Li Wang¹, Ye Cheng¹, Jing Zhao¹, Wei-Yuan Fang¹, Yi Lu¹, Xin-Bao Xie¹, Hong-Mei Xu², Sven C. D. van IJzendoorn³, Jian-She Wang¹
1- The Center for Pediatric Liver Diseases, Children’s Hospital of Fudan University, China
2- Department of Infectious Diseases, Children’s Hospital of Fudan University, China
3- Department of Biomedical Sciences, University of Groningen, Netherlands
Abstract Body
Background and
AIMS: Because of the rarity of MYO5B-associated cholestasis there is limited understanding of its natural course and long-term outcomes. We aimed to provide insights by assembling cases from mainland China.
Methods: Patients with chronic intrahepatic cholestasis and biallelic MYO5B variants were retrospectively analyzed. Patients were categorized into two genotypes: MYO5B-1 (harboring at least one null variant) and MYO5B-2 (harboring no null variants). Null variants were defined as those predicted causing protein-truncation. Median serum total bile acid (TBA) levels within the first year of life were calculated.
Results: Thirty-seven patients were included with a median (interquartile range, IQR) follow-up of 7 .4 (2.9-9.9) years. All developed jaundice, and 91.9% of them experienced pruritus at a median (IQR) age of 7 .0 (5.0-12.0) months. Diarrhea was the most common extra-hepatic manifestation, usually transient. At the last follow-up, the native liver survival rate was 94.4%, with 58.8% of the patients achieving complete resolution of cholestasis and 41.2% reaching a medication-free state. Patients in the MYO5B-1 group had longer cumulative durations of cholestasis (P = 0.004) and lower rates of achieving complete resolution and reaching a medication-free status (23.8% vs. 60.0%, P = 0.041). Patients with an early TBA level < 152.95 μmol/L were significantly more likely to achieve complete resolution (100.0% vs. 39.1%, P = 0.004). Maralixibat showed potential benefit in two MYO5B-1 patients.
Conclusions: MYO5B-associated cholestasis generally has favorable long-term native liver survival. Genotype and early-life TBA levels influence disease course and outcomes. Early intervention may improve prognosis.