Assessing liver function

Real-time identification of life-threatening necrotizing soft-tissue infections using indocyanine green fluorescence imaging

Significance

Necrotizing soft-tissue infections (NSTIs) are life-threatening infections with a cumulative case fatality rate of 21%. The initial presentation of an NSTI is non-specific, frequently leading to misdiagnosis and delays in care. No current strategies yield an accurate, real-time diagnosis of an NSTI.

Aim

A first-in-kind, observational, clinical pilot study tested the hypothesis that measurable fluorescence signal voids occur in NSTI-affected tissues following intravenous administration and imaging of perfusion-based indocyanine green (ICG) fluorescence. This hypothesis is based on the established knowledge that NSTI is associated with local microvascular thrombosis.

Approach

Adult patients presenting to the Emergency Department of a tertiary care medical center at high risk for NSTI were prospectively enrolled and imaged with a commercial fluorescence imager. Single-frame fluorescence snapshot and first-pass perfusion kinetic parameters-ingress slope (IS), time-to-peak (TTP) intensity, and maximum fluorescence intensity (IMAX)-were quantified using a dynamic contrast-enhanced fluorescence imaging technique. Clinical variables (comorbidities, blood laboratory values), fluorescence parameters, and fluorescence signal-to-background ratios (SBRs) were compared to final infection diagnosis.

Results

Fourteen patients were enrolled and imaged (six NSTI, six cellulitis, one diabetes mellitus-associated gangrene, and one osteomyelitis). Clinical variables demonstrated no statistically significant differences between NSTI and non-NSTI patient groups (p -value ≥ 0.22 ). All NSTI cases exhibited prominent fluorescence signal voids in affected tissues, including tissue features not visible to the naked eye. All cellulitis cases exhibited a hyperemic response with increased fluorescence and no distinct signal voids. Median lesion-to-background tissue SBRs based on snapshot, IS, TTP, and IMAX parameter maps ranged from 3.2 to 9.1, 2.2 to 33.8, 1.0 to 7.5, and 1.5 to 12.7, respectively, for the NSTI patient group. All fluorescence parameters except TTP demonstrated statistically significant differences between NSTI and cellulitis patient groups (p -value < 0.05 ).

Conclusions

Real-time, accurate discrimination of NSTIs compared with non-necrotizing infections may be possible with perfusion-based ICG fluorescence imaging.

Change of indocyanine green clearance ability and liver function after transcatheter intra-arterial therapies and its impact on outcomes of resectable hepatocellular carcinoma: a retrospective cohort study

BACKGROUND

Indocyanine green (ICG) clearance test is a classical measurement of hepatic reserve, which involves surgical safety and patient recovery of hepatocellular carcinoma (HCC). The authors aim to compare effects of hepatic arterial infusion chemotherapy (HAIC) and transcatheter arterial chemoembolization (TACE) on liver function and outcomes of subsequent hepatectomy.

MATERIAL AND METHODS

HCC patients receiving HAIC/TACE in SYSUCC with repeated ICG clearance tests were retrospectively enrolled. ICG eliminating rate (ICG-K), ICG retention rate at 15 min (ICG-R15) and ordinary laboratory tests were collected. Peri-therapeutic changes of values were compared between the groups. Propensity score matching (PSM) and inverse probability of treatment weighing (IPTW) were employed to validate findings. Post-hepatectomy liver failure (PHLF), overall survival (OS) and recurrence-free survival (RFS) were analyzed in patients with subsequent curative hepatectomy.

RESULTS

Two hundred and four patients treated with HAIC ( n =130) and TACE ( n =74) were included. ΔICG-R15 was greater in the HAIC arm before matching (mean, 3.8% vs. 0.7%, P <0.001), after PSM (mean, 4.7% vs. 1.1%, P =0.014) and IPTW (mean, 2.0% vs. -3.6%, P <0.001). No difference was found for ΔALB, ΔALBI, ΔTBIL, ΔALT, ΔAST and ΔPT-INR. Multivariable analyses revealed elder age, cirrhosis, HAIC, greater ΔTBIL and ΔALBI were associated with deteriorating ICG-R15. Among those (105 for HAIC and 48 for TACE) receiving hepatectomy, occurrence of grade B/C PHLF (4.8% vs. 8.3%, P =0.616), OS (median, unreached vs. unreached, P =0.94) and RFS (median, 26.7 vs. 17.1 months, P =0.096) were comparable between the two arms. In subgroup analyses, preoperative HAIC yield superior RFS (median, 26.7 vs. 16.2 months, P =0.042) in patients with baseline ICG-R15 less than or equal to 10%.

CONCLUSION

Preoperative FOLFOX-HAIC caused apparent impairment of ICG clearance ability than TACE yet comparable impact on liver function and post-hepatectomy outcomes.

Leveraging stem cells to combat hepatitis: a comprehensive review of recent studies

Hepatitis is a significant global public health concern, with viral infections being the most common cause of liver inflammation. Antiviral medications are the primary treatments used to suppress the virus and prevent liver damage. However, the high cost of these drugs and the lack of awareness and stigma surrounding the disease create challenges in managing hepatitis. Stem cell therapy has arisen as a promising therapeutic strategy for hepatitis by virtue of its regenerative and immunomodulatory characteristics. Stem cells have the exceptional capacity to develop into numerous cell types and facilitate tissue regeneration, rendering them a highly promising therapeutic avenue for hepatitis. In animal models, stem cell therapy has demonstrated worthy results by reducing liver inflammation and improving liver function. Furthermore, clinical trials have been undertaken to assess the safety and effectiveness of stem cell therapy in individuals with hepatitis. This review aims to explore the involvement of stem cells in treating hepatitis and highlight the findings from studies conducted on both animals and humans. The objective of this review is to primarily concentrate on the ongoing and future clinical trials that assess the application of stem cell therapy in the context of hepatitis, including the transplantation of autologous bone marrow-derived stem cells, human induced pluripotent stem cells, and other mesenchymal stem cells. In addition, this review will explore the potential merits and constraints linked to stem cell therapy for hepatitis, as well as its prospective implications in the management of this disease.

The Prognostic Value of a Liver Function Test Using Indocyanine Green (ICG) Clearance in Patients with Multiple Organ Dysfunction Syndrome (MODS)

BACKGROUND

Multiple organ dysfunction syndrome (MODS) is common in intensive care units (ICUs) and is associated with high mortality. Although there have been multiple investigations into a multitude of organ dysfunctions, little is known about the role of liver dysfunction. In addition, clinical and laboratory findings of liver dysfunction may occur with a significant delay. Therefore, the aim of this study was to investigate whether a liver function test, based on indocyanine green (ICG)-clearance, contains prognostic information for patients in the early phase of MODS.

METHODS

The data of this analysis were based on the MODIFY study, which included 70 critically ill patients of a tertiary medical ICU in the early phase of MODS (≤24 h after diagnosis by an APACHE II score ≥ 20 and a sinus rhythm ≥ 90 beats per minute, with the following subgroups: cardiogenic (cMODS) and septic MODS (sMODS)) over a period of 18 months. ICG clearance was characterized by plasma disappearance rate = PDR (%/min); it was measured non-invasively by using the LiMON system (PULSION Medical Systems, Feldkirchen, Germany). The PDR was determined on the day of study inclusion (baseline) and after 96 h. The primary endpoint of this analysis was 28-day mortality.

RESULTS

ICG clearance was measured in 44 patients of the MODIFY trial cohort, of which 9 patients had cMODS (20%) and 35 patients had sMODS (80%). Mean age: 59.7 ± 16.5 years; 31 patients were men; mean APACHE II score: 33.6 ± 6.3; 28-day mortality was 47.7%. Liver function was reduced in the total cohort as measured by a PDR of 13.4 ± 6.3%/min At baseline, there were no relevant differences between survivors and non-survivors regarding ICG clearance (PDR: 14.6 ± 6.1%/min vs. 12.1 ± 6.5%/min; p = 0.21). However, survivors showed better liver function than non-survivors after 96 h (PDR: 21.9 ± 6.3%/min vs. 9.2 ± 6.3%/min, p < 0.05). Consistent with these findings, survivors but not non-survivors show a significant improvement in the PDR (7.3 ± 6.3%/min vs. -2.9 ± 2.6%/min; p < 0.01) within 96 h. In accordance, receiver-operating characteristic curves (ROCs) at 96 h but not at baseline show a link between the PDR and 28-day mortality (PDR at 96 h: AUC: 0.87, 95% CI: 0.76-0.98; p < 0.01.

CONCLUSIONS

In our study, we found that ICG clearance at baseline did not provide prognostic information in patients in the early stages of MODS despite being reduced in the total cohort. However, improvement of ICG clearance 96 h after ICU admission is associated with reduced 28-day mortality.

Intestinal failure-associated liver disease: Current challenges in screening, diagnosis, and parenteral nutrition considerations

Intestinal failure-associated liver disease (IFALD) is a serious life-limiting complication that can occur throughout the clinical course of intestinal failure and its management by parenteral nutrition (PN). Despite this, there is a lack of a standardized definition for IFALD, which makes this insidious condition increasingly difficult to screen and diagnose in clinical practice. Attenuating the progression of liver disease before the onset of liver failure is key to improving morbidity and mortality in these patients. This requires timely detection and promptly addressing reversible factors. Although there are various noninvasive tools available to the clinician to detect early fibrosis or cirrhosis in various chronic liver disease states, these have not been validated in the patient population with IFALD. Such tools include biochemical composite scoring systems for fibrosis, transient elastography, and dynamic liver function tests. This review article aims to highlight the existing real need for an accurate, reproducible method to detect IFALD in its early stages. In addition, we also explore the role PN plays in the pathogenesis of this complex multifactorial condition. Various aspects of PN administration have been implicated in the etiology of IFALD, including the composition of the lipid component, nutrient excess and deficiency, and infusion timing. We aim to highlight the clinical relevance of these PN-associated factors in the development of IFALD and how these can be managed to mitigate the progression of IFALD.

Diagnostic Accuracy of Indocyanine Green Clearance Test for Different Stages of Liver Fibrosis and Cirrhosis

(1) Background: This study aimed to correlate the indocyanine green clearance (ICG) test with histopathological grades of liver fibrosis and liver cirrhosis to assess its diagnostic accuracy in differentiating normal liver parenchyma from liver fibrosis and liver cirrhosis. (2) Methods: A total of 82 patients who received a histopathological liver examination, imaging, and ICG test within three months were included in this retrospective study. The histopathological level of fibrosis was graded using the Ishak scoring system, and the patients were divided into five categories: no liver fibrosis (NLF), mild liver fibrosis (MLF), advanced liver fibrosis (ALF), severe liver fibrosis (SLF), and liver cirrhosis (LC). The non-parametric Kruskal-Wallis test with post hoc pairwise comparison utilizing Mann-Whitney U tests and Bonferroni adjustment was used to analyze differences in the ICG test results between the patient groups. Cross correlation between the individual fibrosis/cirrhosis stages and the score of the ICG test was performed, and the sensitivity, specificity, and positive and negative predictive values were calculated for each model predicting liver fibrosis/cirrhosis. (3) Results: A significant difference (p ≤ 0.001) between stages of NLF, LF, and LC was found for the ICG parameters (ICG plasma disappearance rate (ICG-PDR) and ICG retention percentage at 15 min (ICG-R15)). The post hoc analysis revealed that NLF significantly differed from SLF (ICG-PDR: p = 0.001; ICG-R15: p = 0.001) and LC (ICG-PDR: p = 0.001; ICG-R15: p = 0.001). ALF also significantly differed from SLF (ICG-PDR: p = 0.033; ICG-R15: p = 0.034) and LC (ICG-PDR: p = 0.014; ICG-R15: p = 0.014). The sensitivity for detection of an initial stage of liver fibrosis compared to no liver fibrosis (Ishak  ≥  1) was 0.40; the corresponding specificity was 0.80. The differentiation of advanced liver fibrosis or cirrhosis (Ishak ≥ 4) compared to other stages of liver fibrosis was 0.75, with a specificity of 0.81. (4) Conclusions: This study shows that the ICG test, as a non-invasive diagnostic test, is able to differentiate patients with no liver fibrosis from patients with advanced liver fibrosis and liver cirrhosis. The ICG test seems to be helpful in monitoring patients with liver fibrosis regarding compensation levels, thus potentially enabling physicians to both detect progression from compensated liver fibrosis to advanced liver fibrosis and cirrhosis and to initiate antifibrotic treatment at an earlier stage.

Using AI and Gd-EOB-DTPA-enhanced MR imaging to assess liver function, comparing the MELIF score with the ALBI score

Monitoring disease progression is particularly important for determining the optimal treatment strategy in patients with liver disease. Especially for patients with diseases that have a reversible course, there is a lack of suitable tools for monitoring liver function. The development and establishment of such tools is very important, especially in view of the expected increase in such diseases in the future. Image-based liver function parameters, such as the T1 relaxometry-based MELIF score, are ideally suited for this purpose. The determination of this new liver function score is fully automated by software developed with AI technology. In this study, the MELIF score is compared with the widely used ALBI score. The ALBI score was used as a benchmark, as it has been shown to better capture the progression of less severe liver disease than the MELD and Child‒Pugh scores. In this study, we retrospectively determined the ALBI and MELIF scores for 150 patients, compared these scores with the corresponding MELD and Child‒Pugh scores (Pearson correlation), and examined the ability of these scores to discriminate between good and impaired liver function (AUC: MELIF 0.8; ALBI 0.77) and to distinguish between patients with and without cirrhosis (AUC: MELIF 0.83, ALBI 0.79). The MELIF score performed more favourably than the ALBI score and may also be suitable for monitoring mild disease progression. Thus, the MELIF score is promising for closing the gap in the available early-stage liver disease monitoring tools (i.e., identification of liver disease at a potentially reversible stage before chronic liver disease develops).

Multivariate Evaluation of DNA Quality Differences in Different Preanalytical Procedures in Mouse Livers

Successful histogenetic research relies on proper handling of tissue samples to maximize DNA quality. As the largest gland in the body, the liver is particularly sensitive to sample mishandling owing to its enzymatic and transcriptional activity. However, the impact of preanalytical procedures on the quality of extracted liver DNA remains poorly understood. In this study, we assessed the impact of extraction methods, duration of ex vivo liver ischemia, liver storage time, and temperature on extracted DNA quality. Comprehensive parameters such as DNA yields, purity, DNA integrity number, the percentage of double-stranded DNA (%dsDNA), and PCR amplification of the GAPDH gene fragment were assessed to identify the quality of extracted DNA. Our results revealed that these preanalytical processes had little effect on DIN values and PCR efficiency of GAPDH gene fragments for each sample, whereas the DNA yields, purity, and %dsDNAs varied widely across different processes. For liver DNA extraction, RNase is necessary to isolate "pure" DNA, and the presence of RNase could significantly increase the %dsDNA. In addition, significant increases in the yields, purity, and %dsDNA of extracted DNA were observed in the TissueLyser-processed livers compared with the mortar and pestle or shear cell disruption methods. Further investigation revealed that livers experiencing longer periods of ex vivo ischemia resulted in significantly compromised DNA yields, and to obtain sufficient DNA, the ex vivo liver ischemia should be limited to within 30 minutes. Moreover, compared with storage of livers at -80°C, storage of livers in the vapor phase of liquid nitrogen yielded a higher quality of the extracted DNA. Our findings exhibited significant implications for liver-derived DNA quality assessment and management.

Physiologically-Based Pharmacokinetic Modeling of Blood Clearance of Liver Fluorescent Markers for the Assessment of the Degree of Hepatic Ischemia-Reperfusion Injury. ANNUAL INTERNATIONAL CONFERENCE OF THE IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. ANNUAL INTERNATIONAL CONFERENCE 2023;2023:1-6. [PMID: 38082711 DOI: 10.1109/embc40787.2023.10340273] [Citation(s) in RCA: 0] [Impact Index Per Article: 0]

During liver transplantation, ischemia-reperfusion injury (IRI) is inevitable and decreases the overall success of the surgery. While guidelines exist, there is no reliable way to quantitatively assess the degree of IRI present in the liver. Our recent study has shown a correlation between the bile-to-plasma ratio of FDA-approved sodium fluorescein (SF) and the degree of hepatic IRI, presumably due to IRI-induced decrease in the activity of the hepatic multidrug resistance-associated protein 2 (MRP2); however, the contribution of SF blood clearance via the bile is still convoluted with other factors, such as renal clearance. In this work, we sought to computationally model SF blood clearance via the bile. First, we converted extant SF fluorescence data from rat whole blood, plasma, and bile to concentrations using calibration curves. Next, based on these SF concentration data, we generated a "liver-centric", physiologically-based pharmacokinetic (PBPK) model of SF liver uptake and clearance via the bile. Model simulations show that SF bile concentration is highly sensitive to change in the activity of hepatic MPR2. These simulations suggest that SF bile clearance along with the PBPK model can be used to quantify the effect of IRI on the activity of MRP2.Clinical Relevance- This study establishes the theory necessary to generate a model for predicting the degree of IRI during liver transplantation.

[Indocyanine green in liver tumor resection]

Primary liver cancer and colorectal cancer liver metastases are among the leading causes of cancer-related mortality worldwide. Surgery is one of the main methods of treatment to achieve the best results in overall and recurrence-free survival. The main objectives in this surgery are preoperative planning, assessment of functional viability of liver parenchyma and total resection with low complication rate. Post-resection liver failure is one of the most formidable and often fatal complication following functional failure of liver remnant. Thus, preoperative assessment of liver functional reserves is a necessary step for adequate selection of patients and safe surgery. Passive liver tests, such as biochemical parameters or clinical scales, do not accurately reflect the actual functional component of liver parenchyma. The most accurate method is dynamic quantitative test of liver, such as indocyanine green clearance. The authors discuss the practical aspects of preoperative assessment of liver functional reserves using indocyanine green, as well as the concept and technical foundations of fluorescent imaging in hepatobiliary surgery.

Immunomodulation by Hemoadsorption—Changes in Hepatic Biotransformation Capacity in Sepsis and Septic Shock: A Prospective Study

Background: Sepsis is often associated with liver dysfunction, which is an indicator of poor outcomes. Specific diagnostic tools that detect hepatic dysfunction in its early stages are scarce. So far, the immune modulatory effects of hemoadsorption with CytoSorb^® on liver function are unclear. Method: We assessed the hepatic function by using the dynamic LiMAx^® test and biochemical parameters in 21 patients with sepsis or septic shock receiving CytoSorb^® in a prospective, observational study. Points of measurement: T₁: diagnosis of sepsis or septic shock; T₂ and T₃: 24 h and 48 h after the start of CytoSorb^®; T₄: 24 h after termination of CytoSorb^®. Results: The hepatic biotransformation capacity measured by LiMAx^® was severely impaired in up to 95 % of patients. Despite a rapid shock reversal under CytoSorb^®, a significant improvement in LiMAx^® values appeared from T₃ to T₄. This decline and recovery of liver function were not reflected by common parameters of hepatic metabolism that remained mostly within the normal range. Conclusions: Hepatic dysfunction can effectively and safely be diagnosed with LiMAx^® in ventilated ICU patients under CytoSorb^®. Various static liver parameters are of limited use since they do not adequately reflect hepatic dysfunction and impaired hepatic metabolism.

Triazole-derivatized near-infrared cyanine dyes enable local functional fluorescent imaging of ocular inflammation

Near-infrared (NIR) chemical fluorophores are promising tools for in-vivo imaging in real time but often succumb to rapid photodegradation. Indocyanine green (ICG) is the only NIR dye with regulatory approval for ocular imaging in humans; however, ICG, when employed for applications such as labelling immune cells, has limited sensitivity and does not allow precise detection of specific inflammatory events, for example leukocyte recruitment during uveitic flare-ups. We investigated the potential use of photostable novel triazole NIR cyanine (TNC) dyes for detecting and characterising activated T-cell activity within the eye. Three TNC dyes were evaluated for ocular cytotoxicity in-vitro using a MTT assay and optimised concentrations for intraocular detection within ex-vivo porcine eyes after topical application or intracameral injections of the dyes. TNC labelled T-cell tracking experiments and mechanistic studies were also performed in-vitro. TNC-1 and TNC-2 dyes exhibited greater fluorescence intensity than ICG at 10 μM, whereas TNC-3 was only detectable at 100 μM within the porcine eye. TNC dyes did not demonstrate any ocular cell toxicity at working concentrations of 10 μM. CD4⁺T-cells labelled with TNC-1 or TNC-2 were detected within the porcine eye, with TNC-1 being brighter than TNC-2. Detection of TNC-1 and TNC-2 into CD4⁺T-cells was prevented by prior incubation with dynole 34-2 (50 μM), suggesting active uptake of these dyes via dynamin-dependent processes. The present study provides evidence that TNC dyes are suitable to detect activated CD4⁺T-cells within the eye with potential as a diagnostic marker for ocular inflammatory diseases.

Fluorescein clearance kinetics in blood and bile indicates hepatic ischemia-reperfusion injury in rats

Quantitative measurement of the degree of hepatic ischemia-reperfusion injury (IRI) is crucial for developing therapeutic strategies for its treatment. We hypothesized that clearance of fluorescent dye through bile metabolism may reflect the degree of hepatic IRI. In this study, we investigated sodium fluorescein clearance kinetics in blood and bile for quantifying the degree of hepatic IRI. Warm ischemia times (WITs) of 0, 30, or 60 min followed by 1 h or 4 h of reperfusion, were applied to the median and lateral lobes of the liver in Sprague-Dawley rats. Subsequently, 2 mg/kg of sodium fluorescein was injected intravenously, and blood and bile samples were collected over 60 min to measure fluorescence intensities. The bile-to-plasma fluorescence ratios demonstrated an inverse correlation with WIT and were distinctly lower in the 60-min WIT group than in the control or 30-min WIT groups. Bile-to-plasma fluorescence ratios displayed superior discriminability for short versus long WITs when measured 1 h after reperfusion versus 4 h. We conclude that the bile-to-blood ratio of fluorescence after sodium fluorescein injection has the potential to enable the quantification of hepatic IRI severity.NEW & NOTEWORTHY Previous attempts to use fluorophore clearance to test liver function have relied on a single source of data. However, the kinetics of substrate processing via bile metabolism include decreasing levels in blood and increasing levels in bile. Thus, we analyzed data from blood and bile to better reflect fluorescein clearance kinetics.

MELIF, a Fully Automated Liver Function Score Calculated from Gd-EOB-DTPA-Enhanced MR Images: Diagnostic Performance vs. the MELD Score

In the management of patients with chronic liver disease, the assessment of liver function is essential for treatment planning. Gd-EOB-DTPA-enhanced MRI allows for both the acquisition of anatomical information and regional liver function quantification. The objective of this study was to demonstrate and evaluate the diagnostic performance of two fully automatically generated imaging-based liver function scores that take the whole liver into account. T1 images from the native and hepatobiliary phases and the corresponding T1 maps from 195 patients were analyzed. A novel artificial-intelligence-based software prototype performed image segmentation and registration, calculated the reduction rate of the T1 relaxation time for the whole liver (rrT1_liver) and used it to calculate a personalized liver function score, then generated a unified score—the MELIF score—by combining the liver function score with a patient-specific factor that included weight, height and liver volume. Both scores correlated strongly with the MELD score, which is used as a reference for global liver function. However, MELIF showed a stronger correlation than the rrT1_liver score. This study demonstrated that the fully automated determination of total liver function, regionally resolved, using MR liver imaging is feasible, providing the opportunity to use the MELIF score as a diagnostic marker in future prospective studies.

Assessment of Liver Function With MRI: Where Do We Stand?

Liver disease and hepatocellular carcinoma (HCC) have become a global health burden. For this reason, the determination of liver function plays a central role in the monitoring of patients with chronic liver disease or HCC. Furthermore, assessment of liver function is important, e.g., before surgery to prevent liver failure after hepatectomy or to monitor the course of treatment. Liver function and disease severity are usually assessed clinically based on clinical symptoms, biopsy, and blood parameters. These are rather static tests that reflect the current state of the liver without considering changes in liver function. With the development of liver-specific contrast agents for MRI, noninvasive dynamic determination of liver function based on signal intensity or using T1 relaxometry has become possible. The advantage of this imaging modality is that it provides additional information about the vascular structure, anatomy, and heterogeneous distribution of liver function. In this review, we summarized and discussed the results published in recent years on this technique. Indeed, recent data show that the T1 reduction rate seems to be the most appropriate value for determining liver function by MRI. Furthermore, attention has been paid to the development of automated tools for image analysis in order to uncover the steps necessary to obtain a complete process flow from image segmentation to image registration to image analysis. In conclusion, the published data show that liver function values obtained from contrast-enhanced MRI images correlate significantly with the global liver function parameters, making it possible to obtain both functional and anatomic information with a single modality.

Near infrared triggered chemo-PTT-PDT effect mediated by glioma directed twin functional-chimeric peptide-decorated gold nanoroses

The successful application of nanomedicine against glioma is basically hooked on to the fabrication of specific and efficient glioma targeted multifunctional theranostics. Herein, through an easy synthetic methodology, we fabricated a type of novel multifunctional theranostic nanoplatform comprising of anisotropic gold nanoroses (AuNs) co-loaded with doxorubicin (DOX) and the near-infrared (NIR) active/responsive dye, indocyanine green (ICG). The tailored nanotheranostics upon being exposed to NIR laser helped in achieving combinatorial chemo-phototherapy along with optical cell imaging. BBB/glioma-targeting ability was realized by amalgamating the AuNs with a naive peptide drug with BBB-glioma targeting and anti-glioma twin functionality. Efficacy studies carried out in C6 cells and spheroids demonstrated heightened synergistic glioma chemo-PDT-PTT effect (~85% ablation in C6 cells and ~88% in C6 spheroids) by the AuNDIPs as compared to the individual therapeutic entities. Here, the AuNs derived nanophototheranostics with in force targeting and on-demand drug release nature will further aid in abolishing chemotherapy associated adverse events by adopting a combinatorial approach for synergistic glioma eradication.

Value of Liver Function Tests in Cirrhosis

The liver comprises both parenchymal and non-parenchymal cells with varying functions. Cirrhosis is often complicated by the development of portal hypertension and its associated complications. Hence, assessment of liver in cirrhosis should include assessment of its structural, function of both hepatic and non-hepatic tissue and haemodynamic assessment of portal hypertension. There is no single test that can evaluate all functions of liver and assess prevalence and severity of portal hypertension. Commonly available tests like serum bilirubin, liver enzymes (alanine [ALT] and aspartate aminotransferase [AST], serum alkaline phosphatase [ALP], gamma glutamyl transpeptidase [GGT]), serum albumin and prothrombin time for assessment of liver functions partly assess liver functions. quantitative liver functions like indocyanine clearance tests [ICG-K], methacetin breath test [MBT] were developed to assess dynamic status of liver but has its own limitation and availability. Imaging based assessment of liver by transient elastography, MRI based 99 mTc-coupled asialoglycoprotein mebrofenin scan help the clinician to assess liver function, functional volume of liver left after surgery and portal hypertension [PH]. Hepatic venous pressure gradient still remains the gold standard for the assessment of portal hypertension but is invasive and not available in all centres. Combinations of blood parameters in form of various indices like fibrosis score of 4 [FIB-4], Lok index, scores like model for end stage liver disease (MELD) and Child-Turcotte Pugh score are commonly used for assessing liver function in clinical practice.

A History of the Assessment of Liver Performance

Content available: Author Interview and Audio Recording.

Breath Biomarkers in Diagnostic Applications

The detection of chemical compounds in exhaled human breath presents an opportunity to determine physiological state, diagnose disease or assess environmental exposure. Recent advancements in metabolomics research have led to improved capabilities to explore human metabolic profiles in breath. Despite some notable challenges in sampling and analysis, exhaled breath represents a desirable medium for metabolomics applications, foremost due to its non-invasive, convenient and practically limitless availability. Several breath-based tests that target either endogenous or exogenous gas-phase compounds are currently established and are in practical and/or clinical use. This review outlines the concept of breath analysis in the context of these unique tests and their applications. The respective breath biomarkers targeted in each test are discussed in relation to their physiological production in the human body and the development and implementation of the associated tests. The paper concludes with a brief insight into prospective tests and an outlook of the future direction of breath research.

Functional multispectral optoacoustic tomography imaging of hepatic steatosis development in mice

The increasing worldwide prevalence of obesity, fatty liver diseases and the emerging understanding of the important roles lipids play in various other diseases is generating significant interest in lipid research. Lipid visualization in particular can play a critical role in understanding functional relations in lipid metabolism. We investigated the potential of multispectral optoacoustic tomography (MSOT) as a novel modality to non-invasively visualize lipids in laboratory mice around the 930nm spectral range. Using an obesity-induced non-alcoholic fatty liver disease (NAFLD) mouse model, we examined whether MSOT could detect and differentiate different grades of hepatic steatosis and monitor the accumulation of lipids in the liver quantitatively over time, without the use of contrast agents, i.e. in label-free mode. Moreover, we demonstrate the efficacy of using the real-time clearance kinetics of indocyanine green (ICG) in the liver, monitored by MSOT, as a biomarker to evaluate the organ's function and assess the severity of NAFLD. This study establishes MSOT as an efficient imaging tool for lipid visualization in preclinical studies, particularly for the assessment of NAFLD.

An evaluation of the safety and preliminary efficacy of peri- and post-operative treprostinil in preventing ischemia and reperfusion injury in adult orthotopic liver transplant recipients

Background

Orthotopic liver transplantation (OLT) is the only treatment option for various end‐stage liver diseases. Ischemia and reperfusion (I/R) injury is one of the unavoidable complications/conditions in OLT. In 2019, a total of 8896 livers were transplanted of which >94% organs were procured from deceased donors. An increase in the use of extended criteria donor (ECD) livers for transplantation further unraveled the role of hepatic I/R injury on short‐term and long‐term graft outcomes. Despite promising outcomes with the use of antioxidants, free radical scavengers, and vasodilators; I/R‐mediated liver injury persists and significantly influences the overall clinical outcomes. Treprostinil, a synthetic prostacyclin I₂ (PGI₂) analog, due to its vasodilatory property, antiplatelet activity, and its ability to downregulate pro‐inflammatory cytokines can potentially minimize I/R injury.

Aim

We investigated the safety and preliminary efficacy of continuous intravenous infusion of treprostinil in liver transplant recipients in a prospective, single‐center, non‐randomized, interventional study.

Material and methods

This was a dose escalation (3 + 3 design) phase 1/2 study. Deceased donor liver transplant recipients received 5 ng/kg/min for two days, or 2.5, 5, and 7.5 ng/min/kg for 5 days as a continuous infusion. Multiple blood samples were collected for biochemical parameter assessment and for measuring treprostinil levels. Indocyanine green plasma disappearance rate was used as a measure of hepatic functional capacity.

Results

Subjects tolerated continuous infusion of treprostinil up to 5 ng/kg/min for 120 h with no occurrence of primary graft non‐function (PNF), minimized need for ventilation support, reduced hospitalization time, 100% graft and patient survival, and improved hepatobiliary excretory function comparable to normal healthy adults.

Discussion

Treprostinil can be administered to liver transplant patients safely during the perioperative period.

Conclusion

Based on this phase 1/2 study, further efficacy studies of treprostinil in preventing I/R injury of liver should be conducted to potentially increase the number of livers available for transplantation.

Exploring Liver Mitochondrial Function by 13C-Stable Isotope Breath Tests: Implications in Clinical Biochemistry

The liver is at the crossroad of key metabolic processes, which include detoxification, glycolipidic storage and export, and protein synthesis. The gut-liver axis, moreover, provides hepatocytes with a series of bacterial products and metabolites, which contribute to maintain liver function in health and disease. Breath tests (BTs) are developed as diagnostic tools for indirect, rapid, noninvasive assessment of several metabolic processes in the liver. BTs monitor the appearance of CO₂ in breath as a marker of a specific substrate metabolized in the liver, typically within microsomes, cytosol, or mitochondria. The noninvasiveness of BTs originates from the use of the, nonradioactive, naturally occurring stable isotope ¹³C marking a specific substrate which is metabolized in the liver, leading to the appearance of ¹³CO₂ in expired air. Some substrates (ketoisocaproic acid, methionine, and octanoic acid) provide information about dynamic liver mitochondrial function in health and disease. In humans, the application of ¹³C-breath tests ranges from nonalcoholic and alcoholic liver diseases to liver cirrhosis, hepatocarcinoma, preoperative and postoperative assessment of liver function, and drug-induced liver damage. ¹³C-BTs are an indirect, cost-effective, and easy method to evaluate dynamic liver function and gastric kinetics in health and disease, with ongoing studies focusing on further applications in clinical medicine.

Curcumin Can be Acts as Effective agent for Prevent or Treatment of Alcohol-induced Toxicity in Hepatocytes: An Illustrated Mechanistic Review

Previous studies have shown that alcohol abuse can cause serious liver damage and cirrhosis. The main pathway for these types of hepatocellular cell neurodegeneration is mitochondrial dysfunction, which causes lipid peroxidation and dysfunction of the glutathione ring and the defect of antioxidant enzymes in alcoholic hepatic cells. Alcohol can also initiate malicious inflammatory pathways and trigger the initiation and activation of intestinal and extrinsic apoptosis pathways in hepatocellular tissues that lead to cirrhosis. Previous studies have shown that curcumin may inhibit lipid peroxidation, glutathione dysfunction and restore antioxidant enzymes. Curcumin also modulates inflammation and the production of alcohol-induced biomarkers. Curcumin has been shown to play a critical role in the survival of alcoholic hepatocellular tissue. It has been shown that curcumin can induce and trigger mitochondrial biogenesis and, by this mechanism, prevent the occurrence of both intrinsic and extrinsic apoptosis pathways in liver cells that have been impaired by alcohol. According to this mechanism, curcumin may protect hepatocellular tissue from alcohol-induced cell degeneration and may therefore survive alcoholic hepatocellular tissue. . Based on these mechanisms, the protective functions of curcumin against alcohol-induced cell degeneration due to oxidative stress, inflammation, and apoptosis events in hepatocellular tissue have been recorded. Hence, in this research, we have attempted to evaluate and analyze the main contribution mechanism of curcumin cell defense properties against alcohol-induced hepatocellular damage, according to previous experimental and clinical studies, and in this way we report findings from major studies.

Liver-lung interactions in acute respiratory distress syndrome

Patients with liver diseases are at high risk for the development of acute respiratory distress syndrome (ARDS). The liver is an important organ that regulates a complex network of mediators and modulates organ interactions during inflammatory disorders. Liver function is increasingly recognized as a critical determinant of the pathogenesis and resolution of ARDS, significantly influencing the prognosis of these patients. The liver plays a central role in the synthesis of proteins, metabolism of toxins and drugs, and in the modulation of immunity and host defense. However, the tools for assessing liver function are limited in the clinical setting, and patients with liver diseases are frequently excluded from clinical studies of ARDS. Therefore, the mechanisms by which the liver participates in the pathogenesis of acute lung injury are not totally understood. Several functions of the liver, including endotoxin and bacterial clearance, release and clearance of pro-inflammatory cytokines and eicosanoids, and synthesis of acute-phase proteins can modulate lung injury in the setting of sepsis and other severe inflammatory diseases. In this review, we summarized clinical and experimental support for the notion that the liver critically regulates systemic and pulmonary responses following inflammatory insults. Although promoting inflammation can be detrimental in the context of acute lung injury, the liver response to an inflammatory insult is also pro-defense and pro-survival. A better understanding of the liver–lung axis will provide valuable insights into new diagnostic targets and therapeutic strategies for clinical intervention in patients with or at risk for ARDS.

Near-Infrared Responsive Phase-Shifted Nanoparticles for Magnetically Targeted MR/US Imaging and Photothermal Therapy of Cancer

Accurate diagnosis, providing guidance for early treatment, can greatly improve the survival rate of cancer patients. However, there are still some difficulties with the existing diagnostic technology and early treatment methods. Here, near-infrared responsive phase-shifted nanoparticles (NRPNs) have been designed for magnetically targeted MR/US imaging and photothermal therapy of tumors. In this study, we fabricated a multifunctional polymer nanoparticle encapsulating indocyanine green (ICG), magnetic Fe₃O₄ nanoparticles and perfluoropentane (PFP). Under laser irradiation, the NRPNs, which trigger a phase-shifted expansion effect due to the quick conversion from light to heat by ICG and Fe₃O₄, can be used for ultrasound (US) imaging. At the same time, such nanoparticles can kill cancer cells via photothermal therapy (PTT). As a kind of negative enhancement agent, magnetic Fe₃O₄ nanoparticles in NRPNs showed high spatial resolution in MR imaging. Moreover, with the help of the magnetic field, the NRPNs nanoparticles showed high cellular uptake and high tumor accumulation, indicating their magnetic targeting property without biosafety concerns. Therefore, we present a strategy for magnetically targeted MR/US imaging guided photothermal therapy for the accurate diagnosis and efficient treatment of tumors.

Design of Liver Functional Reserve Estimation Technique Based on Optical Densitometry

This work is aimed at creating a modified invasive technique for assessing the liver's functional reserves. A study of the degree of hepatodepression is carried out by measuring the plasma elimination of indocyanine green using the method of optical densitometry. This paper presents test results for an aqueous solution and an albumin solution, as well as the results of measurements of plasma elimination of indocyanine green for patients with liver disease. Perfecting the proposed method will make an important scientific contribution to modern diagnostic medicine. Diagnosing the stages in the progression of the disease and its developing complications can make it possible to rapidly correct the patient's treatment algorithm, achieving positive outcomes in medical practice.

Pharmacokinetics of tigecycline in critically ill patients with liver failure defined by maximal liver function capacity test (LiMAx)

BACKGROUND

In critically ill patients, tigecycline (TGC) remains an important therapeutic option due to its efficacy against multiresistant Gram-positive and Gram-negative bacteria. TGC is metabolized and eliminated predominantly by the liver. Critical illness-induced liver failure may have a profound impact on the pharmacokinetic of TGC. In the present study, we aimed to establish a link between the degree of liver dysfunction and TGC plasma concentration using the novel maximum liver function capacity (LiMAx) test, as a dynamic liver function test.

MATERIALS/METHODS

The prospective study included 33 patients from a surgical ICU with the clinical indication for antibiotic therapy with TGC. The patients received 100 mg loading dose of TGC followed by intermittent standard doses of 50 mg q12. Blood samples for TGC plasma concentration were collected at 0.3, 2, 5, 8 and 11.5 h in a steady-state condition after at least 36 h post-standard dosage. The results were analyzed by means of a high-performance liquid chromatography (HPLC) method. Within the same day, the LiMAx test was carried out and routine blood parameters were measured.

RESULTS

Peak plasma concentrations of TGC were significantly higher in patients with severe liver failure (LiMAx < 100 µg/kg/h) when compared to patients with normal liver function (LiMAx > 300 µg/kg/h). The pharmacokinetic curves revealed higher values in severe liver failure at any measured point. Moreover, LiMAx and total bilirubin were the only liver-related parameters that correlated with TGC C_max.

CONCLUSIONS

The present study demonstrates a high variability of TGC plasma concentrations in critically ill patients. The results show a significant correlation between the degree of liver dysfunction, measured by the LiMAx test, and TGC C_max. LiMAx test may be a helpful tool beyond others for adjusting the required dosage of hepatic metabolized antibiotics in critically ill patients. Trial registry DRKS-German clinical trials register; Trial registration number: DRKS00008888; Date of registration: 07-17-2015; Date of enrolment of the first participant to the trial: 12-10-2015.

Liver function quantification of patients with portal vein embolization using dynamic contrast-enhanced MRI for assessment of hepatocyte uptake and elimination

PURPOSE

We evaluated pharmacokinetic models which quantify liver function including biliary elimination based on a dynamic Gd-EOB-DTPA-enhanced magnetic resonance imaging (MRI) technique with sparse data collection feasible in clinical routine.

METHODS

Twelve patients with embolized liver segments following interventional treatment of primary liver cancer or hepatic metastasis underwent MRI. During Gd-EOB-DTPA bolus administration, a 3D dynamic gradient-echo (GRE) MRI examination was performed over approx. 28 min. Interrupted data sampling was started approx. 5 min after contrast agent administration. Different implementations of dual-inlet models were tested, namely the Euler method (DE) and convolution with residue functions (C). A simple uptake model (U) and an uptake- elimination model (UE) extended by incorporating the biliary contrast agent elimination rate (K_e) were evaluated.

RESULTS

The uptake-elimination model, calculated via the simple Euler method (UE- DE) and by convolution (UE-C), yielded similar overall estimates in terms of fitting quality and agreement with published values. The Euler method was approx. 50 times faster and yielded a mean elimination rate of K_e=1.8±1.2mL/(min·100 mL) in nonembolized liver tissue, which was significantly higher (p=8.8·10^-4) than in embolized tissue K_e=0.4±0.4 mL/(min·100 mL). Fractional hepatocyte volume v_h was not significantly higher in nonembolized tissue (52.4 ± 13.4 mL/100 mL) compared to embolized tissue (44.4 ± 26.1 mL/100 mL).

CONCLUSIONS

Interrupted late enhancement MRI data sampling in conjunction with the uptake-elimination model, deconvolved by integration of the differential rate equation and combined with the simple uptake model implemented with the Euler method (U-DE), turned out to be a stable and practical method for reliable noninvasive assessment of liver function.

Development of Tumor-Targeted Indocyanine Green-Loaded Ferritin Nanoparticles for Intraoperative Detection of Cancers

Indocyanine green (ICG) is a fluorescent dye with a strong emission in the near-infrared spectral range that allows deep signal penetration and minimal interference of tissue autofluorescence. It has been employed in clinics for different applications, among which the more interesting is certainly near-infrared fluorescence image-guided surgery. This technique has found wide application in surgical oncology for lymph node mapping or for laparoscopic surgery. Despite ICG being useful for tracking loco-regional lymph nodes, it does not provide any information about cancer involvement of such lymph nodes or lymphatic vessels, lacking any tumor-targeting specificity. However, the clinical need in surgical oncology is not only a specific tracking of metastatic nodes but also the intraoperative detection of micrometastatic deposits. Here, we have exploited a nanotechnological solution to improve ICG usefulness by its encapsulation in H-ferritin (HFn) nanocages. They are natural protein-based nanoparticles that exhibit some very interesting features as delivery systems in oncological applications because they display specific tumor homing. We show that HFn loaded with ICG exhibits specific uptake into different cancer cell lines and is able to deliver ICG to the tumor more efficiently than the free dye in an in vivo model of TNBC. Our results pave the way for the application of ICG-loaded HFn in fluorescence image-guided surgery of cancer.

Assessing Non-Invasive Liver Function in Patients with Intestinal Failure Receiving Total Parenteral Nutrition-Results from the Prospective PNLiver Trial

Liver abnormalities in intestinal failure (IF) patients receiving parenteral nutrition (PN) can progress undetected by standard laboratory tests to intestinal failure associated liver disease (IFALD). The aim of this longitudinal study is to evaluate the ability of non-invasive liver function tests to assess liver function following the initiation of PN. Twenty adult patients with IF were prospectively included at PN initiation and received scheduled follow-up assessments after 6, 12, and 24 months between 2014 and 2019. Each visit included liver assessment (LiMAx [Liver Maximum Capacity] test, ICG [indocyanine green] test, FibroScan), laboratory tests (standard laboratory test, NAFLD [non-alcoholic fatty liver disease] score, FIB–4 [fibrosis-4] score), nutritional status (bioelectrical impedance analysis, indirect calorimetry), and quality of life assessment. The patients were categorized post-hoc based on their continuous need for PN into a reduced parenteral nutrition (RPN) group and a stable parenteral nutrition (SPN) group. While the SPN group (n = 9) had significantly shorter small bowel length and poorer nutritional status at baseline compared to the RPN group (n = 11), no difference in liver function was observed between the distinct groups. Over time, liver function determined by LiMAx did continuously decrease from baseline to 24 months in the SPN group but remained stable in the RPN group. This decrease in liver function assessed with LiMAx in the SPN group preceded deterioration of all other investigated liver function tests during the study period. Our results suggest that the liver function over time is primarily determined by the degree of intestinal failure. Furthermore, the LiMAx test appeared more sensitive in detecting early changes in liver function in comparison to other liver function tests.

Gd-EOB-DTPA-enhanced MRI T1 relaxometry as an imaging-based liver function test compared with 13C-methacetin breath test

Background

Gadolinium ethoxybenzyl diethylenetriaminepentaacetic acid (Gd-EOB-DTPA)-enhanced magnetic resonance imaging (MRI) can be used as an imaging-based liver function test. This study aims to further corroborate its validity.

Purpose

To compare Gd-EOB-DTPA-enhanced MRI as an imaging-based liver function test with the 13C-methacetin breath test.

Material and Methods

Fifty-three patients who underwent Gd-EOB-DTPA-enhanced MRI T1 relaxometry before and 20 min after intravenous Gd-EOB-DTPA administration as well as a 13C-methacetin breath test (LiMAx test) were retrospectively analyzed. T1 relaxation times of liver parenchyma, total liver volume (TLV), and functional liver volume (FLV) were determined. Pearson correlations, multiple linear regression analysis, and receiver operating characteristic curve analysis were performed with indices derived from T1 relaxometry, liver volumetry, and laboratory parameters to identify the best predictor of liver function as determined by the LiMAx test.

Results

T1 reduction rate (T1 RR), T1 RR × TLV, T1 RR × FLV, and T1 relaxation time 20 min after intravenous Gd-EOB administration showed a statistically significant correlation with LiMAx and discriminatory capacity between patients with LiMAx of > and < 315 µg/kg/h. Of the indices investigated, T1 RR showed the best discriminatory capacity and proved to be the only statistically significant parameter in multiple linear regression analysis.

Conclusion

Gd-EOB-DTPA-enhanced MRI as an imaging-based liver function test also correlates with the LiMAx test which in turn reflects cytochrome P450 function. The T1 reduction rate of the liver on Gd-EOB-DTPA-enhanced MRI allows prediction of liver function as determined by the LiMAx test both for 1.5 and 3.0 T.

Evaluating hepatotoxic effects of chemotherapeutic agents with gadoxetic-acid-enhanced magnetic resonance imaging

PURPOSE

To evaluate the hepatotoxicity of different chemotherapeutic agents used to treat neuroendocrine tumours (NETs) with gadoxetic acid-enhanced magnetic resonance imaging (MRI).

MATERIAL AND METHODS

A total of 129 patients with NETs who underwent two or more serial gadoxetic-acid-enhanced MRI examinations between 2014 and 2018 and started chemotherapy in the beginning of that time period were retrospectively analysed. Linear mixed model analysis evaluating relative enhancement (RE) of the liver in the hepatobiliary phase with respect to time between MRI examinations, primary chemotherapy, hepatotoxicity score of preceding and subsequent chemotherapies as well as age and gender as fixed variables was performed. Binary logistic regression was used to verify whether the hepatotoxicity score predicts a significant impact of a chemotherapeutic regimen on RE and hence liver function.

RESULTS

Linear mixed model analysis of a total of 539 MRI examinations identified all chemotherapeutic agents with known hepatoxicity as a factor with a statistically significant negative impact on RE of the liver in gadoxetic-acid-enhanced MRI in addition to age. This result was confirmed by binary logistic regression analysis.

CONCLUSION

Our results confirm that gadoxetic acid-enhanced MRI can be used as an imaging-based liver function test for assessing hepatotoxicity of chemotherapeutic agents used for NETs. The findings underscore the known degrees of hepatotoxicity of the chemotherapeutic agents currently used in the treatment of NETs.

Prospective study of gestational diabetes and fatty liver scores 9 to 16 years after pregnancy

BACKGROUND

Women with gestational diabetes mellitus (GDM) may be at an increased risk of liver complications because chronic hyperglycemia is a risk factor for liver fat accumulation and potential liver dysfunction. Large prospective studies examining liver fat accumulation following a GDM pregnancy are lacking.

METHODS

The Diabetes & Women's Health Study (2012-2014) examined the association between GDM and subsequent fatty liver scores among 607 women with and 619 women without GDM in the Danish National Birth Cohort. Nine to 16 years postpartum, a clinical examination was performed, with measurement of alanine aminotransferase (ALT), aspartate aminotransferase (AST), and γ-glutamyl transferase, from which fatty liver scoring indices were calculated to assess liver fat score, fatty liver index, hepatic steatosis index, and liver fat percentage. Relative risks (RR) with 95% confidence intervals (CI) for elevated liver scoring indices by GDM status were assessed adjusting for major risk factors, including prepregnancy body mass index.

RESULTS

Women with prior GDM had higher adjusted ALT and AST levels than women without GDM (by 6.7% [95% CI 1.7-12.0] and 4.8% [95% CI 0.6-9.1], respectively). Women with GDM also had adjusted increased risks for elevated liver fat score (RR 2.34; 95% CI 1.68-3.27), fatty liver index (RR 1.59; 95% CI 1.27-1.99), and hepatic steatosis index (RR 1.44; 95% CI 1.21-1.71).

CONCLUSIONS

Women with GDM during pregnancy were at an increased risk for fatty liver 9 to 16 years postpartum. Gestational diabetes mellitus may serve as another risk indicator for the early identification and prevention of liver fat accumulation.

Visual method for evaluating liver function: targeted in vivo fluorescence imaging of the asialoglycoprotein receptor

The visual evaluation of liver function (LF) has always been a hot topic in research on liver diseases. In vivo fluorescence imaging (IVFI) of the Cy5.5-galactosylated polylysine (Cy5.5-GP) probe targeting asialoglycoprotein receptor (ASGPR), for evaluating LF in chronic alcoholic liver injury (cALI) mice was investigated in this study. The decrease of fluorescence signals in the livers showed a biological relationship with the liver ASGPR expression, histology, and serum marker levels of LF in cALI mice. The targeted IVFI of ASGPR as a novel method can intuitively and noninvasively display the characteristics of liver's ASGPR level to provide a reference for evaluating LF.

Plasma Disappearance Rate of Indocyanine Green for Determination of Liver Function in Three Different Models of Shock

The measurement of the liver function via the plasma disappearance rate of indocyanine green (PDR_ICG) is a sensitive bed-side tool in critical care. Yet, recent evidence has questioned the value of this method for hyperdynamic conditions. To evaluate this technique in different hemodynamic settings, we analyzed the PDR_ICG and corresponding pharmacokinetic models after endotoxemia or hemorrhagic shock in rats. Male anesthetized Sprague-Dawley rats underwent hemorrhage (mean arterial pressure 35 ± 5 mmHg, 90 min) and 2 h of reperfusion, or lipopolysaccharide (LPS) induced moderate or severe (1.0 vs. 10 mg/kg) endotoxemia for 6 h (each n = 6). Afterwards, PDR_ICG was measured, and pharmacokinetic models were analyzed using nonlinear mixed effects modeling (NONMEM^®). Hemorrhagic shock resulted in a significant decrease of PDR_ICG, compared with sham controls, and a corresponding attenuation of the calculated ICG clearance in 1- and 2-compartment models, with the same log-likelihood. The induction of severe, but not moderate endotoxemia, led to a significant reduction of PDR_ICG. The calculated ICG blood clearance was reduced in 1-compartment models for both septic conditions. 2-compartment models performed with a significantly better log likelihood, and the calculated clearance of ICG did not correspond well with PDR_ICG in both LPS groups. 3-compartment models did not improve the log likelihood in any experiment. These results demonstrate that PDR_ICG correlates well with ICG clearance in 1- and 2-compartment models after hemorrhage. In endotoxemia, best described by a 2-compartment model, PDR_ICG may not truly reflect the ICG clearance.

Liver function assessment using indocyanine green plasma disappearance rate in a young male with icteric leptospirosis: a case report

Background

Leptospirosis is one of the leading global zoonotic causes of morbidity and mortality. It is induced by a pathogenic spirochete of the genus Leptospira. The icteric form of leptospirosis is characterized by pronounced hyperbilirubinemia and associated with significantly increased mortality. Conventional static liver function tests insufficiently assess hepatic damage and have limited prognostic value. Dynamic tests, such as indocyanine green plasma (ICG) clearance, more adequately reflect hepatic functional status. In this case report we describe the ICG plasma disappearance rates (ICG-PDR) in a patient with leptospirosis and massive hyperbilirubinemia, expanding our knowledge of liver dysfunction in icteric leptospirosis.

Case presentation

A 21-year-old Caucasian man presented with acute-onset jaundice, myalgia, fever and headaches. Laboratory tests upon admission revealed, most notably, acute kidney failure and hyperbilirubinemia of 17 mg/dl with mild elevation of aminotransferases. In the course of the following 4 days, total serum bilirubin increased to 54 mg/dl. The clinical outcome was favorable with intravenous ceftriaxone and doxycycline. Presumptive diagnosis of leptospirosis was later confirmed by PCR-based amplification of leptospiral DNA in the blood. ICG-PDR values, bilirubin as well as aminotransferases were recorded throughout hospitalization and a 3-month follow-up period. Initially dramatically reduced ICG-PDR (2.0%/min, normal range: 18–25%/min) rapidly normalized within 10 days, while bilirubin remained elevated up to week 7. Mild elevation of serum alanine aminotransferase was at its peak of 124 U/l by day 12 and reached close to normal levels by week 7 upon admission.

Conclusions

Markedly diminished ICG-PDR values presented in this case report suggest severe liver function impairment in the acute phase of icteric leptospirosis. Prolonged elevation of serum bilirubin may not adequately reflect recovery of liver injury in this disease. ICG clearance appears to be a promising marker for the detection of hepatic dysfunction and recovery in icteric leptospirosis in addition to the static tests.

Electronic supplementary material

The online version of this article (10.1186/s12879-019-4101-5) contains supplementary material, which is available to authorized users.

Assessment of Regional Perfusion and Organ Function: Less and Non-invasive Techniques

Sufficient organ perfusion essentially depends on preserved macro- and micro-circulation. The last two decades brought substantial progress in the development of less and non-invasive monitoring of macro-hemodynamics. However, several recent studies suggest a frequent incoherence of macro- and micro-circulation. Therefore, this review reports on interactions of macro- and micro-circulation as well as on specific regional and micro-circulation. Regarding global micro-circulation the last two decades brought advances in a more systematic approach of clinical examination including capillary refill time, a graded assessment of mottling of the skin and accurate measurement of body surface temperatures. As a kind of link between macro- and microcirculation, a number of biochemical markers can easily be obtained. Among those are central-venous oxygen saturation (S_cvO₂), plasma lactate and the difference between central-venous and arterial CO₂ (cv-a-pCO₂-gap). These inexpensive markers have become part of clinical routine and guideline recommendations. While their potential to replace parameters of macro-circulation such as cardiac output (CO) is limited, they facilitate the interpretation of the adequacy of CO and other macro-circulatory markers. Furthermore, they give additional hints on micro-circulatory impairment. In addition, a number of more sophisticated technical approaches to quantify and visualize micro-circulation including video-microscopy, laser flowmetry, near-infrared spectroscopy (NIRS), and partial oxygen pressure measurement have been introduced within the last 20 years. These technologies have been extensively used for scientific purposes. Moreover, they have been successfully used for educational purposes and to visualize micro-circulatory disturbances during sepsis and other causes of shock. Despite several studies demonstrating the association of these techniques and parameters with outcome, their practical application still is limited. However, future improvements in automated and “online” diagnosis will help to make these technologies more applicable in clinical routine. This approach is promising with regard to several studies which demonstrated the potential to guide therapy in different types of shock. Finally several organs have specific patterns of circulation related to their special anatomy (liver) or their auto-regulatory capacities (brain, kidney). Therefore, this review also discusses specific issues of monitoring liver, brain, and kidney circulation and function.

Advanced liver function assessment in patients with intestinal failure on long-term parenteral nutrition

BACKGROUND & AIMS

Intestinal failure associated liver disease (IFALD) is one of the leading complications and causes of deaths in adult patients receiving home parenteral nutrition for chronic intestinal failure (CIF). Early diagnosis of IFALD is key to alleviate the progression of hepatic dysfunction. The aim of this study was to evaluate the capability of noninvasive liver function tests.

METHODS

90 adult patients with CIF receiving long-term home parenteral nutrition were included in a prospective cross-sectional study at our department between 2014 and 2017. All participants underwent dynamic liver function assessment (maximum liver function capacity [LiMAx] test, indocyanine green [ICG] test), transient elastography (FibroScan), blood tests and comprehensive nutritional status assessment. Univariate and multivariable analysis were performed to identify predictors of liver function.

RESULTS

LiMAx, ICG test, and FibroScan highly correlated with standard liver function tests. Multivariable analysis identified intact ileum (B = 520.895; p = 0.010), digestive anatomy type 3 (B = 75.612; p = 0.025), citrulline level (B = 3.428; p = 0.040), parenteral olive oil intake (B = -0.570; p = 0.043), and oral intake (B = 182.227; p = 0.040) as independent risk factors affecting liver function determined by LiMAx test. ICG test and FibroScan showed no correlation with gastrointestinal and nutrition-related parameters.

CONCLUSION

The LiMAx test is significantly associated with widely accepted risk factors for IFALD by multivariable analysis, whereas ICG test and FibroScan failed to show significant correlations. Liver function assessment by LiMAx test may therefore have the potential to detect alterations in liver function and identify patients at risk for the development of IFALD. Longitudinal studies are needed to investigate the impact of liver function determined by LiMAx test on long-term outcome in patients with CIF.

Clearance of Indocyanine Green in Severe Pediatric Burns

BACKGROUND

Clearance of indocyanine green dye (ICGc) reflects sinusoidal perfusion and hepatocyte cell membrane function. Thus, ICGc is a reflection of the functional reserve of intact hepatocytes. The purpose of this study was to identify predictors of ICGc in severely burned children during the acute hospitalization and at the time of discharge from the intensive care unit (ICU). A secondary aim was to determine the relationship between liver size and patient ICGc.

METHODS

Twenty-six children (0.8-17 years old) with 35% or greater total body surface area burned (%TBSA-B) were included. Assessment of ICGc (in milliliters per minute per meter squared) was done during the acute hospitalization (median: 6 days after admission, median: 14 days postburn) and at the time of discharge from the ICU (median: 19 days after admission, median: 27 days postburn). Age, TBSA-B, % third-degree burns, inhalation injury, preexisting chronic malnutrition, hematocrit, liver dysfunction, and time from burn injury were incorporated in multiple linear regressions as predictive variables of ICGc. Only variables with p < 0.05 were retained in the final models.

RESULTS

Time from injury and age were the strongest predictors of ICGc during the acute admission but not at the time of discharge from the ICU. Time from injury was negatively associated with ICGc, whereas age was positively associated. At the time of discharge from the ICU, ICGc was increased in proportion to the %TBSA-B, whereas inhalation injury and preexisting chronic malnutrition were associated with lower ICGc. There was no correlation between change-to-predicted liver length and ICGc.

CONCLUSIONS

The intrinsic ability of the liver to extract ICG from plasma was lower in younger burned patients during the acute admission and in those with preexisting chronic malnutrition and inhalation injury at the time of discharge from the ICU.

LEVEL OF EVIDENCE

Prognostic/Epidemiologic, level III.

Non-invasive Evaluation of NAFLD with Indocyanine Green Clearance Test: a Preliminary Study in Morbidly Obese Patients Undergoing Bariatric Surgery

BACKGROUND

Overweight and obesity dramatically increased in the last years. Hepatic complication of obesity, integrated in the term of non-alcoholic fatty liver disease (NAFLD), is a spectrum of abnormality ranging from steatosis to non-alcoholic steatohepatitis (NASH), potentially leading to cirrhosis. Liver biopsy remains the gold standard to evaluate the stage of NAFLD; however, the procedure is invasive. The indocyanine green (ICG) clearance test is performed since years to assess hepatic function before partial hepatectomy, or after liver transplantation. This study was designed to detect liver complications with the ICG clearance test in a population of obese patients scheduled for bariatric surgery.

METHODS

In a prospective cohort study, morbidly obese individuals receiving bariatric surgery with scheduled hepatic biopsies were investigated. Liver function was determined by the ICG test preoperatively, and blood samples were collected. Liver biopsy specimens were obtained for each patient and classified according to the NAFLD activity score (NAS) by a single pathologist that was blinded to the results of the ICG test.

RESULTS

Twenty-six patients were included (7 male and 19 female). The mean age of participants was 45.8 years; the mean body mass index was 41.4 kg/m². According to the NAS, 6 (23.1%) patients revealed manifest NASH, and 5 patients were considered borderline (19.2%). A closed correlation was observed between the ICG clearance test and hepatic steatosis (r = 0.43, p = 0.03), NAS (r = 0.44, p = 0.025), and fibrosis (r = 0.49, p = 0.01).

CONCLUSIONS

In obese patients, non-invasive evaluation of liver function with the indocyanine green clearance test correlated with histological features of NAFLD. This may detect non-invasively hepatopathy in obese population and could motive biopsy.

Liver Function, Quantified by LiMAx Test, After Major Abdominal Surgery. Comparison Between Open and Laparoscopic Approach

INTRODUCTION

Major abdominal surgery may lead to a systemic inflammatory response (SIRS) with a risk of organ failure. One possible trigger for a postoperative hepatic dysfunction is an altered hepatic blood flow during SIRS, resulting in a decreased oxygen delivery. This pilot study investigated the role of liver dysfunction measured by the LiMAx test after major abdominal surgery, focussing on open and laparoscopic surgical approaches.

METHODS

We prospectively investigated 25 patients (7 females and 18 males, age range 55-72 years) scheduled for upper abdominal surgery. The LiMAx test, ICG-PDR and duplex sonography were carried out preoperatively, followed by postoperative days (PODs) 1, 3, 5 and 10. Laboratory parameters and clinical parameters were measured daily. Clinical outcome parameters were examined at the end of treatment. The population was divided into group A (laparotomy) versus group B (laparoscopy).

RESULTS

LiMAx values decreased significantly on POD 1 (290 µg/kg/h, P < 0.001), followed by a significant increase at POD 3 (348 µg/kg/h, P = 0.013). Only INR showed a significant increase on POD 1 (1.26, P < 0.001). Duplex sonography and ICG-PDR revealed a hyper-dynamic liver blood flow. No differences between group A and B were found.

CONCLUSIONS

Hepatic dysfunction after major abdominal surgery is evident and underestimated. The LiMAx test provides an adequate tool to determine liver dysfunction. Open and laparoscopic approaches appeared similar in terms of liver dysfunction and postoperative SIRS.

Molecular fluorescence-guided surgery of peritoneal carcinomatosis of colorectal origin: A narrative review

Patients with peritoneal carcinomatosis (PC) from colorectal origin may undergo cytoreductive surgery (CRS) with hyperthermic intraperitoneal chemotherapy (HIPEC) as a curative approach. One major prognostic factor that affects survival is completeness of cytoreduction. Molecular Fluorescence Guided Surgery (MFGS) is a novel intraoperative imaging technique that may improve tumor identification in the future, potentially preventing over- and under-treatment in these patients. This narrative review outlines a chronological overview of MFGS development in patients with PC of colorectal origin.

Large-volume paracentesis effects plasma disappearance rate of indo-cyanine green in critically ill patients with decompensated liver cirrhosis and intraabdominal hypertension

BACKGROUND

Ascites is a major complication of decompensated liver cirrhosis. Intraabdominal hypertension and structural alterations of parenchyma involve decisive changes in hepatosplanchnic blood flow. Clearance of indo-cyanine green (ICG) is mainly dependent on hepatic perfusion and hepatocellular function. As a consequence, plasma disappearance rate of ICG (ICG-PDR) is rated as a useful dynamic parameter of liver function. This study primarily evaluates the impact of large-volume paracentesis (LVP) on ICG-PDR in critically ill patients with decompensated cirrhosis. Additionally, it describes influences on intraabdominal pressure (IAP), abdominal perfusion pressure (APP), hepatic blood flow, hemodynamic and respiratory function.

METHODS

We analyzed LVP in 22 patients with decompensated liver cirrhosis. ICG-PDR was assessed by using noninvasive LiMON technology (Pulsion® Medical Systems; Maquet Getinge Group), and hepatic blood flow was analyzed by color-coded duplex sonography.

RESULTS

Paracentesis of a median volume of 3450 mL ascites evoked significant increases of ICG-PDR from 3.6 (2.8-4.6) to 5.1 (3.9-6.2)%/min (p < 0.001). Concomitantly, we observed a raise in "ICG-Clearance" from 99 (73.5-124.5) to 104 (91-143.5) mL/min/m2 (p = 0.005), while circulating blood volume index was unchanged [2412 (1983-3025) before paracentesis vs. 2409 (1997-2805) mL/m2, p = 0.734]. Sonography revealed a significant impact of paracentesis on hepatic blood flow: Hepatic artery resistance index dropped from 0.74 (0.68-0.75) to 0.68 (0.65-0.71) (p < 0.001) and maximum flow velocity in hepatic vein increased from 24 (17-30) to 30 (22-36) cm/s (p < 0.001). Consistent with previous studies, paracentesis caused significant decreases in IAP from 19.0 (15.0-20.3) to 11.0 (8.8-12.3) mmHg (p < 0.001) and central venous pressure from 22.5 (17.8-29.0) to 17.5 (12.8-24.0) mmHg (p < 0.001) with inverse increases in APP from 63.0 (56.8-69.5) to 71.0 (65.5-78.5) mmHg (p < 0.001). Changes in ICG-PDR were concomitant with changes in IAP (r = - 0.602) and APP (r = 0.576). Moreover, we found a substantial improvement in respiratory function. By contrast, hemodynamic parameters assessed by transpulmonary thermodilution, serum bilirubin and international normalized ratio did not change after paracentesis.

CONCLUSION

Critically ill patients with decompensated cirrhosis and elevated IAP showed dramatically impaired ICG-PDR. Paracentesis evoked an improvement in ICG-PDR in parallel with a decreased IAP and an increased APP, while conventional parameters of liver function did not change. This effect on ICG-PDR is mainly referable to a relief of intraabdominal hypertension and changes in hepatosplanchnic blood flow.

Indocyanine Green Fluorescence Imaging-Guided Surgery in Primary and Metastatic Liver Tumors

BACKGROUND

After surgery for liver tumors, recurrence rates remain high because of residual positive margins or undiagnosed lesions. It has been suggested that detection of hepatic tumors can be obtained with near-infrared fluorescence imaging (FI). Indocyanine green (ICG) has been used with contrasting results. The aims of this study were to explore ICG-FI-guided surgery methodology and to assess its potential applications.

MATERIALS AND METHODS

Out of 14 patients with liver tumors, 5 were not operated on, and 9 patients (3 primary and 6 metastatic tumors) underwent surgery. ICG (0.5 mg/kg) was injected intravenously 24 hours before surgery. Fluorescence was investigated prior to resection to detect liver lesions, during hepatic transection to guide surgery, on both cross-section and benchtop to assess surgical margins, and for pathological evaluation.

RESULTS

All operations were successful and had a short duration. ICG-FI detected all already known lesions (n = 10), and identified 2 additional small tumors (1 hepatocarcinoma and 1 metastasis, diagnostic improvement = 20%). Two hepatocarcinomas were hyperfluorescent; the remaining one, with a central hypofluorescent area and a hyperfluorescent ring, was indeed a mixed cholangiohepatocarcinoma. All metastatic nodules were hypofluorescent with a hyperfluorescent rim. In all cases, in vivo and ex vivo fluorescence revealed clear liver margins. Postoperative pathological examination greatly benefited of liver fluorescence to assess radicality.

CONCLUSION

ICG-FI-guided surgery was shown to be an effective tool to improve both intraoperative staging and radicality in the surgical treatment of primary and metastatic liver tumors.