Review: Serum Biomarkers of Lung Fibrosis in Interstitial Pneumonia with Autoimmune Features—What Do We Already Know?

Abstract

Interstitial pneumonia with autoimmune features (IPAF) belongs to a group of diseases called interstitial lung diseases (ILDs), which are disorders of a varied prognosis and course. Finding sufficiently specific and sensitive biomarkers would enable the progression to be predicted, the natural history to be monitored and patients to be stratified according to their treatment. To assess the significance of pulmonary fibrosis biomarkers studied thus far, we searched the PubMed, Medline and Cochrane Library databases for papers published between January 2015 and June 2021. We focused on circulating biomarkers. A primary review of the databases identified 38 articles of potential interest. Overall, seven articles fulfilled the inclusion criteria. This review aims to assess the diagnostic and prognostic value of molecules such as KL-6, SP-A, SP-D, circulating fibrocytes, CCL2, CXCL13, CXCL9, CXCL10 and CXCL11. All of these biomarkers have previously been studied in idiopathic pulmonary fibrosis (IPF) and connective tissue disease-associated interstitial lung disease (CTD-ILD). IPAF is a disorder of a heterogeneous nature. It explains the lack of coherent observations in terms of correlations with functional parameters. There is still no meta-analysis of pulmonary fibrosis biomarkers in IPAF. This is mainly due to the heterogeneity of the methodology and groups analysed in the research. More research in this area is needed.

Endothelin-1 as a Biomarker of Idiopathic Pulmonary Fibrosis and Interstitial Lung Disease Associated with Autoimmune Diseases

“…The study of biomarkers as additional tools in the clinical practice for the diagnosis and severity of ILD has aroused great interest in the last years [ 17 , 22 , 23 , 24 , 25 , 26 , 27 , 28 , 29 ]. In this regard, the role of ET-1 in the pathogenesis of a large and well-defined cohort of ILD patients remains to be investigated in depth.…”

Sustained AWT1 expression by Dupuytren’s disease myofibroblasts promotes a proinflammatory milieu

“…4 and 5). Both CXCR4 /CXCL12/SDF‐1 (Scotton and Chambers 2007) and CXCL10/IP‐10 (Miądlikowska et al 2021) have been identified as potential biomarkers of pulmonary fibrosis, however neither have been previously linked to the enhanced WT1 expression levels in this disease (Karki et al 2015; Sontake et al 2015). Based on our previous studies (Gonga‐Cavé et al 2021), it is likely that IP‐10 is jointly derived from both DD PFMs and from immune cells in DD.…”

Detection of interstitial pneumonia with autoimmune features and idiopathic pulmonary fibrosis are enhanced by involvement of matrix metalloproteinases levels and clinical diagnosis

“…Importantly the addition of the ve investigational biomarkers SP-A, KL-6, LDH, CRP, and tIgE signi cantly increased the AUC to 0.756 for comparison of Stability AUC -Exacerbation AUC in IPAF cohort (P < 0.05 for the difference between the curves) (Table3, Figure 4). [27,[39][40][41][42][43][44][45][46][47][48][49] Pulmonary function testing (PFT) and Blood cell test Whether IPAF is compared with IPF, or simply a comparison among the three strati cations of the severity of IPAF (p<0.05), apart from DLCO, which identi ed 36 patients with moderate interstitial lung disease, the remaining PFT items, including FVC, FEV1 showed that the patients in two cohorts did not show signi cant clinical signi cance in PFT (Figure 5). No abnormality was found in the selected cytokines in the blood cell test in the IPAF and IPF cohorts.…”