Association between Serum Anti-glycopeptidolipid-core IgA Antibody Titers and Clinical Characteristics of Mycobacterium Avium Complex Pulmonary Disease

Abstract

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. From April 2014 to June 2019, we determined the level of anti-GPL-core IgA antibodies in 489 MAC-PD patients at our 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. These patients were divided into antibody-positive (n = 59) or -negative (n = 30) groups according to their serum anti-GPL-core IgA antibody results. Additionally, the positive antibody group was further divided into a strong positive group (n = 27) and a weak positive group (n = 32), and their clinical characteristics were retrospectively compared. Disease progression requiring treatment during the 12 months following diagnosis and extensive radiological findings were significantly abundant in the strong positive group compared with the weak positive group. Our findings revealed that serum anti-GPL-core IgA antibody titers are useful not only for diagnosing MAC-PD but also for predicting the risk of exacerbation.

Combination of anti-glycopeptidolipid-core IgA antibody and clinical features for diagnosing potential nontuberculous mycobacterium pulmonary disease in routine practice

“…Likewise, the value of anti-MAC antibodies has been reported to be associated with disease activity, treatment outcomes, and disease progression. 10,11 Sputum smear-positive results have been reported to be significantly associated with antibody positivity, 12 consistent with the results of this study. These data suggest that the antibody-based results correlated with the bacterial count.…”

Beyond antibiotics: recent developments in the diagnosis and management of nontuberculous mycobacterial infection

“…Other diagnostic approaches which have been explored include measurement of serological markers of infection. Detection of IgA antibody against the 31 serotype-specific glycopeptidolipid (GPL) core surface antigens of MAC has a reported 69.9% sensitivity and 90.6% specificity for the detection of MAC pulmonary disease, and has been used in clinical practice in Japan since 2011 [38][39][40]. A reduction in antibody levels post-treatment has been observed, suggesting this approach may serve as a tool for monitoring disease activity [41].…”