The Relationship between Serum Bilirubin and Inflammatory Bowel Disease

The association between bilirubin concentrations and inflammatory bowel disease: Insights from a systematic review and meta-analysis

BACKGROUND

Inflammatory bowel disease (IBD), including Crohn's disease (CD) and ulcerative colitis (UC), poses a significant challenge to health care systems because of its chronic nature and increasing global prevalence. Effective management of IBD requires accurate diagnostic tools and biomarkers. This systematic review and meta-analysis aimed to evaluate the relationship between bilirubin concentrations and IBD activity and outcomes.

METHODS

A comprehensive search of electronic databases identified 11 studies that included 2606 subjects with IBD and 3607 healthy controls.

RESULTS

Bilirubin concentrations were significantly lower in subjects with IBD when compared to controls (SMD = -0.96, 95% CI -1.21 to -0.70; p < .001). Although substantial heterogeneity was observed, sensitivity analysis confirmed the robustness of the results. Publication bias was detected, but subgroup analyses did not significantly alter the results. Meta-regression showed that age was a significant factor influencing the association between bilirubin concentrations and IBD. Subgroup analyses showed a more pronounced reduction in bilirubin concentrations in subjects with CD than those with UC.

CONCLUSION

This study supports the potential utility of bilirubin as a biomarker in IBD, emphasizing the need for further research to validate its clinical significance.

Absolute monocyte counts could predict disease activity and secondary loss of response of patients with Crohn's disease treated with anti-TNF-α drug

BACKGROUND

Assessing Crohn's disease (CD) activity is critical for monitoring disease progression. In CD, monocytes could release TNF-α. Thus, it is extremely important to study its role in the disease activity and loss of response to anti-TNF-α biologics.

METHODS

In this study, we collected CD patients treated with biologics from January 2017 to May 2022. Indicators associated with disease activity were evaluated by Spearman correlation analysis and Mann-Whitney U test. Specifically, logistic analyses were used to explore the predictors of primary nonresponse (PNR) and secondary loss of response (SLOR) within 1 year of anti-TNF-α agents. In addition, a nomogram was developed for therapeutic effect prediction.

RESULTS

283 patients with CD were identified. Disease activity group, defined as CDAI equal to or greater than 150, had significant elevated absolute monocyte counts than disease remission group based on CDAI score (p = 0.019, Z = -2.354). Logistic analyses showed that absolute monocyte counts could be an independent predictor of 1-year SLOR of anti-TNF-α agents in CD patients (p = 0.013). A nomogram established based on gender, absolute monocyte counts, and hemoglobin could predict SLOR within 1 year of anti-TNF-α agents reliably.

CONCLUSION

The results of this study support the utility of absolute monocyte counts detecting disease activity and anti-TNF-α therapy effect in patients with CD.

C-reactive protein-to-albumin ratio and neutrophil-to-albumin ratio for predicting response and prognosis to infliximab in ulcerative colitis

The C-reactive protein-to-albumin ratio (CAR) and neutrophil-to-albumin ratio (NAR) serve as established markers for inflammatory diseases. However, limited studies have investigated their potential in predicting response and prognosis following infliximab (IFX) treatment. The objective of this paper was to evaluate feasibility of CAR and NAR as biomarkers to assess response to IFX induction therapy. Additionally, we attempted to determine the capacity to predict clinical remission in ulcerative colitis (UC) after 54 weeks of IFX treatment. We enrolled a total of 157 UC patients diagnosed via endoscopic mucosal biopsy at our hospital between October 2018 and June 2023. Additionally, 199 patients presenting with gastrointestinal symptoms, who underwent physical examinations, constituted the control group. Comprehensive clinical data, laboratory indicators, and endoscopic findings were systematically collected. CAR and NAR values were computed before treatment, post-induction, and subsequently at 8-week intervals. Comparisons between two groups were analyzed using the Wilcoxon rank-sum test or the independent samples t-test, and comparisons between multiple groups were analyzed using the one-way ANOVA (analysis of variance) or the Kruskal-Wallis rank sum test. We found CAR and NAR emerged as sensitive biomarkers for assessing disease activity. Notably, our findings indicated their dual predictive capability: foreseeing response post-IFX induction therapy and prognosticating the likelihood of UC patients achieving clinical remission following 54 weeks on IFX therapy.

High indirect bilirubin levels as an independent predictor of postoperative myasthenic crisis: a single-center, retrospective study

Background

Thymectomy is an efficient and standard treatment strategy for patients with myasthenia gravis (MG), postoperative myasthenic crisis (POMC) is the major complication related to thymectomy and has a strongly life-threatening effect. As a biomarker, whether the bilirubin level is a risk factor for MG progression remains unclear. This study aimed to investigate the association between the preoperative bilirubin level and postoperative myasthenic crisis (POMC).

Methods

We analyzed 375 patients with MG who underwent thymectomy at Tangdu Hospital between January 2012 and September 2021. The primary outcome measurement was POMC. The association between POMC and bilirubin level was analyzed by restricted cubic spline (RCS). Indirect bilirubin (IBIL) was divided into two subgroups based on the normal upper limit of IBIL, 14 μmol/L.

Results

Compared with non-POMC group, IBIL levels were significantly higher in patients with POMC. Elevated IBIL levels were closely associated with an increased risk of POMC (p for trend = 0.002). There was a dose-response curve relationship between IBIL levels and POMC incidence (p for non-linearity = 0.93). However, DBIL levels showed a U-shaped association with POMC incidence. High IBIL level (≥14 μmol/L) was an independent predictive factor for POMC [odds ratio = 3.47, 95% confidence interval (CI): 1.56-7.8, p = 0.002]. The addition of high IBIL levels improved the prediction model performance (net reclassification index = 0.186, 95% CI: 0.039-0.334; integrated discrimination improvement = 0.0345, 95% CI: 0.005-0.065).

Conclusion

High preoperative IBIL levels, especially those exceeding the normal upper limit, could independently predict the incidence of POMC.

BilR is a gut microbial enzyme that reduces bilirubin to urobilinogen

Metabolism of haem by-products such as bilirubin by humans and their gut microbiota is essential to human health, as excess serum bilirubin can cause jaundice and even neurological damage. The bacterial enzymes that reduce bilirubin to urobilinogen, a key step in this pathway, have remained unidentified. Here we used biochemical analyses and comparative genomics to identify BilR as a gut-microbiota-derived bilirubin reductase that reduces bilirubin to urobilinogen. We delineated the BilR sequences from similar reductases through the identification of key residues critical for bilirubin reduction and found that BilR is predominantly encoded by Firmicutes species. Analysis of human gut metagenomes revealed that BilR is nearly ubiquitous in healthy adults, but prevalence is decreased in neonates and individuals with inflammatory bowel disease. This discovery sheds light on the role of the gut microbiome in bilirubin metabolism and highlights the significance of the gut-liver axis in maintaining bilirubin homeostasis.

The Association between Serum Total Bilirubin and Severe Headaches or Migraine in American Adults

BACKGROUND

Studies about the association between bilirubin and migraine were few. Therefore, the purpose of this study was to investigate the association between serum total bilirubin and the prevalence of severe headaches or migraine.

METHODS

A multivariable logistic regression was used to assess the association between serum total bilirubin concentration and severe headaches or migraine. We also performed stratified analyses, interaction analyses and multiple interpolations in the sensitivity analysis.

RESULTS

This cross-sectional study included 12,552 adults from the National Health and Nutrition Examination Survey (NHANES) from 1999 to 2004. The overall incidence of migraine was 19.99% (2,509/12,552). With every 1 mg/dl increase in bilirubin, the prevalence of migraine decreased by 23% (95% CI: 0.64, 0.93) after adjustment of all related covariates. Similarly, the risk of migraine was reduced by 17% (95% CI: 0.72, 0.97) in the Q4 group (the fourth quartile, highest serum total bilirubin level) compared with the Q1 group (the lowest level). Furthermore, interaction effects by age groups were significant in this relationship (P for interaction = 0.0004). In the Q4 group compared with Q1, inverse associations were observed in those aged ≥40 years (OR: 0.71,95% CI: 0.59, 0.85) in the stratified analysis.

CONCLUSION

These findings support an association between serum total bilirubin and severe headaches or migraine, revealing an inverse association between serum total bilirubin quartiles and severe headaches or migraine in American adults. Age could play an important role in this association.

Phase angle values and ultra-processed food consumption are associated with changes in oxidative stress in inflammatory bowel disease patients

BACKGROUND & AIMS

Changes in dietary habits including increased intake of refined sugars and fats and decreased intake of fiber have been suggested as potential risk factors for the development of inflammatory bowel diseases (IBD). Bioelectrical impedance analysis-derived phase angle (PhA) has been gaining attention in the clinical evaluation of nutritional status. In this study, we for the first time investigated the relationship of PhA and ultra-processed food intake with oxidative stress, body composition and biochemical parameters in adult patients with IBD.

METHODS

Body composition and PhA were evaluated through electrical bioimpedance. Nitrite (Nox), myeloperoxidase (MPO), glutathione (GSH), malondialdehyde (MDA) and superoxide dismutase (SOD) levels were determined in both groups. Food consumption was obtained by a food frequency questionnaire (FFQ).

RESULTS

In comparison with the control group, the IBD group had increased (p < 0.05) concentrations of Nox (19.95 ± 1.4 vs. 35.43 ± 7.7 μM), MDA (0.70 ± 0.31 vs. 4.56 ± 0.62 nmol/L), and GSH (9.35 ± 0.38 vs. 10.74 ± 0.51 mg NPSH/μL plasma). PhA was positively correlated with GSH (R2:0.22; p:0.02) and SOD (R2:0.25; p:0.01). IBD patients ingested higher amounts of ultra-processed foods (IBD:17.04 ± 2.76 vs. Control:24.88 ± 2.30%). However, IBD patients had better consumption of unprocessed or minimally processed foods (IBD:79.06 ± 3.07 vs. Control:67.83 ± 2.32%). We found a positive correlation between ultra-processed food consumption and MDA (R2 0.43; p:0.01).

CONCLUSIONS

PhA may be a practical and effective measure in clinical follow-up of IBD patients, being associated with bilirubin levels and antioxidant enzymes. Also, we recommend evaluating consumption of ultra-processed foods, since this was related with increasing oxidative stress markers in clinical follow-up of IBD patients.

Clinical significance of the C-reactive protein-to-bilirubin ratio in patients with ulcerative colitis

Background

Ulcerative colitis (UC) is a chronic relapsing remitting disease of the colon. Appropriate monitoring of the disease status is necessary for patients to adopt optimal therapy and obtain a better prognosis. Finding an ideal non-invasive biomarker, which is suitable for long-term monitoring in clinical settings will bring a significant benefit to the individualized management of patients with UC. The aim of this study is to determine the clinical significance of a novel optimizing serological biomarker by integrating C-reactive protein (CRP) and bilirubin levels in monitoring disease activity.

Methods

A total of 182 patients with UC were retrospectively enrolled. Clinical characteristics and laboratory parameters of the subjects were retrieved from the electronic medical record database of our hospital. The CRP-to-bilirubin ratio (CBR) was computed for clinical activity of UC defined by the partial Mayo score and endoscopic activity by the Mayo endoscopic score (MES).

Results

CBR was significantly elevated in patients with UC than that in healthy controls. Patients with clinically or endoscopically active UC showed evidently higher CBR levels compared to those with inactive disease, even in a subset of patients with normal CRP levels. Receiver operating characteristic (ROC) analysis showed that the area under the curve (AUC) of CBR was higher than that of CRP or bilirubin alone for determining clinical remission and endoscopic mucosal improvement. Furthermore, CBR levels were significantly decreased when patients achieved mucosal improvement compared with when they had active endoscopic inflammation.

Conclusion

CBR could be useful to reflect disease activity in patients with UC.

Clinical Utility of the Neutrophil-to-Bilirubin Ratio in the Detection of Disease Activity in Ulcerative Colitis

Background

Ulcerative colitis (UC) is a chronic relapsing remitting form of inflammatory bowel disease (IBD). Current disease monitoring includes evaluation of symptoms, fecal calprotectin, and colonoscopy. Due to limited availability of the latter two modalities in China, we sought a readily available, inexpensive, disease monitoring laboratory assessment. We recently identified a novel serological index (the neutrophil-to-bilirubin ratio, NBR) for monitoring disease activity in Crohn's disease. However, the clinical significance has not been evaluated in UC. Here, we aimed to verify the hypothesis that NBR might be useful in monitoring clinical and endoscopic activity in patients with UC.

Methods

To test our hypothesis, we conducted a single-center, retrospective study including a total of 188 patients with UC and 145 non-IBD controls. NBR was calculated to determine its practical value in monitoring disease activity (including clinical and endoscopic activity). Disease activity of UC was determined by the partial Mayo score and the Mayo endoscopic score (MES) system.

Results

NBR was significantly higher in patients with UC than that in controls (12.10, IQR: 9.85-16.69 versus 5.06, IQR: 3.94-6.55; p < 0.001) and showed positive correlations with clinical and endoscopic disease activity in UC. Additionally, NBR was significantly lower in patients with endoscopic mucosal healing (MH) than that in those without endoscopic MH (8.81, IQR: 6.67-11.67 versus 13.51, IQR: 11.04-18.71; p < 0.001). Serial evaluation of NBR in a subset of patients demonstrated that NBR was significantly decreased during the MH stage compared with that during the endoscopically active stage.

Conclusion

Our study suggests that NBR may be a promising candidate for assessing disease activity in UC, with potential for widespread clinical use and significant clinical implications.

Blockade of PGK1 and ALDOA enhances bilirubin control of Th17 cells in Crohn's disease

Unconjugated bilirubin (UCB) confers Th17-cells immunosuppressive features by activating aryl-hydrocarbon-receptor, a modulator of toxin and adaptive immune responses. In Crohn's disease, Th17-cells fail to acquire regulatory properties in response to UCB, remaining at an inflammatory/pathogenic state. Here we show that UCB modulates Th17-cell metabolism by limiting glycolysis and through downregulation of glycolysis-related genes, namely phosphoglycerate-kinase-1 (PGK1) and aldolase-A (ALDOA). Th17-cells of Crohn's disease patients display heightened PGK1 and ALDOA and defective response to UCB. Silencing of PGK1 or ALDOA restores Th17-cell response to UCB, as reflected by increase in immunoregulatory markers like FOXP3, IL-10 and CD39. In vivo, PGK1 and ALDOA silencing enhances UCB salutary effects in trinitro-benzene-sulfonic-acid-induced colitis in NOD/scid/gamma humanized mice where control over disease activity and enhanced immunoregulatory phenotypes are achieved. PGK1 and/or ALDOA blockade might have therapeutic effects in Crohn's disease by favoring acquisition of regulatory properties by Th17-cells along with control over their pathogenic potential.

Clinical Significance of Novel Neutrophil-Based Biomarkers in the Diagnosis and Prediction of Response to Infliximab Therapy in Crohn’s Disease

With the increasing incidence and prevalence, Crohn’s disease (CD) has become one of the most challenging diseases in both diagnosis and treatment of gastroenterology. Evaluation of the disease activity and mucosal healing guides clinical decisions regarding subsequent therapy for CD. In this study, we enrolled a total of 144 patients with CD and 239 healthy controls were enrolled. Clinical characteristics and laboratory parameters of enrolled subjects were retrieved from the electronic medical record database of our hospital. Serum cytokine levels were measured by enzyme-linked immunosorbent assay (ELISA). Mucosa expression levels of inflammatory agents were measured by quantitative RT-PCR (qRT-PCR). We identified two neutrophil-based indexes, the neutrophil-to-albumin ratio (NAR) and neutrophil-to-bilirubin ratio (NBR), both of which had not yet been explored in CD or UC. NAR and NBR were significantly increased in patients with CD compared to those in healthy controls, and both indexes showed significantly positive correlations with CD activity and inflammatory load. In note, NAR and NBR showed better performance than blood neutrophil percentage, serum albumin, or bilirubin alone in these scenarios. More importantly, both NAR and NBR discriminated CD patients who completely or partially responded to infliximab (IFX) induction therapy from those with primary non-response. Our observations suggest that NAR and NBR may serve as promising biomarkers in the diagnosis and prediction of response to IFX therapy in CD.

Association between lncRNAs in plasma exosomes and diabetic retinopathy

BACKGROUND

Long noncoding RNA (lncRNA) in plasma exosomes is a potential non-invasive diagnostic biomarker for diabetic retinopathy (DR). However, the changes in plasma exosomal lncRNAs and diagnostic relevance in patients with DR patients remain unclear.

METHODS

A case-control study with type 2 diabetes mellitus (T2DM) and patients with comorbid DR were enrolled, and their clinical information and blood samples were collected. Plasma exosomes were extracted, and the relative expression levels of representative differentially expressed exosomal lncRNAs were determined. A logistic regression model was used to analyze the relationships of DR with relative lncRNA expression and DR-related factors, and receiver operating characteristic (ROC) curve analysis was used to evaluate the value of exosomal lncRNAs for DR diagnosis.

RESULTS

Sixty-two patients with T2DM and sixty-two patients with DR were matched by age, sex, and disease duration. The fasting blood glucose concentration, glycosylated hemoglobin level (HbA_1c), and relative expression of the plasma exosomal lncRNA DLX6-AS1 were significantly higher in the DR group than in the T2DM group, whereas the 2-h C-peptide concentration and relative expression of the lncRNAs PRINS and FAM190A-3 were lower in the DR group. After adjusting for relevant confounders, the fasting blood glucose concentration, HbA_1c level, 2-h C-peptide concentration, and relative expression of lncRNA DLX6-AS1, PRINS, and FAM190A-3 were found to be associated with DR. Both DLX6-AS1 [area under the curve (AUC): 0.658 (0.562-0.754)], PRINS [AUC: 0.798 (0.722-0.873)], and FAM190A-3 [AUC: 0.603 (0.503-0.702)] expression had predictive value for DR diagnosis. The combination of DLX6-AS1 and PRINS yielded an AUC of 0.813 (0.740-0.886). In males, the combination of DLX6-AS1 and PRINS yielded an AUC of 0.860 (0.780-0.940).

CONCLUSION

The fasting blood glucose concentration, HbA_1c level, and exosomal DLX6-AS1 expression were identified as risk factors for DR, whereas the 2-h C-peptide concentration and exosomal PRINS and FAM190A-3 were identified as protective against DR. The combination of exosomal DLX6-AS1 and PRINS had good diagnostic value for DR in the general population and males. More attention should be paid to the role of exosomal PRINS expression as a predictive and diagnostic DR biomarker in females.

Effects of Jian Pi Qing Chang Hua Shi decoction on mucosal injuries in a 2,4,6-trinitrobenzene sulphonic acid-induced inflammatory bowel disease rat model

CONTEXT

Jian Pi Qing Chang Hua Shi decoction (JPQCHSD) has been considered as an effective remedy for the treatment of inflammatory bowel disease (IBD) in Chinese traditional medicine.

OBJECTIVE

We evaluated the efficacy of JPQCHSD on 2-4-6-trinitrobenzene sulphonic acid (TNBS)-induced IBD rats and the responsible mechanisms.

MATERIALS AND METHODS

Except the rats of the control group (50% ethanol), Sprague-Dawley rats (180 ± 20 g) induced by TNBS (150 mg/kg in 50% ethanol), received water extract of JPQCHSD daily at 0, 9.5, 19, or 38 g/kg for 12 days. The rats were sacrificed, and their colons were removed to evaluate the disease activity index. Malondialdehyde (MDA), superoxide dismutase (SOD), myeloperoxidase (MPO), immunoglobulin A (IgA), tumour necrosis factor (TNF)-α, interleukin (IL)-1β, IL-6, and nuclear factor-κB were evaluated.

RESULTS

JPQCHSD extract significantly reduced the disease activity index of TNBS-induced colitis with a median effective dose (ED₅₀) of 26.93 g/kg. MPO and MDA were significantly reduced in the 19 and 38 g/kg groups (ED₅₀ values 37.38 and 53.2 g/kg, respectively). The ED₅₀ values for the increased SOD and IgA were 48.98 and 56.3 g/kg. ED₅₀ values for inhibition of TNF-α, IL-1β, and IL-6 were 32.66, 75.72, and 162.06 g/kg, respectively.

DISCUSSION

JPQCHSD promoted mucosal healing in IBD rats via its anti-inflammation, immune regulation, and antioxidation properties.

CONCLUSIONS

JPQCHSD has healing function on IBD. Further clinical trials are needed to demonstrate its efficacy and tolerance to IBD.

The relationship between UGT1A1 gene & various diseases and prevention strategies

UDP-glucuronyltransferase 1A1 (UGT1A1) is a member of the Phase II metabolic enzyme family and the only enzyme that can metabolize detoxified bilirubin. Inactivation and very low activity of UGT1A1 in the liver can be fatal or lead to lifelong Gilbert's syndrome (GS) and Crigler-Najjar syndrome (CN). To date, more than one hundred UGT1A1 polymorphisms have been discovered. Although most UGT1A1 polymorphisms are not fatal, which diseases might be associated with low activity UGT1A1 or UGT1A1 polymorphisms? This scientific topic has been studied for more than a hundred years, there are still many uncertainties. Herein, this article will summarize all the possibilities of UGT1A1 gene-related diseases, including GS and CN, neurological disease, hepatobiliary disease, metabolic difficulties, gallstone, cardiovascular disease, Crohn's disease (CD) obesity, diabetes, myelosuppression, leukemia, tumorigenesis, etc., and provide guidance for researchers to conduct in-depth study on UGT1A1 gene-related diseases. In addition, this article not only summarizes the prevention strategies of UGT1A1 gene-related diseases, but also puts forward some insights for sharing.

LncRNA LUCAT1 as a Plasma Biomarker for Assessing Disease Activity in Adult Patients with Crohn's Disease

Aim

To explore the expression of long noncoding RNA (LncRNA) LUCAT1 in adult patients with Crohn's disease (CD) and evaluate the relationship between LncRNA LUCAT1 and the disease activity in Chinese patients with CD.

Methods

Patients with CD and healthy participants (≥18 years old) were enrolled in this study between January 2018 and December 2019. The expression of LncRNA LUCAT1 in plasma samples was evaluated by quantitative reverse transcription-polymerase chain reaction. Basic characteristics of patients with CD were collected, including gender, age, clinical stage, disease behavior, disease location, C-reactive protein (CRP), platelet (PLT), erythrocyte sedimentation rate (ESR), fecal calprotectin (FC), Crohn's disease activity index (CDAI) score, and simplified Crohn's disease endoscopic score (SES-CD).

Results

In total, 168 patients with CD and 65 healthy participants (≥18 years old) were enrolled in this study. Among them, ninety patients with clinically active CD, seventy-eight patients with CD in clinical remission, forty-eight patients with endoscopically active CD, thirty patients with endoscopically inactive CD, and sixty-five healthy participants. LncRNA LUCAT1 was increased in plasma of patients with CD compared with the control group. The plasma LncRNA LUCAT1 level of patients with CD both in the clinical and endoscopic active phase was higher than that of both the clinical and endoscopic remission phase. The plasma level of LncRNA LUCAT1 in patients with CD was positively correlated with ESR, CRP, FC, CDAI, and SES-CD. There was no significant correlation between the level of LUCAT1 and platelets. The plasma LncRNA LUCAT1 level in patients with CD had significant differences between severe active patients and mild/moderate active patients.

Conclusion

The plasma LncRNA LUCAT1 is positively associated with the disease activity in patients with CD, and it may act as a noninvasive biomarker to identify the degree of disease activity.

Associations between major psychiatric disorder polygenic risk scores and blood-based markers in UK biobank

Major depressive disorder (MDD), schizophrenia (SCZ), and bipolar disorder (BD) have both shared and discrete genetic risk factors, and are associated with peripheral abnormalities. The relationships between such genetic architectures and blood-based markers are, however, unclear. We investigated relationships between polygenic risk scores (PRS) for these disorders and peripheral markers in the UK Biobank cohort. We calculated polygenic risk scores for n = 367,329 (MDD PRS), n = 366,465 (SCZ PRS), and n = 366,383 (BD PRS) UK Biobank cohort subjects. We then examined associations between disorder PRS and 58 inflammatory/immune, hematological, bone, cardiovascular, hormone, liver, renal and diabetes-associated blood markers using two generalized linear regression models: 'minimally adjusted' controlling for variables such as age and sex, and 'fully adjusted' including additional lifestyle covariates: BMI, alcohol and smoking status, and medication intake. There were 38/58 MDD PRS, 32/58 SCZ PRS, and 20/58 BD PRS-blood marker associations detected for our minimally adjusted model. Of these, 13/38 (MDD PRS), 14/32 (SCZ PRS), and 10/20 (BD PRS) associations remained significant after controlling for lifestyle factors. Many were disorder-specific, with 8/13 unique MDD PRS associations identified. Several disorder-specific associations for MDD and SCZ were immune-related, with mostly positive and negative associations identified for MDD and SCZ PRS respectively. This study suggests that MDD, SCZ and BD have both shared and distinct peripheral markers associated with disorder-specific genetic risk. The results also implicate inflammatory dysfunction in MDD and SCZ, albeit with differences in patterns between the two conditions, and enrich our understanding of potential underlying pathophysiological mechanisms in major psychiatric disorders.

Unconjugated Bilirubin Attenuates DSS-Induced Colitis Potentially via Enhancement of Bilirubin Reabsorption

Studies increasingly show that ulcerative colitis (UC) is a consequence of an imbalance between oxidative stress and antioxidant capacity. Bilirubin exerts an anti-inflammatory effect by scavenging reactive oxygen species (ROS), although the exact mechanism is not completely understood. The aim of this study was to determine the role of serum bilirubin in UC using patient data and a mouse model of dextran sodium sulfate (DSS)-induced colitis. We found that low levels of serum bilirubin correlated to a higher risk of UC in a retrospective case-control population. Pre-treatment with exogenous unconjugated bilirubin (UCB) significantly enhanced colonic bilirubin absorption in mice, and attenuated the DSS-induced body weight loss, colon shortening and histopathological damage. Mechanistically, bilirubin prevented the infiltration of inflammatory cells, and decreased the levels of myeloperoxidase and pro-inflammatory cytokines in the serum and colon. Moreover, bilirubin inhibited ROS and malondialdehyde production, scavenged superoxide anions (O₂^·−) from the colon and enhanced the total antioxidant capacity. In conclusion, exogenous UCB attenuated DSS-induced colitis by directly scavenging O₂^·− and enhancing bilirubin reabsorption in the colon via enterohepatic cycling.

Relationship between serum bilirubin levels, urinary biopyrrin levels, and retinopathy in patients with diabetes

Objective

Previous reports have indicated that serum bilirubin levels may be associated with diabetic retinopathy. However, the detailed mechanism is not fully understood. In this study, we evaluated the relationship between the severity of diabetic retinopathy and various factors including bilirubin levels and factors influencing bilirubin metabolism.

Methods

The study participants consisted of 94 consecutive patients with diabetes mellitus admitted to Kyushu University Hospital from April 2011 to July 2012. The patients were classified into three groups: no retinopathy (NDR), simple retinopathy (SDR), and pre-proliferative or proliferative retinopathy (PDR). The relationship between the severity of retinopathy and various factors was evaluated using univariate and logistic regression analyses. In addition, multivariate regression analysis was performed to evaluate the significant determinants for bilirubin levels.

Results

In univariate analysis, a significant difference was found among NDR, SDR and PDR in bilirubin levels, duration of diabetes, systolic blood pressure, and macroalbuminuria. Logistic regression analysis showed that PDR was significantly associated with bilirubin levels, duration of diabetes, and systolic blood pressure (OR 0.737, 95% CI 0.570–0.952, P = 0.012; OR 1.085, 95% CI 1.024–1.149, P = 0.006; OR 1.036, 95% CI 1.011–1.062, P = 0.005, respectively). In turn, multivariate regression analysis showed that bilirubin levels were negatively associated with high-sensitivity C-reactive protein levels and PDR, but positively correlated with urinary biopyrrin levels, oxidized metabolites of bilirubin.

Conclusion

PDR was negatively associated with bilirubin levels. This negative association may be due to a decreased production of bilirubin rather than its increased consumption considering the positive association between bilirubin and biopyrrin levels.

Association between serum bilirubin and mucosal healing among Japanese patients with ulcerative colitis: a cross-sectional study

PURPOSE

Bilirubin is known to have antioxidant effects. Several pieces of evidence regarding association between serum bilirubin and UC exist. Three studies found that serum bilirubin was inversely associated with severity of ulcerative colitis (UC), but no evidence regarding an association between serum bilirubin and mucosal healing (MH) has yet been shown. Thus, we evaluated this issue among Japanese patients with UC.

METHODS

The study subjects consisted of 304 Japanese patients with UC. Serum total bilirubin and indirect bilirubin were divided into quartiles on the basis of the distribution of all study subjects (low, moderate, high, and very high). Several endoscope specialists were responsible for evaluating MH, which was defined as a Mayo endoscopic subscore of 0. The information on clinical remission was collected using medical records.

RESULTS

The mean age was 49.9 years, the percentage of male patients was 59.2%, and the percentage of MH was 29.3%. High serum total bilirubin was independently positively associated with MH (OR 2.26 [95%CI 1.13-4.61]. However, after adjustment for confounding factors, the association between total bilirubin and MH disappeared. Very high serum indirect bilirubin was independently positively associated with MH (OR 2.31 [95%CI 1.10-5.00], p for trend = 0.026). No association between bilirubin and clinical remission was found.

CONCLUSIONS

Among Japanese patients with UC, serum indirect bilirubin, but not total bilirubin, was significantly positively associated with MH but not clinical remission.

Inflammatory Correlated Response in Two Lines of Rabbit Selected Divergently for Litter Size Environmental Variability

A divergent selection experiment for environmental variance of litter size variance was carried out in rabbits over thirteen generations. The aim of this study was to evaluate the inflammatory response in the two lines of the experiment, in order to analyse the effect of selection on susceptibility to diseases after challenging to stressful situations, such as 24 h after the first delivery. A total of 78 females were used in this study, 39 from each line. The line selected for litter size heterogeneity (the high line) showed lower white blood leukocyte count (WBC; -0.87 × 103/µL), lower percentage of basophils (-0.11%), higher concentration of TNF-α (+13.8 pg/mL), and greater concentration of CRP (+38.1 µg/mL) than the line selected for litter size homogeneity (the low line). The high line had also higher concentrations of bilirubin, cholesterol, gamma-glutamyl transferase (GGT) and alkaline phosphatase (ALP) compared to the low line (difference between lines were +0.08 µmol/L, +0.14 µmol/L, +0.35 U/L and +2.4 U/L, respectively). The high line showed higher inflammatory response than the low line, in accordance with a larger susceptibility to infectious disorders. In conclusion, the line selected to increase litter size environmental variability seems to have poor capacity coping with environmental stressors. Therefore, selection for litter size environmental variability can be a useful way to improve animal welfare.

Two Faces of Heme Catabolic Pathway in Newborns: A Potential Role of Bilirubin and Carbon Monoxide in Neonatal Inflammatory Diseases

In an infant's body, all the systems undergo significant changes in order to adapt to the new, extrauterine environment and challenges which it poses. Fragile homeostasis can be easily disrupted as the defensive mechanisms are yet imperfect. The activity of antioxidant enzymes, i.e., superoxide dismutase, catalase, and glutathione peroxidase, is low; therefore, neonates are especially vulnerable to oxidative stress. Free radical burden significantly contributes to neonatal illnesses such as sepsis, retinopathy of premature, necrotizing enterocolitis, bronchopulmonary dysplasia, or leukomalacia. However, newborns have an important ally-an inducible heme oxygenase-1 (HO-1) which expression rises rapidly in response to stress stimuli. HO-1 activity leads to production of carbon monoxide (CO), free iron ion, and biliverdin; the latter is promptly reduced to bilirubin. Although CO and bilirubin used to be considered noxious by-products, new interesting properties of those compounds are being revealed. Bilirubin proved to be an efficient free radicals scavenger and modulator of immune responses. CO affects a vast range of processes such as vasodilatation, platelet aggregation, and inflammatory reactions. Recently, developed nanoparticles consisting of PEGylated bilirubin as well as several kinds of molecules releasing CO have been successfully tested on animal models of inflammatory diseases. This paper focuses on the role of heme metabolites and their potential utility in prevention and treatment of neonatal diseases.

Oxidative Stress Markers in Inflammatory Bowel Diseases: Systematic Review

Precise diagnostic biomarker in inflammatory bowel diseases (IBD) is still missing. We conducted a comprehensive overview of oxidative stress markers (OSMs) as potential diagnostic, differential, progression, and prognostic markers in IBD. A Pubmed, Web of Knowledge, and Scopus search of original articles on OSMs in IBD, published between January 2000 and April 2020, was conducted. Out of 874 articles, 79 eligible studies were identified and used to prepare the interpretative synthesis. Antioxidants followed by lipid peroxidation markers were the most popular and markers of oxidative DNA damage the least popular. There was a disparity in the number of retrieved papers evaluating biomarkers in the adult and pediatric population (n = 6). Of the reviewed OSMs, a promising performance has been reported for serum total antioxidant status as a mucosal healing marker, mucosal 8-OHdG as a progression marker, and for multi-analyte panels of lipid peroxidation products assessed non-invasively in breath as diagnostic and differential markers in the pediatric population. Bilirubin, in turn, was the only validated marker. There is a desperate need for non-invasive biomarkers in IBD which, however, will not be met in the near future by oxidative stress markers as they are promising but mostly at the early research phase of discovery.

Association of total bilirubin and indirect bilirubin content with metabolic syndrome among Kazakhs in Xinjiang

BACKGROUND

Some studies have shown that a high level of bilirubin is a protective factor against metabolic syndrome (MS), while a high level of transaminase is a risk factor for MS. However, the existing results are inconsistent and few cohort studies have been published.

METHODS

Using an ambispective cohort study, 565 Kazakhs from Xinjiang, China were selected as the study subjects. The baseline serum bilirubin and transaminase levels of the subjects were divided into quartiles and the relationship between these values and the incidence of MS was analyzed. The definition of MS was based on the Joint Interim Statement (JIS) diagnostic criteria.

RESULTS

The average follow-up time for the subjects was 5.72 years. The cumulative incidence of MS was 36.11% (204 of the 565 subjects), and the incidence density was 63.10/1000 person-years. Multivariate Cox regression analysis showed that the levels of total bilirubin (TBIL) and indirect bilirubin (IBIL) were negatively correlated with the occurrence of MS, Compared to the lowest quartile level (Q1), the hazard ratios of MS the TBIL levels at the Q2-Q4 quartiles were: 0.47 (0.31-0.71), 0.53 (0.35-0.79), and 0.48 (0.32-0.72), respectively, while IBIL levels at the Q2-Q4 quartiles showed an MS hazard ratio of 0.48 (0.32-0.72), 0.54(0.36-0.81), and 0.52 (0.35-0.77), respectively, all at a 95% confidence level. However, no relationship was found between transaminase levels and the incidence of MS.

CONCLUSION

Serum TBIL and IBIL levels were negatively correlated with the incidence of MS in a Kazakh population in China.

Serum Cholinesterases, a Novel Marker of Clinical Activity in Inflammatory Bowel Disease: A Retrospective Case-Control Study

Background

The aim of our study was to investigate whether serum cholinesterase (ChE) levels were associated with inflammatory bowel disease (IBD).

Materials and Methods

We conducted a retrospective case-control study to clarify the relationship between serum ChE levels and IBD that included 142 patients with ulcerative colitis (UC), 60 patients with Crohn's disease (CD), and 264 healthy controls (HCs). We used ROC curves to evaluate the diagnostic value of serum ChE levels for IBD.

Results

Substantially lower serum ChE levels were detected in patients with UC than in HCs (6376 U/L versus 8418 U/L, P < 0.001) and in patients with CD than in HCs (5181 U/L versus 8418 U/L, P < 0.001). Additionally, patients with CD displayed significantly lower serum ChE levels than patients with UC (5181 U/L versus 6376 U/L, P < 0.01). We also found that there was a negative association between serum ChE levels and the Crohn's Disease Activity Index (CDAI) score of patients with CD (P = 0.011) and the Simple Clinical Colitis Activity Index (SCCAI) score of patients with UC (P = 0.018). The area under the curve (AUC) for serum ChE for the diagnosis of IBD was 0.826, and the AUCs of serum ChE for the diagnosis of CD and UC were 0.890 and 0.800, respectively.

Conclusions

Serum ChE levels have important clinical significance in the diagnosis and assessment of clinical activity in patients with IBD, and the cholinergic anti-inflammatory pathway may provide new ideas for targeted treatment of IBD.

Bilirubin Nanomedicines for the Treatment of Reactive Oxygen Species (ROS)-Mediated Diseases

Reactive oxygen species (ROS) are chemically reactive species that are produced in cellular aerobic metabolism. They mainly include superoxide anion, hydrogen peroxide, hydroxyl radicals, singlet oxygen, ozone, and nitric oxide and are implicated in many physiological and pathological processes. Bilirubin, a cardinal pigment in the bile, has been increasingly investigated to treat cancer, diabetes, ischemia-reperfusion injury, asthma, and inflammatory bowel diseases (IBD). Indeed, bilirubin has been shown to eliminate ROS production, so it is now considered as a promising therapeutic agent for ROS-mediated diseases and can be used for the development of antioxidative nanomedicines. This review summarizes the current knowledge of the physiological mechanisms of ROS production and its role in pathological changes and focuses on discussing the antioxidative effects of bilirubin and its application in the experimental studies of nanomedicines. Previous studies have shown that bilirubin was mainly used as a responsive molecule in the microenvironment of ROS overproduction in neoplastic tissues for the development of anticancer nanodrugs; however, it could also exert powerful ROS scavenging activity in chronic inflammation and ischemia-reperfusion injury. Therefore, bilirubin, as an inartificial ROS scavenger, is expected to be used for the development of nanomedicines against more diseases due to the universality of ROS involvement in human pathological conditions.