[The relationship among plasma soluble vascular cell adhesion molecule-1 level, airway responsiveness and blood eosinophil cationic protein in asthmatics with remission at least 3 years].
OBJECTIVE
To study the mechanism of asthma remission. The plasma soluble vascular cell adhesion molecule-1 (sVCAM-1), airway responsiveness (PC20) and other relative factors were measured in asthmatics with remission at least 3 years and compared with healthy controls.


METHODS
Group I (asthmatics with remission at puberty): 20 cases including 11 males and 9 females, mean age of 21 years. All of the patients were definitely diagnosed as asthmatics in childhood and got natural remission for at least 3 years(with median duration of 6 years). Group II (normal controls): 21 healthy college students including 10 males and 11 females, mean age of 22.5 years, had no history of asthma or other allergic diseases. The intravenous blood was taken from all subjects with EDTA as anticoagulant for study. The airway responsiveness were measured by methacholine bronchial provocation test(PC20). The sVCAM-1 was measured with ELISA, according to the manual of the kit. Methacholine was atomized by Wright atomizer [Devilbiss AP-50, USA, driven by air compressor, with a constant atomizing volume of (0.13 +/- 0.02) ml/min, diameter of atomizes particles 1.3-3.0 microns]. Its concentration was redoubled from 0.03 to 128 g/L until a certain dose as PC20 value triggering forced expiratory volume in one second (FEV1) decreased by 20% reached. The eosinophil cationic protein (ECP) levels were measured with enzyme-linked immuno-CAP system. Blood eosinophils(> 330/mm3 as being above normal) and basophils (> 33/mm3 as abnormally increased) were counted using Acian blue dyeing.


RESULTS
(1) The mean value of sVCAM-1 of group I (63.7 +/- 31.7) micrograms/L was significantly higher than that of group II (41.9 +/- 11.7) micrograms/L. (2) The percentage of the cases with increased eosinophils in group I was 15.0% (3/20), had no significant difference compared with that in group II (4.8%, 1/21). The percentage of the cases with increased basophils of group I was 45.0%(9/20), significantly higher than that of group II, 4.8%(1/21), P < 0.01. (3) The blood ECP level of group I was (2.7 +/- 1.3) micrograms/L, simillar to that of group II (2.18 +/- 0.5) micrograms/L. (4) The PC20 value of group I (M = 2.6 g/L) was significantly lower than that of group II (M = 128 g/L). (5) The basophil count negatively correlated with the PC20(r = -0.66), however, the sVCAM-1 did not have significant correlation with the basophil count or with the PC20.


CONCLUSIONS
The quantity and activity of eosinophils in asthmatics with remission at least 3 years are droped to the normal level, but the expression of VCAM-1, quantity of basophils were still higher than normal. The airway responsiveness had negative correlation with the basophil count.
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Department of Respiratory Medicine, Renji Hospital, Shanghai Second Medical University, Shanghai 200001, China.
Xu
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Yao
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D000328:Adult; D001249:Asthma / Q000378:metabolism* / Q000473:pathology; D001491:Basophils / Q000473:pathology; D001798:Blood Proteins / Q000378:metabolism*; D002452:Cell Count / Q000639:trends; D047091:Eosinophil Granule Proteins; D004804:Eosinophils / Q000473:pathology; D005260:Female; D006801:Humans; D008297:Male; D012075:Remission, Spontaneous; D012129:Respiratory Function Tests / Q000379:methods; D012260:Ribonucleases; D019010:Vascular Cell Adhesion Molecule-1 / Q000378:metabolism*
D001798:Blood Proteins; D047091:Eosinophil Granule Proteins; D019010:Vascular Cell Adhesion Molecule-1; D012260:Ribonucleases