成人特发性孤立性ACTH缺乏症三例临床分析并文献复习

Analysis of three patients with adult idiopathic isolated ACTH deficiency and literature review

目的成人特发性孤立性ACTH缺乏症（adult idiopathic isolated ACTH deftciencv，AIIAD）十分少见，临床漏诊和误诊率高。本文通过分析总结本院3例AIIAD患者的临床特点并复习文献总结特征，以提高对该病的认识。方法采用回顾性分析的方法，收集本院近15年来收治的AIIAD患者共3例，对其临床表现、实验室检查和治疗反应进行分析，并复习文献资料，总结该病的临床特征。结果3例AIIAD患者（男性2例，女性1例）发病时年龄52—68岁。均以乏力、体重下降起病，确诊前病程7个月到4年不等，多次辗转就诊，长期得不到正确诊断，分别误诊为更年期综合征、甲状腺炎和胃肠道疾病。通过分析此3例患者，并结合文献复习，总结该病的临床特征如下：（1）发病年龄多数40岁以上，无糖皮质激素使用史；（2）起病隐匿，多以乏力、消瘦起病，反复多次诊治；（3）皮肤无色素沉着；（4）可表现性功能减退、月经紊乱，但性激素正常；（5）低钠血症较易出现，高钾血症少见；（6）血淋巴细胞和嗜酸性粒细胞常增高；（7）血浆ACTH、皮质醇明显降低，但垂体其他激素轴系包括促甲状腺激素、促性激素轴和生长激素等均正常；（8）多伴有甲状腺疾病或甲状腺自身抗体阳性；（9）常伴有其他自身免疫性疾病，并随糖皮质激素的替代治疗而缓解；（10）垂体MRI未见异常或呈空泡蝶鞍；（11）无器质性病变所致垂体ACTH分泌异常。结论AIIAD起病隐袭，症状不典型，临床上对任何不能解释的低钠血症、乏力、体重下降应该想到该病的可能性。充分认识其临床特征有助于提高临床诊断率，减少漏诊、误诊。

Objective Adult idiopathic isolated ACTH deficiency （AIIAD） is an underestimated disorder which is frequently misdiagnosed. In this paper, we presented 3 new cases of AIIAD and summarized the clinical characteristics by analyzing these cases and available literature for further understanding this disease. Methods Three cases of AIIAD in our hospital from 1998 to 2003 were retrospectively identified. Data of clinical features, laboratory findings, and response to treatment were collected. The clinical characteristics and pertinent literature were reviewed and analysed. Results These 3 cases of AIIAD aged 52-68 years old were misdiagnosed and incorrectly treated for 7 months to 4 years. All three cases presented the symptoms of fatigue and loss of weight at the onset, and were misdiagnosed as climacteric syndrome, thyroiditis, and gastrointestinal disease. The prevalence of AIIAD was very low, and it was thought to he an underestimated disorder. Through analyzing the 3 cases and literature review, the clinical features of this disease were summarized as follows ： （ 1 ） Most patients were aged over 40 years and had no history of glucocorticoid medication. （ 2 ） Clinical presentations were insidious, with symptoms such as fatigue and weight loss. （ 3 ） Patients usually had no excessive pigmentation. （4）Hypogonadisminmenandamenorrheainwomen could be present. （5） Blood chemistry usually revealed hyponatremia but rarely hyperkalemia. （6） Blood lymphocytosis and eosinophilia were common. （7） Plasma ACTH and cortisol levels markedly decreased with normal secretion of other pituitary hormones. （8） High prevalence of thyroid disorder or positive anti-thyroid autoantibody. （9） Usually the other accompanied autoimmune diseases might be ameliorated with glucocorticoid replacement. （10） MRI revealed no structural pituitary defects except for empty sella. （11） No evidence of infiltration, trauma, surgery, infection, and radiotherapy of the pituitary gland was found. Conclusions AIIAD is an unspecified and underestimated condition with quite high incidence of misdiagnosis. Patients with unexplained hyponatremia, fatigue, and weight loss should be evaluated for the possibility of AIIAD. Fully understanding clinical features of AIIAD will help to improve the diagnosis and reduce misdiagnosis.