目的:探讨重症肺炎相关性噬血细胞综合征的病原、临床特点及预后，分析与死亡相关的危险因素。方法:回顾性分析2009年2月至2019年2月深圳市儿童医院收治的诊断重症肺炎相关性噬血细胞综合征患儿的临床资料，包括患儿的一般资料、病原学、临床表现、实验室检查、治疗和转归，对死亡组和生存组一般资料和实验室检查采用独立样本n t检验进行分析。n 结果:1．一般情况：30例患儿年龄3个月～8岁7个月，男15例，女15例，重症肺炎相关性噬血细胞综合征占同期重症肺炎2.74%(30/1 096例)。2.病原学：肺炎支原体感染8例(8/30例，26.67%)，病毒感染(腺病毒感染5例，EB病毒感染1例，巨细胞病毒感染1例)7例(7/30例，23.33%)，肺炎支原体合并腺病毒感染4例(4/30例，13.33%)，细菌感染3例，真菌感染2例，结核感染1例，病原不明确5例。3.临床特点：均有发热、肝大，86.67%(26/30例)患儿热程>10 d，83.33%(25/30例)有咳嗽症状，76.66%(23/30例)患儿伴脾大，33.33%(10/30例)患儿合并神经系统症状，80.00%(24/30例)患儿实验室检查提示不同程度的两系及三系减少，50%患儿伴肝功能损害，患儿均有血清铁蛋白异常及乳酸脱氢酶升高。4.9例(9/30例，30.00%)患儿死亡，生存组和死亡组年龄、最高三酰甘油、最高血清铁蛋白比较差异均有统计学意义(均n P<0.05)。n 结论:重症肺炎相关性噬血细胞综合征是一种高死亡率疾病，肺炎支原体及腺病毒肺炎更容易继发噬血细胞综合征，年龄小、血清铁蛋白及三酰甘油明显升高的患儿预后差。“,”Objective:To investigate the etiology, clinical characteristics and outcome of severe pneumonia-associated hemophagocytic lymphohistiocytosis, and to analyze the risk factors for mortality.Methods:Clinical data of patients with severe pneumonia-associated hemophagocytic lymphohistiocytosis admitted to Shenzhen Children′s Hospital from February 2009 to February 2019 were retrospectively analyzed.The data included clinical characteristics, etiology, clinical manifestations, laboratory data, treatment and outcomes of the patients.The clinical characteristics and laboratory data of the survival group and the death group were compared by independent sample n t-test.n Results:(1) Clinical characteristics: the patients were aged from 3 months to 8 years and 7 months, including 15 males and 15 females.Severe pneumonia-associated hemophagocytic lymphohistiocytosis accounted for 2.74% (30/1 096 cases) of severe pneumonia in the same period.(2) Etiology: Mycoplasma pneumoniae infection was found in 8 cases (8/30 cases, 26.67%), virus infection in 7 cases (7/30 cases, 23.33%, including 5 cases with adenovirus infection, 1 case with EB virus infection, and 1 case with cytomegalovirus infection), Mycoplasma pneumoniae complicated with adenovirus infection in 4 cases (4/30 cases, 13.33%), bacterial infection in 3 cases (3/30 cases, 10%), and fungal infection in 2 cases, Mycobacterium tuberculosis infection in 1 case.The pathogens were not identified in 5 patients.(3) Clinical manifestations: fever and hepatomegaly were present in all patients.Besides, 86.67% (26/30)patients had fever duration more than 10 days, 83.33% (25/30 cases) patients had cough, 76.66% (23/30 cases) patients had splenomegaly, and 33.33% (10/30 cases) patients had nervous system symptoms.Laboratory data showed varying degrees of reduction of binary and ternary systems in 80.00%(24/30 cases) of the patients.Liver function impairment was found in half of the patients, and serum ferritin and lactate dehydrogenase levels were elevated in all patients.(4) The mortality rate was 30.00% (9/30 cases). The differences in age, hypertriglyceridemia and high serum ferritin levels between the survival and death groups were significant (all n P<0.05).n Conclusions:Severe pneumonia-associated hemophagocytic lymphohistiocytosis is a disease with a high mortality rate.Patients with Mycoplasma pneumoniae and adenovirus pneumonia are more likely to suffer from secondary hemophagocytic lymphohistiocytosis.Younger age, hypertriglyceridemia and high serum ferritin levels are indicative of poor prognosis.