Clinical characteristics and outcomes in patients with primary Sjogren's syndrome-associated interstitial lung disease

BACKGROUND: Diagnosing primary Sjogren's syndrome (pSS)-associated interstitial lung disease (ILD) is complex and can be very challenging. In addition, information about the prognostic factors is limited. AIMS: We aimed to determine the clinical characteristics and prognostic factors that impact pSS-ILD survival. METHODS: This retrospective review included 84 consecutive patients diagnosed with pSS-ILD. The information analyzed included the clinical characteristics, laboratory findings, and physiological and hemodynamic data. Prognostic factors were identified using a Cox proportional hazards regression model. RESULTS: The mean age was 60.5 years, and 61.9% were females. The mean time between the onset of symptoms and diagnosis was 21 months (range, 1–98 months). Minor salivary gland biopsy (MSGB) was positive for pSS in 92.3% of the cohort. Fifty percent of the patients had negative autoimmune serology related to pSS. Based on the available hemodynamic data, 40% had pulmonary hypertension (PH), and 20% had severe PH. During follow-up, acute exacerbation was noted in 38% of the cohort. The 5-year survival rate for all patients was 56%. Male sex, usual interstitial pneumonia pattern, and a reduced forced vital capacity were independent predictors of mortality in the pSS-ILD patients. CONCLUSIONS: A significant delay between the onset of symptoms and diagnosis was noted in our cohort. Importantly, our study highlights the importance of MSGB and emphasizes that clinicians should not rely solely on serological tests to diagnose pSS in ILD patients. The overall survival was poor, and more efforts are needed to diagnose pSS-ILD at an early stage and refer patients to experienced centers.