Prieto L, López M, Bertó J M, Peris A
Sección de Alergia, Hospital Dr Peset, Valencia, Spain.
Thorax. 1994 Jul;49(7):711-3. doi: 10.1136/thx.49.7.711.
The effect of cessation of exposure to pollen on the concentration-response curves to inhaled methacholine was investigated.
Methacholine inhalation challenges (up to 200 mg/ml) were performed in 13 non-asthmatic patients with grass and/or Parietaria pollen-induced rhinitis during the pollen season, and one and four months after it. Concentration-response curves were characterised by their PC20, position, and plateau.
Geometric mean methacholine PC20 increased from 6.4 mg/ml during the pollen season to 28.2 mg/ml and 54.9 mg/ml one and four months after the end of season, respectively. The mean (SE) level of the plateau decreased from 30.5 (4.3%) in the pollen season to 23.3 (3.7)% and 20.1 (3.3)% one and four months after the end of pollen season, respectively. Although the methacholine concentration that produced 50% of the maximal response increased from 2.9 mg/ml to 4.3 mg/ml and 6.0 mg/ml, the differences were not significant.
In non-asthmatic patients with pollen-induced rhinitis cessation of exposure to pollen is associated with significant modifications in the methacholine threshold value and level of plateau, and with a small shift in the concentration-response curves to the right.
研究了停止接触花粉对吸入乙酰甲胆碱浓度-反应曲线的影响。
对13例在花粉季节患有草和/或墙草花粉诱发鼻炎的非哮喘患者，以及在花粉季节结束后1个月和4个月进行了乙酰甲胆碱吸入激发试验（最高至200mg/ml）。浓度-反应曲线以其PC20、位置和平坦期为特征。
乙酰甲胆碱PC20的几何平均值从花粉季节的6.4mg/ml分别增加到花粉季节结束后1个月和4个月的28.2mg/ml和54.9mg/ml。平坦期的平均（标准误）水平从花粉季节的30.5（4.3）%分别降至花粉季节结束后1个月和4个月的23.3（3.7）%和20.1（3.3）%。虽然产生最大反应50%的乙酰甲胆碱浓度从2.9mg/ml增加到4.3mg/ml和6.0mg/ml，但差异不显著。
在花粉诱发鼻炎的非哮喘患者中，停止接触花粉与乙酰甲胆碱阈值和平坦期水平的显著改变以及浓度-反应曲线向右的小偏移有关。
