Parotid elastography: a potential alternative to replace labial biopsy in classification of patients with primary Sjögren's syndrome?

BACKGROUND: There has been a substantial improvement in classifying patients with primary Sjögren's syndrome (pSS), with the new 2016 ACR/EULAR classification criteria. It was aimed to investigate the potential role of parotid elastography in the classification of patients with pSS, as well as the clinical diagnosis of those who do not otherwise fulfil the criteria. METHOD: This is a cross-sectional analysis of patients with pSS followed up in tertiary out-patient rheumatology clinic. Patients' medical records were retrospectively investigated whether or not clinically diagnosed pSS patients fulfil 2016 ACR/EULAR criteria sets. Elastographic evaluation of parotid and submandibular glands bilaterally was performed when presented for follow-up. Strain ratio, shear wave velocity and Pascal values of the glands were obtained. RESULTS: Clinical data on 179 patients with Sjögren's syndrome were investigated. Ninety-six patients with pSS and 30 gender and age-matched healthy controls were included in the study. Eighty-six percent of the clinically diagnosed patients satisfied the 2016 ACR /EULAR criteria and were considered 'criteria patients', and the remaining were considered 'non-criteria patients'. Both criteria and non-criteria patients had significantly higher parotid strain ratio and submandibular velocity compared with healthy controls (p < 0.001 and p < 0.001 for parotid strain ratio and p < 0.001 and p = 0.016 for submandibular velocity, respectively). Replacing labial gland biopsy findings with parotid strain ratio in the new classification criteria resulted in similar sensitivity and lower specificity, 91.6% and 80%, respectively. CONCLUSION: Parotid shear elastography is an easy and noninvasive method and might be a useful tool for the classification of patients with pSS, especially when labial gland biopsy is not feasible. Key Points • Salivary gland elastography (SGE) is a useful tool for the classification of patients with pSS. • SGE could be performed instead of labial biopsy without changing the diagnostic power of classification criteria.

Chronic inflammation in adult familial Mediterranean fever patients: underlying causes and association with amyloidosis.

Background: Chronic inflammation, as determined by persistently elevated acute-phase reactants in attack-free periods, can occasionally be observed in patients with familial Mediterranean fever (FMF) and is suggested to be a risk factor for the development of amyloidosis. We aimed to investigate the underlying causes of chronic inflammation in FMF patients and its association with amyloidosis in long-term follow-up. Method: Electronic medical records of FMF patients who had regular follow-up for ≥ 5 years in our cohort were utilized. As part of routine evaluation, detailed history, physical examination, and pertinent laboratory and radiographic investigations were performed in all patients to determine potential causes of elevated C-reactive protein (CRP) levels. Results: The study included 146 FMF patients who had no evidence of amyloidosis at baseline and had regular follow-up for ≥ 5 years. Thirty-seven patients (25.3%) were found to have chronic inflammation in the disease course. Twenty-five (67.5%) of them had either very frequent attacks or chronic manifestations of disease. In the entire study group, amyloidosis developed in five patients (3.42%) during the 5 year follow-up, four in the FMF with chronic inflammation group (10.8%), and only one of the 109 patients without chronic inflammation (odds ratio 13.09, 95% confidence interval 1.41-121.2). Conclusions: The results suggest that persistently high CRP levels during the attack-free periods may be a strong risk factor for the development of amyloidosis in patients with FMF. The vast majority of FMF patients with chronic inflammation had active FMF.