A study of high-sensitivity C-reactive protein in bronchial asthma.

BACKGROUND: Relevance of C-reactive protein an acute phase reactant and a sensitive marker of low-grade systemic inflammation in bronchial asthma has not been fully studied. OBJECTIVE: To evaluate the significance of high-sensitivity C-reactive protein (hs-CRP) in atopic and non-atopic asthma using an ultra sensitive assay. METHODS: The levels of hs-CRP of 200 patients with bronchial asthma and 50 non-asthmatic control subjects were measured using a Latex enhanced immunoturbidimetric test. Spirometry with reversibility study, serum immunoglobulin-E (IgE) measurement and skin test for allergy was done in all the patients. RESULTS: There was a significant increase in hs-CRP levels with age in atopic asthmatics but no such association was observed in the non-atopic asthmatics and control subjects. The hs-CRP levels were not influenced by sex in any group. Smokers in all the three groups had a significantly higher hs-CRP levels as compared to non-smokers. Patients with asthma had higher hs-CRP values as compared to controls. Patients with non-allergic asthma had higher mean hs-CRP as compared to atopic asthmatics and control subjects. CONCLUSIONS: The study suggests that there exists a certain degree of low-grade systemic inflammation in addition to the local bronchial inflammation in non-atopic asthmatics. Hence, hs-CRP may be used as a surrogate marker for the airway inflammation in non-atopic asthma patients.