Heaney L G, Cross L J, Ennis M
Department of Respiratory Medicine, Royal Victoria Hospital, UK.
Clin Exp Allergy. 1998 Feb;28(2):196-204. doi: 10.1046/j.1365-2222.1998.00228.x.
Metachromatic cells obtained from asthmatic subjects demonstrate increased spontaneous and stimulated histamine release in vitro. Their ability to synthesize and store proinflammatory cytokines has focused renewed interest on their role in asthma.
The late asthmatic response provides a useful model of clinical asthma. The aim of the study was to examine metachromatic cell derived mediators and histamine releasability in vitro after in vivo allergen exposure in atopic subjects with and without asthma and relate them to the type of physiological response observed.
Bronchoalveolar lavage (BAL) cells were obtained 4 h after challenge from asthmatics exhibiting a single early response (EAR, n = 5), a dual response (LAR, n = 7), unchallenged (basal, n = 5), atopic non-asthmatic (ANA, n = 6) and non-atopic non-asthmatics (normal, n = 5). BAL histamine and tryptase concentrations and in vitro histamine release (HR) after stimulation with anti-IgE, allergen, A23187, conconavalin A and substance P were compared.
Metachromatic cell numbers were lower in normal controls compared with all asthmatic groups and in LAR compared with EAR. Metachromatic cell derived mediators were higher in asthmatic compared with normal subjects. Spontaneous HR in LAR (20.5 +/- 5.0%) was lower than EAR (29.5 +/- 3.9%) and ANA (30.2 +/- 1.4%) (P < 0.05). No differences were seen in stimulated HR between EAR and LAR. HR in ANA stimulated with anti-IgE was greater than LAR (P < 0.05). HR in ANA stimulated with anti-IgE was greater than LAR (P < 0.05). After stimulation with ionophore A23187 (1 microM), release was greater in LAR compared with basal (P < 0.05) and no different at 5 microM. All subject groups responded to substance P (SP) but was significantly more in the asthmatic subjects compared to normal controls (P < 0.05). Allergen challenge did not modify the response of asthmatic subjects to SP.
Functional differences in metachromatic cell reactivity are present in atopic subjects 4h after in vivo allergen exposure which relate to the physiological response observed after this time and suggest that there is ongoing metachromatic cell degranulation subjects who subsequently develop LAR.
从哮喘患者体内获取的异染性细胞在体外表现出自发性和刺激性组胺释放增加。它们合成和储存促炎细胞因子的能力重新引发了人们对其在哮喘中作用的关注。
迟发性哮喘反应为临床哮喘提供了一个有用的模型。本研究的目的是检测特应性哮喘患者和非哮喘患者体内变应原暴露后体外异染性细胞衍生介质和组胺释放能力，并将其与观察到的生理反应类型相关联。
在激发后4小时，从表现出单一早期反应（EAR，n = 5）、双重反应（LAR，n = 7）、未激发（基础，n = 5）、特应性非哮喘（ANA，n = 6）和非特应性非哮喘（正常，n = 5）的哮喘患者中获取支气管肺泡灌洗（BAL）细胞。比较BAL中组胺和类胰蛋白酶浓度以及用抗IgE、变应原、A23187、刀豆球蛋白A和P物质刺激后的体外组胺释放（HR）。
与所有哮喘组相比，正常对照组的异染性细胞数量较低，与EAR组相比，LAR组的异染性细胞数量较低。与正常受试者相比，哮喘患者中异染性细胞衍生介质含量更高。LAR组的自发性HR（20.5±5.0%）低于EAR组（29.5±3.9%）和ANA组（30.2±1.4%）（P<0.05）。EAR组和LAR组在刺激性HR方面未见差异。抗IgE刺激的ANA组HR大于LAR组（P<0.05）。抗IgE刺激的ANA组HR大于LAR组（P<0.05）。用离子载体A23187（1μM）刺激后，LAR组的释放量高于基础组（P<0.05），在5μM时无差异。所有受试者组对P物质（SP）均有反应，但哮喘患者的反应明显高于正常对照组（P<0.05）。变应原激发未改变哮喘患者对SP的反应。
体内变应原暴露4小时后，特应性受试者的异染性细胞反应存在功能差异，这与此时观察到的生理反应相关，提示随后发生LAR的受试者存在持续的异染性细胞脱颗粒。
