A retrospective study of the patients with positive ImmunoCard Mycoplasma test on an outpatient clinic basis

The simplified ImmunoCard Mycoplasma test for rapidly detecting Mycoplasma pneumoniae-specific IgM antibodies has been widely used. We examined the usefulness of this test for outpatient practices as well as for the association with bronchial asthma. Among 196 patients whose ImmunoCard showed positive, we targeted 57 cases in which we were able to perform this test multiple times. We evaluated the degree of inflammatory response in the laboratory findings at the time of the test, the period until negative seroconversion for antibodies, and the course of their pulmonary function findings. The number of days from the onset of pyrexia until the test was a median of 10 (range 2–70) days, wherein the inflammatory response did not have a significant effect on that number of days. In 35 cases in which we observed the seroconversion to negative for antibodies, the period of the positive phase was 180 (21–421) days, wherein it was significantly longer for smokers. We observed exacerbation in the majority of the asthma patients, and some of the non-asthmatic patients showed either asthma or asthma-like clinical conditions. For ImmunoCard-positive individuals, it is desirable to ascertain the history of respiratory infection retrospectively to about half a year, although this test is known to suffer from lack of both of sensitivity and specificity. Additionally, it is necessary for ImmunoCard-positive patients to pay attention to the exacerbation of asthma and the development of asthma thereafter.