Fluorescence spectroscopy as a tool for the assessment of liver samples with several stages of fibrosis.pdf (original) (raw)
Related papers
Scientific Reports
The study utilizes autofluorescence spectroscopy (AFS) along with multivariate spectral analysis for differentiating various stages of hepatic fibrosis. AFS has recently emerged as an efficient tool for evaluating the variations in different endogenous flurophores. In this study, the potential of AFS for differentiating the stages of liver fibrosis is assessed and compared with the results of enzyme evaluation, histopathology and the most advanced diagnostic tool, MRI. Using a fiber optic probe, the emission profile of the flurophores such as flavin adenine dinucleotide (FAD), lipofuscin-like lipopigments (lipopigments), porphyrins and the variation in the total hemoglobin concentration are evaluated in vivo on liver fibrosis induced animal models adopting a minimally invasive technique. Significant difference (p < 0.05) in the level of these biomarkers was observed between different stages of liver fibrosis. Normal hepatic tissue could be distinguished from mild and moderate hepatic fibrosis with a sensitivity of 95 to 100% and specificity of 90 to 100% using multivariate spectral analysis. The results are favourable to consider this technique as a potential tool for diagnosing liver fibrosis at an early stage, which is monumental as it otherwise can lead to cirrhosis and liver failure. Optical spectroscopic techniques such as Raman, infrared, fluorescence and diffuse reflectance have been widely used and established as reliable tools for disease diagnosis in the last two decades 1-18. Among them, fluorescence spectroscopy has attained ample acceptance in the quantitative and qualitative analysis of biological molecules and tissues. Fluorescence spectroscopy assisted by organic or inorganic chemical systems is used to monitor biologically relevant metallic ions, carbohydrates and proteins 19-21. Meanwhile, the label free method, autofluorescence spectroscopy (AFS) is also found to be useful for the analysis of endogenous fluorophores like amino acids, structural proteins, enzymes, vitamins, lipids and porphyrins of biological tissues or fluids for disease diagnosis. Variations in the concentration of these biochemicals at different stages are useful to discriminate and classify the severity of the diseases. In oncology, AFS is used in the diagnosis of malignancies associated with organs like brain, breast, cervix, colon, liver, prostate and oral cavity 4-14. This is a fast and economically affordable technique and is also useful in the follow up of treatments associated with wound healing progression and identification of saliva stains from human skin 22,23. AFS is also proved to be useful in evaluating biochemical alterations associated with diseases like atherosclerosis and tooth decay 24,25. However, in vivo use of this technique for the diagnosis of different stages of liver fibrosis has not been evaluated so far. Liver fibrosis is the excessive accumulation of extracellular matrix proteins. Advanced liver fibrosis can lead to complications like cirrhosis which is reported as one of the leading cause of death by disease. The primary reasons for the structural and biochemical changes of liver, associated with liver fibrosis are identified to be hepatitis virus infections, fatty liver and excess intake of intoxicants 26,27. Hepatotoxicity evaluation, imaging using techniques like ultrasound sonography (USS), computed tomography (CT), magnetic resonance imaging (MRI) and histopathology of biopsies are the conventional and advanced methods used in the diagnosis of structural and
Liver fibrosis is the decisive step towards the development of cirrhosis; its early detection affects crucially the diagnosis of liver disease, its prognosis and therapeutic decision making. Nowadays, several techniques are employed to this task. However, they have the limitation in estimating different stages of the pathology. In this paper we present a preliminary study to evaluate if optical spectroscopy can be employed as an auxiliary tool of diagnosis of biopsies of human liver tissue to differentiate the fibrosis stages. Ex vivo fluorescence and diffuse reflectance spectra were acquired from biopsies using a portable fiber-optic system. Empirical discrimination algorithms based on fluorescence intensity ratio at 500 nm and 680 nm as well as diffuse reflectance intensity at 650 nm were developed. Sensitivity and specificity of around 80% and 85% were respectively achieved. The obtained results show that combined use of fluorescence and diffuse reflectance spectroscopy could represent a novel and useful tool in the early evaluation of liver fibrosis.
Multi-excitation fluorescence spectroscopy for analysis of non-alcoholic fatty liver disease
Lasers in Surgery and Medicine, 2011
Background and Objectives: The increasing incidence of non-alcoholic fatty liver diseases (NAFLD) and the consequent progression to cirrhosis is expected to become a major cause of liver transplantation. This will exacerbate the organ donor shortage and mean that 'marginal' fatty liver grafts are more frequently used. Autofluorescence spectroscopy is a fast, objective, and non-destructive method to detect change in the endogenous fluorophores distribution and could prove to be a valuable tool for NAFLD diagnosis and transplant graft assessment. Materials and Methods: A system was constructed consisting of a fibre probe with two laser diodes that provided excitation light at 375 and 405 nm, and an imaging spectrograph system. This was used to distinguish fluorescence spectra acquired from the harvested livers from mice with NAFLD of differing severity (healthy, mild steatotic and steatohepatitic). The fluorescence data were entered into a sparse multiclass probabilistic algorithm for disease classification. Histopathology, thiobarbituric acid reactive substances (TBARS) and alanine transaminase (ALT) assays were conducted in addition to the fluorescence measurements Results: TBARS and ALT assays enabled differentiation of the steatohepatitic group from the mild steatosis and control groups (P 0.028) but failed to separate the mild steatotic group from the control group. The three groups were all clearly differentiated from each other using fluorescence spectroscopy, and classification accuracy was found to be 95%. Conclusion: Fluorescence spectroscopy appears to be a promising approach for the analysis of diseased liver tissue.
Evaluation of liver fibrosis: “Something old, something new…”
Annals of Gastroenterology, 2016
Hepatic fibrogenesis may gradually result to cirrhosis due to the accumulation of extracellular matrix components as a response to liver injury. Thus, therapeutic decisions in chronic liver disease, regardless of the cause, should first and foremost be guided by an accurate quantification of hepatic fibrosis. Detection and assessment of the extent of hepatic fibrosis represent a challenge in modern Hepatology. Although traditional histological staging systems remain the "best standard", they are not able to quantify liver fibrosis as a dynamic process and may not accurately substage cirrhosis. This review aims to compare the currently used non-invasive methods of measuring liver fibrosis and provide an update in current tissue-based digital techniques developed for this purpose that may prove of value in daily clinical practice.
Fluorescence spectroscopy to diagnose hepatic steatosis in a rat model of fatty liver
Liver international : official journal of the International Association for the Study of the Liver, 2009
Steatosis is diagnosed on the basis of the macroscopic aspect of the liver evaluated by the surgeon at the time of organ extraction or by means of a frozen biopsy. In the present study, the applicability of laser-induced fluorescence (LIF) spectroscopy was investigated as a method for the diagnosis of different degrees of steatosis experimentally induced in rats. Rats received a high-lipid diet for different periods of time. The animals were divided into groups according to the degree of induced steatosis diagnosis by histology. The concentration of fat in the liver was correlated with LIF by means of the steatosis fluorescence factor (SFF). The histology classification, according to liver fat concentration was, Severe Steatosis, Moderate Steatosis, Mild Steatosis and Control (no liver steatosis). Fluorescence intensity could be directly correlated with fat content. It was possible to estimate an average of fluorescence intensity variable by means of different confidence intervals (...
Abstract— Paper Increase in efficacy rate of early diagnosis of fibrotic changes in the liver remains to be the burning issue in modern hepatology as it is difficult to diagnose the early stage of fibrosis due to its asymptomatic course. Progression of fibrosis in 60-80% of cases results in diagnosis of the disease at the stage of liver cirrhosis. This results in the increased rates of hospitalization, invalidity and mortality as well as economic losses due to therapy of liver cirrhosis and its complications including liver transplantation. The degree of fibrosis and its progression rate predetermine prognosis of the disease and the choice of therapy. Specification of the stage of the disease in hepatologic diagnosis is an obligatory component along with etiology and activity rate of the process. Therefore, it is of importance to diagnose the disease at its early stages and to evaluate the dynamics in accumulation of the fibrotic tissue.