Plasma TGF-B1 in asthma: Influence of inhaled steroids

ABSTRACT

The aetiology and pathophysiology of asthma remain complex. The role of systemic cytokines, especially Transforming Growth Factor B1 [TGF beta-1] and its response to inhaled steroids has not been explored before. Therefore, we studied plasma TGF-beta 1 levels in stable asthmatics on inhaled steroids. Asthmatics and age and sex matched controls were recruited prospectively from an outpatient department of a university hospital from January 2001 to February 2002. Information on asthma and its management including the status of inhaled steroid usage were collected by a questionnaire and subsequent review of medical records. Plasma TGF-beta 1 and serum IgE levels were estimated using established methods in our laboratory. The median age of the 40 patients was 26.5 [22.25 - 33.25] years. 18 patients were on regular inhaled steroids. Plasma TGF-beta 1 levels varied significantly between patients on regular inhaled steroids, not on steroids and controls [p=0.003]. The median TGF-beta 1 in asthmatics on inhaled steroids [1.4ng/ml, 1.16 - 1.92] was significantly lower compared to those not on it of asthma was not significantly different in atopic and non-atopic groups. Low plasma TGF beta-1 in asthmatics on regular inhaled steroids may reflect a better control of airway inflammation