OBJECTIVE: To investigate salivary gland ultrasound (SGUS) abnormalities in relation to clinical phenotype and patient characteristics, disease activity and disease damage in patients with primary Sjögren's syndrome (pSS).
METHODS: Consecutive outpatients included in our REgistry of Sjögren Syndrome LongiTudinal (RESULT) cohort were selected. Included pSS patients were classified according to the ACR-EULAR criteria and underwent full ultrasonographic examination (Hocevar score 0-48) at baseline. Total SGUS scores of ≥15 were considered positive. Patient characteristics, disease activity and disease damage were compared between the different SGUS groups.
RESULTS: In total, 172/186 pSS patients were eligible, of whom 136 (79%) were SGUS positive. SGUS positive patients had significantly longer disease duration, higher ESSDAI, higher SSDDI, more often a positive parotid gland biopsy, anti-SSA/SSB antibodies, abnormal unstimulated whole saliva (UWS) and ocular staining score (OSS), and higher levels of IgG and rheumatoid factor compared with SGUS negative patients. Regarding patient-reported outcome measurements (PROMs), SGUS positive patients scored significantly lower on ESSPRI fatigue and pain, and more often found their disease state acceptable compared with SGUS negative patients. SGUS total score showed significant associations with various clinical and serological parameters, and with PROMs. Highest associations were found for UWS (ρ=-0.551) and OSS (ρ=0.532).
CONCLUSION: SGUS positive patients show a distinct clinical phenotype compared with SGUS negative patients in all aspects of the disease: clinical, functional, serological and PROMs. SGUS could be a helpful tool in selecting patients for clinical trials and estimating treatment need.