Methacholine challenge in asthmatics is protected by aerosolised hyaluronan at high (∼1,000 KDa) but not low (∼300 KDa) molecular weight

L. Allegra, W. M. Abraham, V. Fasano, G. Petrigni

Research output: Contribution to journalArticlepeer-review

8 Scopus citations


Hyaluronic acid, also called hyaluronan (HA) is a biopolymer presnt in nature at variable molecular weights (m.w.), member of the glycosaminoglycan family and one of the most important components of the connective amorphous colloidal matrix, specially in the mammalian lungs, where is present in particularly high concentrations. HA, as well as other members of the same family (namely heparin and its derivatives) is provided with preventive, as well as therapeutic properties, demonstrated in asthma, COPD and lung emphysema, both in experimental animals and humans. In this study we have investigated the possibility that HA, at a m.w. of ∼1.000 KDa (but not at a m.w. of ∼300 KDa) improves bronchial patency in asthmatics exposed to the nebulisation of progressively increasing doses of methacholine (Mch), a direct non-specific bronchoconstrictive challenge. So, we have submitted to such provocation 28 asthmatic patients of allergic nature evaluated out of the season of their specific allergy, divided into two groups according to a randomised, cross over, double-blind design: 14 pts (5 males, 9 females; 39.8 ± 4.3 yrs, mean age ± standard error) were pretreated (-30/-45 min') with an aerosol of 3 ml of placebo (P) or HA ∼1.000 KDa, 0,3%; 14 other patients (6 males, 8 females, 34.8 ± 3.2 yrs) were treated with similar modalities, but HA had a m.w. of ∼300 KDa. Only HA ∼1.000 KDa induced (vs P) a statistically significant (p=0.034) increase of PD20FEV1 (dose of Mch causing a fall of FEV1 ≥20% vs its basal value), while changes induced by HA ∼300 KDa (vs P) resulted nonsignificant (p=0.462). In conclusion, aerosolised HA, but only at relatively high m.w. (∼1.000 KDa) shows the capacity of significantly preventing in asthmatics the bronchocontrictive effect of Mch, a direct specific challenge which is considered pathognomonic in the diagnosis of bronchial asthma.

Original languageEnglish (US)
Pages (from-to)297-301
Number of pages5
JournalGIMT - Giornale Italiano delle Malattie del Torace
Issue number5
StatePublished - 2008
Externally publishedYes


  • Bronchial asthma
  • Hyaluronan
  • Methacholine
  • Provocation test

ASJC Scopus subject areas

  • Pulmonary and Respiratory Medicine


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