Characterizing the lavage and serum cytokine profiles of interstitial pneumonia with autoimmune features and their implications for progressive fibrosis

To explore whether cytokines could be potential biomarkers to predict the occurrence of progressive fibrosis (PF) phenotype among interstitial pneumonia with autoimmune features (IPAF) patients.This study prospectively collected 51 IPAF and 15 Idiopathic Pulmonary Fibrosis (IPF) patients who were diagnosed at First Affiliated Hospital of Guangzhou Medical University from July 2020 to June 2021. All IPAF patients were followed up for one year to assess the development of PF phenotype. Paired Broncho Alveolar Lavage Fluid (BALF) and serum samples were collected at enrolment and analyzed for differences in 39 cytokines expression. Principal component analysis (PCA) and cluster analysis were conducted to identify a high-risk subgroup of IPAF patients for developing the PF phenotype. Finally, cytokine differences were compared between subgroups to identify potential biomarkers for PF-IPAF occurrence.According to the PCA analysis, 81.25% of PF-IPAF patients share overlapped BALF cytokine profiles with IPF. Cluster analysis indicated IPAF patients in subtype 2 had a higher risk to develop PF phenotype within one year (P = 0.048), characterized by higher levels of CCL2, CXCL12 and lower lymphocyte proportion (LYM%) in BALF. Elevated levels of BALF CCL2 (>299.16 pg./ml) or CXCL12 (>600.115 pg./ml) were associated with a significantly higher risk of developing PF phenotype within one year follow-up period (P = 0.009, 0.001).PF-IPAF phenotype exhibits similar inflammatory cytokine profiles to IPF. Cytokine CCL2, CXCL12, and LYM% in BALF serving as potential biomarkers for predicting the PF phenotype in IPAF patients.Register: Qian Han, Website: http://www.chictr.org.cn/showproj.aspx?proj=61619, Registration number: ChiCTR2000040998.