Enhanced soluble interleukin-5 receptor alpha expression in nasal polyposis

Allergy. 2003 May;58(5):371-9. doi: 10.1034/j.1398-9995.2003.00110.x.


Background: Alternative splicing of the interleukin-5 receptor alpha (IL-5Ralpha)-subunit leads to the generation of a signalling, membrane-anchored (TM) isoform, or a secreted [soluble (SOL)], antagonistic variant. Given the key role of IL-5 in eosinophil function, we investigated SOL IL-5Ralpha expression pattern in an eosinophil-associated disease such as nasal polyposis (NP).

Methods: An SOL IL-5Ralpha enzyme-linked immunosorbent assay and quantitative real-time polymerase chain reaction (PCR) were established and applied in serum, nasal secretion and nasal tissue of controls (n = 12), and NP patients (n = 42) with or without asthma.

Results: Analysis of serum, nasal secretion, and nasal tissue samples revealed that SOL IL-5Ralpha protein concentrations were significantly increased in NP vs control tissue. Within the NP group, there was a significant up-regulation of SOL IL-5Ralpha in patients with systemic airway disease. These findings were confirmed at the mRNA level, using an optimized real-time reverse-transcriptase PCR procedure.

Conclusions: This report demonstrates SOL IL-5Ralpha transcript and protein up-regulation in NP. Soluble IL-5Ralpha differentiates nasal polyps with or without concomitant asthma. As SOL IL-5Ralpha is strongly up-regulated for disease and has antagonistic properties in vitro, our studies shed new light on the mechanisms of specific immunomodulatory therapies, such as anti-IL-5.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Aged
  • Antibodies, Monoclonal
  • Asthma / immunology
  • Case-Control Studies
  • Enzyme-Linked Immunosorbent Assay
  • Eosinophils / immunology
  • Female
  • Humans
  • Interleukin-5 / blood
  • Interleukin-5 / metabolism*
  • Male
  • Middle Aged
  • Nasal Mucosa / immunology
  • Nasal Polyps / immunology*
  • RNA, Messenger / blood
  • Receptors, Interleukin / blood
  • Receptors, Interleukin / metabolism*
  • Receptors, Interleukin-5
  • Reverse Transcriptase Polymerase Chain Reaction
  • Up-Regulation


  • Antibodies, Monoclonal
  • Interleukin-5
  • RNA, Messenger
  • Receptors, Interleukin
  • Receptors, Interleukin-5