Which chemical mediators are found in pediatric nasal polyps?

Updated: Oct 25, 2019
  • Author: John E McClay, MD; Chief Editor: Ravindhra G Elluru, MD, PhD  more...
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The stromata of nasal polyps have numerous mediators, including cytokines, growth factors, adhesion molecules, and immunoglobulins; polyps also contain vasoactive amines, serotonin, prostaglandins [11] , leukotrienes, norepinephrine, kinins, esterases, heparin, and histamine. The level of histamine in nasal polyps is 100-1000 times the level found in the bloodstream.

Cytokines present in polyps include the following:

  • IL-1 - Found regularly
  • IL-3 - Varies according to study, from absent to intermittent at low levels to regularly present
  • IL-4 - Inconsistently detected
  • IL-5 - Found regularly; IL-5 is essential for proliferation and differentiation of eosinophils. IL-5 is chemotactic to eosinophils, promotes the migration of eosinophils from the systemic circulation to the polyps, and inhibits eosinophil cell death.
  • IL-6 - Same as in controls (no increase)
  • IL-8 - Varies, based on study, from undetected to regularly detected; may cause sustained recruitment of leukocytes into nasal polyps and may decrease fibroblastic proliferation
  • IL-10 - Same as in controls; no increase regulated on activation, normal T cell expressed and secreted (RANTES); varies, based on study, from same as controls to regularly detected to increased levels interferon gamma; increases in eosinophils, seromucous glands, and epithelium of nasal polyps

Growth factors found in nasal polyps include the following:

  • Tumor necrosis factor (TNF)-α and TNF-β - Varies, depending on the study, from same as controls to regularly detected; believed to be from eosinophils
  • GM-CSF - mRNA and protein amount varies, based on study, from never to intermittent to present
  • Platelet-derived growth factor (PDGF) - Present
  • Vascular permeable factors (VPFs) - Present
  • Vascular endothelial growth factors (VEGFs) - Present
  • Insulinlike growth factor (IGF)-1 - Present
  • Stem cell factor - Present

Adhesion molecules include the following:

  • Vascular adhesion molecule (VCAM)-1 - Present
  • E and P selectin - Present

Immunoglobulins include the following:

  • IgG - No increase; same levels as in the middle and inferior turbinate mucosa
  • IgA - More in polyps than in the middle and inferior turbinate mucosa, especially IgA1 over IgA2
  • IgM - No increase, same as in the middle and inferior turbinate mucosa
  • IgD - No increase, same as in the middle and inferior turbinate mucosa
  • IgE - Increased levels compared with the middle and inferior turbinate mucosa; same level in patients without allergy as in those with allergy

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