ABSTRACT
<p><b>OBJECTIVE</b>To investigate the expression of eosinophil major basic protein (MBP) mRNA in bronchial asthma and explore its significance.</p><p><b>METHODS</b>Peripheral blood eosinophil MBP mRNA levels were measured in 40 patients with asthma and 20 normal controls by semi-quantitative RT-PCR. The association of MBP mRNA levels with eosinophil count and pulmonary function was also analyzed.</p><p><b>RESULTS</b>Compared with the normal control group, MBP mRNA level were significantly increased in asthma patients (0.37-/+0.11 vs 0.17-/+0.04, P<0.001), so was the eosinophil count (0.86-/+0.52 vs 0.21-/+0.10, P<0.001). MBP mRNA levels in patients with moderate persistent asthma (0.42-/+0.05) and those with severe persistent asthma (0.47-/+0.05) were significantly higher than those in patients with mild persistent asthma (0.25-/+0.06, P<0.001), and the difference in MBP mRNA levels between moderate persistent asthma patients and severe ones was also significant (P<0.05). Among the asthma patients, MBP mRNA levels showed an inverse correlation with pulmonary function (r=-0.7490, P<0.001).</p><p><b>CONCLUSION</b>Increased MBP mRNA expression level may correlate with the severity of asthma. MBP may play an important role in the development of asthma.</p>