Epigenetic alterations in primary Sjögren's syndrome - an overview

Primary Sjögren's syndrome (pSS) is a chronic autoimmune rheumatic disease characterized by inflammation of exocrine glands, mainly salivary and lacrimal glands. In addition, pSS may affect multiple other organs resulting in systemic manifestations. Although the precise etiology of pSS remains elusive, pSS is considered to be a multi-factorial disease, where underlying genetic predisposition, environmental factors and epigenetic mechanisms contribute to disease development. Epigenetic mechanisms, such as DNA methylation, histone modifications and non-coding RNAs, may constitute a dynamic link between genome, environment and phenotypic manifestation by their modulating effects on gene expression. A growing body of studies reporting altered epigenetic landscapes in pSS suggests that epigenetic mechanisms play a role in the pathogenesis of pSS, and the reversible nature of epigenetic modifications suggests therapeutic strategies targeting epigenetic dysregulation in pSS. This article reviews our current understanding of epigenetic mechanisms in pSS and discusses implications for novel diagnostic and therapeutic approaches.

Biomarkers of interstitial lung disease associated with primary Sjögren's syndrome

Objectives

The aim of this study was to investigate serum biomarkers linked to primary Sjögren's syndrome (pSS)-associated interstitial lung disease (ILD).

Methods

69 pSS patients were consecutively enrolled and evaluated via quantitative ILD scoring based on high-resolution computed tomography (HRCT). Biomarkers of interest were assessed by multiplex enzyme-linked immunosorbent assays (ELISAs).

Results

Among consecutively enrolled patients with pSS, the presence of pSS–ILD was 50% based on the presence of radiographically defined interstitial lung abnormalities (ILA) meeting specified criteria for mild/moderate (ILA 2) or severe (ILA 3) disease. Age, immunoglobulin M (IgM), C-reactive protein (CRP), and serum levels of eotaxin/CCL11, Krebs von den Lungen-6 (KL-6), TNFα, and TGFα were significantly higher in the combined pSS–ILD group (ILA 2 + ILA 3) than in the pSS–no-ILD and pSS–indeterminate ILD groups (ILA 0 and ILA 1, respectively) in unadjusted analyses (p < 0.05 for all variables). A binary logistic regression model revealed that disease duration and KL-6 levels were associated with the presence of pSS–ILD (p < 0.05). Complementary least absolute shrinkage and selection operator (LASSO) modeling showed that age, KL-6, and TNF-α effectively differentiated pSS–ILD (ILA 2 + ILA3) from pSS without ILD (ILA 0 + ILA 1), with an area under the curve (AUC) of 0.883 (p value < 0.0001).

Conclusions

Patient age, disease duration, and serum levels of both KL-6 and TNFα were the most discriminating factors associated with the presence of ILD in our pSS patients. Higher levels of CRP, IgM, eotaxin, TGFα, and TNFα should also prompt the search for occult as well as clinically evident lung involvement based on statistically significant univariate associations with pSS–ILD.

Clinical trial registration

None.

Supplementary Information

The online version contains supplementary material available at 10.1186/s40001-022-00828-3.

Sjögren's syndrome and pulmonary hypertension: Exploring the intricate link with interstitial lung disease

BACKGROUND

Primary Sjögren's syndrome (pSS) is a systemic autoimmune disease commonly presenting with sicca symptoms and, in approximately one-third of cases, extra-glandular manifestations, including pulmonary involvement. Pulmonary hypertension (pH) is a recognized, though less frequently studied, complication in pSS, particularly in patients with interstitial lung disease (ILD). This study evaluates the prevalence of PH in pSS and the relationship between ILD and cardiovascular risk in this population.

METHODS

This cross-sectional study included 63 patients with pSS, diagnosed according to ACR/EULAR criteria. Among them, 24 patients (38.1 %) had ILD, with 9 presenting pulmonary fibrosis. Comprehensive evaluations were conducted, including 2D/3D echocardiography, HRCT, and pulmonary function tests. Right heart catheterization confirmed PH when indicated. Patients were categorized into pSS-ILD and pSS-noILD groups for comparative analysis.

RESULTS

The cohort comprised 7 males (11.1 %) and 56 females (88.9 %), with a mean age of 69.1 ± 12.5 years. The prevalence of PH was low (1.6 %), with only one confirmed case via right heart catheterization, significantly below previous reports. Notably, pSS-ILD patients were older (77.1 ± 10.7 years) and diagnosed with pSS later (68.5 ± 12.6 years; p = 0.001) than pSS-noILD patients. Cardiovascular comorbidities, including arterial hypertension (32.8 %) and dyslipidemia (24.2 %), were more prevalent in pSS-ILD patients (p = 0.003 and p = 0.001, respectively). Pulmonary function tests revealed lower FVC (2.23 ± 0.70 vs. 2.98 ± 0.56; p = 0.004) and DLCO-Sb (3.87 ± 1.52 vs. 5.31 ± 1.26; p = 0.017) in pSS-ILD patients, indicating reduced lung function. Echocardiographic findings showed higher sPAP values (>35 mmHg) and reduced TAPSE/sPAP ratios in the pSS-ILD group (p = 0.028 and p = 0.026, respectively), suggesting early signs of right ventricular impairment.

CONCLUSIONS

PH prevalence in pSS is lower than previously reported, likely due to rigorous diagnostic criteria. Patients with pSS-ILD exhibit a higher risk of cardiovascular comorbidities and lung function decline. Echocardiographic monitoring of parameters like TAPSE/sPAP may aid in early PH detection, emphasizing the need for tailored management in pSS-ILD patients. Further studies are warranted to explore PH subtypes in diverse populations and to optimize follow-up protocols for at-risk patients.