New prospectives of Hyaluronic Acid in the upper airway chronic inflammation diseases by Casale Manuele in GJO in Juniper Publishers
Hyaluronic
acid (HA) is a naturally occurring polysaccharide which consists of a linear
chain of fragments of d-glucuronic acid and N-acetyl-glucosamine linked by
alternating β-3 and-β4 bonds.
It
is an abundant constituent of the extracellular matrix of connective tissue,
synovial fluid, embryonic mesenchyme, vitreous humor, skin, and several other
organs and tissues of the human body [1]. HA plays a pivotal role in the
homeostasis of respiratory apparatus.
High
molecular weight HA is broken down under the influence of free radicals and
enzymes during inflammation. Low molecular weight fragments deliver signal
about tissue damage and mobilize immune cells, while high molecular weight form
suppresses immune response preventing from excessive exacerbations of
inflammation [2,3].
HA,
which is a hygroscopic macromolecule and its solutions are highly osmotic,
forms a scaffold that several sulfur proteoglycans bind to. Such structures can
reach large size and are able to trap large quantities of water and ions,
providing hydration and tissue turgescence. In the upper airway HA is primarily
involved in the regulation of vasomotor tone and gland secretion and it
significantly contributes to nasal mucosal host defense, stimulating ciliary
clearance. Up to date, HA is widely used in several other branches of medicine
and neither contraindications nor interactions with drugs are reported [4-6]. Some
studies showed a role of HA in patients with upper aereo-digestive tract (UADT)
chronic inflammatory disease [7], first of all in patients affected by chronic
rhinosinusitis (CRS). CRS
is one of the most common chronic diseases in the United States affecting an
estimated 35 million people and is one of the most common causes of absence
from work and for visits to a family doctor’s office. HA could be a new CRS
treatment strategy that can minimize symptoms, promote recovery and prevent
exacerbations [8,9]. In
the same time, despite many advances in functional endoscopic nasal and sinus
surgery, in the first weeks after procedures painless lavages of nasal fossae
provide to eliminate secretions, crusts, and debris, procedure necessary to
achieve complete recovery. Several different solutions are usually used for
nasal lavages such as isotonic, hypertonic, or alkaline-buffered saline as well
as ocean water have been used for nasal lavage. Topical HA administration could
represent a supportive treatment for faster improvement of nasal respiration,
also minimizing patients' discomfort in postoperative nasal and sinus surgery,
promoting nasal mucosa healing in the first weeks after procedure [10-14].
Last
but not least, some studies showed that topical HA can be an useful tool also
in children affected by recurrent upper respiratory tract infections and to
relief respiratory symptoms in cystic fibrosis [15,16].
To
date, topical therapies guarantee a better delivery of high concentrations of
pharmacologic agents to the nasal mucosa.
The
strong connection between particle diameter and site of the high concentration
of nebulized particles in the upper airway suggests that it should be mandatory
to carefully choose the nebulizer device to get better therapeutic results.
Further
studies on larger populations and with new specific nebulization devices for
upper airway are needed to confirm these encouraging results on HA in chronic
upper airway inflammation disease.
No comments:
Post a Comment