Systemic inflammation and its response to treatment in patients with asthma.

BACKGROUND Asthma is an obstructive airway disease characterized by airway inflammation. OBJECTIVE To measure systemic inflammation in asthma patients, and to assess the effect of treatment on systemic inflammation. METHODS In 30 newly diagnosed non-randomized adult asthma patients we measured systemic inflammation markers (serum high-sensitivity C-reactive protein, total leukocyte count, and erythrocyte sedimentation rate) before and after a 6-week standard treatment with inhaled steroids and inhaled β(2) agonist. The comparison group comprised 20 healthy control subjects. All the subjects were non-smokers. RESULTS The measured systemic inflammation markers were higher in the asthma patients: high-sensitivity C-reactive protein 4.8 ± 6.0 mg/dL vs 1.5 ± 1.4 mg/dL, P < .001; total leukocyte count 8,936 ± 2,592 cells/μL versus 7,741 ± 1,924 cells/μL, P < .001; erythrocyte sedimentation rate 24.8 ± 12.3 mm/h versus 15.3 ± 6.5 mm/h, P < .001. In the asthma patients, high-sensitivity C-reactive protein negatively correlated with percent-of-predicted FEV(1) (r = -0.64, P = .001), percent-of-predicted forced vital capacity (FVC) (r = -0.39, P = .03), FEV(1)/FVC% (r = -0.71, P < .001), and percent-of-predicted forced expiratory flow during the middle half of the FVC maneuver (FEF(25-75)) (r = -0.51, P = .004). Total leukocyte count negatively correlated with percent-of-predicted FEV(1) (r = -0.64, P = .001), percent-of-predicted FEV(1)/FVC (r = -0.74, P < .001), and percent-of-predicted FEF(25-75) (r = -0.58, P = .001). Body mass index positively correlated with high-sensitivity C-reactive protein (r = 0.65, P < .001). Multiple linear regression showed significant correlation of high-sensitivity C-reactive protein (r(2) = 0.75) with age (β = 0.31, P = .008), body mass index (β = 0.99, P = .001), family size (β = 0.33, P = .008), and weight (β = -0.45, P = .01). The systemic inflammation markers decreased significantly (P < .001 for all comparisons) after 6 weeks of treatment: high-sensitivity C-reactive protein decreased from 4.8 ± 6.0 mg/dL to 2.4 ± 5.4 mg/dL, total leukocyte count decreased from 8,936 ± 2,592 cells/μL to 6,960 ± 1,785 cells/μL, and erythrocyte sedimentation rate decreased from 24.8 ± 12.3 mm/h to 15.8 ± 10.1 mm/h. CONCLUSIONS Inhaled steroids plus inhaled β(2) agonist significantly reduced systemic inflammation in asthma patients.