The AST-to-Platelet Ratio Index (APRi) at Kasai Portoenterostomy: Standing the Test of Time

The outcomes following surgical treatment of infants with biliary atresia (BA) varies across the world with many possible confounding factors. APRi (AST-to-platelet ratio index) is a simple surrogate marker of liver fibrosis and we sought to determine its long-term relationship (if any) with outcome post-Kasai portoenterostomy (KPE).Prospectively acquired database (Jan 1998-Dec 2021). Clearance of jaundice was defined as achieving <20 umol/L post-KPE. Categorical and survival data were tested using Chi2 tests and a log rank test respectively. P ≤ 0.05 was regarded as significant. Data are quoted as median (interquartile range) unless otherwise stated.There were 473 infants with a calculated APRi at time of KPE [0.70 (IQR 0.45-1.2)] and known outcomes. There was significant but moderate correlation with age at KPE (rS = 0.43; P < 0.0001). APRi was divided into quartiles (1st 0.11-0.44, n = 120; 2nd 0.45-0.69, n = 120; 3rd 0.70-1.18, n = 115 and 4th 1.2-15.1; n = 118). There was a clear distinction in APRi levels between CMV + ve BA and the other groups (Syndromic BA, Cystic BA, Isolated BA), with an overrepresentation of CMV IgM + ve BA in the higher APRi quartiles (Χ2 = 26.6; P = 0.0002). Clearance of jaundice showed a stepwise decrease across the quartiles (67%; 58%; 55%; 49%; overall Χ2 = 7.8, P = 0.049 and P = 0.005 for trend). Decreasing native liver survival also showed a significant trend (P = 0.01).APRi appears to be of fundamental prognostic value in stratifying the BA population. In our series, CMV status was associated with higher APRi score and appears to be different. This simple variable offers an objective method of assessing the biological status of BA at presentation and variability between different series.II (prospective comparison).