LongiTudinal (RESULT) cohort; METc 2014/491. Bristol-Myers Squibb, unrestricted research grant for the RESULT cohort. Horizon 2020, a research project supported by European Commission: HarmoncSS primary Sjögren’s Syndrome (pSS) towards improved satisfaction, treatment and health policy making (H2020-SC1-2016-RTD, proposal 731944).
Competing interests None declared.
Ethics approval This study was conducted in accordance with the Medical Ethics Committee of the UMCG; waiver 016/120.
Provenance and peer review Not commissioned; externally peer reviewed.
Data sharing statement No additional data available.
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