Association between serum anti-glycopeptidolipid-core IgA antibody titers and clinical characteristics of Mycobacterium avium complex pulmonary disease.

ABSTRACT

OBJECTIVES: Mycobacterium avium complex pulmonary disease (MAC-PD) can be serologically diagnosed according to the presence of anti-glycopeptidolipid (GPL)-core IgA antibodies. However, few studies have examined the association between serum anti-GPL-core IgA antibody titers and the clinical characteristics of patients with MAC-PD. METHODS: From April 2014 to June 2019, the levels of anti-GPL-core IgA antibodies in 489 MAC-PD patients were determined at the current institute. Of them, 89 patients fulfilled the criteria of the American Thoracic Society and the Infectious Diseases Society of America statement on the diagnosis, treatment, and prevention of nontuberculous mycobacterial diseases. Patients were categorized into the antibody strong-positive (n = 27), weak-positive (n = 32), and negative (n = 30) groups according to their serum anti-GPL-core IgA antibody results. Their clinical characteristics were retrospectively compared. RESULTS: Disease progression requiring treatment and extensive radiological findings were significantly abundant in the strong-positive group compared with the weak-positive group. Clinical characteristics of the antibody weak-positive and negative groups did not significantly differ. CONCLUSIONS: The findings revealed that serum anti-GPL-core IgA antibody titers are useful for diagnosing MAC-PD and also for predicting the risk of exacerbation.