TY - JOUR T1 - Clinical utility of serum anti-mycobacterium avium complex (MAC) antibody for diagnosis of MAC lung disease in asymptomatic patients with radiologically suspected MAC lung disease: A pilot study JF - European Respiratory Journal JO - Eur Respir J DO - 10.1183/13993003.congress-2015.PA2632 VL - 46 IS - suppl 59 SP - PA2632 AU - Naoki Nishimura AU - Hiroshi Nakaoka AU - Torahiko Jinta AU - Yutaka Tomishima AU - Kohei Okafuji AU - Noboru Uchiyama AU - Naohiko Chohnabayashi Y1 - 2015/09/01 UR - http://erj.ersjournals.com/content/46/suppl_59/PA2632.abstract N2 - Background: Recently, an enzyme immunoassay kit detecting serum IgA antibody to glycopeptidolipid core antigen specific for mycobacterium avium complex (MAC) was developed. Sensitivity and specificity of the kit for diagnosing MAC lung disease were reported as 84.3% and 100%, respectively. However, usefulness of detecting anti-MAC antibody for diagnosis of MAC lung disease in asymptomatic patients with radiologically suspected MAC lung disease has not been established.Aims and objectives: To clarify whether testing for serum anti-MAC antibody is useful for diagnosis of MAC lung disease in asymptomatic patients.Methods: Patients who received serum anti-MAC antibody test have been extracted retrospectively. Those who have respiratory symptoms or have been suspected to have diseases other than MAC lung disease by chest CT scan were excluded. Relationship between anti-MAC antibody results and clinical factors were investigated.Results: Eighteen patients were extracted from May 2013 to Dec 2014. All patients had nodular bronchiectatic features in chest CT scan images. Only 2 (11.1%) patients were found to be positive for anti-MAC antibody. On the other hand, 8 (44.4%) patients became sputum culture-positive for MAC, and 1 (5.6%) patient was culture-positive for MAC using bronchoscopy. Five patients (27.8%) met ATS criteria for diagnosis of MAC lung disease, of which only 1 patient tested positive for anti-MAC antibody.Conclusions: The clinical utility of serum anti-MAC antibody for diagnosis of MAC lung disease in asymptomatic patients was presumed to be low. ER -