Abstract
Background: Diagnosis of Mycobacterium avium complex pulmonary disease (MAC-PD) requires identification of pathogens either from sputum on multiple occasions or from bronchoscopic examination. Bronchoscopic examination is useful for diagnosing MAC-PD, but is difficult to perform in all patients. Glycopeptidolipid (GPL)-core antibody to MAC is useful for diagnosing MAC-PD and easy to perform. However, this serological test is new, and its directionality for diagnosis has yet to be clearly demonstrated. Few studies have analyzed correlations between GPL-core antibody and bronchoscopically confirmed diagnosis of MAC-PD.
Aims: This study aimed to estimate the usefulness of GPL-core antibody for diagnosing MAC-PD by investigating patients who had undergone bronchoscopic examination.
Method: A total of 28 patients who were positive for GPL-core antibody and who had undergone bronchoscopic examination were retrospectively investigated and characteristically evaluated. The cut-off value for a positive finding was 0.7 U/mL.
Results: Mean GPL-core antibody titer was 4.67±5.38 U/mL (range, 0.7-20.2 U/mL). Thirteen of the 28 patients who had undergone bronchoscopic examination were diagnosed with MAC-PD. Eleven patients were diagnosed with M. avium, and 2 patients with M. intracellulare. Mean antibody titer among those patients positive for GPL-core antibody was 7.78±6.42 U/mL in patients with identification of pathogens by bronchoscopic examination and 1.98±1.98 U/ml in patients without (p=0.0074).
Conclusion: Significant differences in mean antibody titer were seen between MAC-PD and non-MAC-PD patients who underwent bronchoscopic examination.
- Copyright ©ERS 2015
