目的:探讨小儿肺孢子菌肺炎(pneumocystis jirovecii pneumonia，PCP)的临床特征，提高儿科医师对该病的认识。方法:回顾性分析西安市儿童医院儿童重症监护病房(pediatric intensive care unit，PICU)2019年1月至12月收治的7例非人类免疫缺陷病毒感染PCP患儿的临床资料、实验室检查、诊治经过及治疗转归。结果:7例患儿中，男6例，女1例，平均年龄(6.09±3.80)岁。6例患儿既往长期服用糖皮质激素或免疫抑制剂治疗，平均使用时间(80±30)d，1例虽无激素和免疫抑制剂使用史，但最终确诊为免疫缺陷病。7例患儿均以发热、咳嗽、进行性呼吸困难为主要表现，肺部体征轻而胸部影像学重；白细胞计数大多正常，淋巴细胞计数不同程度降低，C-反应蛋白、降钙素原及革兰阴性菌脂多糖轻度升高或正常，乳酸脱氢酶明显升高，PaOn 2/FiOn 2明显降低；所有患儿均合并不同程度心、肝及消化道损害。肺孢子菌感染均由宏基因二代测序(metagenomics next generation sequencing，mNGS)确诊，其中1例由支气管肺泡灌洗液检出，余6例经血液mNGS检出。7例患儿入PICU后均给予机械通气、静脉用丙种球蛋白、连续性肾脏替代等治疗。所有患儿院外均无预防性使用复方磺胺甲噁唑(TMP-SMZ)，1例患儿入PICU前已确诊PCP并给予TMP-SMZ治疗20 d，余6例入PICU后开始TMP-SMZ治疗。最终，1例治愈，3例死亡，3例放弃治疗后死亡。平均住院(11.28±8.78)d，平均住院费用(7.8±2.4)万元。n 结论:非人类免疫缺陷病毒感染PCP患儿通常有基础性疾病或免疫缺陷病，以发热、干咳及进行性呼吸困难为主要表现，进展快，病死率高，应早期行血液mNGS确诊PCP，及时给予TMP-SMZ治疗；对高度怀疑而无条件进行病原学检查者可给予TMP-SMZ预防治疗。“,”Objective:To better understand the clinical characteristics of children with pneumocystis pneumonia(PCP).Methods:Seven cases of non-human immunodeficiency virus infected children with PCP admitted to pediatric intensive care unit(PICU) at Xi′an Children′s Hospital from January 1, 2019 to December 31, 2019 were enrolled.Clinical findings, laboratory examination results, diagnosis, treatment, and outcome data were retrospectively reviewed.Results:There were seven children enrolled in this study including six boys and one girl.The average age was(6.09±3.80)years.Six patients received a long-term steroid or immunosuppressive therapy, and the average duration of medication was(80±30)days.One patient was eventually diagnosed with immunodeficiency disease despite no history of steroid and immunosuppressive therapy.Fever, cough and progressive dyspnea were the main manifestations.The pulmonary signs were not obvious, however, the chest radiographs showed serious ground glass changes.Laboratory examination showed that white blood cell counts were normal, lymphocyte counts were decreased to varying degrees, while C-reactive protein, calcitonin and lipopolysaccharide increased slightly or normal.Lactate dehydrogenase significantly increased and PaOn 2/FiOn 2 decreased, respectively.All children combined with different degrees of heart, liver and digestive tract damage.Pneumocystis jirovecii infection was diagnosed by metagenomics next-generation sequencing(mNGS), of which one case was detected by bronchoalveolar lavage fluid, and the remaining six cases were detected by peripheral blood.After entering PICU, mechanical ventilation, intravenous injection of human immunoglobulin, and continuous renal replacement therapy were performed.None of the children used TMP-SMZ for prophylaxis outside the hospital.Among them, one case was diagnosed with PCP before entering PICU and was given TMP-SMZ for 20 days, while the remaining six patients started to receive TMP-SMZ after entering PICU.Finally, one patient was cured, three died and another three cases died after giving up treatment.The average hospitalization days were(11.28±8.78)days, and the average hospitalization costs were (78, 000±24, 000) RMB.n Conclusion:Children with non-human immunodeficiency virus infected PCP usually have underlying diseases or immunodeficiency diseases.Due to non-specific manifestations, rapid progression and high mortality, clinicians should pay more attention to it.It is necessary to dynamically observe the respiratory symptoms, perform mNGS as soon as possible, and give TMP-SMZ treatment in time.TMP-SMZ prophylaxis can be given to patients who are highly suspected of PCP but unable to perform pathogenic examinations.