Pentraxin levels in non-eosinophilic versus eosinophilic asthma

Clin Exp Allergy. 2018 Aug;48(8):981-989. doi: 10.1111/cea.13168. Epub 2018 Jun 19.

Abstract

Background: Innate immunity has been thought to be involved in asthma pathogenesis. Pentraxins, acting as soluble pattern recognition molecules, play an important role in humoral innate immunity. Asthma is a heterogeneous inflammatory disease of airways and can be classified as eosinophilic or non-eosinophilic asthma.

Objective: To investigate whether pentraxin levels differ in subjects with eosinophilic versus non-eosinophilic asthma. Furthermore, to access the predictive performance of pentraxin levels for discriminating asthma inflammatory phenotypes.

Methods: A total of 80 asthmatic patients and 24 healthy control subjects underwent sputum induction at study inclusion. Differential leucocyte counts were performed on selected sputum. Plasma C-reactive protein (CRP), serum amyloid P (SAP), pentraxin 3 (PTX3), and sputum SAP, PTX3, IL-8 levels were determined by enzyme-linked immunosorbent assay.

Results: Subjects with non-eosinophilic asthma had significantly increased pentraxin levels compared with those with eosinophilic asthma and healthy controls, with median (interquartile range) plasma CRP levels of 0.86 (0.28-2.07), 0.26 (0.14-0.85), and 0.15 (0.09-0.45)mg/L (P < .001), respectively, plasma SAP levels of 33.69 (19.79-58.39), 19.76 (16.11-30.58), and 20.06 (15.68-31.11)mg/L (P = .003), respectively, and sputum PTX3 levels of 4.9 (1.35-18.72), 0.87 (0.30-2.07), and 1.08 (0.31-4.32)ng/mL (P < .001), respectively. Conversely, sputum SAP concentrations of eosinophilic asthmatics (median, 21.49 ng/mL; IQR, 6.86-38.79 ng/mL) were significantly higher than those of non-eosinophilic patients (median, 8.15 ng/mL; IQR, 2.82-18.01 ng/mL) and healthy controls (median, 8.79 ng/mL; IQR, 2.00-16.18 ng/mL). Asthma patients with high plasma CRP (P = .004), SAP (P = .005) and sputum PTX3 levels (P < 0.001) also had significantly lower sputum eosinophil percentages. Sputum PTX3 levels had the best power (11.18-fold, P < .001) to predict non-eosinophilic airway inflammation in asthma patients.

Conclusion and clinical relevance: Pentraxin levels differed significantly between patients with non-eosinophilic asthma and those with eosinophilic asthma. Furthermore, elevated pentraxin expressions may predict non-eosinophilic airway inflammation in asthmatic patients.

Keywords: asthma; clinical immunology; eosinophilic; innate immunity; non-eosinophilic; pentraxins.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Asthma / diagnosis
  • Asthma / etiology*
  • Asthma / metabolism*
  • Biomarkers*
  • C-Reactive Protein / metabolism*
  • Case-Control Studies
  • Eosinophils / immunology*
  • Eosinophils / metabolism*
  • Female
  • Humans
  • Inflammation Mediators / metabolism
  • Leukocyte Count
  • Male
  • Middle Aged
  • ROC Curve
  • Respiratory Function Tests
  • Serum Amyloid P-Component / metabolism*
  • Sputum

Substances

  • Biomarkers
  • Inflammation Mediators
  • Serum Amyloid P-Component
  • PTX3 protein
  • C-Reactive Protein