Mondal Sanjib, Vignesh Pandiarajan, Loganathan Sathish Kumar, Arora Kanika, Das Jhumki, Rawat Amit, Singh Surjit
Allergy Immunology Unit, Department of Pediatrics, Advanced Pediatrics Centre, Post Graduate Institute of Medical Education and Research, Chandigarh, India.
Front Pediatr. 2023 Jan 11;10:964025. doi: 10.3389/fped.2022.964025. eCollection 2022.
Due to the lack of widespread availability of flow cytometry services for immunodeficiency, nitroblue tetrazolium test (NBT) is the commonly used screening modality to identify patients with chronic granulomatous disease (CGD) in developing countries.
We report a child with X-linked CGD with residual NADPH oxidase activity who had an indeterminate NBT result even in the presence of classical manifestations of CGD.
A 7-year-old boy presented with recurrent episodes of inflammatory colitis and septicaemia at the age of 3 years. He also had cervical adenitis due to . NBT performed on multiple occasions was not suggestive of CGD. Dihydrorhodamine (DHR) test using phorbol myristate acetate (PMA) as a stimulant revealed a small blunt peak suggestive of AR-CGD; however, significant reduction in NADPH oxidase activity was noted with milder stimulants such as and . Genetic analysis revealed a hemizygous pathogenic variant in . Flow cytometry showed diminished gp91phox expression in the patient's neutrophils suggestive of X-linked CGD.
Our case highlights that early-onset inflammatory bowel disease can be a presenting manifestation of CGD and diagnosis of CGD can be missed if NBT alone is used for screening, especially in the presence of NADPH oxidase activity. Diagnosis of "CGD with residual NADPH oxidase activity" requires a high degree of clinical suspicion, and performing DHR with different stimulants can unravel the diagnosis.
由于免疫缺陷的流式细胞术检测服务在发展中国家尚未广泛普及，硝基蓝四氮唑试验（NBT）是发展中国家用于识别慢性肉芽肿病（CGD）患者的常用筛查方法。
我们报告了一名患有X连锁CGD且具有残余NADPH氧化酶活性的儿童，即使存在CGD的典型表现，其NBT结果仍不确定。
一名7岁男孩在3岁时出现复发性炎症性结肠炎和败血症发作。他还因……患有颈部腺炎。多次进行的NBT检查未提示CGD。使用佛波酯肉豆蔻酸酯（PMA）作为刺激剂的二氢罗丹明（DHR）试验显示出一个小的钝峰，提示为AR-CGD；然而，使用……等较弱刺激剂时，NADPH氧化酶活性有显著降低。基因分析显示……存在半合子致病性变异。流式细胞术显示患者中性粒细胞中gp91phox表达减少，提示为X连锁CGD。
我们的病例强调，早发性炎症性肠病可能是CGD的首发表现，如果仅使用NBT进行筛查，尤其是在存在NADPH氧化酶活性的情况下，可能会漏诊CGD。诊断“具有残余NADPH氧化酶活性的CGD”需要高度的临床怀疑，使用不同刺激剂进行DHR试验有助于明确诊断。
