Background: Pulmonary Langerhans cell histiocytosis (PLCH) is an interstitial primary pulmonary disease, characterized by Langerhans cell proliferation. It is easily misdiagnosed in children. This study aimed to characterize the clinical manifestations and features of PLCH by retrospective analysis.
Methods: A retrospective analysis was performed in 117 PLCH patients out of 338 LCH patients who were admitted in our center from November 2006 to October 2013. Variables between two groups were compared by Mann-Whitney U-test and Chi-square test. Kaplan-Meier curves were constructed to compare the survival rates and Cox regression to evaluate the effect of risk factors.
Results: The median age of PLCH group was significantly lower than that of non-PLCH group (18.63 months vs. 43.4 months, P < 0.001). All PLCH children had other organ involvement and only 11 cases (9.4%) had respiratory symptoms. The most common radiologic finding was cystic lesions (29 cases, 24.8%). Pulmonary function abnormalities were dominated by obstructive ventilatory dysfunction (63 cases, 82.9%). The 5-year overall survival (OS) of PLCH children was 93.6% ± 2.3% and the event-free survival (EFS) was 55.7% ± 5.2%. Among the 38 cases with progressed or relapsed disease, five cases (13.2%) were due to progression or recurrence of lung damage. The 5-year OS of PLCH children with "risk organ" involvement was significantly lower than those without "risk organ" involvement (86.0% ± 4.9% vs. 100%, χ2 = 8.793, P = 0.003). The difference of EFS between two groups was also significant (43.7% ± 7.7% vs. 66.3% ± 6.5%, χ2 = 5.399, P = 0.020). The "risk organ" involvement had a significant impact on survival (hazard ratio = 1.9, P = 0.039).
Conclusions: PLCH mainly occurs in young children, and only a small percentage of patients have respiratory symptoms. They generally have other organ involvement. Most of PLCH children have a good prognosis and most lung lesions could have improved or stabilized. Management of "risk organ" involvement is the key point to improving EFS.
儿童肺朗格罕细胞组织细胞增生症的临床研究摘要背景：肺朗格罕细胞组织细胞增生症(PLCH) 是一种原发于肺、以朗格罕细胞增生为特点的间质性疾病。它是一种特殊类型的朗格罕细胞组织细胞增生症（LCH），容易在儿童中误诊。本研究的目的是通过回顾性分析来描述PLCH的临床表现和特征。 方法：回顾性分析2006年11月至2013年10月我院收治的338例LCH患者中的117例PLCH患者临床资料，采用Mann-Whitney U检验法比较连续变量，采用卡方检验或Fisher确切概率法比较分类变量。通过Kaplan-Meier曲线比较两组间生存率，并应用多因素Cox比例风险回归分析评估风险因素对生存率的影响。 结果：PLCH患儿与非PLCH患儿相比无显著性别差异。PLCH患儿的中位年龄显著低于非PLCH患者（18.63个月vs.43.4个月，P<0.001）。在117例PLCH患儿中，仅有11例（9.4%）患儿有呼吸系统症状，全部患儿均伴有其他脏器受累。PLCH患儿肺部影像学表现主要包括囊泡（29例，24.8%）、磨玻璃（25例，21.4%）、结节（19例，16.2%）及其他特征。肺功能异常以小气道阻塞性通气功能障碍（63例，82.9%）为主。PLCH患儿的5年总生存率（OS）为93.6±2.3%，无事件生存率（EFS）为55.7±5.2%。在疾病进展或复发的患儿中，仅有13.2%是由于肺部病变的进展或复发导致的。有危险器官受累的PLCH患儿的5年总生存率显著低于无危险器官受累者（86.0±4.9% vs.100%， χ2=8.793, P = 0.003），无事件生存率也存在显著差异（43.7±7.7% vs. 66.3±6.5%, χ2=5.399, P=0.020）。在多因素分析中，危险器官受累对生存率有显著影响（风险比= 1.9，P = 0.039）。 结论：PLCH主要发生于婴幼儿，仅有小部分患者伴有呼吸道症状。PLCH患儿通常伴有其他器官受累。大部分PLCH患儿预后良好，且肺部病变转归大多为好转或稳定。控制危险器官的受累是提高无事件生存率（EFS）的关键。.
Keywords: Children; Langerhans Cell Histiocytosis; Lung.