Some endocrine disorders, including hypophysitis and isolated adrenocorticotropic hormone (ACTH) deficiency, are caused by an autoimmune response to endocrine organs. Although the pathogenesis of some autoimmune endocrine diseases has been elucidated, it remains obscure for most. Anti-PIT-1 hypophysitis (anti-PIT-1 antibody syndrome) is a newly described pituitary autoimmune disease characterized by acquired and specific growth hormone (GH), prolactin (PRL), and thyroid-stimulating hormone (TSH) deficiencies. This disorder is associated with a thymoma or neoplasm that ectopically expresses pituitary-specific transcription factor 1 (PIT-1) protein. Circulating anti-PIT-1 antibody is a disease marker, and PIT-1-reactive cytotoxic T cells (CTLs) play a pivotal role in disease development. In addition, isolated ACTH deficiency appears to be caused by autoimmunity to corticotrophs; however, the pathogenesis remains unclear. A recently described case of isolated ACTH deficiency with large cell neuroendocrine carcinoma (LCNEC) showed ectopically expressed proopiomelanocortin (POMC), and circulating anti-POMC antibody and POMC-reactive CTLs were also detected. As CTL infiltrations around corticotrophs were also observed, isolated ACTH deficiency may be associated at least in part with a paraneoplastic syndrome. Although several underlying mechanisms for pituitary autoimmunity have been proposed, these observations highlight the importance of paraneoplastic syndrome as a cause of pituitary autoimmune disease. In this review, we focus on the pathophysiology and connection of anti-PIT-1 hypophysitis and isolated ACTH deficiency and discuss the state-of-art knowledge for understanding pituitary autoimmunity.

中文翻译：

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自身免疫性垂体疾病：具有临床意义的新概念。

一些内分泌疾病，包括垂体炎和孤立的促肾上腺皮质激素（ACTH）缺乏症，是由对内分泌器官的自身免疫反应引起的。尽管已经阐明了某些自身免疫性内分泌疾病的发病机制，但对于大多数人来说仍然不清楚。抗PIT-1垂体炎（抗PIT-1抗体综合症）是一种新描述的垂体自身免疫疾病，其特征在于获得性和特异性生长激素（GH），催乳素（PRL）和甲状腺刺激激素（TSH）缺乏。这种疾病与异位表达垂体特异性转录因子1（PIT-1）蛋白的胸腺瘤或肿瘤有关。循环抗PIT-1抗体是一种疾病标志物，PIT-1反应性细胞毒性T细胞（CTL）在疾病发展中起关键作用。此外，孤立的ACTH缺乏症似乎是由对皮质激素的自身免疫引起的；然而，其发病机理仍不清楚。最近描述的一个孤立的ACTH缺乏伴大细胞神经内分泌癌（LCNEC）的病例显示了异位表达的proopiomelanocortin（POMC），并且还检测到循环的抗POMC抗体和POMC反应性CTL。由于还观察到了皮质激素周围的CTL浸润，孤立的ACTH缺乏可能至少部分与副肿瘤综合征相关。尽管已提出了几种垂体自身免疫的潜在机制，但这些观察结果突出了副肿瘤综合症作为垂体自身免疫疾病病因的重要性。在这篇评论中，