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.