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BACKGROUND: Bronchial hyperresponsiveness testing is useful for diagnosing and predicting the risk of bronchial asthma attacks. The Astograph is a tidal breathing method often used in as bronchial provocation testing in Japan. The minimum methachorine dose (Dmin) indicates bronchial sensitivity and is used mainly as an index of bronchial hyperresponsiveness. However, Dmin does not measured hyperresponsiveness, it cannot be compared directly with PC20 in standard methods using FEV1. METHODS: We investigated the relationship among sensitivity, reactivity, and hyperresponsiveness with the Astograph. We recruited 142 patients with confirmed or suspected bronchial asthma from outpatient clinic at St. Marianna University School of Medicine, Yokohama City Seibu Hospital. We calculated Dmin, SGrs/Grscont, PD35Grs, and PD15Grs compared them as bronchial hyperresponsiveness indices. RESULTS: Subjects had suspected asthma (n=103), or required assessment of asthma remission (n=39). There were significant relationships between logDmin and logPD35Grs (r=0.838, p<0.001), and between parameters and SGrs/Grscont (log PD35Grs r=-0.504, p<0.001, strong, logDmin: r=-0.191, p=0.023, weaker). Among subjects positive for hypersensitivity, (Dmin<10), 38 (36.5%) showed negative hyperresponsiveness (PD35Grs>25). PD15Grs was a strongly and significantly correlated with Dmin and PD35Grs. The ROC curve to detect PD35Grs<25, showed that the cutoff of PD15Grs was 10.7 (AUC 0.983, sensitivity 0.984, specificity 0.905). CONCLUSION: In Astograph, evaluation of bronchial hyperresponsiveness, we focused on relationship differences between sensitivity and reactivity, and hyperresponsiveness. We revealed the usefulness of the PD15Grs evaluation method.
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Asma , Hiperreactividad Bronquial , Humanos , Asma/diagnóstico , Bronquios , Pruebas de Provocación Bronquial , JapónRESUMEN
Objective To investigate the diagnostic value of Astograph methacholine provocation test in patients with chest tightness variant asthma ( CTVA)??Methods From January 2011 to February 2017,156 patients with CTVA in outpatient or inpatient department of respiratory medicine of Kailuan General Hospital affiliated to North China University of Science and Technology were selected as case group ( chest tightness variant asthma group )??The control group were 361 non?asthmatic patients including interstitial lung disease ( 23 cases), coronary disease ( 157 cases), hypertensive cardiopathy ( 22 cases), myocardiosis (16 cases),congenital heart disease ( 3 cases),rheumatic valvular heart disease (6 cases), central airway disease (3 cases),thyromegaly (10 cases),mediastinal tumor (5 cases),thoracic or spinal deformity (8 cases),phrenoparalysis (2 cases) and vegetative nerve functional disturbance (106 cases)??All participants received pulmonay ventilation test, average daily and nightly variation rate of PEF ( Peak expiratory flow) or PEF weekly variability, Astograph methacholine provocation test ( forced expirataory volume in one second≥70% expectation),and other relevant examinations??The diagnostic value of Astograph methacholine provocation test on CTVA was assessed by analyzing the sensitivity, specificity, positive predictive value,negative predictive value,and Yunden index of Astograph methacholine airway??Results Compared with the control group (( 1??18 ± 0??44)%), theforced expiratory flow from 75% of Forced vital capcacity ( FEF75 ) index of CTVA group (( 1??29 ± 0??50 )%) had significant difference (, t＝ 2??96, P＝0??006)??The sensitivity,specificity,positive predictive value,negative predictive value,Yunden index,and diagnostic accuracy of Astograph methacholine provocation test on CTVA were 0??814,0??695,0??536,0??305, 0??509 and 0??731, respectively??Conclusion The sensitivity, negative predictive value, Yunden index and diagnostic accuracy of Astograph methacholine provocation test on CTVA were higher,whereas the specificity and positive predictive value were relatively lower,suggesting that Astograph methacholine provocation test had a reliable diagnostic value on CTVA,with lower false negative and higher false positive??
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Objective To evaluate the diagnostic value of astograph methacholine provocation test for bronchial asthma.Methods A total of 238 asthma patients and 499 non-asthma patients participated in the detection by astograph methacholine provocation test.Statistical methods were used to analyze the differences of astograph parameters and find the indicators of asthma diagnosis and the critical value.Results Dmin,Cmin and PD15 were much lower in the asthma group (P ＜ 0.01),compared with the the non-asthma group,when SGrs,SGrs/Grs cont were much higher (P ＜ 0.01).SGrs was relevant with Dmin,Cmin,PD15 in the asthma group (P =0.000;r =0.685,r =0.657,r =0.639) as well as the SGrs/Grs cont did (P =0.000,r =0.775;r =0.740,r =0.708).In ROC analysis,Dmin presented an AUC of 0.661,the cutoff value was 2.71 unit,with a sensitivity of 0.739 and specificity of 0.551.PD15 presented an AUC of 0.746,the cutoff value was 4.856 5 unit,with a sensitivity of 0.693 and specificity of 0.684.Conclusion Astograph methacholine provocation test shows good sensitivity and specificity in the diagnosis of asthma,particularly when Dmin ≤ 2.71 Unit or PD15 ≤ 4.8565 Unit as the cutoff value.