Both type I and II interferons (IFNs) have been implicated in the pathogenesis of Sjogren's syndrome (SS). We aimed to explore the contribution of type I and II IFN signatures in the generation of distinct SS clinical phenotypes including lymphoma development. Peripheral blood (PB) from SS patients (n=31), SS patients complicated by lymphoma (n=13) and healthy controls (HC, n=30) were subjected to real-time PCR for 3 interferon inducible genes (IFIGs) preferentially induced by type I IFN, 2 IFIGs preferentially induced by IFNγ as well as for IFNα and IFNγ genes. The same analysis was performed in minor salivary gland tissues (MSG) derived from 31 SS patients, 10 SS-lymphoma patients and 17 sicca controls (SC). In PB and MSG tissues, overexpression of both type I and type II IFIGs was observed in SS patients versus HC and SC, respectively, with a predominance of type I IFN signature in PB and a type II IFN signature in MSG tissues. In SS-lymphoma MSG tissues, lower IFNα, but higher IFNγ and type II IFIG transcripts compared to both SS and SC were observed. In receiver operating characteristic curve analysis, IFNγ/IFNα mRNA ratio in MSG tissues showed the best discrimination for lymphoma development. Discrete expression patterns of type I and II IFN signatures might be related to distinct SS clinical phenotypes. Additionally, IFNγ/IFNα mRNA ratio in diagnostic salivary gland biopsies is proposed as a novel histopathological biomarker for the prediction of in situ lymphoma development in the setting of SS.

IntroductionTo determine the prevalence and clinical/laboratory associations of subclinical atherosclerosis and impaired bone health in primary Sjogren’s syndrome (SS).Methods64 consecutive patients with primary SS, 77 with rheumatoid arthritis (RA) and 60 healthy controls (HC) οf similar age and sex distribution were enrolled. Demographics, clinical/laboratory features, classical risk factors for atherosclerosis and osteoporosis (OP) were recorded. Intima-medial thickness scores (IMT) and carotid/femoral (C/F) plaque formation, as well as bone mineral density (BMD) and fractures were evaluated. Determinants of IMT/BMD levels and the presence of plaque were assessed by univariate and multivariate models. Serum levels of the Wnt signaling mediators Dickkopf-related protein 1(DKK1) and sclerostin were determined in primary SS patients and HC.ResultsIncreased arterial wall thickening (IMT > 0.90 mm) and impaired bone health (defined as OP or osteopenia), were detected in approximately two-thirds of primary SS and RA patients, with a mean IMT value being significantly increased compared to HC. The presence of primary SS emerged as an independent risk factor for arterial wall thickening when traditional risk factors for cardiovascular disease (CVD) including age, sex, hypertension, smoking (pack/years), LDL and HDL levels were taken into account in a multivariate model [adjusted OR 95% (CI): 2.8 (1.04-7.54)]. In primary SS, age was revealed as independent predictor of increased IMT scores; age and lymphopenia as well as increased urine pH as independent determinants of C/F plaque formation and OP/osteopenia, respectively. An independent association of OP/osteopenia with plaque formation was observed when independent predictors for both variables were considered, with low DKK1 levels being associated with both plaque formation and lower BMD levels.ConclusionsComorbidities such as subclinical atherosclerosis and impaired bone health occur frequently in primary SS, in association with disease related features and traditional risk factors. Wnt signaling mediators are potentially involved in the pathogenesis of both entities.Electronic supplementary materialThe online version of this article (doi:10.1186/s13075-015-0613-6) contains supplementary material, which is available to authorized users.

Objectives RA and primary SS carry increased atherosclerotic risk, while B-cell activating factor holds a vital role in disease pathogenesis and atherosclerosis. We aimed to compare subclinical atherosclerosis profiles between the two clinical entities and define whether BAFF genetic variants alter atherosclerotic risk. Methods DNA from 166 RA, 148 primary SS patients and 200 healthy controls of similar age and sex distribution was subjected to PCR-based assay for the detection of five single nucleotide polymorphisms of the BAFF gene (rs1224141, rs12583006, rs9514828, rs1041569 and rs9514827). Genotype and haplotype frequencies were determined by SNPStats software and statistical analysis was performed by SPSS and Graphpad Software. Subclinical atherosclerosis was defined by the presence of carotid/femoral plaque formation and arterial wall thickening. Results Atherosclerotic plaque formation was more frequently detected in the RA vs primary SS group (80.7% vs 62.2%, P-value <0.001), along with higher rates of family CVD history, current steroid dose and serum inflammatory markers. The TT genotype of the rs1224141 variant was more prevalent in RA but not primary SS patients with plaque and arterial wall thickening vs their counterparts without. Regarding the rs1014569 variant, among RA patients the TT genotype increased the risk for plaque formation while in primary SS patients the AT genotype conferred increased risk. Haplotype GTTTT was protective in the RA cohort, while TATTT and TTCTT haplotypes increased susceptibility for arterial wall thickening in the primary SS cohort. Conclusions Increased inflammatory burden, higher steroid doses and distinct BAFF gene variations imply chronic inflammation and B-cell hyperactivity as key contributors for the augmented atherosclerotic risk among autoimmune patients.

Objective. To evaluate the prevalence of antibodies to 21-hydroxylase (anti-21[OH]), a marker of autoimmune adrenal disease, in a cohort of patients with primary Sjögren's syndrome (SS) and to investigate whether the presence of anti-21(OH) correlates with clinical, serologic, and salivary gland features of the disease.Methods. Sera from 63 consecutive patients with primary SS, 32 patients with autoimmune thyroid disease (AITD), and 20 healthy controls were obtained and anti-21(OH) levels were determined by radioimmunoassay. Clinical, serologic, and histopathologic features were recorded, and a short Synacthen test was used to assess adrenal function reserve. Seven available minor salivary gland (MSG) tissue specimens from patients in the primary SS cohort were also assessed for interferon-␣ (IFN␣), BAFF, and interleukin-21 (IL-21) cytokine transcripts, which are all implicated in B cell activation.Results. Anti-21(OH) positivity was detected in 17.5% and 28.1% of primary SS and AITD patients, respectively, and in none of the healthy controls. While no evidence of adrenal insufficiency was detected in any of the patients studied, a blunted rate of increase in cortisol levels was observed in patients with detectable serum autoantibodies against 21(OH), compared to their anti-21(OH)-negative counterparts. A strong correlation between the serum titer of anti-21(OH) antibodies and expression of IFN␣, BAFF, and IL-21 messenger RNA in MSG tissues was also detected. Conclusion.Adrenal autoimmunity occurs in almost 20% of patients with primary SS in association with markers of B cell activation. Although the presence of adrenal autoantibodies was not associated with adrenal insufficiency in the present study, there was a blunted adrenal response, suggesting the need for further followup and monitoring of adrenal function in patients with primary SS who are positive for the autoantibodies.

BackgroundB-cell non-Hodgkin’s lymphoma (B-NHL) is one of the major complications of primary Sjögren’s syndrome (SS). Chronic inflammation and macrophages in SS minor salivary glands have been previously suggested as significant predictors for lymphoma development among SS patients. Lipoprotein-associated phospholipase A2 (Lp-PLA2)—a product mainly of tissue macrophages—is found in the circulation associated with lipoproteins and has been previously involved in cardiovascular, autoimmune, and malignant diseases, including lymphoma.ObjectiveThe purpose of the current study was to investigate the contributory role of Lp-PLA2 in B-NHL development in the setting of primary SS.MethodsLp-PLA2 activity in serum samples collected from 50 primary SS patients with no lymphoma (SS-nL), 9 primary SS patients with lymphoma (SS-L), and 42 healthy controls (HC) was determined by detection of [3H]PAF degradation products by liquid scintillation counter. Moreover, additional sera from 50 SS-nL, 28 SS-L, and 32 HC were tested for Lp-PLA2 activity using a commercially available ELISA kit. Lp-PLA2 mRNA, and protein expression in minor salivary gland (MSG) tissue samples derived from SS-nL, SS-L patients, and sicca controls (SC) were analyzed by real-time PCR, Western blot, and immunohistochemistry.ResultsSerum Lp-PLA2 activity was significantly increased in SS-L compared to both SS-nL and HC by two independent methods implemented [mean ± SD (nmol/min/ml): 62.0 ± 13.4 vs 47.6 ± 14.4 vs 50.7 ± 16.6, p-values: 0.003 and 0.04, respectively, and 19.4 ± 4.5 vs 15.2 ± 3.3 vs 14.5 ± 3.0, p-values: <0.0001, in both comparisons]. ROC analysis revealed that the serum Lp-PLA2 activity measured either by radioimmunoassay or ELISA has the potential to distinguish between SS-L and SS-nL patients (area under the curve [AUC]: 0.8022, CI [95%]: 0.64–0.96, p-value: 0.004 for radioimmunoassay, and AUC: 0.7696, CI [95%]: 0.66–0.88, p-value: <0.0001, for ELISA). Lp-PLA2 expression in MSG tissues was also increased in SS-L compared to SS-nL and SC at both mRNA and protein level. ROC analysis revealed that both MSG mRNA and protein Lp-PLA2 have the potential to distinguish between SS-nL and SS-L patients (area under the curve [AUC] values of 0.8490, CI [95%]: 0.71–0.99, p-value: 0.0019 and 0.9444, CI [95%]: 0.79–1.00, p- value: 0.0389 respectively). No significant difference in either serum Lp-PLA2 activity or MSG tissue expression was observed between SS-nL and HC.ConclusionsLp-PLA2 serum activity and MSG tissue mRNA/protein expression could be a new biomarker and possibly a novel therapeutic target for B-cell lymphoproliferation in the setting of SS.