Pulmonary arterial hypertension associated with primary Sjögren's syndrome: a multicentre cohort study from China

OBJECTIVES: Primary Sjögren's syndrome (pSS) is an important cause of pulmonary arterial hypertension (PAH), which remains insufficiently studied and needs attention. This study aimed to investigate the clinical characteristics, risk factors, prognosis and risk assessment of pSS-PAH. METHODS: We established a multicentre cohort of pSS-PAH diagnosed by right heart catheterisation. The case-control study was conducted with pSS-non-PAH patients as a control group to identify the risk factors for PAH. In the cohort study, survival was calculated, and risk assessment was performed at both baseline and follow-up visits. RESULTS: In total, 103 patients with pSS-PAH were enrolled, with 526 pSS-non-PAH patients as controls. The presence of anti-SSB (p<0.001, OR 4.095) and anti-U1RNP antibodies (p<0.001, OR 29.518), the age of pSS onset (p<0.001, OR 0.651) and the positivity of corneal staining (p=0.003, OR 0.409) were identified as independent risk factors for PAH. The 1-, 3- and 5-year survival rates were 94.0%, 88.8% and 79.0%, respectively. Cardiac index (p=0.010, hazard ratio (HR) 0.161), pulmonary vascular resistance (p=0.016, HR 1.105) and Sjögren's syndrome disease damage index (p=0.006, HR 1.570) were identified as potential predictors of death in pSS-PAH. Long-term outcomes were improved in patients in the low-risk category at baseline (p=0.002) and follow-up (p<0.0001). CONCLUSION: The routine screening of PAH is suggested in pSS patients with early onset and positivity for anti-SSB or anti-U1RNP antibodies. Patient prognosis might be improved by improving reserved cardiopulmonary function, by achieving a damage-free state and especially by achieving low-risk category, which supports the treat-to-target strategy for pSS-PAH.