Association Between Serum Anti Glycopeptidolipid Core IgA Antibody Levels and Clinical Characteristics of Mycobacterium Avium Complex Pulmonary Disease

RATIONALE: Anti-glycopeptidolipid (GPL)-core IgA antibodies is a representative serodiagnostic test for Mycobacterium avium complex pulmonary disease (MAC-PD). However, few previous studies have examined the association between serum MAC antibody levels and the clinical characteristics of MAC-PD patients. METHODS: From April 2014 to June 2019, serum anti-GPL-core IgA antibody were determined in 89 MAC-PD patients fulfilled the 2007 criteria of the American Thoracic Society and the Infectious Diseases Society of America (ATS/IDSA) statement at our institute. These patients were divided into antibody positive (n=59) or negative (n= 30) groups according to serum anti-GPL-core IgA antibody results. Their medical records were retrospectively examined for clinical characteristics. Additionally, positive antibody groups were further divided into a strong positive (n=27) group or a weak positive (n=32) group based on antibody titers, and their clinical characteristics were also compared. RESULTS: In the present study, bloody sputum, positive acid-fast bacilli smears from the sputum test, lower CRP, and lower smoking history were significantly abundant in the antibody positive group compared to the negative group. In the antibody positive group, lower BMI, extensive radiological findings, and Mycobacterium avium were significantly abundant in the strong positive group compared to the weak positive group. Additionally, requiring MAC treatment were tended to be more frequent in the antibody positive group. CONCLUSIONS: Serum anti-GPL-core IgA antibody levels are associated with clinical characteristics of MAC-PD and could be a useful predictor for requiring treatment.