The cross-section study will be performed in pediatric patients who underwent liver transplantation from year 2016-2021. Patients will be enrolled after collecting their informed consent from their parents. As soon as the patient is included, arrangements will be made for the liver biopsy according to the schedule.
Liver biopsies will be performed at 3 months, 6 months and 12 months post-transplant. For the purpose of this study, each section was independently and blindly reassessed by expert pathologists. Fibrosis was evaluated using the liver allograft fibrosis score (LAFSc) staging system [Fibrosis deposition was classified in three main areas of the liver parenchyma: portal tracts, sinusoids (zones 1 and 2) and centrolobular veins (zone 3); in each area, fibrosis was staged from 0 to 3 (0 = absent, 1 = mild, 2 = moderate and 3 = severe fibrosis), with a total score of 9. Equal score weight was assigned to each area] and the Ishak staging system (0 = no fibrosis; 1 = fibrous expansion of some portal area; 2 = fibrous expansion of most portal areas; 3 = fibrous expansion of most portal areas with occasional bridging; 4 = fibrous expansion of most portal areas with marked bridging; 5 = marked bridging occasional nodules; and 6 = cirrhosis).
At the time of biopsy, a fasting blood sample was obtained and routine biochemical tests were performed using standard methods and assays. Additional blood samples were drawn and frozen at -80℃ for future research. Type III collagen formation was assessed in serum using the Fibrosis Panel(PRO-C3, PIIINP, TIMP-1, HA) competitive enzyme-linked immunosorbent assay.