Abstract:

Objective To summarize the perioperative characteristics and management of isolatedmethylmalonic acidemia after liver transplantation. Methods A total of 13 MMA patients undergoing LT wereenrolled in our study from December 2014 to December 2019，the clinical characteristics，laboratory datas，chronological changes in urine MMA levels and treatment were analyzed retrospectively. Results All the 13 caseswere diagnosed with isolated MMA. Five cases were received deceased donor liver transplantation（DDLT），and eight cases received living donor liver transplantation（LDLT）. Within the early days after LT surgery，metabolic condition fluctuated. The mean base excess of blood value and plasma bicarbonate（HCO3 - ）restored to normal graduallywithin two weeks after LT. Our study also indicated that propionyl carnitine（C3）and C3/C2 level showed markedreduction after LT. The mean urine MMA was reduced by 82.41% compared with the urine level of MMA before liver transplantation（P ＜ 0.01），but remained ＞ 63 folds higher than upper limit of normal. The two patients with renal insufficiency before LT maintained stable by adjusting the immunosuppressive regimen during the observation period. Imaging changes of the nervous system were observed in 2 cases. All patients survive to date. Conclusion LT is regarded as an effective treatment to prevent metabolic crisis of MMA，we should give closely monitor the blood gas analysis to avoid the acidosis episodes by implementing sodium bicarbonate. Personalized immunosuppressive regimen should be developed for those MMA patients with kidney dysfunction. 

Key words:

Methylmalonic acidemia, Methylmalonic acid, Liver transplantation, Perioperative management

摘要：

目的 总结甲基丙二酸血症（methylmalonic acidemia，MMA）的肝移植围术期临床特点和管理经验。 方法 回顾性分析 2014 年 12 月至 2019 年 12 月 13 例肝移植术后 MMA 患者的围术期临床特征、实验室检查结果、尿 MMA 变化及治疗情况。 结果 纳入的 13 例患者均被诊断为单纯型 MMA，5 例患者接受了公民逝世后器官捐献的肝脏移植（deceased donor liver transplantation，DDLT），8 例接受了活体肝移植（living donor liver transplantation，LDLT）。肝移植术后早期 MMA 患儿代谢情况有所波动，碱剩余及HCO3 - 水平在术后 3 d 及 2 周较术前逐渐好转。肝移植术后 C3、C3/C2 水平较术前明显下降，术后尿 MMA水平较术前下降了 82.41%（P ＜ 0.01），但仍高于正常值上限。在肝移植围术期，通过制定个性化免疫抑制方案，2 例肝移植术前存在肾功能不全患者的肾脏功能逐渐恢复并趋于稳定。2 例患儿出现神经系统的影像学改变。所有患儿至今存活。中位随访时间为 63.6（30 ～ 100.8）个月。 结论 肝移植是 MMA 患者代谢危象的有效治疗方法，在围术期需严密监测血气结果，避免酸中毒发生，酌情给予碳酸氢钠纠正酸中毒， MMA 合并肾功能不全的患者需制定个性化的免疫抑制方案。

关键词:

甲基丙二酸血症 , 甲基丙二酸 , 肝移植 , 围术期管理