title: Levels of Antibody against Glycopeptidolipid Core as a Marker for Monitoring Treatment Response in Mycobacterium avium Complex Pulmonary Disease: a Prospective Cohort Study.
abstract: The diagnosis ofMycobacterium aviumcomplex pulmonary disease (MAC-PD) is sometimes complicated and time-consuming. A serodiagnostic kit that measures the serum levels of IgA antibodies against the glycopeptidolipid (GPL) core is commercially available and has good diagnostic accuracy for MAC-PD. However, the significance of measurement of GPL core IgA antibody levels in monitoring for chemotherapy response in patients with MAC-PD was not well investigated. Thirty-four treatment naive MAC-PD patients who were started on multidrug chemotherapy were enrolled. Their antibody levels were prospectively measured at regular intervals. The relationships between their antibody levels and the therapeutic outcomes were examined. The patients were classified into three groups (conversion, recurrence, and nonconversion) based on the bacteriological outcomes after chemotherapy. There were no significant differences in the antibody levels before treatment between the culture conversion (n= 19), recurrence (n= 7), and nonconversion (n= 8) groups (P= 0.9881). The levels decreased significantly after the chemotherapy (P< 0.0001). Recurrence and/or worsening of chest radiography findings were observed in cases whose antibody levels subsequently increased after cessation of the chemotherapy. No significant difference in the percent decrease in antibody levels by the chemotherapy was observed between the culture conversion and recurrence groups (P= 0.9338). The initial antibody levels are not a predictor of therapeutic outcomes, and also the percent decrease in antibody levels is not a sufficient indicator of the cessation of chemotherapy. However, serial measurements of antibody levels may allow objective monitoring of disease activity in individual MAC-PD patients.
authors.affiliation: Department of Respiratory Medicine, National Hospital Organization, National Toneyama Hospital, Osaka, Japan kitadase@toneyama.go.jp.
authors.forename: Seigo
authors.initials: S
authors.lastname: Kitada
authors.affiliation: Department of Respiratory Medicine, National Hospital Organization, National Toneyama Hospital, Osaka, Japan.
authors.forename: Ryoji
authors.initials: R
authors.lastname: Maekura
authors.affiliation: Department of Respiratory Medicine, National Hospital Organization, National Toneyama Hospital, Osaka, Japan.
authors.forename: Kenji
authors.initials: K
authors.lastname: Yoshimura
authors.affiliation: Department of Respiratory Medicine, National Hospital Organization, National Toneyama Hospital, Osaka, Japan.
authors.forename: Keisuke
authors.initials: K
authors.lastname: Miki
authors.affiliation: Department of Respiratory Medicine, National Hospital Organization, National Toneyama Hospital, Osaka, Japan.
authors.forename: Mari
authors.initials: M
authors.lastname: Miki
authors.affiliation: Department of Respiratory Medicine, National Hospital Organization, National Toneyama Hospital, Osaka, Japan.
authors.forename: Yohei
authors.initials: Y
authors.lastname: Oshitani
authors.affiliation: Department of Respiratory Medicine, National Hospital Organization, National Toneyama Hospital, Osaka, Japan.
authors.forename: Kohei
authors.initials: K
authors.lastname: Nishida
authors.affiliation: Department of Respiratory Medicine, National Hospital Organization, National Toneyama Hospital, Osaka, Japan.
authors.forename: Nobuhiko
authors.initials: N
authors.lastname: Sawa
authors.affiliation: Department of Respiratory Medicine, National Hospital Organization, National Toneyama Hospital, Osaka, Japan.
authors.forename: Masahide
authors.initials: M
authors.lastname: Mori
authors.affiliation: Sakai City Institute of Public Health, Osaka, Japan.
authors.forename: Kazuo
authors.initials: K
authors.lastname: Kobayashi
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D000907:Antibodies, Bacterial / Q000097:blood*; D000995:Antitubercular Agents / Q000627:therapeutic use*; D016903:Drug Monitoring / Q000379:methods*; D005260:Female; D006017:Glycolipids / Q000276:immunology; D006801:Humans; D007070:Immunoglobulin A / Q000097:blood; D008171:Lung Diseases / Q000188:drug therapy*; D008297:Male; D008875:Middle Aged; D015269:Mycobacterium avium Complex / Q000276:immunology*; D015270:Mycobacterium avium-intracellulare Infection / Q000188:drug therapy*; D011446:Prospective Studies; D012698:Serologic Tests / Q000379:methods*
chemical_list: D000907:Antibodies, Bacterial; D000995:Antitubercular Agents; D006017:Glycolipids; D007070:Immunoglobulin A
keywords: enzyme immunoassay; nontuberculous mycobacteria; serodiagnosis