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Digestive Diseases (Basel, Switzerland) 2022Jaundice is a common clinical finding in clinical practice of hepatologists and general practitioners. It occurs when serum bilirubin levels exceed 3 mg/dL. (Review)
Review
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.
Topics: Bilirubin; Cholestasis; General Practitioners; Humans; Jaundice; Liver Function Tests
PubMed: 34015787
DOI: 10.1159/000517301 -
Trends in Molecular Medicine Apr 2023Bilirubin has several physiological functions, both beneficial and harmful. In addition to reactive oxygen species-scavenging activities, bilirubin has potent... (Review)
Review
Bilirubin has several physiological functions, both beneficial and harmful. In addition to reactive oxygen species-scavenging activities, bilirubin has potent immunosuppressive effects associated with long-term pathophysiological sequelae. It has been recently recognized as a hormone with endocrine actions and interconnected effects on various cellular signaling pathways. Current studies show that bilirubin also decreases adiposity and prevents metabolic and cardiovascular diseases. All in all, the physiological importance of bilirubin is only now coming to light, and strategies for increasing plasma bilirubin levels to combat chronic diseases are starting to be considered. This review discusses the beneficial effects of increasing plasma bilirubin, incorporates emerging areas of bilirubin biology, and provides key concepts to advance the field.
Topics: Humans; Bilirubin; Heme Oxygenase-1; Cardiovascular Diseases; Reactive Oxygen Species
PubMed: 36828710
DOI: 10.1016/j.molmed.2023.01.007 -
American Journal of Physiology.... Feb 2021Recent research on bilirubin, a historically well-known waste product of heme catabolism, suggests an entirely new function as a metabolic hormone that drives gene... (Review)
Review
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.
Topics: Animals; Bilirubin; Energy Metabolism; Gene Expression Regulation; Gilbert Disease; Heme; Hormones; Humans; Hyperbilirubinemia; Metabolic Networks and Pathways; PPAR alpha
PubMed: 33284088
DOI: 10.1152/ajpendo.00405.2020 -
The Cochrane Database of Systematic... Mar 2023Phototherapy is a widely accepted, effective first-line therapy for neonatal jaundice. It is traditionally used continuously but intermittent phototherapy has been... (Review)
Review
BACKGROUND
Phototherapy is a widely accepted, effective first-line therapy for neonatal jaundice. It is traditionally used continuously but intermittent phototherapy has been proposed as an equally effective alternative with practical advantages of improved maternal feeding and bonding. The effectiveness of intermittent phototherapy compared with continuous phototherapy is unknown.
OBJECTIVES
To assess the safety and effectiveness of intermittent phototherapy compared with continuous phototherapy.
SEARCH METHODS
Searches were conducted on 31 January 2022 in the following databases: CENTRAL via CRS Web, MEDLINE and Embase via Ovid. We also searched clinical trials databases and the reference lists of retrieved articles for randomised controlled trials (RCTs) and quasi-randomised trials.
SELECTION CRITERIA
We included RCTs, cluster-RCTs and quasi-RCTs comparing intermittent phototherapy with continuous phototherapy in jaundiced infants (both term and preterm) up to the age of 30 days. We compared intermittent phototherapy with continuous phototherapy by any method and at any dose and duration as defined by the authors.
DATA COLLECTION AND ANALYSIS
Three review authors independently selected trials, assessed trial quality and extracted data from included studies. We performed fixed-effect analyses and expressed treatment effects as mean difference (MD), risk ratio (RR) and risk difference (RD) with 95% confidence intervals (CIs). Our primary outcomes of interest were rate of decline of serum bilirubin, and kernicterus. We used the GRADE approach to assess the certainty of evidence.
MAIN RESULTS
We included 12 RCTs (1600 infants) in the review. There is one ongoing study and four awaiting classification. There was little or no difference between intermittent phototherapy and continuous phototherapy with respect to rate of decline of bilirubin in jaundiced newborn infants (MD -0.09 micromol/L/hr, 95% CI -0.21 to 0.03; I² = 61%; 10 studies; 1225 infants; low-certainty evidence). One study involving 60 infants reported no incidence of bilirubin induced brain dysfunction (BIND). It is uncertain whether either intermittent or continuous phototherapy reduces BIND because the certainty of this evidence is very low. There was little or no difference in treatment failure (RD 0.03, 95% CI 0.08 to 0.15; RR 1.63, 95% CI 0.29 to 9.17; 1 study; 75 infants; very low-certainty evidence) or infant mortality (RD -0.01, 95% CI -0.03 to 0.01; RR 0.69, 95% CI 0.37 to 1.31 I² = 0%; 10 studies, 1470 infants; low-certainty evidence). AUTHORS' CONCLUSIONS: The available evidence detected little or no difference between intermittent and continuous phototherapy with respect to rate of decline of bilirubin. Continuous phototherapy appears to be more effective in preterm infants, however, the risks of continuous phototherapy and the potential benefits of a slightly lower bilirubin level are unknown. Intermittent phototherapy is associated with a decrease in the total number of hours of phototherapy exposure. There are theoretical benefits to intermittent regimens but there are important safety outcomes that were inadequately addressed. Large, well designed, prospective trials are needed in both preterm and term infants before it can be concluded that intermittent and continuous phototherapy regimens are equally effective.
Topics: Infant; Infant, Newborn; Humans; Jaundice, Neonatal; Phototherapy; Bilirubin; Family
PubMed: 36867730
DOI: 10.1002/14651858.CD008168.pub2 -
The Cochrane Database of Systematic... May 2023Jaundice is a very common condition in newborns, affecting up to 60% of term newborns and 80% of preterm newborns in the first week of life. Jaundice is caused by... (Meta-Analysis)
Meta-Analysis Review
BACKGROUND
Jaundice is a very common condition in newborns, affecting up to 60% of term newborns and 80% of preterm newborns in the first week of life. Jaundice is caused by increased bilirubin in the blood from the breakdown of red blood cells. The gold standard for measuring bilirubin levels is obtaining a blood sample and processing it in a laboratory. However, noninvasive transcutaneous bilirubin (TcB) measurement devices are widely available and used in many settings to estimate total serum bilirubin (TSB) levels.
OBJECTIVES
To determine the diagnostic accuracy of transcutaneous bilirubin measurement for detecting hyperbilirubinaemia in newborns.
SEARCH METHODS
We searched CENTRAL, MEDLINE, Embase, CINAHL and trial registries up to 18 August 2022. We also checked the reference lists of all included studies and relevant systematic reviews for other potentially eligible studies.
SELECTION CRITERIA
We included cross-sectional and prospective cohort studies that evaluated the accuracy of any TcB device compared to TSB measurement in term or preterm newborn infants (0 to 28 days postnatal age). All included studies provided sufficient data and information to create a 2 × 2 table for the calculation of measures of diagnostic accuracy, including sensitivities and specificities. We excluded studies that only reported correlation coefficients.
DATA COLLECTION AND ANALYSIS
Two review authors independently applied the eligibility criteria to all citations from the search and extracted data from the included studies using a standard data extraction form. We summarised the available results narratively and, where possible, we combined study data in a meta-analysis.
MAIN RESULTS
We included 23 studies, involving 5058 participants. All studies had low risk of bias as measured by the QUADAS 2 tool. The studies were conducted in different countries and settings, included newborns of different gestational and postnatal ages, compared various TcB devices (including the JM 101, JM 102, JM 103, BiliChek, Bilitest and JH20-1C) and used different cutoff values for a positive result. In most studies, the TcB measurement was taken from the forehead, sternum, or both. The sensitivity of various TcB cutoff values to detect significant hyperbilirubinaemia ranged from 74% to 100%, and specificity ranged from 18% to 89%.
AUTHORS' CONCLUSIONS
The high sensitivity of TcB to detect hyperbilirubinaemia suggests that TcB devices are reliable screening tests for ruling out hyperbilirubinaemia in newborn infants. Positive test results would require confirmation through serum bilirubin measurement.
Topics: Humans; Infant; Infant, Newborn; Bilirubin; Cross-Sectional Studies; Hyperbilirubinemia; Jaundice, Neonatal; Neonatal Screening; Prospective Studies
PubMed: 37158489
DOI: 10.1002/14651858.CD012660.pub2 -
Nutrients May 2023Breast milk is tailored for optimal growth in all infants; however, in some infants, it is related to a unique phenomenon referred to as breast milk jaundice (BMJ). BMJ... (Review)
Review
Breast milk is tailored for optimal growth in all infants; however, in some infants, it is related to a unique phenomenon referred to as breast milk jaundice (BMJ). BMJ is a type of prolonged unconjugated hyperbilirubinemia that is often late onset in otherwise healthy-appearing newborns, and its occurrence might be related to breast milk itself. This review aims to systematically evaluate evidence regarding breast milk composition and the development of BMJ in healthy neonates. PubMed, Scopus and Embase were searched up to 13 February 2023 with key search terms, including neonates, hyperbilirubinemia, and breastfeeding. A total of 678 unique studies were identified and 12 were ultimately included in the systematic review with narrative synthesis. These included studies covered both nutritional compositions (e.g., fats and proteins) and bioactive factors (e.g., enzymes and growth factors) of breast milk and formally assessed the difference in the concentration (or presence) of various endogenous components of breast milk collected from mothers of BMJ infants and healthy infants. The results were inconsistent and inconclusive for most of the substances of interest, and there was only a single study available (e.g., total energy and mineral content, bile salts and cytokines); conflicting or even contradictory results arose when there were two or more studies on the subject matter (e.g., fats and free fatty acids contents and epidermal growth factor). The etiology of BMJ is likely multifactorial, and no single constituent of breast milk could explain all the BMJ cases observed. Further well-designed studies are warranted to investigate the complex interaction between maternal physiology, the breast milk system and infant physiology before this field could be progressed to uncover the etiology of BMJ.
Topics: Infant; Female; Humans; Infant, Newborn; Milk, Human; Bilirubin; Jaundice, Neonatal; Breast Feeding; Hyperbilirubinemia; Jaundice
PubMed: 37242142
DOI: 10.3390/nu15102261 -
Circulation Research Mar 2023The rupture of atherosclerotic plaque contributes significantly to cardiovascular disease. Plasma concentrations of bilirubin-a byproduct of heme catabolism-inversely...
BACKGROUND
The rupture of atherosclerotic plaque contributes significantly to cardiovascular disease. Plasma concentrations of bilirubin-a byproduct of heme catabolism-inversely associate with risk of cardiovascular disease, although the link between bilirubin and atherosclerosis remains unclear.
METHODS
To assess the role of bilirubin in atherosclerotic plaque stability, we crossed with mice and used the tandem stenosis model of plaque instability. Human coronary arteries were obtained from heart transplant recipients. Analysis of bile pigments, heme metabolism, and proteomics were performed by liquid chromatography tandem mass spectrometry. MPO (myeloperoxidase) activity was determined by in vivo molecular magnetic resonance imaging, liquid chromatography tandem mass spectrometry analysis, and immunohistochemical determination of chlorotyrosine. Systemic oxidative stress was evaluated by plasma concentrations of lipid hydroperoxides and the redox status of circulating Prx2 (peroxiredoxin 2), whereas arterial function was assessed by wire myography. Atherosclerosis and arterial remodeling were quantified by morphometry and plaque stability by fibrous cap thickness, lipid accumulation, infiltration of inflammatory cells, and the presence of intraplaque hemorrhage.
RESULTS
Compared with tandem stenosis littermates, tandem stenosis mice were deficient in bilirubin, showed signs of increased systemic oxidative stress, endothelial dysfunction, as well as hyperlipidemia, and had a higher atherosclerotic plaque burden. Heme metabolism was increased in unstable compared with stable plaque of both and tandem stenosis mice and in human coronary plaques. In mice, deletion selectively destabilized unstable plaque, characterized by positive arterial remodeling and increased cap thinning, intraplaque hemorrhage, infiltration of neutrophils, and MPO activity. Proteomic analysis confirmed deletion enhanced extracellular matrix degradation, recruitment and activation of neutrophils, and associated oxidative stress in unstable plaque.
CONCLUSIONS
Bilirubin deficiency, resulting from global deletion, generates a proatherogenic phenotype and selectively enhances neutrophil-mediated inflammation and destabilization of unstable plaque, thereby providing a link between bilirubin and cardiovascular disease risk.
Topics: Humans; Animals; Mice; Plaque, Atherosclerotic; Bilirubin; Cardiovascular Diseases; Constriction, Pathologic; Proteomics; Atherosclerosis; Antioxidants; Hemorrhage; Heme; Apolipoproteins E; Lipids; Disease Models, Animal
PubMed: 36876485
DOI: 10.1161/CIRCRESAHA.122.322418 -
Physiological Reviews Jul 2020Bilirubin is the end product of heme catabolism formed during a process that involves oxidation-reduction reactions and conserves iron body stores. Unconjugated... (Review)
Review
Bilirubin is the end product of heme catabolism formed during a process that involves oxidation-reduction reactions and conserves iron body stores. Unconjugated hyperbilirubinemia is common in newborn infants, but rare later in life. The basic physiology of bilirubin metabolism, such as production, transport, and excretion, has been well described. However, in the neonate, numerous variables related to nutrition, ethnicity, and genetic variants at several metabolic steps may be superimposed on the normal physiological hyperbilirubinemia that occurs in the first week of life and results in bilirubin levels that may be toxic to the brain. Bilirubin exists in several isomeric forms that differ in their polarities and is considered a physiologically important antioxidant. Here we review the chemistry of the bilirubin molecule and its metabolism in the body with a particular focus on the processes that impact the newborn infant, and how differences relative to older children and adults contribute to the risk of developing both acute and long-term neurological sequelae in the newborn infant. The final section deals with the interplay between the brain and bilirubin and its entry, clearance, and accumulation. We conclude with a discussion of the current state of knowledge regarding the mechanism(s) of bilirubin neurotoxicity.
Topics: Bilirubin; Brain; Humans; Infant, Newborn; Intestinal Mucosa; Liver
PubMed: 32401177
DOI: 10.1152/physrev.00004.2019 -
Critical Care (London, England) Sep 2022Organ dysfunction or overt failure is a commonplace event in the critically ill affecting up to 70% of patients during their stay in the ICU. The outcome depends on the... (Review)
Review
Organ dysfunction or overt failure is a commonplace event in the critically ill affecting up to 70% of patients during their stay in the ICU. The outcome depends on the resolution of impaired organ function, while a domino-like deterioration of organs other than the primarily affected ones paves the way for increased mortality. "Acute Liver Failure" was defined in the 1970s as a rare and potentially reversible severe liver injury in the absence of prior liver disease with hepatic encephalopathy occurring within 8 weeks. Dysfunction of the liver in general reflects a critical event in "Multiple Organ Dysfunction Syndrome" due to immunologic, regulatory and metabolic functions of liver parenchymal and non-parenchymal cells. Dysregulation of the inflammatory response, persistent microcirculatory (hypoxic) impairment or drug-induced liver injury are leading problems that result in "secondary liver failure," i.e., acquired liver injury without underlying liver disease or deterioration of preexisting (chronic) liver disease ("Acute-on-Chronic Liver Failure"). Conventional laboratory markers, such as transaminases or bilirubin, are limited to provide insight into the complex facets of metabolic and immunologic liver dysfunction. Furthermore, inhomogeneous definitions of these entities lead to widely ranging estimates of incidence. In the present work, we review the different definitions to improve the understanding of liver dysfunction as a perpetrator (and therapeutic target) of multiple organ dysfunction syndrome in critical care.
Topics: Bilirubin; Biomarkers; Critical Care; Critical Illness; Gastroenterology; Humans; Incidence; Intensive Care Units; Liver Diseases; Liver Failure; Microcirculation; Multiple Organ Failure; Prognosis; Transaminases
PubMed: 36163253
DOI: 10.1186/s13054-022-04163-1 -
European Journal of Medical Research Oct 2022Bile pigments, such as bilirubin and biliverdin, are end products of the heme degradation pathway in mammals and are widely known for their cytotoxic effects. However,... (Review)
Review
Bile pigments, such as bilirubin and biliverdin, are end products of the heme degradation pathway in mammals and are widely known for their cytotoxic effects. However, recent studies have revealed that they exert cytoprotective effects through antioxidative, anti-inflammatory, and immunosuppressive properties. All these mechanisms are indispensable in the treatment of diseases in the field of emergency and critical care medicine, such as coronary ischemia, stroke, encephalomyelitis, acute lung injury/acute respiratory distress syndrome, mesenteric ischemia, and sepsis. While further research is required before the safe application of bile pigments in the clinical setting, their underlying mechanisms shed light on their utilization as therapeutic agents in the field of emergency and critical care medicine. This article aims to summarize the current understanding of bile pigments and re-evaluate their therapeutic potential in the diseases listed above.
Topics: Animals; Humans; Bile Pigments; Biliverdine; Antioxidants; Respiratory Distress Syndrome; Critical Care; Mammals
PubMed: 36309733
DOI: 10.1186/s40001-022-00863-0