Extracellular Vesicle Surface Signatures in IPF Patients: A Multiplex Bead-Based Flow Cytometry Approach

Abstract

Background: Extracellular vesicles (EVs) are secreted by cells from their membrane within circulation and body fluids. Knowledge of the involvement of EVs in pathogenesis of lung diseases is increasing. The present study aimed to evaluate the expression of exosomal surface epitopes in a cohort of idiopathic pulmonary fibrosis (IPF) patients followed in two Italian Referral Centres for Interstitial Lung Diseases, comparing them with a group of healthy volunteers. Materials and Methods: Ninety IPF patients (median age and interquartile range (IQR) 71 (66–75) years; 69 males) were selected retrospectively. Blood samples were obtained from patients before starting antifibrotic therapy. A MACSPlex Exosome Kit, human, (Miltenyi Biotec, Bergisch-Gladbach, Germany), to detect 37 exosomal surface epitopes, was used. Results: CD19, CD69, CD8, and CD86 were significantly higher in IPF patients than in controls (p = 0.0023, p = 0.0471, p = 0.0082, and p = 0.0143, respectively). CD42a was lower in IPF subjects than in controls (p = 0.0153), while CD209, Cd133/1, MCSP, and ROR1 were higher in IPF patients than in controls (p = 0.0007, p = 0.0050, p = 0.0139, and p = 0.0335, respectively). Kaplan–Meier survival analysis for IPF patients: for median values and a cut-off of 0.48 for CD25, the two subgroups showed a significant difference in survival rate (p = 0.0243, hazard ratio: 0.52 (95%CI 0.29–0.92); the same was true for CD8 (cut-off 1.53, p = 0.0309, hazard ratio: 1.39 (95%CI 0.75–2.53). Conclusion: Our multicenter study showed for the first time the expression of surface epitopes on EVs from IPF patients, providing interesting data on the communication signatures/exosomal profile in serum from IPF patients and new insights into the pathogenesis of the disease and a promising reliability in predicting mid-term survival of IPF patients.

Exosomes in pathogenesis, diagnosis, and treatment of pulmonary fibrosis

“…In addition, increased expression of CD8 was associated with poor prognosis in IPF in survival analysis. These results provide the basis for the use of blood exosome surface epitopes as candidate biomarkers for the diagnosis and prognosis of IPF ( D'Alessandro et al, 2021 ).…”

Extracellular Vesicles in Pulmonary Fibrosis Models and Biological Fluids of Interstitial Lung Disease Patients: A Scoping Review

“…To our knowledge, only one paper investigates the expression of exosomal surface markers in serum from IPF patients [48]. The authors found an increase in the expression of CD19, CD8, CD69 and CD86 in such patients, suggesting and confirming the "immune profile" of IPF pathogenesis.…”

“…They also reported high expression of ROR1, a key mediator of WNT5a signalling, on EVs. WNT5a signalling is a regulator of fibroblast proliferation and resistance to apoptosis, both mechanisms involved in the development and progression of lung fibrosis in IPF [48].…”

Extracellular Lipids in the Lung and Their Role in Pulmonary Fibrosis

“…A growing body of literature shows that EVs are a key component in the pathobiology of IPF. Those vesicles accumulate in the lungs of patients with IPF [ 164 ], and they harbor specific cargoes of proteins and microRNA [ 164 , 165 , 166 , 167 , 168 , 169 ]. Mechanistically, fibrosis-derived EVs activate the mechanism of fibrosis, such as fibroblast proliferation and activation, by controlling developmental signaling such as Wnt or TGF-β1 [ 164 , 167 ].…”