Nakajima M, Manabe T, Niki Y, Matsushima T
Department of Medicine, Kawasaki Medical School, Kurashiki, Japan.
Nihon Kyobu Shikkan Gakkai Zasshi. 1996 Oct;34(10):1168-73.
The serum IgE level is usually not high in hypersensitivity pneumonitis (HP) because it develops from Type III and Type IV allergies (Gell and Coombs). However, we have previously reported infiltration of lymphocytes and mast cells in patients with summer-type HP and a high serum IgE level. We encountered a 56-year-old woman with summer-type HP who had a high serum IgE level and a positive skin reaction to the causative antigen. She was admitted to our hospital because of coughing, fever, and dyspnea. On admission, a chest X-ray film and a chest CT scan disclosed ground-glass opacity and diffuse small nodular shadows. Her PaO2 was 56 mmHg on room air and her serum IgE level was high (725 U/ml). Pulmonary-function testing revealed a low DLCo, but the FEV1 was normal. Summer-type HP was diagnosed because of a positive test for serum antibody to Trichosporon mucoides (TIMM1573), a positive result on an antigen challenge test, and because pathological examination of specimens obtained by transbronchial lung biopsy showed severe infiltration of lymphocytes. After admission, her serum IgE levels gradually improved along with the symptoms and the PaO2. A skin test for the causative antigen was done to study the early immunological reaction, and a positive result (22 mm x 24 mm) was obtained for T. mucoides (TIMM1573) in only 15 minutes. We could not elicit any history of atopy that may have been associated with the high serum IgE level and the positive skin test. Therefore, we suspect that this patient had an early immunologic reaction (Type I allergy) to T. mucoides, and that Type I allergy is involved in the development of HP.
在过敏性肺炎（HP）中，血清IgE水平通常不高，因为它是由III型和IV型过敏反应（盖尔和库姆斯分类法）引起的。然而，我们之前曾报道过夏季型HP患者存在淋巴细胞和肥大细胞浸润以及血清IgE水平升高的情况。我们遇到了一名56岁的夏季型HP女性患者，其血清IgE水平较高，且对致病抗原的皮肤反应呈阳性。她因咳嗽、发热和呼吸困难入院。入院时，胸部X线片和胸部CT扫描显示磨玻璃影和弥漫性小结节阴影。在室内空气中她的动脉血氧分压（PaO2）为56 mmHg，血清IgE水平较高（725 U/ml）。肺功能测试显示一氧化碳弥散量（DLCo）降低，但第一秒用力呼气容积（FEV1）正常。由于针对黏液样毛孢子菌（TIMM1573）的血清抗体检测呈阳性、抗原激发试验结果为阳性，且经支气管肺活检标本的病理检查显示淋巴细胞严重浸润，故诊断为夏季型HP。入院后，她的血清IgE水平随症状和PaO2逐渐改善。为研究早期免疫反应，对致病抗原进行了皮肤试验，仅15分钟后黏液样毛孢子菌（TIMM1573）的皮肤试验结果即为阳性（22 mm×24 mm）。我们未能发现任何可能与高血清IgE水平和阳性皮肤试验相关的特应性病史。因此，我们怀疑该患者对黏液样毛孢子菌存在早期免疫反应（I型过敏），且I型过敏参与了HP的发病过程。
