Nagamura Norihiro, Imada Toshihiro
Department of Rheumatology and Allergology, Shimane Prefectural Central Hospital, Izumo, Japan.
Department of General Medicine, Shimane Prefectural Central Hospital, Izumo, Japan.
Immunol Med. 2022 Mar;45(1):48-53. doi: 10.1080/25785826.2021.1914962. Epub 2021 May 25.
A 72-year-old man who was diagnosed as pulmonary mycobacterium avium complex (MAC) disease had suffered from antibiotics resistant fever with left renal enlargement surrounded by inflammatory change and multiple osteolytic lesions on computed tomography (CT). The renal biopsied samples pathologically showed immunoglobulin G4 (IgG4) positive plasma cell infiltration and many acid-fast bacilli without granuloma formation. Nucleic acid identification test for MAC from the samples of vertebral osteolytic lesion was positive. In the autopsy samples from left kidney, epithelioid cell granuloma and Langhans giant cell with many acid-fast bacilli were shown pathologically. In addition to osteolytic lesions on CT study, these pathological findings were not consistent with IgG4-related disease (IgG4-RD). The diagnosis of disseminated nontuberculous mycobacteriosis was made, and plasma anti-interferon-gamma (IFN-γ) autoantibody was found as the cause of underlying immunodeficiency. Disturbed function of IFN-γ resulted in impaired ability of phagocytic cells against pathogens and leading to spread of infection. T-helper type 2 dominant immune response was induced by prolonged antigenic stimulation of mycobacteria, which might have contributed to form the pathological features of IgG4-RD.
一名72岁男性被诊断为肺部鸟分枝杆菌复合群（MAC）病，曾患有抗生素耐药性发热，计算机断层扫描（CT）显示左肾肿大，周围有炎症改变，并有多处溶骨性病变。肾活检样本病理显示免疫球蛋白G4（IgG4）阳性浆细胞浸润，有许多抗酸杆菌，但无肉芽肿形成。从椎体溶骨性病变样本中进行的MAC核酸鉴定试验呈阳性。在左肾尸检样本中，病理显示有上皮样细胞肉芽肿和朗汉斯巨细胞，并有许多抗酸杆菌。除了CT检查显示的溶骨性病变外，这些病理结果与IgG4相关疾病（IgG4-RD）不一致。诊断为播散性非结核分枝杆菌病，发现血浆抗干扰素-γ（IFN-γ）自身抗体是潜在免疫缺陷的原因。IFN-γ功能紊乱导致吞噬细胞对抗病原体的能力受损，从而导致感染扩散。分枝杆菌的长期抗原刺激诱导了2型辅助性T细胞主导的免疫反应，这可能有助于形成IgG4-RD的病理特征。
