患儿，男，5岁2个月，因确诊急性髓系白血病10月余入院。入院20 d后接受人类白细胞抗原8/10相合无关脐带血干细胞移植，移植后第6天出现高热、全身红色丘疹样皮疹伴肝酶及白细胞介素-6升高，诊断为植入前综合征，经过对症治疗后症状好转。移植后第22天患儿出现顽固性低钠血症，排除药物、感染、中枢神经系统病变、其他器官功能障碍及肾性失钠，诊断抗利尿激素分泌不当综合征（syndrome of inappropriate antidiuretic hormone secretion, SIADH）。通过限制液体量、补充3%氯化钠溶液及服胶囊食盐，随着植入前综合征缓解，SIADH最终得到完全纠正。该文报道1例儿童造血干细胞移植后SIADH的病例，并对文献已报道的病例资料进行归纳总结，为该病的早期诊断、治疗提供参考。

A boy aged 5 years and 2 months with a history of acute myeloid leukemia of more than 10 months was admitted. Twenty days after admission, he underwent an HLA 8/10-matched unrelated umbilical cord blood stem cell transplantation. On day 6 post-transplant, high fever and a generalized erythematous papular rash occurred, with elevations of liver enzymes and interleukin-6; pre-engraftment syndrome was diagnosed and symptoms improved after symptomatic treatment. On day 22 post-transplant, refractory hyponatremia occurred. After drug effects, infection, central nervous system lesions, other organ dysfunction, and renal salt wasting were excluded, syndrome of inappropriate antidiuretic hormone secretion (SIADH) was diagnosed. Fluid restriction, 3% sodium chloride infusion, and oral salt capsules were administered, and SIADH resolved completely as the pre-engraftment syndrome resolved. One pediatric case of SIADH after hematopoietic stem cell transplantation is reported, and published cases are summarized to inform early diagnosis and treatment.