Circadian changes in granulocyte-macrophage colony-stimulating factor message in circulating eosinophils

Waisman Center for Developmental Disabilities, Madison, Wisconsin, USA.
Annals of allergy, asthma & immunology: official publication of the American College of Allergy, Asthma, & Immunology (Impact Factor: 2.6). 02/2007; 98(1):75-82. DOI: 10.1016/S1081-1206(10)60863-0
Source: PubMed

ABSTRACT Granulocyte-macrophage colony-stimulating factor (GM-CSF), which stimulates eosinophil recruitment, activation, and survival, is expressed by activated eosinophils. Although eosinophil recruitment and enhanced survival have been associated with nocturnal asthma (NA), the contribution of GM-CSF to NA is unknown.
To determine whether circulating eosinophil GM-CSF expression correlates with the symptoms of NA.
The GM-CSF messenger RNA (mRNA) expression at 4 PM and 4 AM was determined by reverse-transcriptase polymerase chain reaction with Southern blot analysis in subjects with and without NA and in controls.
A total of 142 asthma subjects were screened for nocturnal asthma with 1-week home peak expiratory flow rate (PEFR) monitoring. Eleven subjects had NA (>20% diurnal variation in PEFR on 4 of 7 days), and 6 met the criteria for non-NA (<10% diurnal variation in PEFR on 7 of 7 days); 8 controls were studied. In subjects with NA, GM-CSF mRNA expression in circulating eosinophils increased 3-fold at 4 AM compared with 4 PM. Diurnal changes in GM-CSF mRNA expression were not detected in the non-NA and control groups.
Day-night variation in eosinophil GM-CSF expression is associated with circadian variation in airway function in asthma, a key manifestation of asthma severity.

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