Significance of progressive liver fibrosis in pediatric liver transplants: A review of current evidence

Table 1 Incidence of liver allograft fibrosis in protocol liver biopsies in various studies

Ref.	1-2 yr (%)	3-5 yr (%)	10 yr (%)
Fouquet et al[4], 2005			73
Evans et al[3], 2006	32	55	69
Ekong et al[2], 2008		97
Scheenstra et al[6], 2009	34	65	69
Miyagawa-Hayashino et al[11], 2012		84
Sanada et al[5], 2014	24.7	34.5
Sheikh et al[23], 2018		2

Table 2 Comparison of METAVIR and Liver Allograft Fibrosis scores for fibrosis assessment

METAVIR score[25]	Liver allograft fibrosis score – LAFSc[26]
Portal and periportal (Figure 1B) tract-based fibrosis scoring systems	Periportal (Figure 1B), Perisinusoidal and perivenular (Figure 1C) fibrosis-based staging
Used for assessing fibrosis in post viral hepatitis, may not accurately quantify LAF in pediatric population. Assesses fibrosis located in portal tracts, underestimating LAF in the other areas	LAFSc system stages fibrosis adding portal tracts, sinusoids and centrilobular areas. Advantage of LAFSc is the individual assessment of fibrosis in portal tracts, sinusoids and centrilobular veins providing good representation of the whole hepatic acinus
The stage of fibrosis was assessed on a five-point scale: F0 = no fibrosis, F1 = portal fibrosis without septa, F2 = few septa, F3 = numerous septa without cirrhosis, F4 = cirrhosis; Activity was graded according to the intensity of necro inflammatory lesions: A0 = no histological activity, A1 = mild activity, A2 = moderate activity, A3 = severe activity	Fibrosis deposition was classified in three main areas of the liver parenchyma: Portal tracts, sinusoids (zones 1 and 2) and centrilobular 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 to accurately reflect fibrosis distribution in liver allograft specimens
A histopathological abnormality is a Metavir score of ≥ A1 or ≥ F1 and such scores indicate the need for treatment because liver fibrosis is reversible if early treatment is initiated	LAFSc: ≤ 3 – mild fibrosis; 4-5 – moderate fibrosis; ≥6 – severe fibrosis
In a sample of PLB specimens METAVIR detected LAF in 81.6% specimens[26]	LAFSc showed fibrosis in 93.5% of specimens[26]

LAFSc: Liver Allograft Fibrosis Score; LAF: Liver allograft fibrosis.