METHACHOLINE INHALATION CHALLENGE IN PATIENTS WITH POST-MYCOPLASMA PNEUMONIAE PNEUMONIA

We studied methacholine bronchial inhalation challenge in 12 patients at 4(th) week and 12(th) week after recovered from Mycoplasma pneumoni ae pneumonia, compared with 12 healthy subjects as controls. The aeros olized methacholine was produced by an atomized nebulizer of the Provo cationtest I, Pari-Starnberg, Germany and the aerosol was kept Into a reservoir bag, Then, it was inhaled slowly by a subject. Increasing co ncentration of methacholine solutions (0, 0.5, 1, 5, 10, and 25 mg/ml) were used, The results revealed that 67% of the patients had bronchia l reactivity to methacholine at the first time of challenge with a mea n concentration of meth acholine producing a fall in FEV(1) of 20% fro m baseline (PC20) of 12.3 +/- 6.44 mg/ml. Fifty percent of the patient s were still positive to the test on the second time of challenge with a mean PC20 of 20.1 +/- 6.89 mg/ml. None of the healthy subjects had bronchial hyperreactivity (PC20 > 25 mg/ml). Two patients experienced wheezing and asthmatic attacks requiring bronchodilator therapy during acute phase pneumonia. They were also diagnosed as having bronchial a sthma for the first time, Many patients had prolonged coughing during the recovery phase lasting more than 4 weeks. This prolonged coughing seemed to have a correlation with the development of bronchial hyperre sponsiveness (BHR), We concluded that M. pneumoniae could induce BHR w hich may be transient or persistent, The effect of mycoplasma respirat ory tract infection may result in airway inflammations and asthamtic a ttacks.