Pathology of hepatic iron overload

A clinical predictive score of high liver iron content in metabolic hyperferritinemia: a retrospective cohort pilot study

BACKGROUND

In metabolic hyperferritinemia, most patients do not require bloodletting as the liver iron content is mildly increased. We aimed to develop a clinical predictive score of high liver iron content in metabolic hyperferritinemia to guide the prescription of magnetic resonance imaging of the liver.

METHODS

We conducted a single-center retrospective cohort study including consecutive patients with metabolic hyperferritinemia who underwent a liver iron content evaluation at diagnosis. Excessive alcohol consumption was an exclusion criterion. A multivariate analysis followed by a 1000 bootstrap replicate analysis with an expectation-maximization algorithm was used to identify the predictive factors of high liver iron content. A ROC curve analysis was built to study the performance of the score based on the odds-ratio provided by the multivariate analysis.

RESULTS

217 patients (180 men, mean age 57 years old) were included. Fifty-five patients (25%) had high liver iron content (≥ 100 µmol/g). In univariate analysis, a family history of hyperferritinemia requiring phlebotomies was associated with high LIC, as well as an increase of transferrin saturation > 45% (p < 0.001). In multivariate regression, a family history of hyperferritinemia (OR 6.15, CI95 [2.11-17.92]), increased ferritin level ≥ 600 µg/L (OR 5.53, CI95 [1.43-21.42]) and increased transferrin saturation ≥ 45% (OR 2.63, CI95 [1.32-5.23]) were significantly associated with high liver iron content. A 15-point predictive score (area-under-the-curve 0.72, CI95 [0.64-0.79], p < 0.001) was built, providing an OR of 4.17 (CI95 [2.15-8.07], p < 0.001) for high liver iron content (sensitivity 60%, specificity 97%, negative predictive value 84%).

CONCLUSION

in this pilot study, ferritin ≥ 600 µg/L, transferrin saturation ≥ 45% and a family history of hyperferritinemia requiring bloodletting provided a simple clinical score to predict high liver iron content in metabolic adult hyperferritinemia. The bootstrap analysis confirmed the robustness of our model.

Effects of Aging on the Severity of Liver Injury in Mice With Iron Overload

Although iron is a vital component in the body, excessive iron leads to iron toxicity, which affects vital organs. In particular, the liver is considerably affected by iron toxicity because it stores the highest amount of iron in the body. Nonetheless, the relationship between iron overload and aging in the liver has not yet been clearly identified. This study aimed to observe the effects of aging on iron overload in the liver. Female C57BL/6J mice were randomly divided into vehicle control and iron overload groups (n = 7-22 per group). The iron overload group was injected with iron-dextran (Fe-dextran, ferric hydroxide dextran complex) (0.5 g/kg) for 4 weeks. After the experimental period, liver and blood samples were obtained from 2-, 15-, and 22-month-old mice. Liver weight, iron deposition, structural changes, cell death, extracellular matrix deposition, and fenestration of sinusoidal vessels were analyzed and compared between the groups. Additionally, biochemical analyses (aspartate aminotransferase, alanine aminotransferase, and serum total iron levels) were performed. The iron overload group exhibited significant differences compared with the control group with age. In the elderly iron overload model, iron deposition, inflammatory cell infiltration, and cell death were significantly increased (p < 0.0001). Moreover, deposition of the extracellular matrix and defenestration of sinusoidal fenestrae were observed among 22-month-old mice in the iron overload group. These results suggest that aging is a risk factor for iron-induced liver injury. Therefore, caution should be exercised when performing iron-related treatments in the elderly.

Tissue histology and depuration of per- and polyfluoroalkyl substances (PFAS) from dairy cattle with lifetime exposures to PFAS-contaminated drinking water and feed

Plasma, milk and tissue samples were collected from 30 dairy cattle (0.4 to 8.9 years of age) with lifetime exposures to perfluoroalkyl substances (PFAS) removed from a PFAS-contaminated farm and provided PFAS-free feed and water. Twenty cattle were slaughtered 2 weeks after removal from the farm and tissues were collected for histological and residue analyses. Milk and/or plasma were collected from all remaining cattle at 2-week intervals and milk samples were collected daily but were analyzed at the same intervals as plasma samples. The remaining cattle were slaughtered 20 and 22 weeks after the initial set of 20 animals were slaughtered. While many incidental and normal background findings were noted on histological evaluation, no consistent histological finding was associated with PFAS exposure. Perfluoroalkyl carboxylic acids (PFCA) and perfluoro butane sulfonic acid (PFBS) were not generally detected in milk, plasma and tissues, but perfluoroalkyl sulfonic acids (PFSA) were quantifiable throughout the 22-week withdrawal period in most matrices. Estimated plasma half-lives of perfluorohexane sulfonic acid (PFHxS), perfluoroheptane sulfonic acid (PFHpS), linear perfluorooctane sulfonic acid (L-PFOS), perfluoro-3-methyl heptanesulfonate (3Me-PFOS) and perfluoro-6-methyl heptanesulfonate (6Me-PFOS) ranged from 4 to 10 weeks, but the estimates were associated with large confidence intervals. Across animal status (heifer, lactating, dry), natural log transformed (Ln) plasma residues of PFHxS and L-PFOS were generally well correlated with Ln-transformed PFHxS and L-PFOS residues in lung, muscle, liver and kidney (R2, 0.7572 to 0.9394) whereas the strongest relationships of Ln-transformed L-PFOS residues among tissues were between lung and liver, kidney and muscle (R2, 0.8287 to 0.9138).

Influence of Gadoxetate disodium to the hepatic proton density fat fraction quantified with the Dixon sequences in a rabbit model

OBJECTIVE

To study the impact of Gx on quantification of hepatic fat contents under metabolic dysfunction-associated steatotic liver disease (MASLD) imaged on VIBE Dixon in hepatobiliary specific phase.

METHODS

Forty-two rabbits were randomly divided into control group (n = 10) and high-fat diet group (n = 32). Imaging was performed before enhancement (Pre-Gx) and at the 13th (Post-Gx13) and 17th (Post-Gx17) min after Gx enhancement with 2E- and 6E-VIBE Dixon to determine hepatic proton density fat fractions (PDFF). PDFFs were compared with vacuole percentage (VP) measured under histopathology.

RESULTS

33 animals were evaluated and including control group (n = 11) and MASLD group (n = 22). Pre-Gx, Post-Gx13, Post-Gx17 PDFFs under 6E-VIBE Dixon had strong correlations with VPs (r2 = 0.8208-0.8536). PDFFs under 2E-VIBE Dixon were reduced significantly (P < 0.001) after enhancement (r2 = 0.7991/0.8014) compared with that before enhancement (r2 = 0.7643). There was no significant difference between PDFFs of Post-Gx13 and Post-Gx17 (P = 0.123) for which the highest consistency being found with 6E-VIBE Dixon before enhancement (r2 = 0.8536). The signal intensity of the precontrast compared with the postcontrast, water image under 2E-VIBE Dixon increased significantly (P < 0.001), fat image showed no significant difference (P = 0.754).

CONCLUSION

2E- and 6E-VIBE Dixon can obtain accurate PDFFs in the hepatobiliary specific phase from 13 to 17th min after Gx enhancement. On 2E-VIBE Dixon (FA = 10°), effective minimization of T1 Bias by the Gx administration markedly improved the accuracy of the hepatic PDFF quantification.

Free-breathing MRI techniques for fat and R2* quantification in the liver

OBJECTIVE

To review the recent advancements in free-breathing MRI techniques for proton-density fat fraction (PDFF) and R2* quantification in the liver, and discuss the current challenges and future opportunities.

MATERIALS AND METHODS

This work focused on recent developments of different MRI pulse sequences, motion management strategies, and reconstruction approaches that enable free-breathing liver PDFF and R2* quantification.

RESULTS

Different free-breathing liver PDFF and R2* quantification techniques have been evaluated in various cohorts, including healthy volunteers and patients with liver diseases, both in adults and children. Initial results demonstrate promising performance with respect to reference measurements. These techniques have a high potential impact on providing a solution to the clinical need of accurate liver fat and iron quantification in populations with limited breath-holding capacity.

DISCUSSION

As these free-breathing techniques progress toward clinical translation, studies of the linearity, bias, and repeatability of free-breathing PDFF and R2* quantification in a larger cohort are important. Scan acceleration and improved motion management also hold potential for further enhancement.

The Cellular Stability Hypothesis: Evidence of Ferroptosis and Accelerated Aging-Associated Diseases as Newly Identified Nutritional Pentadecanoic Acid (C15:0) Deficiency Syndrome

Ferroptosis is a newly discovered form of cell death caused by the peroxidation of fragile fatty acids in cell membranes, which combines with iron to increase reactive oxygen species and disable mitochondria. Ferroptosis has been linked to aging-related conditions, including type 2 diabetes, cardiovascular disease, and nonalcoholic fatty liver disease (NAFLD). Pentadecanoic acid (C15:0), an odd-chain saturated fat, is an essential fatty acid with the primary roles of stabilizing cell membranes and repairing mitochondrial function. By doing so, C15:0 reverses the underpinnings of ferroptosis. Under the proposed "Cellular Stability Hypothesis", evidence is provided to show that cell membranes optimally need >0.4% to 0.64% C15:0 to support long-term health and longevity. A pathophysiology of a newly identified nutritional C15:0 deficiency syndrome ("Cellular Fragility Syndrome") is provided that demonstrates how C15:0 deficiencies (≤0.2% total circulating fatty acids) can increase susceptibilities to ferroptosis, dysmetabolic iron overload syndrome, type 2 diabetes, cardiovascular disease, and NAFLD. Further, evidence is provided that C15:0 supplementation can reverse the described C15:0 deficiency syndrome, including the key components of ferroptosis. Given the declining dietary intake of C15:0, especially among younger generations, there is a need for extensive studies to understand the potential breadth of Cellular Fragility Syndrome across populations.

Supplementation of Micro- and Macronutrients-A Role of Nutritional Status in Non-Alcoholic Fatty Liver Disease

Non-alcoholic fatty liver disease (NAFLD) is a condition in which the pathological cumulation of fat with coexisting inflammation and damage of hepatic cells leads to progressive dysfunctions of the liver. Except for the commonly well-known major causes of NAFLD such as obesity, dyslipidemia, insulin resistance, or diabetes, an unbalanced diet and imbalanced nutritional status should also be taken into consideration. In this narrative review, we summarized the current knowledge regarding the micro- and macronutrient status of patients suffering from NAFLD considering various diets and supplementation of chosen supplements. We aimed to summarize the knowledge indicating which nutritional impairments may be associated with the onset and progression of NAFLD at the same time evaluating the potential therapy targets that could facilitate the healing process. Except for the above-mentioned objectives, one of the most important aspects of this review was to highlight the possible strategies for taking care of NAFLD patients taking into account the challenges and opportunities associated with the micronutrient status of the patients. The current research indicates that a supplementation of chosen vitamins (e.g., vitamin A, B complex, C, or D) as well as chosen elements such as zinc may alleviate the symptoms of NAFLD. However, there is still a lack of sufficient data regarding healthy ranges of dosages; thus, further research is of high importance in this matter.

Hereditary hemochromatosis caused by a C282Y/H63D mutation in the HFE gene: A case report

Hereditary hemochromatosis (HH) is a disease characterized by disordered iron metabolism. It often involves mutations of the HFE gene, which encodes the homeostatic iron regulator protein (HFE), as well as mutations affecting hepcidin antimicrobial peptide, hemojuvelin, or transferrin receptor 2. Historically, HH has been observed primarily in European and European diaspora populations, while classical HH is rare in Asian populations, including in China. In this article, we report a rare case of HH in a Chinese man that could be attributed to a heterozygous C282Y/H63D HFE mutation. Based on clinical examination, liver biopsy, and genetic testing results, the patient was diagnosed with HH. Clinical signs and symptoms and serum iron-related test results were recorded for a period of two years after the patient began treatment. Over this observation period, the patient was subjected to 25 phlebotomies (accounting for a total blood loss of 10.2 L). His serum ferritin levels decreased from 1550 μg/L to 454 μg/L, his serum iron concentration decreased from 40 μmol/L to 24.6 μmol/L, and his transferrin saturation decreased from 97.5% to 55.1%. Early diagnosis is essential for patients with HH to obtain good outcomes. Regular phlebotomy after diagnosis can improve HH symptoms and delay HH disease progression.

CONCURRENT IRON OVERLOAD AND NEOPLASIA IN LESCHENAULT'S ROUSETTES (ROUSETTUS LESCHENAULTII): A CASE SERIES

This case series investigates a cluster of deaths in a captive colony of Leschenault's rousettes (Rousettus leschenaultii). Six of seven bats that died between March and September 2021 were diagnosed postmortem with both iron overload (IO) and neoplasia, neither of which have previously been reported in this species. Iron status was assessed via hepatic histopathological grading, hepatic iron concentration, and, in two cases, serum iron concentration. On histopathological grading, all cases had hemochromatosis except one, which had hemosiderosis. Hepatic iron concentrations did not correlate with histopathological grading. Neoplasms in these six bats included hepatocellular carcinoma (HCC; 4), bronchioloalveolar adenocarcinoma (1), pancreatic adenocarcinoma (1), and sarcoma of the spleen and stomach (1). One bat had two neoplasms (HCC and sarcoma of the spleen and stomach). One additional case of HCC in 2018 was identified on retrospective case review. Etiology was investigated to the extent possible in a clinical setting. Nutritional analysis and drinking water testing found oral iron intake within acceptable bounds; however, dietary vitamin C was potentially excessive and may have contributed to IO. Panhepadnavirus PCR testing of liver tissue was negative for all bats. A species-associated susceptibility to IO, as seen in Egyptian fruit bats (Rousettus aegyptiacus), is possible. The high incidence of HCC is suspected to be related to IO; other differentials include viral infection. Causes or contributing factors were not definitively identified for the other neoplasms seen but could include age, inherited risk (given a high level of inbreeding), or an oncogenic virus. Pending further research in this species, it is recommended that keepers of Leschenault's rousettes offer conservative amounts of vitamin C and iron (as for Egyptian fruit bats), submit for postmortem examination any euthanized or found dead, and share records of similar cases.

Extracellular Fe2+ and Fe3+ modulate osteocytic viability, expression of SOST, RANKL and FGF23, and fluid flow-induced YAP1 nuclear translocation

Iron overload negatively affects bone mass and strength. However, the impact of iron excess on osteocytes-important bone cells for mechanotransduction and remodeling-is poorly understood. Herein, we examined the effects of iron exposure on osteocytes during their maturation process. We discovered that iron overload caused apoptosis of osteocytes in early and late stages of differentiation. Notably, the expression of key proteins for iron entry was downregulated during differentiation, suggesting that mature osteocytes were less susceptible to iron toxicity due to limited iron uptake. Furthermore, iron overload also enriched a subpopulation of mature osteocytes, as indicated by increased expression of Dmp1, a gene encoding protein for bone mineralization. These iron-exposed osteocytes expressed high levels of Sost, Tnfsf11 and Fgf23 transcripts. Consistently, we demonstrated that exogenous FGF23 stimulated the formation and survival of osteoclasts, suggesting its regulatory role in bone resorption. In addition, iron overload downregulated the expression of Cx43, a gene encoding gap junction protein in the dendritic processes, and impaired YAP1 nuclear translocation in response to fluid flow in differentiated osteocytes. It can be concluded that iron overload induces cellular adaptation in differentiating osteocytes, resulting in insensitivity to mechanical stimulation and potential disruption of the balance in bone remodeling.

Digital Hepatic Iron Content: An Artificial Intelligence Model for Spatially Resolved Histologic Iron Quantitative Analysis in Liver Samples

Currently, the precise evaluation of tissue hepatic iron content (HIC) requires laboratory testing using tissue-destructive methods based on colorimetry or spectrophotometry. To maximize the use of routine histologic stains in this context, we developed an artificial intelligence (AI) model for the recognition and spatially resolved measurement of iron in liver samples. Our AI model was developed using a cloud-based, supervised deep learning platform (Aiforia Technologies). Using digitized Pearl Prussian blue iron stain whole slide images representing the full spectrum of changes seen in hepatic iron overload, our training set consisted of 59 cases, and our validation set consisted of 19 cases. The study group consisted of 98 liver samples from 5 different laboratories, for which tissue quantitative analysis using inductively coupled plasma mass spectrometry was available, collected between 2012 and 2022. The correlation between the AI model % iron area and HIC was Rs = 0.93 for needle core biopsy samples (n = 73) and Rs = 0.86 for all samples (n = 98). The digital hepatic iron index (HII) was highly correlated with HII > 1 (area under the curve [AUC] = 0.93) and HII > 1.9 (AUC = 0.94). The percentage area of iron within hepatocytes (vs Kupffer cells and portal tract iron) identified patients with any hereditary hemochromatosis-related mutations (either homozygous or heterozygous) (AUC = 0.65, P = .01) with at least similar accuracy than HIC, HII, and any histologic iron score. The correlation between the Deugnier and Turlin score and the AI model % iron area for all patients was Rs = 0.87 for total score, Rs = 0.82 for hepatocyte iron score, and Rs = 0.84 for Kupffer cell iron score. Iron quantitative analysis using our AI model was highly correlated with both detailed histologic scoring systems and tissue quantitative analysis using inductively coupled plasma mass spectrometry and offers advantages (related to the spatial resolution of iron analysis and the nontissue-destructive nature of the test) over standard quantitative methods.

Pancreatic steatosis and iron overload increases cardiovascular risk in non-alcoholic fatty liver disease

Objective

To assess the prevalence of pancreatic steatosis and iron overload in non-alcoholic fatty liver disease (NAFLD) and their correlation with liver histology severity and the risk of cardiometabolic diseases.

Method

A prospective, multicenter study including NAFLD patients with biopsy and paired Magnetic Resonance Imaging (MRI) was performed. Liver biopsies were evaluated according to NASH Clinical Research Network, hepatic iron storages were scored, and digital pathology quantified the tissue proportionate areas of fat and iron. MRI-biomarkers of fat fraction (PDFF) and iron accumulation (R2*) were obtained from the liver and pancreas. Different metabolic traits were evaluated, cardiovascular disease (CVD) risk was estimated with the atherosclerotic CVD score, and the severity of iron metabolism alteration was determined by grading metabolic hiperferritinemia (MHF). Associations between CVD, histology and MRI were investigated.

Results

In total, 324 patients were included. MRI-determined pancreatic iron overload and moderate-to severe steatosis were present in 45% and 25%, respectively. Liver and pancreatic MRI-biomarkers showed a weak correlation (r=0.32 for PDFF, r=0.17 for R2*). Pancreatic PDFF increased with hepatic histologic steatosis grades and NASH diagnosis (p<0.001). Prevalence of pancreatic steatosis and iron overload increased with the number of metabolic traits (p<0.001). Liver R2* significantly correlated with MHF (AUC=0.77 [0.72-0.82]). MRI-determined pancreatic steatosis (OR=3.15 [1.63-6.09]), and iron overload (OR=2.39 [1.32-4.37]) were independently associated with high-risk CVD. Histologic diagnosis of NASH and advanced fibrosis were also associated with high-risk CVD.

Conclusion

Pancreatic steatosis and iron overload could be of utility in clinical decision-making and prognostication of NAFLD.

Beyond the Usual Suspects: Hereditary Hemochromatosis and Transaminitis in Primary Care

An annual physical examination within a primary care setting, including evaluation of liver enzymes and abnormal serology, is incidental and often asymptomatic. Fatty liver is the most common etiology for transaminitis. Hepatobiliary imaging studies, viral hepatitis serology, evaluation of metabolic liver disease, and alcohol consumption history should be performed for transaminitis evaluation. In patients with prior history of excessive alcohol consumption, transaminitis is often assumed to be alcohol-related. It is prudent to evaluate other infectious and metabolic etiologies, which can change patient management. Iron studies, including ferritin and transferrin saturation, are performed to evaluate hereditary hemochromatosis (HH). We present the case of a 46-year-old patient who visited the clinic for a routine health checkup, during which elevated ferritin levels were detected. Subsequent diagnosis revealed hemochromatosis. The patient underwent phlebotomy, resulting in a reduction of ferritin levels.

Dynamic chromatin accessibility during nutritional iron overload reveals a BMP6-independent induction of cell cycle genes

Iron is essential to organism physiology as it participates in numerous biological processes including oxygen transport, respiration and erythropoiesis. Although iron is critical to physiology, excess iron is toxic to cells and tissues due to generation of reactive oxygen species. Therefore, well-kept iron homeostasis is a mainstay of proper cell and organ function. Iron overload disorders, caused by nutritional or genetic factors, contribute to many pathologies such as diabetes, non-alcoholic steatohepatitis and hepatocellular carcinoma. The liver is not only vulnerable to the effects of iron overload, it is also the major organ controlling iron homeostasis. During iron overload, Bone Morphogenic Protein (BMP) levels increase and initiate a hepatic response aimed at lowering iron levels. The transcriptional effects of iron overload are not well-characterized and the underlining enhancer regulation is uncharted. Here, we profiled the liver's transcriptome and chromatin accessibility following nutritional iron overload. We found marked changes in gene expression and enhancer accessibility following iron overload. Surprisingly, 16% of genes induced following iron overload participate in propagating the cell cycle. Induction of cell cycle genes was independent of BMP. Genome-wide enhancer landscape profiling revealed hundreds of enhancers with altered activity following iron overload. Characterization of transcription factor motifs and footprints in iron-regulated enhancers showed a role for the Activator Protein 1 (AP-1) transcription factor in promoting cell cycle-related transcription. In summary, we found that the transcriptional program at play during iron overload is bifurcated in which BMP signaling controls iron homeostasis genes while an AP-1-driven program controls cell cycle genes.

QSM Throughout the Body

Magnetic materials in tissue, such as iron, calcium, or collagen, can be studied using quantitative susceptibility mapping (QSM). To date, QSM has been overwhelmingly applied in the brain, but is increasingly utilized outside the brain. QSM relies on the effect of tissue magnetic susceptibility sources on the MR signal phase obtained with gradient echo sequence. However, in the body, the chemical shift of fat present within the region of interest contributes to the MR signal phase as well. Therefore, correcting for the chemical shift effect by means of water-fat separation is essential for body QSM. By employing techniques to compensate for cardiac and respiratory motion artifacts, body QSM has been applied to study liver iron and fibrosis, heart chamber blood and placenta oxygenation, myocardial hemorrhage, atherosclerotic plaque, cartilage, bone, prostate, breast calcification, and kidney stone.

Quantification of Liver Iron Overload with MRI: Review and Guidelines from the ESGAR and SAR

Accumulation of excess iron in the body, or systemic iron overload, results from a variety of causes. The concentration of iron in the liver is linearly related to the total body iron stores and, for this reason, quantification of liver iron concentration (LIC) is widely regarded as the best surrogate to assess total body iron. Historically assessed using biopsy, there is a clear need for noninvasive quantitative imaging biomarkers of LIC. MRI is highly sensitive to the presence of tissue iron and has been increasingly adopted as a noninvasive alternative to biopsy for detection, severity grading, and treatment monitoring in patients with known or suspected iron overload. Multiple MRI strategies have been developed in the past 2 decades, based on both gradient-echo and spin-echo imaging, including signal intensity ratio and relaxometry strategies. However, there is a general lack of consensus regarding the appropriate use of these methods. The overall goal of this article is to summarize the current state of the art in the clinical use of MRI to quantify liver iron content and to assess the overall level of evidence of these various methods. Based on this summary, expert consensus panel recommendations on best practices for MRI-based quantification of liver iron are provided.

Dysmetabolic Iron Overload Syndrome: Going beyond the Traditional Risk Factors Associated with Metabolic Syndrome

Dysmetabolic iron overload syndrome (DIOS) corresponds to the increase in iron stores associated with components of metabolic syndrome (MtS) and in the absence of an identifiable cause of iron excess. The objective of this work was to review the main aspects of DIOS. PUBMED and EMBASE were consulted, and PRISMA guidelines were followed. DIOS is usually asymptomatic and can be diagnosed by investigating MtS and steatosis. About 50% of the patients present altered hepatic biochemical tests (increased levels of γ-glutamyl transpeptidase itself or associated with increased levels of alanine aminotransferase). The liver may present parenchymal and mesenchymal iron overload, but the excess of iron is commonly mild. Steatosis or steatohepatitis is observed in half of the patients. Fibrosis is observed in about 15% of patients. Hyperferritinemia may damage the myocardium, liver, and several other tissues, increasing morbidity and mortality. Furthermore, DIOS is closely related to oxidative stress, which is closely associated with several pathological conditions such as inflammatory diseases, hypertension, diabetes, heart failure, and cancer. DIOS is becoming a relevant finding in the general population and can be associated with high morbidity/mortality. For these reasons, investigation of this condition could be an additional requirement for the early prevention of cardiovascular diseases.

The Emerging Role of Ferroptosis in Liver Cancers

Liver cancer represents a global health challenge with worldwide growth. Hepatocellular carcinoma (HCC) is the most common type of liver cancer. Indeed, approximately 90% of HCC cases have a low survival rate. Moreover, cholangiocarcinoma (CC) is another malignant solid tumor originating from cholangiocytes, the epithelial cells of the biliary system. It is the second-most common primary liver tumor, with an increasing course in morbidity and mortality. Tumor cells always show high metabolic levels, antioxidant modifications, and an increased iron uptake to maintain unlimited growth. In recent years, alterations in iron metabolism have been shown to play an important role in the pathogenesis of HCC. Several findings show that a diet rich in iron can enhance HCC risk. Hence, elevated iron concentration inside the cell may promote the development of HCC. Growing evidence sustains that activating ferroptosis may potentially block the proliferation of HCC cells. Even in CC, it has been shown that ferroptosis plays a crucial role in the treatment of tumors. Several data confirmed the inhibitory effect in cell growth of photodynamic therapy (PDT) that can induce reactive oxygen species (ROS) in CC, leading to an increase in malondialdehyde (MDA) and a decrease in intracellular glutathione (GSH). MDA and GSH depletion/modulation are crucial in inducing ferroptosis, suggesting that PDT may have the potential to induce this kind of cell death through these ways. A selective induction of programmed cell death in cancer cells is one of the main treatments for malignant tumors; thus, ferroptosis may represent a novel therapeutic strategy against HCC and CC.

Protocols of Investigation of Neonatal Cholestasis-A Critical Appraisal

Neonatal cholestasis (NC) starts during the first three months of life and comprises extrahepatic and intrahepatic groups of diseases, some of which have high morbimortality rates if not timely identified and treated. Prolonged jaundice, clay-colored or acholic stools, and choluria in an infant indicate the urgent need to investigate the presence of NC, and thenceforth the differential diagnosis of extra- and intrahepatic causes of NC. The differential diagnosis of NC is a laborious process demanding the accurate exclusion of a wide range of diseases, through the skillful use and interpretation of several diagnostic tests. A wise integration of clinical-laboratory, histopathological, molecular, and genetic evaluations is imperative, employing extensive knowledge about each evaluated disease as well as the pitfalls of each diagnostic test. Here, we review the difficulties involved in correctly diagnosing the cause of cholestasis in an affected infant.

A critical evaluation of the role of iron overload in fatty liver disease

Nonalcoholic fatty liver disease (NAFLD) has been associated with a condition known as the dysmetabolic iron overload syndrome, but the frequency and severity of iron overload in NAFLD is not well described. There is emerging evidence that mild to moderate excess hepatic iron can aggravate the risk of progression of NAFLD to nonalcoholic steatohepatitis and eventually cirrhosis. Mechanisms are postulated to be via reactive oxygen species, inflammatory cytokines, lipid oxidation, and oxidative stress. The aim of this review is to assess the evidence for true hepatic iron overload in NAFLD, to discuss the pathogenesis by which excess iron may be toxic, and to critically evaluate the studies designed to deplete iron by regular venesection. In brief, the studies are inconclusive due to heterogeneity in eligibility criteria, sample size, randomization, hepatic iron measurement, serial histological endpoints, target ferritin levels, length of venesection, and degree of confounding lifestyle intervention. We propose a trial designed to overcome the limitations of these studies.

Trace Element Interactions, Inflammatory Signaling, and Male Sex Implicated in Reduced Growth Following Excess Oral Iron Supplementation in Pre-Weanling Rats

Iron supplements are frequently provided to infants in high-income countries despite low incidence of iron deficiency. There is growing concern regarding adverse health and development outcomes of excess iron provision in early life. Excess iron may directly damage developing organs through the formation of reactive oxygen species, alter systemic inflammatory signaling, and/or dysregulate trace mineral metabolism. To better characterize the in vivo effects of excess iron on development, we utilized a pre-weanling rat pup model. Lewis rat litters were culled to eight pups (four males and four females) and randomly assigned to daily supplementation groups receiving either vehicle control (CON; 10% w/v sucrose solution) or ferrous sulfate (FS) iron at one of the following doses: 10, 30, or 90 mg iron/kg body weight—FS-10, FS-30, and FS-90, respectively—from postnatal day (PD) 2 through 9. FS-90 litters, but not FS-30 or FS-10, failed to thrive compared to CON litters and had smaller brains on PD 10. Among the groups, FS-90 liver iron levels were highest, as were white blood cell counts. Compared to CON, circulating MCP-1 and liver zinc were increased in FS-90 pups, whereas liver copper was decreased. Growth defects due to excess FS provision in pre-weanling rats may be related to liver injury, inflammation, and altered trace mineral metabolism.

Case Report: Lack of Response to Givosiran in a Case of ALAD Porphyria

Introduction: 5-Aminolevulinic acid dehydratase (ALAD) porphyria (ADP) is an autosomal recessive disease characterized by a profound deficiency in ALAD, the second enzyme in the heme biosynthetic pathway, and acute neurovisceral attacks with abdominal pain and peripheral neuropathy. Hemin infusions are often effective in treating and preventing such attacks. Givosiran was recently approved for prevention of attacks of acute hepatic porphyrias (AHPs), including ADP, but, to our knowledge, has not yet been applied in patients with this ultrarare disease.

Case Description: We update the clinical course and report new treatment outcomes of a 32-year-old man with ADP managed for many years with weekly prophylactic hemin infusions. He has developed evidence of iron overload and was more recently found to have compensated cirrhosis. The patient was started on givosiran (Givlaari™, Alnylam), a small interfering RNA (siRNA) therapeutic that is effective in preventing frequently recurring attacks of acute intermittent porphyria (AIP), the most common type of AHP.

Discussion: No adverse effects of givosiran on the liver were observed in this patient with cirrhosis during 6 months of treatment with givosiran. The patient has continued to have recurrent attacks, with transient decreases in ALA levels only as related to treatment of his attacks with hemin. Our experience limited to one patient with ADP suggests that givosiran may not be effective in this type of acute porphyria. Since ADP may have an erythropoietic component, treatment with hydroxyurea, which was beneficial in one previous case, is planned.

Genetic effects of iron levels on liver injury and risk of liver diseases: A two-sample Mendelian randomization analysis

Background and aims

Although iron homeostasis has been associated with liver function in many observational studies, the causality in this relationship remains unclear. By using Mendelian Randomization analyses, we aimed to evaluate the genetic effects of increased systemic iron levels on the risk of liver injury and various liver diseases. Moreover, in light of the sex-dependent iron regulation in human beings, we further estimated the sex-specific effect of iron levels in liver diseases.

Methods

Independent single nucleotide polymorphisms associated with systemic iron status (including four indicators) at the genome-wide significance level from the Genetics of Iron Status (GIS) Consortium were selected as instrumental variables. Summary data for six liver function biomarkers and five liver diseases were obtained from the UK Biobank, the Estonian Biobank, the eMERGE network, and FinnGen consortium. Mendelian Randomization assessment of the effect of iron on liver function and liver diseases was conducted.

Results

Genetically predicted iron levels were positively and significantly associated with an increased risk of different dimensions of liver injury. Furthermore, increased iron status posed hazardous effects on non-alcoholic fatty liver disease, alcoholic liver disease, and liver fibrosis/cirrhosis. Sex-stratified analyses indicated that the hepatoxic role of iron might exist in NAFLD and liver fibrosis/cirrhosis development among men. No significantly causal relationship was found between iron status and viral hepatitis.

Conclusion

Our study adds to current knowledge on the genetic role of iron in the risk of liver injury and related liver diseases, which provides clinical and public health implications for liver disease prevention as iron status can be modified.

Pre- and post-therapeutic evaluation of liver and spleen in type I and type III Gaucher's disease using diffusion tensor imaging

PURPOSE

To assess the role of diffusion tensor imaging in assessing liver and splenic parenchymal infiltration in Gaucher's disease (G.D.) type I and III before and after therapy.

METHODS

A prospective study was conducted upon 28 consecutive patients with G.D. type I and III and 28 age and sex-matched controls. They underwent an MRI and DTI of the liver and spleen. Mean diffusivity (M.D.) and fractional anisotropy (F.A.) values of the liver and spleen were evaluated before and after treatment and compared with control.

RESULTS

There was a statistically significant difference in the M.D. value of the liver and spleen between untreated patients and controls and between control and treated patients and in the M.D. value of the liver and spleen between untreated and treated patients. There is a statistically significant difference in the F.A. value of the liver and spleen between untreated patients and controls and in the F.A. value of the liver and spleen between untreated and treated patients. Hemoglobin level was positively correlated with the M.D. value of the spleen. Clinical score was negatively correlated with M.D. value of the spleen and was positively correlated with F.A. values of the liver and F.A. values of the spleen. Spleen volume was negatively correlated with M.D. values of the spleen.

CONCLUSION

Significant difference in M.D. and F.A. values of liver and splenic parenchyma in p atients with type I and III G.D. and controls, and between untreated and treated patients. The M.D. and F.A. values were well correlated with some biomarkers of disease activity.

Automated Whole-Liver MRI Segmentation to Assess Steatosis and Iron Quantification in Chronic Liver Disease

Background Standardized manual region of interest (ROI) sampling strategies for hepatic MRI steatosis and iron quantification are time consuming, with variable results. Purpose To evaluate the performance of automatic MRI whole-liver segmentation (WLS) for proton density fat fraction (PDFF) and iron estimation (transverse relaxometry [R2*]) versus manual ROI, with liver biopsy as the reference standard. Materials and Methods This prospective, cross-sectional, multicenter study recruited participants with chronic liver disease who underwent liver biopsy and chemical shift-encoded 3.0-T MRI between January 2017 and January 2021. Biopsy evaluation included histologic grading and digital pathology. MRI liver sampling strategies included manual ROI (two observers) and automatic whole-liver (deep learning algorithm) segmentation for PDFF- and R2*-derived measurements. Agreements between segmentation methods were measured using intraclass correlation coefficients (ICCs), and biases were evaluated using Bland-Altman analyses. Linear regression analyses were performed to determine the correlation between measurements and digital pathology. Results A total of 165 participants were included (mean age ± standard deviation, 55 years ± 12; 96 women; 101 of 165 participants [61%] with nonalcoholic fatty liver disease). Agreements between mean measurements were excellent, with ICCs of 0.98 for both PDFF and R2*. The median bias was 0.5% (interquartile range, -0.4% to 1.2%) for PDFF and 2.7 sec^-1 (interquartile range, 0.2-5.3 sec^-1) for R2* (P < .001 for both). Margins of error were lower for WLS than ROI-derived parameters (-0.03% for PDFF and -0.3 sec^-1 for R2*). ROI and WLS showed similar performance for steatosis (ROI AUC, 0.96; WLS AUC, 0.97; P = .53) and iron overload (ROI AUC, 0.85; WLS AUC, 0.83; P = .09). Correlations with digital pathology were high (P < .001) between the fat ratio and PDFF (ROI r = 0.89; WLS r = 0.90) and moderate (P < .001) between the iron ratio and R2* (ROI r = 0.65; WLS r = 0.64). Conclusion Proton density fat fraction and transverse relaxometry measurements derived from MRI automatic whole-liver segmentation (WLS) were accurate for steatosis and iron grading in chronic liver disease and correlated with digital pathology. Automated WLS estimations were higher, with a lower margin of error than manual region of interest estimations. © RSNA, 2021 Online supplemental material is available for this article. See also the editorial by Moura Cunha and Fowler in this issue.

Antioxidant Effects of Anthocyanin-Rich Riceberry™ Rice Flour Prepared Using Dielectric Barrier Discharge Plasma Technology on Iron-Induced Oxidative Stress in Mice

Redox-active iron generates reactive oxygen species that can cause oxidative organ dysfunction. Thus, the anti-oxidative systems in the body and certain dietary antioxidants, such as anthocyanins, are needed to control oxidative stress. We aimed to investigate the effects of dielectric barrier discharge (DBD) plasma technology in the preparation of Riceberry™ rice flour (PRBF) on iron-induced oxidative stress in mice. PRBF using plasma technology was rich in anthocyanins, mainly cyanidine-3-glucoside and peonidine-3-glucoside. PRBF (5 mg AE/mg) lowered WBC numbers in iron dextran (FeDex)-loaded mice and served as evidence of the reversal of erythrocyte superoxide dismutase activity, plasma total antioxidant capacity, and plasma and liver thiobarbituric acid-reactive substances in the loading mice. Consequently, the PRBF treatment was observed to be more effective than NAC treatment. PRBF would be a powerful supplementary and therapeutic antioxidant product that is understood to be more potent than NAC in ameliorating the effects of iron-induced oxidative stress.

Intestinal iron absorption is appropriately modulated to match physiological demand for iron in wild-type and iron-loaded Hamp (hepcidin) knockout rats during acute colitis

Mucosal damage, barrier breach, inflammation, and iron-deficiency anemia (IDA) typify ulcerative colitis (UC) in humans. The anemia in UC appears to mainly relate to systemic inflammation. The pathogenesis of this ‘anemia of inflammation’ (AI) involves cytokine-mediated transactivation of hepatic Hamp (encoding the iron-regulatory hormone, hepcidin). In AI, high hepcidin represses iron absorption (and iron release from stores), thus lowering serum iron, and restricting iron for erythropoiesis (causing anemia). In less-severe disease states, inflammation may be limited to the intestine, but whether this perturbs iron homeostasis is uncertain. We hypothesized that localized gut inflammation will increase overall iron demand (to support the immune response and tissue repair), and that hepatic Hamp expression will decrease in response, thus derepressing (i.e., enhancing) iron absorption. Accordingly, we developed a rat model of mild, acute colitis, and studied iron absorption and homeostasis. Rats exposed (orally) to DSS (4%) for 7 days had intestinal (but not systemic) inflammation, and biomarker analyses demonstrated that iron utilization was elevated. Iron absorption was enhanced (by 2-3-fold) in DSS-treated, WT rats of both sexes, but unexpectedly, hepatic Hamp expression was not suppressed. Therefore, to gain a better understanding of regulation of iron absorption during acute colitis, Hamp KO rats were used for further experimentation. The severity of DSS-colitis was similar in Hamp KOs as in WT controls. In the KOs, increased iron requirements associated with the physiological response to colitis were satisfied by mobilizing hepatic storage iron, rather than by increasing absorption of enteral iron (as occurred in WT rats). In conclusion then, in both sexes and genotypes of rats, iron absorption was appropriately modulated to match physiological demand for dietary iron during acute intestinal inflammation, but regulatory mechanisms may not involve hepcidin.

Iron biodistribution profile changes in the rat spleen after administration of high-fat diet or iron supplementation and the role of curcumin

Curcumin as active metal chelating and antioxidant agent has a potential role in metal reduction and free radicals' neutralization in tissues. Of note, long-term administration of high fat diet (HFD) is considered as a main factor of blood serum iron deficiency. This study aimed to investigate the biodistribution profiles of iron in the spleen after long-term administration of HFD along with iron supplementation. Furthermore, the ameliorative role of curcumin to reduce iron accumulation level and improve the histological abnormalities produced by iron in spleen will be evaluated in the rats. Treated albino rats of this experiment were divided into six groups. Group I was a control group where group II was treated with HFD. Group III and group IV were treated with combination of HFD and curcumin or HFD and iron supplement respectively. Additionally, group V and group VI were treated with combination of HFD, iron supplement and curcumin or curcumin only respectively. Mainly histological analysis was used to investigate iron biodistribution and induced abnormalities in spleen under light microscope. The histochemical specific staining of iron in the spleen showed different biodistribution profiles of iron in the spleen. Administration of the HFD or HFD and iron supplementation increased the iron accumulation in the spleen. Where, curcumin administration with HFD (Group III) or with HFD and iron supplementation (Group V) significantly reduced the iron levels in the spleen. The splenic tissue inflammation, cellular apoptosis and fibrosis produced by higher iron accumulation was ameliorated after administration of curcumin supplementation as shown in the animals treated with HFD/curcumin (Group III) or HFD/iron supplement/curcumin (Group V). This study recommended that, it is preferable to use iron supplementation along with curcumin supplement for less than 4 months to avoid additional iron accumulation in the healthy organs.

Precise whole liver automatic segmentation and quantification of PDFF and R2* on MR images

OBJECTIVE

To automate the segmentation of whole liver parenchyma on multi-echo chemical shift encoded (MECSE) MR examinations using convolutional neural networks (CNNs) to seamlessly quantify precise organ-related imaging biomarkers such as the fat fraction and iron load.

METHODS

A retrospective multicenter collection of 183 MECSE liver MR examinations was conducted. An encoder-decoder CNN was trained (107 studies) following a 5-fold cross-validation strategy to improve the model performance and ensure lack of overfitting. Proton density fat fraction (PDFF) and R2* were quantified on both manual and CNN segmentation masks. Different metrics were used to evaluate the CNN performance over both unseen internal (46 studies) and external (29 studies) validation datasets to analyze reproducibility.

RESULTS

The internal test showed excellent results for the automatic segmentation with a dice coefficient (DC) of 0.93 ± 0.03 and high correlation between the quantification done with the predicted mask and the manual segmentation (rPDFF = 1 and rR2* = 1; p values < 0.001). The external validation was also excellent with a different vendor but the same magnetic field strength, proving the generalization of the model to other manufacturers with DC of 0.94 ± 0.02. Results were lower for the 1.5-T MR same vendor scanner with DC of 0.87 ± 0.06. Both external validations showed high correlation in the quantification (rPDFF = 1 and rR2* = 1; p values < 0.001). In both internal and external validation datasets, the relative error for the PDFF and R2* quantification was below 4% and 1% respectively.

CONCLUSION

Liver parenchyma can be accurately segmented with CNN in a vendor-neutral virtual approach, allowing to obtain reproducible automatic whole organ virtual biopsies.

KEY POINTS

• Whole liver parenchyma can be automatically segmented using convolutional neural networks. • Deep learning allows the creation of automatic pipelines for the precise quantification of liver-related imaging biomarkers such as PDFF and R2*. • MR "virtual biopsy" can become a fast and automatic procedure for the assessment of chronic diffuse liver diseases in clinical practice.

Quantitative magnetic resonance imaging for chronic liver disease

Chronic liver disease (CLD) has rapidly increased in prevalence over the past two decades, resulting in significant morbidity and mortality worldwide. Historically, the clinical gold standard for diagnosis, assessment of severity, and longitudinal monitoring of CLD has been liver biopsy with histological analysis, but this approach has limitations that may make it suboptimal for clinical and research settings. Magnetic resonance (MR)-based biomarkers can overcome the limitations by allowing accurate, precise, and quantitative assessment of key components of CLD without the risk of invasive procedures. This review briefly describes the limitations associated with liver biopsy and the need for non-invasive biomarkers. It then discusses the current state-of-the-art for MRI-based biomarkers of liver iron, fat, and fibrosis, and inflammation.

Digital pathology: accurate technique for quantitative assessment of histological features in metabolic-associated fatty liver disease

BACKGROUND

Histological evaluation of metabolic-associated fatty liver disease (MAFLD) biopsies is subjective, descriptive and with interobserver variability.

AIMS

To examine the relationship between different histological features (fibrosis, steatosis, inflammation and iron) measured with automated whole-slide quantitative digital pathology and corresponding semiquantitative scoring systems, and the distribution of digital pathology measurements across Fatty Liver Inhibition of Progression (FLIP) algorithm and Steatosis, Activity and Fibrosis (SAF) scoring system METHODS: We prospectively included 136 consecutive patients who underwent liver biopsy for MAFLD at three Spanish centres (January 2017-January 2020). Biopsies were scored by two blinded pathologists according to the Non-alcoholic Steatohepatitis (NASH) Clinical Research Network system for fibrosis staging, the FLIP/SAF classification for steatosis and inflammation grading and Deugnier score for iron grading. Proportionate areas of collagen, fat, inflammatory cells and iron deposits were measured with computer-assisted digital image analysis. A test-retest experiment was performed for precision repeatability evaluation.

RESULTS

Digital pathology showed strong correlation with fibrosis (r = 0.79; P < 0.001), steatosis (r = 0.85; P < 0.001) and iron (r = 0.70; P < 0.001). Performance was lower when assessing the degree of inflammation (r = 0.35; P < 0.001). NASH cases had a higher proportion of collagen and fat compared to non-NASH cases (P < 0.005), whereas inflammation and iron quantification did not show significant differences between categories. Repeatability evaluation showed that all the coefficients of variation were ≤1.1% and all intraclass correlation coefficient values were ≥0.99, except those of collagen.

CONCLUSION

Digital pathology allows an automated, precise, objective and quantitative assessment of MAFLD histological features. Digital analysis measurements show good concordance with pathologists´ scores.

Spontaneous Disease and Pathology of Naked Mole-Rats

Naked mole-rats are highly valuable research models and popular exhibition animals at zoos worldwide. Here, we provide comprehensive descriptions of common postmortem findings of naked mole-rats from both research colonies and populations managed in zoological institutions. Included are brief reviews of their natural history and related physiologic adaptations, unique anatomical features, gross and histologic lesions of common as well as rarely reported disease processes, and discussions of possible pathogeneses with recommendations for future investigations to fill knowledge gaps. Based on postmortem data of several hundreds of naked mole-rats in managed care, it is clear that cancer is extremely rare and infectious disease is infrequently reported. However, despite relatively benign aging phenotypes in this species, several degenerative processes have been nevertheless observed in older populations of naked mole-rats. As such, some potential diet and husbandry-related issues are discussed in addition to the one of the most prominent causes of morbidity and mortality, conspecific aggression and traumas. From this review of lesions and disease, it is clear that pathology, including histopathology, is integral to better understanding mechanisms of healthy aging and cancer resistance of these extraordinary rodents.

Protective effects of Bidens pilosa on hepatoxicity and nephrotoxicity induced by carbon tetrachloride in rats

The aim of this study was to assess the protective effects of oral and topical treatment with Bidens pilosa (BP) against carbon tetrachloride (CCl4)- induced toxicity. Fifty-six rats were divided into seven groups: A: CCl4 only; B: CCl4+oral BP; C: CCl4 and topical BP; D: CCl4+oral and topical BP; E: oral BP only; F: negative control; and G: positive control (cyclophosphamide). The animals were treated for 10 weeks. Blood samples were collected for tests of hepatic and renal function, and fragments of the liver, spleen, pancreas, kidney, and intestine were collected for histopathological analyses. Cells from the femoral bone marrow were used for a micronucleus test and 'comet assay'. Statistically significant differences were observed in the levels of gamma-glutamyl transpeptidase (GGT), albumin, urea and creatinine, hepatic inflammation, renal tubular lesion, and inflammation of the intestinal mucosa between the BP-treated groups and untreated group. The median number of micronuclei in group A was 4.00, in group G was 9.00 and in the other groups was 0.00. Group A had the lowest number of cells with a score of 0 and the greatest number with scores of 3 and 4, similar to the results obtained from group G using the 'comet assay'. Thus, BP effectively protected against the toxic effects of CCl4 on the liver, kidney, and intestine and exerted an antimutagenic effect on rats exposed to CCl4.

MR imaging assessment and quantification of liver iron

Iron overload is a common clinical problem resulting from hereditary hemochromatosis or secondary hemosiderosis (mainly associated with transfusion therapy), being also associated with chronic liver diseases and metabolic disorders. Excess of iron accumulates in organs like the liver, pancreas and heart. Without treatment, patients with iron overload disorders will develop liver cirrhosis, diabetes and cardiomyopathy. Iron quantification is therefore crucial not only for diagnosis of iron overload but also to monitor iron-reducing therapies. Liver iron concentration is considered the surrogate marker of total body iron stores. Because liver biopsy is invasive and prone to high variability and sampling bias, MR imaging has emerged as a non-invasive method and gained wide acceptance, now being considered the standard of care for assessing iron overload. Nevertheless, there are different MR techniques for iron quantification and there is still no consensus about the best technique or postprocessing tool for hepatic iron quantification, with the choice of imaging technique depending mainly on the local expertise as well on the available equipment and software. Because different methods should not be used interchangeably, it is important to choose one method and use the same one when following up patients over time.

Iron Regulation in Elderly Asian Elephants (Elephas maximus) Chronically Infected With Mycobacterium tuberculosis

Restriction of nutrients to pathogens (nutritional immunity) is a critical innate immune response mechanism that operates when pathogens such as Mycobacterium tuberculosis have the potential to evade humoral immunity. Tuberculosis is of growing concern for zoological collections worldwide and is well-illustrated by infections of Asian and African elephants, where tuberculosis is difficult to diagnose. Here, we investigated hematological parameters and iron deposition in liver, lung, and spleen of three Asian elephants (Elephas maximus) infected with Mycobacterium tuberculosis. For reference purposes, we analyzed tissue samples from control M. tuberculosis-negative elephants with and without evidence of inflammation and/or chronic disease. Molecular analyses of bacterial lesions of post mortally collected tissues confirmed M. tuberculosis infection in three elephants. DNA sequencing of the bacterial cultures demonstrated a single source of infection, most likely of human origin. In these elephants, we observed moderate microcytic anemia as well as liver (mild), lung (moderate) and spleen (severe) iron accumulation, the latter mainly occurring in macrophages. Macrophage iron sequestration in response to infection and inflammation is caused by inhibition of iron export via hepcidin-dependent and independent mechanisms. The hepatic mRNA levels of the iron-regulating hormone hepcidin were increased in only one control elephant suffering from chronic inflammation without mycobacterial infection. By contrast, all three tuberculosis-infected elephants showed low hepcidin mRNA levels in the liver and low serum hepcidin concentrations. In addition, hepatic ferroportin mRNA expression was high. This suggests that the hepcidin/ferroportin regulatory system aims to counteract iron restriction in splenic macrophages in M. tuberculosis infected elephants to provide iron for erythropoiesis and to limit iron availability for a pathogen that predominantly proliferates in macrophages. Tuberculosis infections appear to have lingered for more than 30 years in the three infected elephants, and decreased iron availability for mycobacterial proliferation may have forced the bacteria into a persistent, non-proliferative state. As a result, therapeutic iron substitution may not have been beneficial in these elephants, as this therapy may have enhanced progression of the infection.

Effects of Deoxynivalenol and Zearalenone on the Histology and Ultrastructure of Pig Liver

The purpose of this study was to determine the effects of single and combined administrations of deoxynivalenol (DON) and zearalenone (ZEN) on the histology and ultrastructure of pig liver. The study was performed on immature gilts, which were divided into four equal groups. Animals in the experimental groups received DON at a dose of 12 μg/kg body weight (BW) per day, ZEN at 40 μg/kg BW per day, or a mixture of DON (12 μg/kg BW per day) and ZEN (40 μg/kg BW). The control group received vehicle. The animals were killed after 1, 3, and 6 weeks of experiment. Treatment with mycotoxins resulted in several changes in liver histology and ultrastructure, including: (1) an increase in the thickness of the perilobular connective tissue and its penetration to the lobules in gilts receiving DON and DON + ZEN; (2) an increase in the total microscopic liver score (histology activity index (HAI)) in pigs receiving DON and DON + ZEN; (3) dilatation of hepatic sinusoids in pigs receiving ZEN, DON and DON + ZEN; (4) temporary changes in glycogen content in all experimental groups; (5) an increase in iron accumulation in the hepatocytes of gilts treated with ZEN and DON + ZEN; (6) changes in endoplasmic reticulum organization in the hepatocytes of pigs receiving toxins; (7) changes in morphology of Browicz-Kupffer cells after treatment with ZEN, DON, and DON + ZEN. The results show that low doses of mycotoxins used in the present study, even when applied for a short period, affected liver morphology.

Liver involvement in patients with Gaucher disease types I and III

Background & aims

Gaucher disease (GD) is a multisystemic disease. Liver involvement in GD is not well characterised and ranges from hepatomegaly to cirrhosis and hepatocellular carcinoma. We aim to describe, and assess the effect of treatment, on the hepatic phenotype of a cohort of patients with GD types I and II.

Methods

Retrospective study based on the review of the medical files of the Gaucher Reference Centre of the Hospital de Clínicas de Porto Alegre, Brazil. Data from all GD types I and III patients seen at the centre since 2003 were analysed. Variables were compared as pre- (“baseline”) and post-treatment (“follow-up”).

Results

Forty-two patients (types I: 39, III: 3; female: 22; median age: 35 y; enzyme replacement therapy: 37; substrate reduction therapy: 2; non-treated: 3; median time on treatment-MTT: 124 months) were included. Liver enzyme abnormalities, hepatomegaly, and steatosis at baseline were seen in 19/28 (68%), 28/42 (67%), and 3/38 patients (8%), respectively; at follow-up, 21/38 (55%), 15/38 (39%) and 15/38 (39%). MRI iron quantification showed overload in 7/8 patients (treated: 7; MTT: 55 months), being severe in 2/7 (treated: 2/2; MTT: 44.5 months). Eight patients had liver biopsy (treated: 6; MTT: 58 months), with fibrosis in 3 (treated: 1; time on treatment: 108 months) and steatohepatitis in 2 (treated: 2; time on treatment: 69 and 185 months). One patient developed hepatocellular carcinoma.

Conclusions

GD is a heterogeneous disease that causes different patterns of liver damage even during treatment. Although treatment improves the hepatocellular damage, it is associated with an increased rate of steatosis. This study highlights the importance of a follow-up of liver integrity in these patients.

3D Multi-Echo Dixon technique for simultaneous assessment of liver steatosis and iron overload in patients with chronic liver diseases: a feasibility study

BACKGROUND

Patients with chronic liver diseases (CLDs) often suffer from lipidosis or siderosis. Proton density fat fraction (PDFF) and R2* can be used as quantitative parameters to assess the fat/iron content of the liver. The aim of this study was to evaluate the influence of liver fibrosis and inflammation on the 3D Multi-echo Dixon (3D ME Dixon) parameters (MRI-PDFF and R2*) in patients with CLDs and to determine the feasibility of 3D ME Dixon technique for the simultaneous assessment of liver steatosis and iron overload using histopathologic findings as the reference standard.

METHODS

Ninety-nine consecutive patients with CLDs underwent T1-independent, T2*-corrected 3D ME Dixon sequence with reconstruction using multipeak spectral modeling on a 3T MR scanner. Liver specimen was reviewed in all cases, grading liver steatosis, siderosis, fibrosis, and inflammation. Spearman correlation analysis was performed to determine the relationship between 3D ME Dixon parameters (MRI-PDFF and R2*) and histopathological and biochemical features [liver steatosis, iron overload, liver fibrosis, inflammation, alanine aminotransferase (ALT), aspartate aminotransferase (AST), total bilirubin (TBIL)]. Multiple regression analysis was applied to identify variables associated with 3D ME Dixon parameters. Receiver operating characteristic (ROC) analysis was performed to determine the diagnostic performance of these parameters to differentiate liver steatosis or iron overload.

RESULTS

In multivariate analysis, only liver steatosis independently influenced PDFF values (R2=0.803, P<0.001), liver iron overload and fibrosis influenced R2* values (R2=0.647, P<0.001). The Spearman analyses showed that R2* values were moderately correlated with fibrosis stages (r=0.542, P<0.001) in the subgroup with the absence of iron overload. The area under the ROC curve of PDFF was 0.989 for the diagnosis of steatosis grade 1 or greater, and 0.986 for steatosis grade 2 or greater. The area under the ROC curve of R2* was 0.815 for identifying iron overload grade 1 or greater, and 0.876 for iron overload grade 2 or greater.

CONCLUSIONS

3D Multi-Echo Dixon can be used to simultaneously evaluate liver steatosis and iron overload in patients with CLDs, especially for quantification of liver steatosis. However, liver R2* value may be affected by the liver fibrosis in the setting of CLDs with absence of iron overload.

Noninvasive Differential Diagnosis of Liver Iron Contents in Nonalcoholic Steatohepatitis and Simple Steatosis Using Multiecho Dixon Magnetic Resonance Imaging

RATIONALE AND OBJECTIVES

The roles of iron stores in nonalcoholic fatty liver disease have not yet been clearly identified, and it is lack of uniform criteria and a standardized study design for assessing the liver iron content (LIC) in nonalcoholic steatohepatitis (NASH). This study was to compare LICs in biopsy-proven simple steatosis (SS) and NASH based on T₂^⁎-relaxometry.

MATERIAL AND METHODS

A total of 32 subjects divided to three groups, consisting of 10 healthy controls, 12 SS and 10 NASH. All MRI examinations were performed on a 3 T MRI with a 32-channel body coil. To measure T₂^⁎-value, we used a gradient echo sequence with six multiechoes within a single breath-hold. Hepatic iron contents among three groups were compared using Kruskal-Wallis H test and Mann-Whitney's posthoc tests. Diagnostic accuracy was determined by calculating the area under the receiver operating characteristics curve. To identify the reliability of iron measurements in the different region of interests, coefficient of variance (CV) was calculated overall CV values for the variability of measurements. Interobserver agreement and reliability were estimated by calculating the intraclass correlation coefficient.

RESULTS

The variations of all LIC measurements are not exceeded 20%, as a mean CV value 18.3%. intraclass correlation coefficients were higher than 0.9. Mean T₂^⁎-values at localized region of interests were healthy controls 45.42 ± 7.19 ms, SS 20.96 ± 4.28 ms, and NASH 15.49 ± 2.87 ms. The mean T₂^⁎-value in NASH is significantly shorter than that in SS (p = 0.008). The area under the receiver operating characteristics curve to distinguish NASH from SS was 0.908 (95% confidence interval 0.775-1.000, p = 0.001) at a cut-off of iron contents greater than 17.95 ms, and its diagnostic accuracy had 0.833 sensitivity and 0.800 specificity.

CONCLUSION

This study demonstrates that the T₂^⁎ calculation can help to differentially diagnose NASH.

Deregulation of Hepatic Mek1/2⁻Erk1/2 Signaling Module in Iron Overload Conditions

The liver, through the production of iron hormone hepcidin, controls body iron levels. High liver iron levels and deregulated hepcidin expression are commonly observed in many liver diseases including highly prevalent genetic iron overload disorders. In spite of a number of breakthrough investigations into the signals that control hepcidin expression, little progress has been made towards investigations into intracellular signaling in the liver under excess of iron. This study examined hepatic signaling pathways underlying acquired and genetic iron overload conditions. Our data demonstrate that hepatic iron overload associates with a decline in the activation of mitogen-activated protein kinase (MAPK)/extracellular signal-regulated kinase (Erk) kinase (Mek1/2) pathway by selectively affecting the phosphorylation of Erk1/2. We propose that Mek1/2-Erk1/2 signaling is uncoupled from iron-Bmp-Smad-mediated hepcidin induction and that it may contribute to a number of liver pathologies in addition to toxic effects of iron. We believe that our findings will advance the understanding of cellular signaling events in the liver during iron overload of different etiologies.

Medical liver biopsy: background, indications, procedure and histopathology

Histological analysis of liver tissue continues to play an important role in modern hepatological practice. This review explores the indications for medical liver biopsy in addition to the procedure itself, potential complications, preparation of tissue and routine staining. A broad selection of histological images is included to illustrate the appearance of liver tissue both in health and in several important diseases.

Liver R2* is affected by both iron and fat: A dual biopsy-validated study of chronic liver disease

BACKGROUND

Liver iron content (LIC) in chronic liver disease (CLD) is currently determined by performing an invasive liver biopsy. MRI using R2* relaxometry is a noninvasive alternative for estimating LIC. Fat accumulation in the liver, or proton density fat fraction (PDFF), may be a possible confounder of R2* measurements. Previous studies of the effect of PDFF on R2* have not used quantitative LIC measurement.

PURPOSE

To assess the associations between R2*, LIC, PDFF, and liver histology in patients with suspected CLD.

STUDY TYPE

Prospective.

POPULATION

Eighty-one patients with suspected CLD.

FIELD STRENGTH/SEQUENCE

1.5 T. Multiecho turbo field echo to quantify R2*. PRESS MRS to quantify PDFF.

ASSESSMENT

Each patient underwent an MR examination, followed by two needle biopsies immediately following the MR examination. The first biopsy was used for conventional histological assessment of LIC, whereas the second biopsy was used to quantitatively measure LIC using mass spectrometry. R2* was correlated with both LIC and PDFF. A correction for the influence of fat on R2* was calculated.

STATISTICAL TESTS

Pearson correlation, linear regression, and area under the receiver operating curve.

RESULTS

There was a positive linear correlation between R2* and PDFF (R = 0.69), after removing data from patients with elevated iron levels, as defined by LIC. R2*, corrected for PDFF, was the best method for identifying patients with elevated iron levels, with a correlation of R = 0.87 and a sensitivity and specificity of 87.5% and 98.6%, respectively.

DATA CONCLUSION

PDFF increases R2*.

LEVEL OF EVIDENCE

2 Technical Efficacy: Stage 2 J. Magn. Reson. Imaging 2019;50:325-333.

Steatosis and steatohepatitis found in adults after death due to non-burn trauma

OBJECTIVE

With the increasing prevalence of steatosis, the number of steatotic liver grafts from deceased donors is also increasing. Thus, determining the prevalence and the population risk factors of steatosis may assist in risk stratification. The aim of this study was to evaluate the prevalence and predictors of steatosis and steatohepatitis among livers from adults who died due to non-burn trauma.

METHODS

Specimens were collected from 224 adults undergoing autopsy at a regional autopsy referral center from September 2011 to April 2013. Histopathological examination was performed on six samples obtained from different lobes of each liver. The outcomes of interest were the presence of steatosis, steatohepatitis, NASH inflammation and NASH fibrosis. The main predictors were body mass index, abdominal circumference, liver weight and volume, presence of cholelithiasis, and siderosis. Our modeling strategy made use of a series of generalized linear models with a binomial family.

RESULTS

Our sample had a mean age of 40 years; steatosis was diagnosed in 48.2% of cases, and steatohepatitis was diagnosed in 2.7%. The presence of a high proportion of fatty changes was more prevalent among males and older individuals, with the most affected age group being 41-60 years. When evaluating the crude odds ratio for steatosis, the factors significantly associated with an increased risk of steatosis were greater abdominal circumference, BMI, and liver weight and the presence of siderosis.

CONCLUSION

Our study reinforces the role of older age, obesity and hepatomegaly as predictors of fatty liver disease. These variables should be considered in the assessment of fatty changes in the livers of potential liver donors.

Distinct Iron Deposition Profiles of Liver Zones in Various Models with Iron Homeostasis Disorders

Determination of iron accumulation is crucial in diagnosing the occurrence and progression of many liver- and iron-related diseases. Thus far, little is known about the profiles of iron deposition in different liver zones, particularly under conditions with disordered iron homeostasis. Here, uneven iron distribution in livers of patients with hereditary hemochromatosis (HH) is uncovered, showing the region with the highest iron concentration near the entrance site of the portal vein and hepatic artery in contrast to the sites with the lowest iron concentration close to the distal edge. Distinct iron distribution profiles are also found throughout liver zones in wild-type mice and various mouse models with iron metabolism disorders, including hemochromatosis (Hfe-/- ), iron deficiency, and inflammation. Of note, similar findings observed in HH patients are further demonstrated in Hfe-/- mice. Moreover, the zones with greater iron accumulation appear to be more sensitive to iron changes, e.g., there is iron increase upon iron overload and iron loss in response to iron deficiency. Mechanistic investigation manifests that these differential iron changes in liver zones are subjected to the regulation by the hepcidin-ferroportin axis. Additionally, the data corroborate the reliability of magnetic resonance imaging (MRI) in recognizing the differential iron deposition profiles among liver zones.

Gut Microbiota and Iron: The Crucial Actors in Health and Disease

Iron (Fe) is a highly ample metal on planet earth (~35% of the Earth’s mass) and is particularly essential for most life forms, including from bacteria to mammals. Nonetheless, iron deficiency is highly prevalent in developing countries, and oral administration of this metal is so far the most effective treatment for human beings. Notably, the excessive amount of unabsorbed iron leave unappreciated side effects at the highly interactive host–microbe interface of the human gastrointestinal tract. Recent advances in elucidating the molecular basis of interactions between iron and gut microbiota shed new light(s) on the health and pathogenesis of intestinal inflammatory diseases. We here aim to present the dynamic modulation of intestinal microbiota by iron availability, and conversely, the influence on dietary iron absorption in the gut. The central part of this review is intended to summarize our current understanding about the effects of luminal iron on host–microbe interactions in the context of human health and disease.

Liver Iron Quantification with MR Imaging: A Primer for Radiologists

Iron overload is a systemic disorder and is either primary (genetic) or secondary (exogenous iron administration). Primary iron overload is most commonly associated with hereditary hemochromatosis and secondary iron overload with ineffective erythropoiesis (predominantly caused by β-thalassemia major and sickle cell disease) that requires long-term transfusion therapy, leading to transfusional hemosiderosis. Iron overload may lead to liver cirrhosis and hepatocellular carcinoma, in addition to cardiac and endocrine complications. The liver is one of the main iron storage organs and the first to show iron overload. Therefore, detection and quantification of liver iron overload are critical to initiate treatment and prevent complications. Liver biopsy was the historical reference standard for detection and quantification of liver iron content. Magnetic resonance (MR) imaging is now commonly used for liver iron quantification, including assessment of distribution, detection, grading, and monitoring of treatment response in iron overload. Several MR imaging techniques have been developed for iron quantification, each with advantages and limitations. The liver-to-muscle signal intensity ratio technique is simple and widely available; however, it assumes that the reference tissue is normal. Transverse magnetization (also known as R2) relaxometry is validated but is prone to respiratory motion artifacts due to a long acquisition time, is presently available only for 1.5-T imaging, and requires additional cost and delay for off-line analysis. The R2* technique has fast acquisition time, demonstrates a wide range of liver iron content, and is available for 1.5-T and 3.0-T imaging but requires additional postprocessing software. Quantitative susceptibility mapping has the highest sensitivity for detecting iron deposition; however, it is still investigational, and the correlation with liver iron content is not yet established. ^©RSNA, 2018.

Serum Markers of Iron Metabolism in Chronic Liver Diseases

BACKGROUND:

Disorders in the metabolism of iron in the direction of iron overload are observed not only in primary hemochromatosis but also in some chronic liver diseases other aetiology. Elevation of serum iron, ferritin and transferrin saturation is reported in nonalcoholic fatty liver disease and alcohol, chronic hepatitis C and liver cirrhosis.

AIM:

Aim of the study was to evaluate and compare the frequency of the iron serum markers in patients with various chronic liver diseases.

MATERIAL AND METHODS:

The study included a total of 246 persons -186 patients with chronic liver disease without cirrhosis (-115 men, women -71; average age of 50.41 ± 12.85, from 23 to 77 years) and 60 healthy controls (-30 men, women -30, middle-aged 50.50 ± 11.31, from 29 to 83 years). Medical history, physical examination and demographic data including height, weight, laboratory and instrumental studies were performed.

RESULTS:

The highest incidence of elevated serum iron, transferrin saturation and ferritin and decreased serum hepcidin found in cases of alcoholic liver disease (ALD), nonalcoholic fatty liver disease (NAFLD) and chronic hepatitis C (CHC).

CONCLUSION:

Finally, analysis of the changes in serum markers of iron metabolism shows that the difference between healthy and sick with liver disease is primarily due to changes in alcoholic and nonalcoholic fatty liver disease, particularly steatohepatitis, and chronic hepatitis C.

Hepcidin levels correlate to liver iron content, but not steatohepatitis, in non-alcoholic fatty liver disease

Background

One-third of patients with non-alcoholic fatty liver disease (NAFLD) develop dysmetabolic iron overload syndrome (DIOS), the pathogenesis of which is unknown. Altered production of the iron-regulatory peptide hepcidin has been reported in NAFLD, but it is unclear if this is related to iron accumulation, lipid status or steatohepatitis.

Methods

Eighty-four patients with liver disease, 54 of which had iron overload, underwent liver biopsy (n = 66) and/or magnetic resonance imaging (n = 35) for liver iron content determination. Thirty-eight of the patients had NAFLD, 29 had chronic liver disease other than NAFLD, and 17 had untreated genetic hemochromatosis. Serum hepcidin was measured with ELISA in all patients and in 34 controls. Hepcidin antimicrobial peptide (HAMP) mRNA in liver tissue was determined with real-time-quantitative PCR in 36 patients.

Results

Serum hepcidin was increased similarly in NAFLD with DIOS as in the other chronic liver diseases with iron overload, except for genetic hemochromatosis. HAMP mRNA in liver tissue, and serum hepcidin, both correlated to liver iron content in NAFLD patients (r² = 0.45, p < 0.05 and r² = 0.27, p < 0.05 respectively) but not to body mass index, NAFLD activity score or serum lipids. There was a good correlation between HAMP mRNA in liver tissue and serum hepcidin (r² = 0.39, p < 0.01).

Conclusions

In NAFLD with or without dysmetabolic iron overload, serum hepcidin and HAMP mRNA in liver correlate to body iron content but not to the degree of steatohepatitis or lipid status. Thus, the dysmetabolic iron overload syndrome seen in NAFLD is not caused by an altered hepcidin synthesis.