由于抗干扰素-γ抗体（AIGA）的存在，成人发病的免疫缺陷（AOID）综合征表现为多种多样的机会性感染。我们报告了一起65岁的健康女性病例，她患有军团菌和肺巨细胞分枝杆菌共同感染，其临床表现类似于转移性肺癌。她出现慢性咳嗽和体重减轻。碳同位素发射断层成像扫描显示右上叶肿块、纵隔淋巴结肿大和多发骨病变。肺肿块和纵隔淋巴结上的抗酸杆菌培养显示为肺巨细胞分枝杆菌，并且经过长期抗生素治疗后有所改善。治疗后15个月，发生全身性肺巨细胞分枝杆菌复发感染，同时AIGA呈阳性，并且具有对下游免疫途径的功能性中和活性。被诊断为AIGA引起的AOID综合征。该病例凸显了对AOID综合征的高度警惕性的重要性和早期诊断的难度。迫切需要进一步研究其预测因素和针对AIGA的治疗方法。© 2023 The Authors. Respirology Case Reports由澳大利亚约翰威利出版社代表亚太呼吸学会出版。

Adult-onset immunodeficiency (AOID) syndrome due to the presence of anti-interferon gamma antibody (AIGA) is characterized by multiple opportunistic infections. We report a case of a 65-year old healthy woman who suffered from Legionella pneumophila and Mycobacterium intracellulare co-infection with clinical presentation mimicking metastatic lung cancer. She presented with chronic cough and weight loss. Her positron emission tomography scan showed a right upper lobe mass, mediastinal lymphadenopathy and multiple bone lesions. Acid fast bacilli culture of the lung mass and mediastinal lymph node revealed Mycobacterium intracellulare and she improved with prolonged antibiotic. Relapse of disseminated Mycobacterium intracellulare infection occurred 15 months post-treatment and AIGA was positive with functional neutralizing activity on downstream immune pathway. AOID syndrome secondary to AIGA was diagnosed. This case illustrated the importance of high index of suspicion of AOID syndrome and the difficulty of early diagnosis. Further studies on its predictive factors and AIGA-targeted treatment modalities are urgently needed.© 2023 The Authors. Respirology Case Reports published by John Wiley & Sons Australia, Ltd on behalf of The Asian Pacific Society of Respirology.