Long-term clinical outcomes and health-related quality of life in patients with isolated methylmalonic acidemia after liver transplantation: experience from the largest cohort study in China

Background Liver transplantation (LT) has been proposed as a viable treatment option for selected methylmalonic acidemia (MMA) patients. However, there are still controversies regarding the therapeutic value of LT for MMA. The systematic assessment of health-related quality of life (HRQoL)-targeted MMA children before and after LT is also undetermined. This study aimed to comprehensively assess the long-term impact of LT on MMA, including multiorgan sequelae and HRQoL in children and families. Methods We retrospectively evaluated 15 isolated MMA patients undergoing LT at our institution between June 2013 and March 2022. Pre- and post-transplant data were compared, including metabolic profiles, neurologic consequences, growth parameters, and HRQoL. To further assess the characteristics of the HRQoL outcomes in MMA, we compared the results with those of children with biliary atresia (BA). Results All patients had early onset MMA, and underwent LT at a mean age of 4.3 years. During 1.3–8.2 years of follow-up, the patient and graft survival rates were 100%. Metabolic stability was achieved in all patients with liberalized dietary protein intake. There was a significant overall improvement in height Z scores (P = 0.0047), and some preexisting neurological complications remained stable or even improved after LT. On the Pediatric Quality of Life Inventory (PedsQL™) generic core scales, the mean total, physical health, and psychosocial health scores improved significantly posttransplant ( P < 0.05). In the family impact module, higher mean scores were noted for all subscales post-LT, especially family function and daily activities ( P < 0.01). However, the total scores on the generic core scales and transplant module were significantly lower (Cohen’s d = 0.57–1.17) when compared with BA recipients. In particular, social and school functioning (Cohen’s d = 0.86–1.76), treatment anxiety, and communication (Cohen’s d = 0.99–1.81) were far behind, with a large effect size. Conclusions This large single-center study of the mainland of China showed an overall favorable impact of LT on isolated MMA in terms of long-term survival, metabolic control, and HRQoL in children and families. The potential for persistent neurocognitive impairment and inherent metabolic fragility requires long-term special care. F92j7K3vL8yMEEzsip9Zc8 Video Abstract (MP4 153780 KB)