Toward Rapid Screening of Liver Grafts at the Operating Room Using Mid-infrared Spectroscopy

Abstract

The estimation of steatosis in a liver graft is mandatory prior to liver transplantation, as the risk of graft failure increases with the level of infiltrated fat. However, the assessment of liver steatosis before transplantation is typically based on a qualitative or semiquantitative characterization by visual inspection and palpation and histological analysis. Thus, there is an unmet need for transplantation surgeons to have access to a diagnostic tool enabling an in situ fast classification of grafts prior to extraction. In this study, we have assessed an attenuated total reflection–Fourier transform infrared (ATR–FTIR) spectroscopic method compatible with the requirements of an operation room for the evaluation of the lipid contents in human livers. A set of 20 human liver biopsies obtained from organs intended for transplantation were analyzed by expert pathologists, ATR–FTIR spectroscopy, lipid biochemical analysis, and UPLC–ESI­(+/−)­TOFMS for lipidomic profiling. Comparative analysis of multisource data showed strong correlations between ATR–FTIR, clinical, and lipidomic information. Results show that ATR–FTIR captures a global picture of the lipid composition of the liver, along with information for the quantification of the triradylglycerol content in liver biopsies. Although the methodology performance needs to be further validated, results support the applicability of ATR–FTIR for the in situ determination of the grade of liver steatosis at the operation room as a fast, quantitative method, as an alternative to the qualitative and subjective pathological examination.

Enhancing the accuracy of mid-infrared spectroscopy-based liver steatosis quantification using digital image analysis as a reference

“…Previous results have shown that the performance of ATR-FTIR methods for steatosis quantification can be improved using dry films to increase the concentration of biomolecules and avoid the intense contribution of water in the mid-IR region. 21 The ATR spectra of dry films showed significant spectral contributions from proteins, carbohydrates, phospholipids, DNA and RNA, and lipids, in agreement with previous reports. Among others, protein bands at 1650 cm −1 (amide I), 1547 cm −1 (amide II), and 1309 cm −1 (amide III), 28 and lipid bands at 1749 cm −1 (saturated ester CO stretching from lipids and cholesterol esters), 1456 cm −1 (CH 2 bending of acyl chains), and 1402 cm −1 (COO– symmetric stretching of fatty acids and amino acids) were identified in the samples.…”

“…Recent research on using IR spectroscopy to analyze liver tissue directly has shown that it could be used as a real-time tool to quantify steatosis. 10,19–21 Preliminary results from pilot studies have been positively correlated with qualitative results from histopathology evaluations and off-line biochemical analysis of triglyceride contents. 21 These results indicate that IR spectroscopy could be a valuable tool for the rapid assessment of the grade of steatosis in donated livers, prior to explantation, and provide information about the fat content and overall composition of livers in terms of their proteins, lipids, and phospholipids.…”

“…10,19–21 Preliminary results from pilot studies have been positively correlated with qualitative results from histopathology evaluations and off-line biochemical analysis of triglyceride contents. 21 These results indicate that IR spectroscopy could be a valuable tool for the rapid assessment of the grade of steatosis in donated livers, prior to explantation, and provide information about the fat content and overall composition of livers in terms of their proteins, lipids, and phospholipids. However, further steps to validate the development of IR-based methods have been hindered by the lack of appropriate quantitative reference values, as there can be significant inter-patient variability in triglyceride content, even in patients with similar degrees of steatosis.…”

The Synbiotic Combination of Akkermansia muciniphila and Quercetin Ameliorates Early Obesity and NAFLD through Gut Microbiota Reshaping and Bile Acid Metabolism Modulation

“…Frozen liver tissue (15−20 mg) was mixed with 450 μL of water in a 2 mL polypropylene tube for tissue homogenization using CK14 ceramic beads (Precellys, France) (two homogenization cycles of 25 s, 6000 rpm, 5 °C) in a Precellys 24 Dualsystem. Hepatic triglycerides isolation was carried out as previously described [ 23 ]. A colorimetric kit (Spinreact, Barcelona, Spain) was employed to analyze total hepatic triglyceride content.…”

Quantitative Prediction of Steatosis in Patients with Non-Alcoholic Fatty Liver by Means of Hepatic MicroRNAs Present in Serum and Correlating with Hepatic Fat

“…Homogenates from human livers were extracted with a methanol-chloroform mixture and evaporated under nitrogen as described elsewhere [ 36 ]. TG and total lipid concentrations were measured in the lipid residue using colorimetric kits from Spinreact (Gerona, Spain) based on the GPO-POD enzymatic method (#1001311) and the sulfo-phospo-vanillin reaction (#1001270), respectively.…”