High sensitivity C-reactive protein: its correlation with sputum cell counts in bronchial asthma

Two major acute-phase proteins were identified in human, C-reactive protein and serum amyloid A. There are 3 types of C-reactive protein assays: conventional C-reactive protein, high sensitivity C-reactive protein and cardiac C-reactive protein. High sensitivity C-reactive protein assays can detect minor inflammatory changes that could be missed by other indices of inflammation. Induced sputum cell counts are relatively non-invasive, safe and reliable method for identifying the presence and type of airway inflammation in asthmatic patients.

This study was designed to detect the role of serum levels of high sensitivity C-reactive protein in asthmatic patients with or without inhaled corticosteroids treatment. Also to determine the relationship of serum high sensitivity C-reactive protein levels to clinical indices of asthma and inflammatory cell counts in induced sputum.

Serum high sensitivity C-reactive protein level, pulmonary function tests, body mass index and induced sputum cell counts were estimated in 50 asthmatic patients (26 steroid inhaled and 24 steroid naïve). Fifteen healthy volunteers, who matched in age and sex with the other groups, were used as a control group.

There was an increase of high sensitivity C-reactive protein in asthmatic patients among both steroid inhaled and steroid naïve patients compared to the healthy controls. Serum high sensitivity C-reactive protein correlated negatively with pulmonary function tests and positively with sputum eosinophil % in both inhaled steroid and steroid naïve groups.

High sensitivity C-reactive protein is one of the markers of systemic inflammation that can be indirectly reflecting the degree of severity of airway inflammation in bronchial asthma.