Blog
About

0
views
0
recommends
+1 Recommend
0 collections
    0
    shares
      • Record: found
      • Abstract: found
      • Article: found
      Is Open Access

      Serological diagnosis of Mycobacterium avium complex lung diseases by enzyme immunoassay of IgA antibodies against MAC-specific glycopeptidolipid core antigen

      Read this article at

      Bookmark
          There is no author summary for this article yet. Authors can add summaries to their articles on ScienceOpen to make them more accessible to a non-specialist audience.

          Abstract

          Introduction

          There is an increasing trend worldwide in the incidence of Mycobacterium avium complex pulmonary diseases (MAC-PD) and the diagnosis is sometimes complicated. Recently, an enzyme immunoassay (EIA) kit that detects serum IgA antibody against MAC-specific glycopeptidolipid (GPL) core antigen had been developed and found to be useful in discriminating MAC-PD from other lung diseases. The antibody was subsequently also found to be elevated in patients suffering Mycobacterium abscessus pulmonary diseases (MAB-PD). This study is to evaluate this EIA kit in the serological diagnosis of MAC-PD in Hong Kong Chinese patients.

          Methods

          The study was conducted in Grantham Hospital, Hong Kong between July 2017 and July 2018. Assay of the IgA antibody level using the EIA kit was done on blood samples collected from patients suffering from MAC-PD, MAB-PD, pulmonary tuberculosis and other lung diseases.

          Results

          There were 100 subjects recruited into the study, among which 11 were excluded. By using the cut-off value 0.7 U/mL provided by the manufacturer, the sensitivity and specificity for diagnosis were 73.7% and 77.6% for MAC-PD; 50% and 77.6% for MAB-PD. By receiver operating characteristic curves analysis, new cut-off for MAC-PD and MAB-PD were calculated as 1.771 U/mL and 0.172 U/m, respectively. The sensitivity and specificity were 68.4% and 86.2% for MAC-PD, whereas 66.7% and 72.4% for MAB-PD.

          Conclusions

          Our study showed that the enzyme immunoassay of IgA antibodies against MAC-specific glycopeptidolipid core antigen could help to distinguishing MAC and M. abscessus pulmonary diseases from pulmonary tuberculosis and other lung diseases among Hong Kong Chinese patients. Further larger scale studies in our local population for the usefulness of this antibody test in the diagnosis and monitoring of MAC and M. abscessus lung diseases might be warranted.

          Related collections

          Most cited references 12

          • Record: found
          • Abstract: found
          • Article: found
          Is Open Access

          British Thoracic Society Guideline for the management of non-tuberculous mycobacterial pulmonary disease (NTM-PD)

          The full guideline for the management of non-tuberculous mycobacterial pulmonary disease is published in Thorax. The following is a summary of the recommendations and good practice points. The sections referred to in the summary refer to the full guideline.
            Bookmark
            • Record: found
            • Abstract: found
            • Article: not found

            Use of glycopeptidolipid core antigen for serodiagnosis of mycobacterium avium complex pulmonary disease in immunocompetent patients.

            We report the development of a serodiagnostic method for Mycobacterium avium complex (MAC) disease with an enzyme immunoassay (EIA) with the MAC-specific glycopeptidolipid (GPL) core as the antigen. In this study, we confirmed by EIA that the GPL core antibody was in the sera of immunocompetent patients with MAC disease. The EIA for quantifying the GPL core antibody was evaluated as a clinical tool for serodiagnosis of pulmonary MAC disease. A significant increase in GPL core antibodies (immunoglobulins G, A, and M) was detected in sera of patients with MAC pulmonary diseases when they were compared to patients who were colonized with MAC, patients with Mycobacterium kansasii disease or tuberculosis, and healthy subjects. The sensitivities and specificities of the GPL core-based EIA for diagnosis of MAC pulmonary disease were 72.6% and 92.2%, respectively, for IgG, 92.5% and 95.1%, respectively, for IgA, and 78.3% and 91.0%, respectively, for IgM. The best sensitivity and specificity were obtained by measuring immunoglobulin A antibodies against GPL core antigen. The level of GPL core antibodies reflected disease activity, since it decreased in cured MAC patients who had responded to chemotherapy. Measurement of serum antibodies against GPL core is useful for both diagnosis and assessment of disease activity in MAC disease of the lung.
              Bookmark
              • Record: found
              • Abstract: found
              • Article: found
              Is Open Access

              Diagnostic test accuracy of anti-glycopeptidolipid-core IgA antibodies for Mycobacterium avium complex pulmonary disease: systematic review and meta-analysis

              Currently, an anti-glycopeptidolipid (GPL)-core IgA antibody assay kit for diagnosing Mycobacterium avium complex (MAC) is commercially available. We conducted this systematic review and meta-analysis to reveal the precise diagnostic accuracy of anti-GPL-core IgA antibodies for MAC pulmonary disease (MAC-PD). We systematically searched reports that could provide data for both sensitivity and specificity by anti-GPL-core IgA antibody for clinically diagnosed MAC-PD. Diagnostic test accuracy was estimated using the bivariate model. Of the 257 articles that we had found through primary search, we finally included 16 reports consisted of 1098 reference positive subjects and 2270 reference negative subjects. The diagnostic odds ratio was 24.8 (95% CI 11.6–52.8, I2 = 5.5%) and the area under the hierarchical summary receiver operating characteristic curves was 0.873 (95% CI 0.837–0.913). With a cutoff value of 0.7 U/mL, the summary estimates of sensitivity and specificity were 0.696 (95% CI 0.621–0.761) and 0.906 (95% CI 0.836–0.951), respectively. The positive and negative likelihood ratios were 7.4 (95% CI 4.1–13.8) and 0.34 (95% CI 0.26–0.43), respectively. The demanding clinical diagnostic criteria may be a cause of false positive of the index test. The index test had good overall diagnostic accuracy and was useful to ruling in MAC-PD with the cutoff value.
                Bookmark

                Author and article information

                Contributors
                Journal
                J Clin Tuberc Other Mycobact Dis
                J Clin Tuberc Other Mycobact Dis
                Journal of Clinical Tuberculosis and Other Mycobacterial Diseases
                Elsevier
                2405-5794
                11 September 2020
                December 2020
                11 September 2020
                : 21
                Affiliations
                [a ]Tuberculosis and Chest Unit, Grantham Hospital, 125 Wong Chuk Hang Road, Hong Kong
                [b ]Department of Microbiology, The University of Hong Kong, Queen Mary Hospital, 102 Pokfulam Road, Hong Kong
                [c ]Department of Surgery, The University of Hong Kong, 21 Sassoon Road, Pokfulam, Hong Kong
                Author notes
                [* ]Corresponding author. tamwo@ 123456ha.org.hk
                Article
                S2405-5794(20)30053-X 100189
                10.1016/j.jctube.2020.100189
                7516128
                © 2020 The Authors

                This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).

                Categories
                Article

                Comments

                Comment on this article