Tsuyoshi Shirai1, Yoshinori Tanino2, Takefumi Nikaido2, Yotaro Takaku3, Seishu Hashimoto4, Yoshio Taguchi4, Tomohisa Baba5, Takashi Ogura5, Kensuke Kataoka6, Masayuki Nakayama7, Yoshihito Yamada8, Sayomi Matsushima9, Satoshi Nakayama10, Yasunari Miyazaki11. 1. Department of Respiratory Medicine, Tokyo Medical and Dental University, Tokyo, Japan. 2. Department of Pulmonary Medicine, Fukushima Medical University School of Medicine, Fukushima, Japan. 3. Department of Respiratory Medicine, Saitama Cardiovascular and Respiratory Center, Saitama, Japan. 4. Department of Respiratory Medicine, Tenri Hospital, Nara, Japan. 5. Department of Respiratory Medicine, Kanagawa Cardiovascular and Respiratory Center, Kanagawa, Japan. 6. Department of Respiratory Medicine and Allergy, Tosei General Hospital, Aichi, Japan. 7. Division of Pulmonary Medicine, Department of Medicine Jichi Medical University, Tochigi, Japan. 8. Department of Respiratory Medicine, JR Tokyo General Hospital, Tokyo, Japan. 9. Second Division, Department of Internal Medicine, Hamamatsu University School of Medicine, Hamamatsu, Japan. 10. Immuno Diagnostic Division, Thermo Fisher Scientific, Tokyo, Japan. 11. Department of Respiratory Medicine, Tokyo Medical and Dental University, Tokyo, Japan. Electronic address: miyazaki.pilm@tmd.ac.jp.
Abstract
BACKGROUND: Bird antigens are some of the most relevant antigens in hypersensitivity pneumonitis (HP). Possible sources of bird antigens are bird breeding, feather products and fertilizer with fowl droppings. For the screening and diagnosis of HP, the measurement of bird-specific antibodies should be standardized. The aim of this study was to clarify the utility of serum IgG (sIgG) and IgA (sIgA) antibodies to bird antigens in screening and diagnosing acute/chronic bird-related HP with ImmunoCAP® in multi-centre clinical research. METHODS: We executed a clinical performance test by conducting a multi-institutional study to measure the levels of sIgG/sIgA against pigeon, parrot and budgerigar antigens by the ImmunoCAP® system in 29 acute and 46 chronic bird-related HP patients. RESULTS: The levels of sIgG/sIgA against the bird antigens of the three species were significantly higher in subjects with acute bird-related HP and chronic bird-related HP with acute episodes (recurrent type) than in the control subjects. For sIgG, the optimal cutoff values by receiver operating characteristic (ROC) analysis were 24.6 mgA/L for pigeon, 14.0 mgA/L for parrot, and 8.7 mgA/L for budgerigar. By measuring multiple bird antigens and combining sIgG values of two species, the sensitivity and specificity for acute and recurrent-type chronic bird-related HP patients were 85-91% and 73-80%, respectively. For recurrent and insidious types of chronic bird-related HP, the sensitivity and specificity were 48-61% and 73-80%, respectively. CONCLUSIONS: Measurement of the levels of sIgG/sIgA against pigeon, budgerigar and parrot antigens by ImmunoCAP® was useful for screening and diagnosis in bird-related HP.
BACKGROUND: Bird antigens are some of the most relevant antigens in hypersensitivity pneumonitis (HP). Possible sources of bird antigens are bird breeding, feather products and fertilizer with fowl droppings. For the screening and diagnosis of HP, the measurement of bird-specific antibodies should be standardized. The aim of this study was to clarify the utility of serum IgG (sIgG) and IgA (sIgA) antibodies to bird antigens in screening and diagnosing acute/chronic bird-related HP with ImmunoCAP® in multi-centre clinical research. METHODS: We executed a clinical performance test by conducting a multi-institutional study to measure the levels of sIgG/sIgA against pigeon, parrot and budgerigar antigens by the ImmunoCAP® system in 29 acute and 46 chronic bird-related HP patients. RESULTS: The levels of sIgG/sIgA against the bird antigens of the three species were significantly higher in subjects with acute bird-related HP and chronic bird-related HP with acute episodes (recurrent type) than in the control subjects. For sIgG, the optimal cutoff values by receiver operating characteristic (ROC) analysis were 24.6 mgA/L for pigeon, 14.0 mgA/L for parrot, and 8.7 mgA/L for budgerigar. By measuring multiple bird antigens and combining sIgG values of two species, the sensitivity and specificity for acute and recurrent-type chronic bird-related HP patients were 85-91% and 73-80%, respectively. For recurrent and insidious types of chronic bird-related HP, the sensitivity and specificity were 48-61% and 73-80%, respectively. CONCLUSIONS: Measurement of the levels of sIgG/sIgA against pigeon, budgerigar and parrot antigens by ImmunoCAP® was useful for screening and diagnosis in bird-related HP.