Association of High Mobility Group Box Chromosomal Protein 1 and Receptor for Advanced Glycation End Products Serum Concentrations With Extraglandular Involvement and Disease Activity in Sjögren's Syndrome.

OBJECTIVE: To assess serum levels of high mobility group box chromosomal protein 1 (HMGB-1) and the soluble receptor for advanced glycation end products (sRAGE) in patients with Sjögren's syndrome (SS) and explore correlations with disease activity. METHODS: Thirty-nine patients with SS and 21 healthy controls were included in this cross-sectional study. Clinical and laboratory values were obtained from all patients. Disease activity was assessed using the European League Against Rheumatism SS Disease Activity Index (ESSDAI). Serum samples were collected and HMGB-1 and sRAGE levels were measured using enzyme-linked immunosorbent assay (ELISA), and HMGB-1 concentrations were semiquantified by Western blotting. RESULTS: In ELISA, HMGB-1 serum levels did not differ between healthy controls and patients with SS (P = 0.783). When measured by semiquantitative Western blotting, HMGB-1 levels were increased in patients with SS compared to healthy controls (P = 0.012). HMGB-1 serum levels detected by Western blotting were higher in patients with extraglandular manifestations (P = 0.003) and were correlated with ESSDAI disease activity (r = 0.544, P < 0.0001). Furthermore, sRAGE was elevated in the sera of patients with SS (P = 0.003) compared to healthy controls and was also correlated with the ESSDAI (r = 0.545, P = 0.002). CONCLUSION: Serum levels of total HMGB-1 and sRAGE were elevated in patients with SS compared to healthy controls and correlated with disease activity as measured by the ESSDAI. Patients with extraglandular involvement had high serum levels of HMGB-1.

Serological lymphocytic activity and patient-reported outcomes in Sjögren's syndrome.

This study was set to investigate whether serum markers of lymphocytic activity are associated with patient-reported outcomes in Sjögren's syndrome (SS). Forty-six patients with SS were included in this cross-sectional study. Patients with monoclonal gammopathy, history of malignant lymphoma, or with secondary SS were excluded. Serum levels of IgG, ß2-microglobulin (ß2M), soluble interleukin-2 receptor (sIL2-R), and free light chains (FLC) were assessed. Systemic disease activity was measured by the EULAR SS disease activity index (ESSDAI). Patient-reported symptoms were recorded by visual analogue scales (VAS) of pain, fatigue, and dryness, as compiled in the EULAR SS patient-reported index (ESSPRI). Depressive symptoms were determined by the Patient Health Questionnaire 9 (PHQ-9). Serum concentrations of κFLC (r = 0.491, p = 0.001), λFLC (r = 0.326, p = 0.027), and ß2M (r = 0.421, p = 0.004) correlated with the ESSDAI, whereas sIL-2R and IgG did not. No correlations between serum markers of lymphocytic activity and the ESSPRI, or single VAS measures of pain, dryness, or fatigue, were found. In patients with VAS fatigue scores in the upper quartile, sIL-2R serum levels were even decreased (p = 0.019). Only depressive symptoms as determined by PHQ-9 were positively correlated with fatigue (r = 0.536, p < 0.001). In this well-defined cohort of patients with SS, serological lymphocytic activity was not correlated with patient-reported outcomes and sIL-2R levels were even decreased in patients with high fatigue scores. Only depressive symptoms were correlated with fatigue. This highlights the need to further understand the link between inflammation and disease characteristics in SS.