Cysteinyl leukotriene receptors are expressed by tonsillar T cells of children with obstructive sleep apnea.

Abstract

BACKGROUND:

Increased expression of cysteinyl leukotriene receptors (cysteinyl leukotriene receptor-1 [LT1-R]; cysteinyl leukotriene receptor-2 [LT2-R]) has been detected in adenotonsillar tissue from children with sleep-disordered breathing (SDB) compared to control subjects. LT1-R has been localized in myeloperoxidase-positive cells. This phenomenon possibly contributes to lymphoid tissue enlargement and may be related to systemic inflammation.

OBJECTIVE:

To characterize cells expressing LT1-R and LT2-R in tonsillar tissue and assess serum C-reactive protein (CRP) levels in children with and without SDB.

METHODS:

Immunohistochemistry with LT1-R and LT2-R antibodies was used to examine tonsils from children who had tonsillectomy (with or without adenoidectomy) for SDB and from control subjects operated for recurrent tonsillitis/otitis. All participants underwent preoperative polysomnography and measurement of morning serum CRP.

RESULTS:

Fifteen children with SDB (mean age +/- SD, 6.4 +/- 2.1 years; apnea-hypopnea index, 9.6 +/- 5.6 episodes per hour) and 11 control subjects (age, 7.5 +/- 2.8 years; apnea-hypopnea index, 7 +/- 0.3/h) were examined. Immunoreactivity for LT1-R and LT2-R was detected in tonsillar extrafollicular areas of all subjects with SDB but not of control subjects. Cells expressing leukotriene receptors were CD3+ lymphocytes. Children with SDB and control subjects were similar regarding CRP levels: 0.11 +/- 0.15 mg/dL vs 0.09 +/- 0.15 mg/dL, respectively (p > 0.05).

CONCLUSIONS:

Tonsils of children with SDB but not of control subjects have enhanced expression of cysteinyl leukotriene receptors in T lymphocytes without an associated increase in serum CRP concentration. Up-regulation of LT1-R and LT2-R could potentially promote tonsillar enlargement in children with obstructive sleep apnea.

• Authors: Athanasios G Kaditis, Maria G Ioannou, Konstantinos Chaidas, Emmanouel I Alexopoulos, Maria Apostolidou, Theoharis Apostolidis, George Koukoulis, Konstantinos Gourgoulianis
• Journal: Chest (Chest) Vol. 134 Issue 2 Pg. 324-331 (Aug 2008) ISSN: 0012-3692 [Print] United States
• PMID: 18490405 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)

Chemical References

• Receptors, Leukotriene
• C-Reactive Protein
• cysteinyl leukotriene receptor 2
• leukotriene D4 receptor

Topics

• C-Reactive Protein (metabolism)
• Case-Control Studies
• Child
• Child, Preschool
• Female
• Humans
• Male
• Palatine Tonsil (metabolism, pathology)
• Receptors, Leukotriene (metabolism)
• Sleep Apnea, Obstructive (metabolism, pathology, surgery)
• T-Lymphocytes (physiology)
• Tonsillectomy