McSharry C, MacLeod K, McGregor S, Speekenbrink A B, Sriram S, Boyd F, Boyd G
Department of Immunology, Western Infirmary, Glasgow, UK.
Clin Exp Allergy. 1999 Jul;29(7):957-64. doi: 10.1046/j.1365-2222.1999.00591.x.
Inhaled antigens from pigeons can cause extrinsic allergic alveolitis (EAA); a model disease of pulmonary inflammation. Among pigeon breeders, serum antibody and sensitized lymphocytes specific for these antigens have been described primarily, but not always, with disease. Antibody activity within the lung may have a closer association with disease, however, sampling by alveolar lavage at bronchoscopy is impractical for screening, therefore we used saliva to quantify the mucosal antibody response.
To establish: (a) if antibody activity against inhaled avian antigens was detectable in the saliva of pigeon breeders, (b) if the distribution of saliva antibody and total immunoglobulin levels were quantitatively or qualitatively different from serum, and (c) whether the hypersensitivity symptoms of EAA were associated more with the mucosal or the systemic humoral immune response.
Saliva and serum total and avian antigen-specific IgG, IgA (IgA1 and IgA2) antibody activity in 87 pigeon breeders and 24 control subjects with no avian exposure. Albumin levels were used as a protein reference and cotinine levels confirmed smoking status. Specific hypersensitivity symptoms and various exposure indices to pigeons were established by interview.
Absolute levels and relative proportions (vs albumin) of IgG, IgA and IgA1 in saliva, and IgG in serum, were significantly higher in pigeon breeders compared with controls, suggesting mucosal inflammation. Avian antigen-specific antibody of all isotypes was readily demonstrable in saliva (predominantly IgA) and serum (predominantly IgG) from pigeon breeders, and there were no significant titres in controls. The levels of IgG antibody in saliva and in serum correlated significantly (r = 0.52, P < 0.001), and both correlated with the raised immunoglobulin levels. In both saliva and serum the IgG rather than the IgA antibody activity was associated with symptoms of EAA.
Antibody activity in saliva and serum, representing the mucosal and systemic responses, respectively, were both strongly stimulated by inhaled antigens. The IgG antibody titres of saliva and serum correlated significantly and were a useful index of inflammation, as measured by the raised total immunoglobulin levels, and symptoms. This suggests that IgG antibody in serum may reflect clinical and immunological sensitization of the lung mucosa. Collecting saliva is noninvasive, and saliva antibody measurement is a convenient method for monitoring EAA, especially in children, and will facilitate sampling for example in epidemiological studies of antibody prevalence.
鸽子吸入的抗原可引发外源性过敏性肺泡炎（EAA），这是一种肺部炎症的典型疾病。在鸽子饲养者中，针对这些抗原的血清抗体和致敏淋巴细胞已被主要描述，但并非总是与疾病相关。然而，肺内的抗体活性可能与疾病有更密切的关联，不过，通过支气管镜检查进行肺泡灌洗采样用于筛查并不实际，因此我们使用唾液来量化黏膜抗体反应。
确定：（a）在鸽子饲养者的唾液中是否可检测到针对吸入禽类抗原的抗体活性；（b）唾液抗体和总免疫球蛋白水平的分布在数量或质量上是否与血清不同；（c）EAA的超敏症状与黏膜或全身体液免疫反应的关联更强。
检测87名鸽子饲养者和24名无禽类接触史的对照者的唾液和血清中总免疫球蛋白以及针对禽类抗原的IgG、IgA（IgA1和IgA2）抗体活性。以白蛋白水平作为蛋白质参照，用可替宁水平确认吸烟状况。通过访谈确定特定的超敏症状和各种鸽子接触指数。
与对照组相比，鸽子饲养者唾液中IgG、IgA和IgA1的绝对水平及相对比例（相对于白蛋白），以及血清中IgG的水平显著更高，提示存在黏膜炎症。在鸽子饲养者的唾液（主要为IgA）和血清（主要为IgG）中均能轻易检测到所有同种型的禽类抗原特异性抗体，而对照组中未检测到显著滴度。唾液和血清中IgG抗体水平显著相关（r = 0.52，P < 0.001），且二者均与免疫球蛋白水平升高相关。在唾液和血清中，与EAA症状相关的均是IgG而非IgA抗体活性。
分别代表黏膜和全身反应的唾液和血清中的抗体活性均受到吸入抗原的强烈刺激。唾液和血清中的IgG抗体滴度显著相关，并且是炎症的一个有用指标，可通过总免疫球蛋白水平升高及症状来衡量。这表明血清中的IgG抗体可能反映肺黏膜的临床和免疫致敏情况。采集唾液是非侵入性的，唾液抗体检测是监测EAA的一种便捷方法，尤其适用于儿童，并且将便于例如在抗体患病率的流行病学研究中进行采样。
