Jaundice associated pruritis: A review of pathophysiology and treatment

Metabonomics and pharmacodynamics studies of Gentiana radix and wine-processed Gentiana radix in damp-heat jaundice syndrome rats

ETHNOPHARMACOLOGICAL RELEVANCE

Gentiana radix (GR) and wine-processed Gentiana radix (WGR) have been commonly used in folk medicine for the treatment of bile or liver disorders, including jaundice, hepatitis, swelling and inflammation for thousands of years. However, the therapeutic effects of gentian root (GR) and wine-made gentian root (WGR) treatment on damp-heat jaundice syndrome (DHJS) have not been studied in animal experiments.

AIM OF THE STUDY

This study aimed to investigate the protective effects and mechanisms of GR and WGR on DHJS in rats.

MATERIALS AND METHODS

In a high-fat and high-sugar diet in a humidified hot environment, hepatic injury induced by giving alpha-naphthalene isothiocyanate (ANIT) in rats were used as a DHJS model. Histological analysis, enzyme-linked immunosorbent assay (ELISA), PCR analysis, and metabolomics were used to elucidate the mechanism of GR and WGR for DHJS.

RESULTS

The results indicated that GR and WGR affected DHJS by inhibiting the release of aspartate aminotransferase (AST), alanine aminotransferase (ALT), alkaline phosphatase (ALP), direct bilirubin (D-BIL), total bilirubin (TBIL), total bile acid (TBA), malondialdehyde (MDA), glutathione S-transferase (GST) (P < 0.05). In addition, they significantly reduced the gene expression levels of Na+/taurocholate cotransporting polypeptide (NTCP), bile salt export pump (BESP), multidrug resistance-associated protein 2 (MRP2) and multidrug resistance-associated protein 3 (MRP3) (P < 0.05). The WGR group improved the above function indicators better than the GR group. GR and WGR could restore 11 potential biomarkers in rats with DHJS tended to return to normal levels, these biomarkers were involved in arachidonic acid metabolism, steroid hormone biosynthesis, biosynthesis of unsaturated fatty acids, porphyrin and chlorophyll metabolism, retinol metabolism, arginine biosynthesis. The results of the metabolic pathway showed that WGR was significantly better than GR in the improvement of porphyrin and chlorophyll metabolism.

CONCLUSIONS

These findings suggest that treatment with GR and WGR has a beneficial effect on DHJS in rats, the major mechanisms may be involved in improving functional indicators of the body and endogenous metabolism, and WGR is more effective than GR. It provides important evidence for the clinical application of GR and WGR in the treatment of DHJS.

Orexin neurons play contrasting roles in itch and pain neural processing via projecting to the periaqueductal gray

Pain and itch are recognized as antagonistically regulated sensations; pain suppresses itch, whilst pain inhibition enhances itch. The neural mechanisms at the central nervous system (CNS) underlying these pain-itch interactions still need to be explored. Here, we revealed the contrasting role of orexin-producing neurons (ORX neurons) in the lateral hypothalamus (LH), which suppresses pain while enhancing itch neural processing, by applying optogenetics to the acute pruritus and pain model. We also revealed that the circuit of ORX neurons from LH to periaqueductal gray regions served in the contrasting modulation of itch and pain processing using optogenetic terminal inhibition techniques. Additionally, by using an atopic dermatitis model, we confirmed the involvement of ORX neurons in regulating chronic itch processing, which could lead to a novel therapeutic target for persistent pruritus in clinical settings. Our findings provide new insight into the mechanism of antagonistic regulation between pain and itch in the CNS.

Synthetic augmentation of bilirubin metabolism in human pluripotent stem cell-derived liver organoids

UGT1A1 (UDP glucuronosyltransferase family 1 member A1) is the primary enzyme required for bilirubin conjugation, which is essential for preventing hyperbilirubinemia. Animal models lack key human organic anion transporting polypeptides with distinct epigenetic control over bilirubin metabolism, necessitating a human model to interrogate the regulatory mechanism behind UGT1A1 function. Here, we use induced pluripotent stem cells to develop human liver organoids that can emulate conjugation failure phenotype. Bilirubin conjugation assays, chromatin immunoprecipitation, and transcriptome analysis elucidated the role of glucocorticoid antagonism in UGT1A1 activation. This antagonism prevents the binding of transcriptional repressor MECP2 at the expense of NRF2 with associated off-target effects. Therefore, we introduced functional GULO (L-gulonolactone oxidase) in human organoids to augment intracellular ascorbate for NRF2 reactivation. This engineered organoid conjugated more bilirubin and protected against hyperbilirubinemia when transplanted in immunosuppressed Crigler-Najjar syndrome rat model. Collectively, we demonstrate that our organoid system serves as a manipulatable model for interrogating hyperbilirubinemia and potential therapeutic development.

Refractory pruritus from malignant cholestasis: management

This case report deals with a patient managed in a tertiary-care cancer hospital who suffered pruritus associated with malignant cholestasis. His symptoms were resistant to conventional treatment with ursodeoxycholic acid, chlorpheniramine and cholestyramine. Hence, the multifactorial origin of malignancy-associated pruritus was considered. Correctable factors were corrected and generally the treatment was aimed at possible aetiologies. There were barriers related to insufficient resources available for symptom palliation in this particular setting, which could potentially reduce optimum symptom control. However, various pharmacotherapies and non-pharmacological measures which could potentially have helped relieve pruritus are described and future scope for research in this area discussed.

Bilirubin gates the TRPM2 channel as a direct agonist to exacerbate ischemic brain damage

Stroke prognosis is negatively associated with an elevation of serum bilirubin, but how bilirubin worsens outcomes remains mysterious. We report that post-, but not pre-, stroke bilirubin levels among inpatients scale with infarct volume. In mouse models, bilirubin increases neuronal excitability and ischemic infarct, whereas ischemic insults induce the release of endogenous bilirubin, all of which are attenuated by knockout of the TRPM2 channel or its antagonist A23. Independent of canonical TRPM2 intracellular agonists, bilirubin and its metabolic derivatives gate the channel opening, whereas A23 antagonizes it by binding to the same cavity. Knocking in a loss of binding point mutation for bilirubin, TRPM2-D1066A, effectively antagonizes ischemic neurotoxicity in mice. These findings suggest a vicious cycle of stroke injury in which initial ischemic insults trigger the release of endogenous bilirubin from injured cells, which potentially acts as a volume neurotransmitter to activate TRPM2 channels, aggravating Ca²⁺-dependent brain injury.

Yellow urticaria revealing overlap syndrome of autoimmune hepatitis and primary biliary cholangitis

Yellow urticaria is a variant of urticaria that is rarely reported in the literature. It usually occurs in the setting of a chronic liver disease and reflects the accumulation of bilirubin in the skin tissues. We report a case of yellow urticaria that occurred in a 33-year-old female patient suffering from systemic lupus erythematosus and overlap syndrome of autoimmune hepatitis and primary biliary cholangitis revealed by a migratory pruritic yellowish urticarial eruption on the trunk and limbs. Yellow urticaria may be an important clue to previously unknown liver or biliary disease as it generally occurs in the setting of hyperbilirubinemia.

An Anterior Cingulate Cortex-to-Midbrain Projection Controls Chronic Itch in Mice

Itch is an unpleasant sensation that provokes the desire to scratch. While acute itch serves as a protective system to warn the body of external irritating agents, chronic itch is a debilitating but poorly-treated clinical disease leading to repetitive scratching and skin lesions. However, the neural mechanisms underlying the pathophysiology of chronic itch remain mysterious. Here, we identified a cell type-dependent role of the anterior cingulate cortex (ACC) in controlling chronic itch-related excessive scratching behaviors in mice. Moreover, we delineated a neural circuit originating from excitatory neurons of the ACC to the ventral tegmental area (VTA) that was critically involved in chronic itch. Furthermore, we demonstrate that the ACC→VTA circuit also selectively modulated histaminergic acute itch. Finally, the ACC neurons were shown to predominantly innervate the non-dopaminergic neurons of the VTA. Taken together, our findings uncover a cortex–midbrain circuit for chronic itch-evoked scratching behaviors and shed novel insights on therapeutic intervention.

Targets and Effective Constituents of ZhiziBaipi Decoction for Treating Damp-Heat Jaundice Syndrome Based on Chinmedomics Coupled with UPLC-MS/MS

Background: Damp-heat jaundice syndrome (DHJS) is a diagnostic model of traditional Chinese medicine (TCM) that refers to jaundice caused by damp-heat pathogen invasion. DHJS is the most common clinical manifestation of TCM, with yellow skin, yellow eyes and anorexia. ZhiziBaipi Decoction (ZBD) is a classic TCM formula that is effective at treating DHJS and various liver diseases. However, the effective components of ZBD in the context of DHJS and the underlying mechanism are unclear.

Purpose: This study of ZBD using the DHJS rat model aimed to elucidate the pathobiology of DHJS and the metabolic targets of therapeutic ZBD, construct the network relationship between the components of ZBD and endogenous biomarkers, and clarify the underlying mechanism of ZBD in preventing and treating DHJS.

Methods: Using chinmedomics as the core strategy, an animal model was generated, and the therapeutic effect of ZBD was evaluated based on behavioral, histopathological and biochemical indicators. Metabonomics tools were used to identify biomarkers of DHJS, TCM-based serum pharmacochemistry was used to analyze the effective constituents of ZBD, and chinmedomics technology was used to identify ZBD components highly related to DHJS biomarkers.

Results: A total of 42 biomarkers were preliminarily identified, and ZBD significantly affected the levels of 29 of these biomarkers. A total of 59 compounds in ZBD were characterized in vivo. According to chinmedomics analysis, the highly correlated components found in blood were isoformononetin, 3-O-feruloylquinic acid, glycyrrhizic acid, oxyberberine, obaculactone and five metabolites.

Conclusions: Chinmedomics combined with UPLC-MS/MS was used to study the targets and effective constituents of ZBD for the treatment of DHJS.

Bile Acid Sequestrants for Hypercholesterolemia Treatment Using Sustainable Biopolymers: Recent Advances and Future Perspectives

Bile acids, the endogenous steroid nucleus containing signaling molecules, are responsible for the regulation of multiple metabolic processes, including lipoprotein and glucose metabolism to maintain homeostasis. Within our body, they are directly produced from their immediate precursors, cholesterol C (low-density lipoprotein C, LDL-C), through the enzymatic catabolic process mediated by 7-α-hydroxylase (CYP7A1). Bile acid sequestrants (BASs) or amphiphilic resins that are nonabsorbable to the human body (being complex high molecular weight polymers/electrolytes) are one of the classes of drugs used to treat hypercholesterolemia (a high plasma cholesterol level) or dyslipidemia (lipid abnormalities in the body); thus, they have been used clinically for more than 50 years with strong safety profiles as demonstrated by the Lipid Research Council-Cardiovascular Primary Prevention Trial (LRC-CPPT). They reduce plasma LDL-C and can slightly increase high-density lipoprotein C (HDL-C) levels, whereas many of the recent clinical studies have demonstrated that they can reduce glucose levels in patients with type 2 diabetes mellitus (T2DM). However, due to higher daily dosage requirements, lower efficacy in LDL-C reduction, and concomitant drug malabsorption, research to develop an "ideal" BAS from sustainable or natural sources with better LDL-C lowering efficacy and glucose regulations and lower side effects is being pursued. This Review discusses some recent developments and their corresponding efficacies as bile removal or LDL-C reduction of natural biopolymer (polysaccharide)-based compounds.

Efficacy and Safety of Dupilumab in Chinese Patients With Atopic Dermatitis: A Real-World Study

Background

Atopic dermatitis (AD) is a common skin disease, but treatment of this disease has been challenging. Dupilumab is a new biological agent for AD that has been proven to be safe and effective in clinical trials. Although dupilumab was approved for listing in China in June 2020, real-world data about the application of dupilumab in China are lacking. This study aimed to collect and analyze real-world data on dupilumab among Chinese AD patients.

Methods

Demographic and clinical data for 116 AD patients receiving dupilumab treatment were reviewed. The Eczema Area and Severity Index (EASI), SCORing Atopic Dermatitis (SCORAD), Numerical Rating Scale (NRS), Patient Oriented Eczema Measure (POEM), and Dermatology Quality of Life Index (DLQI) of patients were evaluated every 2 weeks from baseline to 16 weeks of treatment. Any adverse events during treatment were recorded.

Results

Among the 116 patients in this study, baseline levels of IgE, eosinophils, and LDH were elevated in 62.79% (n = 86), 45.30% (n = 86), and 54.20% of patients (n = 48), respectively. The SCORAD index and POEM, DLQI, and NRS scores were significantly improved in all patients at 2 weeks (p < 0.0001), 4 weeks (p < 0.01), and 16 weeks (p < 0.001). EASI scores also improved significantly in all patients at 2 weeks (p < 0.01), 4 weeks (> 0.05), and 16 weeks (p < 0.01). However, 11 patients (9.48%) had no response. IgE and LDH levels (p > 0.05), Eosinophil counts (p < 0.01) in blood increased temporarily in the first 4 weeks and then decreased and stabilized during dupilumab treatment. Conjunctivitis was the most common adverse event (2.59%) among the patients. We found that the curative efficacy of dupilumab at 4th weeks was related to the patient’s age and course of disease. Nevertheless, there is no relationship between levels of eosinophils, IgE, LDH and the therapeutic efficacy of dupilumab.

Conclusion

The real-world data in China showed that dupilumab can effectively treat AD and is well tolerated with a low incidence of adverse events.

Indian College of Radiology and Imaging Evidence-Based Guidelines for Percutaneous Image-Guided Biliary Procedures

Percutaneous biliary interventions are among the commonly performed nonvascular radiological interventions. Most common of these interventions is the percutaneous transhepatic biliary drainage for malignant biliary obstruction. Other biliary procedures performed include percutaneous cholecystostomy, biliary stenting, drainage for bile leaks, and various procedures like balloon dilatation, stenting, and large-bore catheter drainage for bilioenteric or post-transplant anastomotic strictures. Although these procedures are being performed for ages, no standard guidelines have been formulated. This article attempts at preparing guidelines for performing various percutaneous image-guided biliary procedures along with discussion on the published evidence in this field.

Treatment of Malignant Bile Duct Obstruction: What the Interventional Radiologist Needs to Know

Management of malignant bile duct obstruction is both a clinically important and technically challenging aspect of caring for patients with advanced malignancy. Bile duct obstruction can be caused by extrinsic compression, intrinsic tumor/stone/debris, or by biliary ischemia, inflammation, and sclerosis. Common indications for biliary intervention include lowering the serum bilirubin level for chemotherapy, ameliorating pruritus, treating cholangitis or bile leak, and providing access for bile duct biopsy or other adjuvant therapies. In some institutions, biliary drainage may also be considered prior to hepatic or pancreatic resection. Prior to undertaking biliary intervention, it is essential to have high-quality cross-sectional imaging to determine the level of obstruction, the presence of filling defects or atrophy, and status of the portal vein. High bile duct obstruction, which we consider to be obstruction above, at, or just below the confluence (Bismuth classifications IV, III, II, and some I), is optimally managed percutaneously rather than endoscopically because interventional radiologists can target specific ducts for drainage and can typically avoid introducing enteric contents into isolated undrained bile ducts. Options for biliary drainage include external or internal/external catheters and stents. In the setting of high obstruction, placement of a catheter or stent above the ampulla, preserving the function of the sphincter of Oddi, may lower the risk of future cholangitis by preventing enteric contamination of the biliary tree. Placement of a primary suprapapillary stent without a catheter, when possible, is the procedure most likely to keep the biliary tree sterile.

MRGPRX4 in Cholestatic Pruritus

Pruritus (itch) is a debilitating symptom in liver diseases with cholestasis, which severely affects patients' quality of life. Limited treatment options are available for cholestatic itch, largely due to the incomplete understanding of the underlying molecular mechanisms. Several factors have been proposed as pruritogens for cholestatic itch, such as bile acids, bilirubin, lysophosphatidic acid, and endogenous opioids. Recently, two research groups independently identified Mas-related G protein-coupled receptor X4 (MRGPRX4) as a receptor for bile acids and bilirubin and demonstrated its likely role in cholestatic itch. This discovery not only opens new avenues for understanding the molecular mechanisms in cholestatic itch but provides a promising target for developing novel anti-itch treatments. In this review, we summarize the current theories and knowledge of cholestatic itch, emphasizing MRGPRX4 as a bile acid and bilirubin receptor mediating cholestatic itch in humans. We also discuss some future perspectives in cholestatic itch research.

Jaundice as a Diagnostic and Therapeutic Problem: A General Practitioner's Approach

BACKGROUND

Jaundice is a common clinical finding in clinical practice of hepatologists and general practitioners. It occurs when serum bilirubin levels exceed 3 mg/dL.

SUMMARY

In this review, we summarize the pathophysiological mechanism of jaundice, clinical approach to the patient with jaundice, and laboratory and imaging techniques. Clinical presentation of jaundice manifests through yellow skin and sclera coloration. Evaluation of every patient includes detailed medical history and examination. In the laboratory, evaluation of enzymes of hepatic inflammation as well as cholestatic enzymes with serum bilirubin must be included. Additional laboratory analysis and imaging modalities are needed in order to differentiate jaundice etiology. Moreover, imaging is available and needed in further evaluation, and treatment is dependent on the underlying cause.

KEY MESSAGES

In this review, we will outline the pathophysiological mechanism of jaundice, clinical approach to the patient with jaundice, and diagnostic and treatment approach to these patients.

Naltrexone for cholestatic itch: a systematic review

BACKGROUND

Cholestatic itch is caused by intrahepatic liver diseases, such as primary biliary cirrhosis and extrahepatic obstruction of the biliary tree, often caused by tumours. The pathophysiology of cholestatic itch is complex and no single treatment has proved definitive. Naltrexone is an opioid receptor antagonist, which reduces central opioidergic tone, believed to be raised in patients with cholestatic pruritus.

AIM

To review and assess the efficacy of oral naltrexone for the treatment of cholestatic itch.

METHODS

Search of electronic databases, grey literature, clinical trials registries and handsearching for studies including naltrexone for cholestatic itch. Full papers were obtained if relevant and studies graded.

RESULTS

Thirteen papers were included in the analysis, including three randomised controlled trials, one controlled clinical trial, one open-label pilot study, seven case reports and one retrospective notes review. All studies found naltrexone to be effective in relieving pruritus. In all five studies performing statistical analysis, naltrexone significantly reduced pruritus compared with baseline. 37% of patients reported side effects, notably opioid withdrawal-type reactions and recurrence of previous pain, from all pathologies.

CONCLUSIONS

Oral naltrexone therapy helps relieve cholestatic itch and although it should be used with caution in patients using exogenous opioids for analgesia, it should be considered when treating refractory pruritus in patients with end-stage liver disease.

Evaluation of Associated Markers of Neonatal Pathological Jaundice Due to Bacterial Infection

Background

To evaluate changes of associated markers in neonatal pathological jaundice due to bacterial infection in newborns, to provide an experimental basis for early diagnosis and treatment of neonatal pathological jaundice.

Methods

A total of 126 newborns with neonatal pathological jaundice in the Pediatrics Department of Qilu Hospital (Qingdao), Cheeloo College of Medicine, Shandong University from Jan 2016 to Jun 2018 were enrolled. The patients were divided into bacterial infection group (76 cases with combined bacterial infection) and non-infection group (50 cases without bacterial infection). Peripheral blood was drawn from patients, and levels of inflammatory factors, levels of indexes of liver function and levels of cardiac markers were detected. Correlation between inflammatory factors and neonatal pathological jaundice was assessed.

Results

The levels of WBC, hs-CRP and PCT in the bacterial infection group were significantly higher than those in the non-infected group (P<0.05). The level of TRF in the bacterial infection group was significantly lower than that in the non-infection group (P<0.01). In the bacterial infection group, the levels of WBC, hs-CRP, PCT, and TRF were positively correlated with the levels of CK, CKMB, LDH, and α-HBDB, respectively (all P<0.05). The TRF level after treatment was significantly higher than that before treatment (P<0.01).

Conclusion

Markers such as WBC, hs-CRP, PCT, and TRF can be used as effective indicators in diagnosis of pathological jaundice due to bacterial infection in newborns. The combined testing of WBC, hs-CRP, PCT, and TRF was helpful for early diagnosis and early clinical intervention of neonatal pathological jaundice, which can lower the risk of clinical complications.

Bilirubin as a metabolic hormone: the physiological relevance of low levels

Recent research on bilirubin, a historically well-known waste product of heme catabolism, suggests an entirely new function as a metabolic hormone that drives gene transcription by nuclear receptors. Studies are now revealing that low plasma bilirubin levels, defined as "hypobilirubinemia," are a possible new pathology analogous to the other end of the spectrum of extreme hyperbilirubinemia seen in patients with jaundice and liver dysfunction. Hypobilirubinemia is most commonly seen in patients with metabolic dysfunction, which may lead to cardiovascular complications and possibly stroke. We address the clinical significance of low bilirubin levels. A better understanding of bilirubin's hormonal function may explain why hypobilirubinemia might be deleterious. We present mechanisms by which bilirubin may be protective at mildly elevated levels and research directions that could generate treatment possibilities for patients with hypobilirubinemia, such as targeting of pathways that regulate its production or turnover or the newly designed bilirubin nanoparticles. Our review here calls for a shift in the perspective of an old molecule that could benefit millions of patients with hypobilirubinemia.

Recent advances in understanding the molecular mechanisms of cholestatic pruritus: A review

Cholestasis, a condition characterized by an abnormal decrease in bile flow, is accompanied by various symptoms such as pruritus. Although cholestatic pruritus is a prominent condition, its precise mechanisms have largely been elusive. Recently, advancements have been made for understanding the etiology and pathogenesis of cholestatic pruritus. The current review therefore focuses on summarizing the overall progress made in the elucidation of its molecular mechanisms. We have reviewed the available animal models on cholestasis to compare the differences between them, characterized potential pruritogens involved in cholestatic pruritus, and have summarized the receptor and ion channels implicated in the condition. Finally, we have discussed the available treatment options for alleviation of cholestatic pruritus. As our understanding of the mechanisms of cholestatic pruritus deepens, novel strategies to cure this condition are awaited.

Pruritus secondary to primary biliary cholangitis: a review of the pathophysiology and management with phototherapy

BACKGROUND

Primary biliary cholangitis (PBC) is an autoimmune hepatobiliary disorder characterized by destruction of liver bile ducts leading to intrahepatic cholestasis. It causes intractable pruritus for which ultraviolet (UV)B phototherapy is an experimental treatment when alternative therapies fail. The pathophysiology of cholestatic itch and the mechanism of action of narrowband UVB in this condition remains poorly understood.

OBJECTIVES

To summarize the current literature and propose testable hypotheses for the mechanism of action of phototherapy in attenuating itch.

METHODS

A focused PubMed search for articles relating to the pathogenesis of itch in cholestatic disease was performed. A total of 3855 articles were screened and 50 were found suitable for literature review. Evidence from this literature review was combined with author expertise in the area.

RESULTS

Formulated hypotheses focus on the role of bile salts, autotaxin and specific receptors including G-protein-coupled bile acid receptor, Gpbar1 (also known as TGR5) and the nuclear transcription factor farnesoid X receptor.

CONCLUSIONS

Several testable mechanisms through which phototherapy may exert its effects are discussed in this review. The next steps are to carry out an objective assessment of the efficacy of phototherapy in cholestatic pruritus, gain further knowledge on the underlying pathways, and subsequently trial its use against current licensed therapies. Such studies could lead to increased mechanistic understanding, identification of novel therapeutic targets and the potential to refine phototherapy protocols, leading to improved control of itch and quality of life in patients with PBC. What's already known about this topic? Primary biliary cholangitis (PBC) is frequently associated with intractable pruritus for which current treatment options are often unsuccessful. Phototherapy is used as an experimental treatment for PBC-associated pruritus when alternative better-studied treatments fail. What does this study add? This study reviews the current literature on the pathophysiology and management of cholestatic pruritus, an area which remains poorly understood. We propose testable hypotheses of the mechanisms behind the attenuation of cholestatic pruritus with phototherapy.

Clinical presentation, diagnosis and staging of cholangiocarcinoma

Cholangiocarcinoma (CCA) is a heterogeneous group of tumours, derived from cells of the biliary tree, which represent the second most frequent primary liver tumour. According to the most recent classifications, CCA can be subdivided into intrahepatic (iCCA) and extrahepatic (eCCA) which include perihilar (pCCA) and distal (dCCA) CCA. CCA are usually identified at advanced stages, when the primary tumour grows enough to produce a large liver mass or when jaundice has developed because of biliary tree obstruction. The ongoing challenges in the identification of risk factors and definition of a specific population at higher risk of developing CCA are the main challenges for the development of screening programs. Therefore, late diagnosis remains an unresolved issue in CCA. Imaging plays an important role in the detection and characterization of CCA, helping with radiological diagnosis, guiding biopsy procedures and allowing staging of the tumour. This review focuses on clinical presentations and diagnosis and staging techniques of CCA.

Comparison of Sertraline with Rifampin in the treatment of Cholestatic Pruritus: A Randomized Clinical Trial

BACKGROUND

Pruritus is one of the most common and disabling symptoms of liver disease such as Primary Sclerosing Cholangitis and Primary Biliary Cholangitis. Cholestyramine, rifampin, opioid antagonists, antihistaminic agents and SSRIs are used for the management of pruritus. Due to rifampin drug interactions as well as its serious side effects such as hepatotoxicity, clinicians are endeavoruing to find a safer and a more effective substitution.

OBJECTIVE

The purpose of this study was to compare the efficacy and safety of sertraline with rifampin in the management of cholestatic pruritus.

METHODS

In a single-blinded randomized clinical trial a total of 36 patients of PSC and PBC were divided into two equal groups, one group received 100 mg/day sertraline and the other group received rifampin 300 mg/day for 4 weeks. Visual analog scale was used to record pruritus severity at baseline and 4 weeks after drug intervention, also, ALT, AST, ALP and total bilirubin of all patients were measured at three different time points.

RESULTS

Over the follow-up period, pruritus had relieved in both groups, but there was no significant differences between sertraline and rifampin in pruritus management (pvalue=0.740), also there was no significant difference between the two intervention strategies (A versus B) in total bilirubin level (pvalue=0.106). Moreover, the ALT, AST and ALP levels were found to be significantly different between the two groups (Pvalue˂0.01).

CONCLUSION

There is no difference between sertraline and rifampin in pruritus improvement, but sertraline has less adverse effects on hepatobiliary enzyme levels, so it seems to be safer than rifampin.

Identification of a bilirubin receptor that may mediate a component of cholestatic itch

Various pathologic conditions result in jaundice, a yellowing of the skin due to a buildup of bilirubin. Patients with jaundice commonly report experiencing an intense non-histaminergic itch. Despite this association, the pruritogenic capacity of bilirubin itself has not been described, and no bilirubin receptor has been identified. Here, we demonstrate that pathophysiologic levels of bilirubin excite peripheral itch sensory neurons and elicit pruritus through MRGPRs, a family of G-protein coupled receptors expressed in primary sensory neurons. Bilirubin binds and activates two MRGPRs, mouse MRGPRA1 and human MRGPRX4. In two mouse models of pathologic hyperbilirubinemia, we show that genetic deletion of either Mrgpra1 or Blvra, the gene that encodes the bilirubin-producing enzyme biliverdin reductase, attenuates itch. Similarly, plasma isolated from hyperbilirubinemic patients evoked itch in wild-type animals but not Mrgpra1^-/- animals. Removing bilirubin decreased the pruritogenic capacity of patient plasma. Based on these data, targeting MRGPRs is a promising strategy for alleviating jaundice-associated itch.

Jaundice causes the skin to yellow as a result of a build-up of a pigment called bilirubin. Normally, bilirubin is made in the liver and removed from the body in digestive fluid called bile, but people with liver or gallbladder problems may end up with too much bilirubin that accumulates in their blood and skin. One side effect of jaundice is intense and uncontrollable itching. Researchers are not sure what causes this itching, and there are few treatments that help to relieve it.

At the molecular level, itching sensations occur when compounds bind to particular receptors on the surface of nerve cells. One family of receptors that can trigger itch is called the Mas-related G-protein Coupled Receptor (MRGPR). Could one of these receptors trigger jaundice-related itching?

Now, Meixiong, Vasavda et al. show that bilirubin binds to and activates MRGPRs to cause itch in mice. Whereas injecting bilirubin into normal mice causes them to scratch, mice that have been genetically engineered to lack MRGPRs do not itch when their own bilirubin levels rise, or when they are injected with bilirubin or with plasma from patients who experience jaundice-related itching. Furthermore, removing bilirubin from the plasma of patients before it was injected into normal mice reduced the amount of itching that the mice felt.

Overall, the results reported by Meixiong, Vasavda et al. suggest that drugs that prevent bilirubin from attaching to MRGPRs might help to alleviate jaundice-related itching. However, researchers must first verify that bilirubin interacts with MRGPRs in people to cause itch. If bilirubin causes itch in people like in mice, scientists could then evaluate existing drugs or make new ones to prevent bilirubin from attaching to the MRGPRs.

Is melatonin effective for pruritus caused by liver disease?

There is still no definitive treatment to relieve pruritus associated with liver disease, because the precise mechanism of itching has not yet been determined. Different mechanisms have been proposed. One recent explanation is thought to be the rise in serum levels of lysophosphatidic acid which is a metabolite of lysophosphatidyl choline conversion by autotaxin enzyme in liver disease is. Over expression of autotaxin which occurs in atopic dermatitis has been shown to be involved in itching pathology. Importantly, gene amplification of autotaxin also occurs in cholestasis. Melatonin has pleiotropic properties such as suppressive effects on serum level of autotaxin which relieves itching of atopic dermatitis. Due to some similarities in mechanism of itching, it is hypothesized that melatonin may improve itching of liver diseases.

TRP Channels as Drug Targets to Relieve Itch

Although acute itch has a protective role by removing irritants to avoid further damage, chronic itch is debilitating, significantly impacting quality of life. Over the past two decades, a considerable amount of stimulating research has been carried out to delineate mechanisms of itch at the molecular, cellular, and circuit levels. There is growing evidence that transient receptor potential (TRP) channels play important roles in itch signaling. The purpose of this review is to summarize our current knowledge about the role of TRP channels in the generation of itch under both physiological and pathological conditions, thereby identifying them as potential drug targets for effective anti-itch therapies.

Pathophysiological consequences of obstructive jaundice and perioperative management

BACKGROUND

Obstructive jaundice is a common problem in daily clinical practice. Understanding completely the pathophysiological changes in obstructive jaundice remains a challenge for planning current and future management.

DATA SOURCES

A PubMed was searched for relevant articles published up to August 2016. The effect of obstructive jaundice on proinflammatory cytokines, coagulation status, hemodynamics and organ functions were evaluated.

RESULTS

The effects of obstructive jaundice included biliary tree, the hepatic cell and liver function as well as systemic complications. The lack of bile in the gut, the disruption of the intestinal mucosal barrier, the increased absorption of endotoxin and the subsequent endotoxemia cause proinflammatory cytokine production (TNF-α, IL-6). Bilirubin induces systemic inflammatory response syndrome which may lead to multiple organ dysfunction syndrome. The principal clinical manifestations include hemodynamic instability and acute renal failure, cardiovascular suppression, immune compromise, coagulation disorders, nutritional impairment, and wound healing defect. The proper management includes full replacement of water and electrolyte deficiency, prophylactic antibiotics, lactulose, vitamin K and fresh frozen plasma, albumin and dopamine. The preoperative biliary drainage has not been indicated in overall, but only in a few selected cases.

CONCLUSION

The perioperative management is an essential measure in improving the outcome after the appropriate surgical operation in jaundiced patients especially those with malignancy.