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Updated: Jul 9, 2026
Antigen-Capture Enzyme-Linked Immunosorbent Assay for Specific Detection of Mycoplasma pneumoniae
Published on: February 24, 2023
Serodiagnosis of Mycobacterium avium-complex pulmonary disease using an enzyme immunoassay kit
Seigo Kitada1, Kazuo Kobayashi, Satoshi Ichiyama
1Department of Internal Medicine, National Hospital Organization National Toneyama Hospital, 5-1-1 Toneyama, Toyonaka-shi, Osaka 560-8552, Japan. kitadas@toneyama.hosp.go.jp
Rationale:
The diagnosis of Mycobacterium avium-complex pulmonary disease (MAC-PD) and/or its discrimination from pulmonary tuberculosis (TB) is sometimes complicated and time consuming.
Objectives:
We investigated in a six-institution multicenter study whether a serologic test based on an enzyme immunoassay (EIA) kit was useful for diagnosing MAC-PD and for distinguishing it from other lung diseases.
Methods:
An EIA kit detecting serum IgA antibody to glycopeptidolipid core antigen specific for MAC was developed. Antibody levels were measured in sera from 70 patients with MAC-PD, 18 with MAC contamination, 37 with pulmonary TB, 45 with other lung diseases, and 76 healthy subjects.
Measurements And Main Results:
Significantly higher serum IgA antibody levels were detected in patients with MAC-PD than in the other groups (P < 0.0001). Setting the cutoff point at 0.7 U/ml resulted in a sensitivity and specificity of the kit for diagnosing MAC-PD of 84.3 and 100%, respectively. Significantly higher antibody levels were also found in patients with nodular-bronchiectatic disease compared with fibrocavitary disease in MAC-PD (P < 0.05). There was a positive correlation between the extent of disease on chest computed tomography scans and the levels of antibody (r = 0.43, P < 0.05) in patients with MAC-PD.
Conclusions:
The EIA kit is useful for the rapid diagnosis of MAC-PD and for differentiating MAC-PD from pulmonary TB and, if validated by studies in other populations, could find wide application in clinical practice.
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