Abstract：
BACKGROUND: Disseminated bacillus Calmette-Guérin (BCG) disease is a rare but serious BCG complication in children. Early diagnosis and timely interventions are essential to improve prognosis. However, its manifestations can closely mimic those of Langerhans cell histiocytosis (LCH), which usually leads to a high rate of misdiagnoses. Herein we report the first case of successful application of biopsy tissue metagenomic next-generation sequencing (mNGS) in the differential diagnosis of disseminated BCG disease and LCH.
METHODS: A 5-month-old female infant was transferred to our center for the treatment of paroxysmal cough, intermittent hematochezia and trunk rash. Examination on admission showed moderate anemia, erythropenia, thrombocytopenia and hepatosplenomegaly. The immunohistochemistry of her intestinal biopsy samples showed CD1a (+) and Langerin (+). Genetic testing of both peripheral blood and bone marrow samples suggested BRAFV600E mutation. Hence, she was initially diagnosed with LCH. However, no improvement was observed after a course of systemic chemotherapy. The left axillary lymph node and colonic mucosal biopsy specimens were sent for mNGS which resulted in sequence reads of Mycobacterium bovis-BCG. Triple antimycobacterial therapy was started according to the diagnosis.
RESULTS: The diagnosis of this case was corrected as disseminated BCG disease by mNGS. Currently, she is doing well clinically and continues to follow-up at our outpatient clinic.
CONCLUSIONS: This case suggests that mNGS is a valuable tool in the differential diagnosis of disseminated BCG disease and LCH, which can improve the early diagnosis rate of disseminated BCG disease.
METHODS: A 5-month-old female infant was transferred to our center for the treatment of paroxysmal cough, intermittent hematochezia and trunk rash. Examination on admission showed moderate anemia, erythropenia, thrombocytopenia and hepatosplenomegaly. The immunohistochemistry of her intestinal biopsy samples showed CD1a (+) and Langerin (+). Genetic testing of both peripheral blood and bone marrow samples suggested BRAFV600E mutation. Hence, she was initially diagnosed with LCH. However, no improvement was observed after a course of systemic chemotherapy. The left axillary lymph node and colonic mucosal biopsy specimens were sent for mNGS which resulted in sequence reads of Mycobacterium bovis-BCG. Triple antimycobacterial therapy was started according to the diagnosis.
RESULTS: The diagnosis of this case was corrected as disseminated BCG disease by mNGS. Currently, she is doing well clinically and continues to follow-up at our outpatient clinic.
CONCLUSIONS: This case suggests that mNGS is a valuable tool in the differential diagnosis of disseminated BCG disease and LCH, which can improve the early diagnosis rate of disseminated BCG disease.
摘要：
背景：卡介苗（BCG）是一种罕见但严重的儿童卡介苗并发症。早期诊断和及时干预对改善预后至关重要。然而,它的表现可以密切模仿那些朗格汉斯细胞组织细胞增生症（LCH），这通常会导致高误诊率。在此，我们报告了活检组织宏基因组下一代测序（mNGS）在播散性BCG疾病和LCH的鉴别诊断中成功应用的第一例。
方法：一名5个月大的女婴被转移到我们中心治疗阵发性咳嗽，间歇性便血和躯干皮疹。入院时检查显示中度贫血，红细胞减少症,血小板减少和肝脾肿大。她的肠活检样本的免疫组织化学显示CD1a（）和Langerin（）。外周血和骨髓样本的基因检测均提示BRAFV600E突变。因此，她最初被诊断为LCH。然而,经过一个疗程的全身化疗后未观察到改善.将左腋窝淋巴结和结肠粘膜活检标本送去mNGS,其导致牛分枝杆菌-BCG的序列读数。根据诊断开始三重抗分枝杆菌治疗。
结果：mNGS纠正了该病例的诊断为播散性BCG病。目前,她的临床表现良好，并继续在我们的门诊进行随访。
结论：本病例提示mNGS是鉴别诊断播散性BCG和LCH的有价值的工具，可提高播散性BCG病的早期诊断率。
方法：一名5个月大的女婴被转移到我们中心治疗阵发性咳嗽，间歇性便血和躯干皮疹。入院时检查显示中度贫血，红细胞减少症,血小板减少和肝脾肿大。她的肠活检样本的免疫组织化学显示CD1a（）和Langerin（）。外周血和骨髓样本的基因检测均提示BRAFV600E突变。因此，她最初被诊断为LCH。然而,经过一个疗程的全身化疗后未观察到改善.将左腋窝淋巴结和结肠粘膜活检标本送去mNGS,其导致牛分枝杆菌-BCG的序列读数。根据诊断开始三重抗分枝杆菌治疗。
结果：mNGS纠正了该病例的诊断为播散性BCG病。目前,她的临床表现良好，并继续在我们的门诊进行随访。
结论：本病例提示mNGS是鉴别诊断播散性BCG和LCH的有价值的工具，可提高播散性BCG病的早期诊断率。
