BRONCHIAL HYPERREACTIVITY IN PATIENTS WITH ENDOBRONCHIAL TUBERCULOSIS

Some patients with endobronchial tuberculosis (EBTB) have wheeze on ph ysical examination and normal chest PA, which mimic bronchial asthma. Non-specific bronchial challenge tests have been used to confirm the p resence of bronchial hyperreactivity, which is a hallmark of bronchial asthma. To evaluate the effect of endobronchial tuberculous inflammat ion on bronchial responsiveness to histamine, the provocation concentr ations of histamine required to reduce FEV(1) by 20% of the pre-challe nge baseline (PC20) were compared between patients with EBTB, patients with symptomatic bronchial asthma and normal, healthy controls. PC20 in EBTB patients (17.2 +/- 2.3 mg ml(-1)) and normal controls (19.5 +/ - 1.4 mg ml(-1)) were significantly higher than in bronchial asthma pa tients (0.99 +/- 0.15 mg ml(-1)). PC20 in EBTB patients was not affect ed by disease location in the bronchial tree and was not correlated wi th FVC or FEV(1). In conclusion, one should consider the possibility o f EBTB for differential diagnosis from bronchial asthma, if airway res ponsiveness appears normal in wheezy patients.