Risk factors for progression of interstitial lung disease in Sjögren's syndrome: a single-centered, retrospective study

To identify clinical characteristics and risk factors related to the progression of interstitial lung disease (ILD) in patients with primary Sjogren’s syndrome (pSS). In this single-centered, retrospective study, a total of 83 identified pSS-ILD patients with relatively complete clinical data were finally enrolled. Clinical symptoms, laboratory data, high-resolution computed tomography (HRCT), and pulmonary function test (PFT) results were collected. A logistic regression analysis was performed to determine the independent risk factors for ILD progression, and a nomogram was plotted to construct a predictive model. The prevalence of pSS-ILD in our study was 18.89%. Among the 83 enrolled patients, 32 (38.6%) underwent ILD progression. The characteristic features associated with the progression of ILD included male sex, non-sicca onset, reticular pattern on HRCT, higher levels of baseline lactic dehydrogenase (LDH), and low baseline forced vital capacity (FVC). The results of multivariate logistic regression indicated that LDH (OR 1.008, p = 0.030) was an independent risk factor for ILD progression, while sicca onset (OR 0.254, p = 0.044) and FVC (OR 0.952, p = 0.003) were protective factors for ILD progression. A simple predictive model for ILD progression in pSS was developed and validated. pSS patients with non-sicca onset, high baseline LDH level, and low baseline FVC were at higher risk of ILD progression.