title: The relationship between structural/MHC changes in upper airway palatopharyngeal muscle morphology and obstructive sleep apnea/hypopnea syndrome.
abstract: The aim of this study is to explore the relationship between structural/MHC changes in upper airway palatopharyngeal muscle morphology and obstructive sleep apnea/hypopnea syndrome. Palatopharyngeal muscle specimens were taken from 51 patients with obstructive sleep apnea hypopnea syndrome (OSAHS) who underwent uvulopalatopharyngoplasty (UPPP) resection. Patients were divided into light, medium and severe in terms of the severity of their OSAHS. There were 17 patients in each severity group. Palatopharyngeal muscle specimens were also taken from 17 patients suffering from chronic tonsillitis for comparison as the control group. All specimens were stained using Masson and observed for structural changes, especially in muscle fiber morphology, density and arrangement, as well as intermuscular connective tissues, under light microscopy. All specimens were also analyzed for MHC-I, MHC-IIa and MHC-IIb phenotype and protein expression differences using mRNA quantitative reverse transcription polymerase chain reaction (RT-PCR) and immunofluorescence staining. The results from each group were then statistically analyzed using semi-quantitative analysis. Light microscopy with Masson staining revealed that in the control group, the muscle fibers are closely connected and arranged neatly. In specimens from patients suffering from OSAHS, the palatopharyngeal muscle fibers are larger with obvious hypertrophy and there was an increase in elastic fibers. The mucosal lamina propria was thickened, and the density of muscle fibers was reduced. Muscle fibers are not neatly arranged and degeneration was observed. The amount of muscular pathology and fibrosis corresponds to the severity of disease in the patients. In patients with severe OSAHS, the proportion of collagen to muscle fibers was increased significantly. Immunofluorescence results reveal that there were significantly more fast muscle fibers and less slow muscle fibers in the study group than the control group. mRNA quantitative reverse transcription polymerase chain reaction (RT-PCR) revealed similar results, i.e., the proportion of MHC-II palatopharyngeal muscle fibers is higher in the study group than the control group, and increases with the severity of OSAHS. Pathological change occurs in both the collagen and muscle of OSAHS patients and corresponds to the degree of severity of OSAHS. Pathological change in palatopharyngeal muscle tissues is therefore, likely to be related to the occurrence and development of OSAHS. The increase in the proportion of the MHC-1I type fibers in OSAHS patients is likely to have an effect on the amount of airway support conferred by the muscle. This is likely the reason behind the lack of clinical improvement in some patients with severe OSAHS despite surgical treatment.
authors: Department of Otorhinolaryngology Head and Neck Surgery, Changhai Hospital, Second Military Medical University of PLA, No. 168, Changhai Rd, 200433, Shanghai, China.
authors: Song
authors: S
authors: Shi
authors: Yanghui
authors: Y
authors: Xia
authors: Shicai
authors: S
authors: Chen
authors: Meng
authors: M
authors: Li
authors: Donghui
authors: D
authors: Chen
authors: Fei
authors: F
authors: Liu
authors: Hongliang
authors: H
authors: Zheng
mesh_terms: D000328:Adult; D004547:Elastic Tissue / Q000473:pathology; D006801:Humans; D006984:Hypertrophy; D008297:Male; D008875:Middle Aged; D018995:Myosin Heavy Chains; D017286:Polysomnography; D020133:Reverse Transcriptase Polymerase Chain Reaction; D020181:Sleep Apnea, Obstructive / Q000473:pathology*; D055158:Velopharyngeal Sphincter / Q000473:pathology
chemical_list: D018995:Myosin Heavy Chains
references: Regul Pept. 1997 Jul 23;71(1):29-36
references: 9299639
references: Int J Sports Med. 1994 Apr;15(3):136-41
references: 8005726
references: Arch Neurol. 1970 Jan;22(1):27-30
references: 5409598
references: Med Clin North Am. 1985 Nov;69(6):1221-42
references: 3906301
references: Respir Physiol. 1993 Apr;92(1):65-75
references: 8511409
references: Laryngoscope. 1996 Aug;106(8):1018-20
references: 8699893
references: Eur Respir J. 1996 Oct;9(10):2139-44
references: 8902480
references: Psychiatry Clin Neurosci. 2002 Jun;56(3):269-70
references: 12047590
references: J Appl Physiol (1985). 2008 Nov;105(5):1454-61
references: 18787090
references: Paediatr Anaesth. 2004 Aug;14(8):697, author reply 697
references: 15283833
references: Otolaryngol Clin North Am. 2003 Jun;36(3):437-60
references: 12956093
references: Am J Respir Crit Care Med. 2004 Sep 1;170(5):541-6
references: 15151922
references: Eur J Histochem. 1992;36(1):81-90
references: 1374668
references: Lancet. 1991 Mar 9;337(8741):597-9
references: 1671953
references: Laryngoscope. 1991 Dec;101(12 Pt 1):1318-22
references: 1766303
references: J Clin Invest. 1995 Jan;95(1):20-5
references: 7814616
references: J Appl Physiol (1985). 1999 Mar;86(3):1002-8
references: 10066716