Upper Airway Epithelial Structural Changes in Obstructive Sleep-disordered Breathing

Abstract

The etiology of upper airway collapsibility in patients with snoring and obstructive sleep apnea (OSA) remains unclear. Structural mucosal changes could be contributory factors. The objective of this study was to determine whether pathologic changes in the epithelium or the epithelial-connective tissue interface are present in patients with snoring and/or OSA by means of scanning electron microscopy and immunohistochemistry. Uvulae were obtained by uvulopalatopharyngoplasty from three patients with habitual snoring and nine patients with mild to severe OSA, as well as by dissection from 43 nonsnoring body donors. Scanning electron microscopy revealed structural changes in the epithelial-connective tissue boundary that significantly differed from age-related changes in the control subjects. The immunohistochemical staining with antibodies against epithelial cytokeratins showed differences in the expression pattern of cytokeratin 13 between patients and control subjects. No differences were found in the distribution pattern of laminin. Analysis of defense cells revealed a significant diffuse infiltration of leukocytes, mainly T cells, inside the lamina propria of the patient group, which was not observed in the control group. In conclusion, these results support the hypothesis that progressive structural changes in the mucosa caused by the trauma of snoring are a possible contributory factor to upper airway collapsibility.

The Anatomy of the Dog Soft Palate. II. Histological Evaluation of the Caudal Soft Palate in Brachycephalic Breeds With Grade I Brachycephalic Airway Obstructive Syndrome

“…Inspiratory effort occur in brachycephalic dogs since the beginning of their postnatal life, even if no or mild clinical signs are present (Hendricks et al, 1987). Features like acanthosis and reduction of connective tissue papillae have been invoked as possible contributory factor to upper airway collapsibility in human patients with OSA (Paulsen et al, 2002). In the specimens of brachycephalic dog soft palate we observed epithelial hyperplasia together with keratinocyte swelling and intracellular oedema.…”

“…Significantly thicker covering epithelium and increased amount of intercellular space considered as expression of edema was described also in OSA patients and snorers (Hamans et al, 2000). Mechanical trauma can produce changes in epithelial surfaces under the influence of unphysiological mechanical stress, resulting in different modifications of the overlying epithelium or underlying connective tissue (Paulsen et al, 2002). These findings could explain both the enlarged thickness of the soft palate in brachycephalic dogs and the marked sliding between tissues we found during sample collection, that made orientation more difficult to obtain compared with mesaticephalic dogs.…”

“…Structural changes were observed in the soft palate mucosa of human patients with snoring and obstructive sleep apnea (OSA) and interpreted as a consequence of the trauma of snoring (Paulsen et al, 2002). Inspiratory effort occur in brachycephalic dogs since the beginning of their postnatal life, even if no or mild clinical signs are present (Hendricks et al, 1987).…”

Etiological treatment of OSA

“…Recent studies confirm that destabilization of the pharynx can be a result of deterioration of its mucosal 11 , muscular 14 , and/or neural 2,13,14 components of either or both sides, sensory or motor, of the mechanism that controls the geometric effects of the inspiratory gradient on the pharyngeal lumen. Accordingly, electromyography analyses show that chronic partial enervation of the palatopharyngeal muscle can occur during episodes of OSA 5,14 .…”

Facial envelope, labium superior alaeque nasi morpho-physiologic integration and malocclusion

“…It helps explain the mechanism of transmission of pathologic snoring vibrations from the veil to the walls of the pharynx. 9 , the extent of the altered mucous region must be reevaluated by including the turbinal mucosa that makes the need for orthopedic treatment of young patients even more of an imperative 38 .…”