Diagnostic value of salivary gland ultrasonography for secondary Sjögren syndrome in patients with systemic lupus erythematosus.

BACKGROUND: Salivary gland ultrasound (SGUS) is a reliable technique for assessing the salivary glands in patients with primary Sjögren's syndrome (SS); however, the role of SGUS for diagnosis of secondary SS (sSS) in patients with systemic lupus erythematosus (SLE) was not examined. OBJECTIVE: To assess the diagnostic value of SGUS for sSS in patients with SLE, and to investigate the relationship between SGUS findings with clinical and laboratory characteristics of patients with SLE. PATIENTS AND METHODS: This cross-sectional study included 49 patients with SLE. The diagnosis of sSS was confirmed according to the 2016 ACR/EULAR criteria. Salivary gland US was performed for all patients and graded using a validated Hocevar scoring system. A complete clinical and laboratory workup for SLE was assessed. Schirmer's test and the ocular staining were performed. RESULTS: Of the 49 patients with a mean age of 30.2 ± 9.6 years, 98% were female. 19 (38.8%) had sSS. SGUS changes consistent with sSS (≥17) were found in 29 (59.2%) of the patients. Patients with higher SGUS score had more sicca findings as well as positive anti-Ro, anti-La antibodies, and poorer psychological stress (p < 0.05). The SGUS (≥17) showed a sensitivity of 84.2% and a specificity of 56.7% for sSS diagnosis, with an area under the curve of 0.77 (95% CI: 0.63, 0.91). CONCLUSION: We propose salivary gland ultrasound as a non-invasive method in the diagnostic workup for sSS in patients with SLE. Further studies to confirm the diagnostic value of SGUS in a larger sample of patients with sSS will be necessary.

Peripheral neuropathy in systemic lupus erythematosus: what can neuromuscular ultrasonography (NMUS) tell us? A cross-sectional study.

OBJECTIVE: To evaluate peripheral nerve involvement in patients with SLE with neuromuscular ultrasonography (NMUS) and understand its role in investigating SLE-related peripheral neuropathy. METHODS: This is an observational cross-sectional study on patients with SLE and healthy controls. Five nerves in each patient were examined bilaterally with NMUS, and the cross-sectional area (CSA) of each nerve at certain sites was estimated. The mean CSA at each site, for each nerve, in each group was statistically analysed and compared between groups. RESULTS: 370 nerves were evaluated in 37 patients. By nerve conduction study (NCS), 36 patients had polyneuropathy (80.6% mixed type, 19.4% sensory). Significant mean CSA enlargement was present among the ulnar nerve at the Guyon's canal and mid-humerus (both p=0.001); tibial nerve at the distal leg and proximal to the tarsal tunnel (p=0.003 and p=0.001, respectively); and peroneal nerve at the popliteal fossa (p=0.042). The mean CSA showed high specificity compared with NCS. CONCLUSION: Our study shows that CSA could be a complementary tool to NCS for studying peripheral neuropathy in SLE. Furthermore, NMUS provides data on the different pathophysiological aspects of nerve involvement in SLE. Future studies using more than one sonographic parameter in combination with NCS and nerve histopathology are recommended to further investigate SLE-related neuropathy.Trial registration number NCT04527172.

Serum 14-3-3η protein is associated with clinical and serologic features of Sjögren's syndrome in patients with systemic lupus erythematosus: a cross-sectional analysis.

INTRODUCTION/OBJECTIVES: Systemic lupus erythematosus (SLE) and Sjögren's syndrome (SS) may coexist and carry a higher risk for future comorbidities. Although 14-3-3η protein is recently a known diagnostic marker in rheumatoid arthritis (RA), its role has not been investigated in SLE. The aim of this study was to compare serum 14-3-3η protein level in SLE and RA patients and to examine its association with clinical and laboratory features in SLE patients. METHODS: Eighty-four SLE patients and 39 RA patients were included. Sociodemographic, SLE disease activity index (SLEDAI), and damage index were assessed for SLE patients. Data about secondary SS were collected. 14-3-3η was measured by ELISA; titres above 0.19 ng/ml were considered positive. RESULTS: Serum 14-3-3η protein in SLE was significantly lower than in RA (0.37 ± 0.09 vs 1.5 ± 0.51; p < 0.001). 14-3-3η protein level was comparable between SLE patients with and without arthritis (0.29 ± 0.8 vs 0.15 ± 0.08 respectively; p = 0.20). Serum 14-3-3η protein level was higher in SLE with secondary SS features compared to those without (0.22 ± 0.10 IU/ml vs 0.11 ± 0.04 IU/ml; respectively, p < 0.001). There were no differences in 14-3-3η positivity for other lupus criteria or correlation of 14-3-3η titer with SLEDAI. 14-3-3η protein at 1.11 ng/mL yield a secondary SS diagnostic accuracy of 71%. CONCLUSIONS: Serum 14-3-3η protein level is high in SLE-associated SS. The 14-3-3η protein level was able to distinguish patients with secondary SS among patients with SLE. Studying the role of 14-3-3η protein in Sjögren's syndrome would be considered in further larger scale studies to confirm the impact of any association. Key Points • Serum 14-3-3η protein level is significantly higher in systemic lupus patients with secondary Sjögren's syndrome (SS) in comparison to those without. • Serum 14-3-3η protein can be used as a useful marker to distinguish patients with secondary SS among patients with systemic lupus. • 14-3-3η protein level shows no difference between systemic lupus patients with and without arthritis.