The Contribution of Methotrexate Exposure and Host Factors on Transcriptional Variance in Human Liver

Overview on the Link Between the Complement System and Auto-Immune Articular and Pulmonary Disease

Complement system (CS) dysregulation is a key factor in the pathogenesis of different autoimmune diseases playing a central role in many immune innate and adaptive processes. Rheumatoid arthritis (RA) is a chronic inflammatory disease characterized by ta breach of self-tolerance leading to a synovitis and extra-articular manifestations. The CS is activated in RA and seems not only to mediate direct tissue damage but also play a role in the initiation of RA pathogenetic mechanisms through interactions with citrullinated proteins. Interstitial lung disease (ILD) represents the most common extra-articular manifestation that can lead to progressive fibrosis. In this review, we focused on the evidence of CS dysregulation in RA and in ILD, and highlighted the role of the CS in both the innate and adaptive immune responses in the development of diseases, by using idiopathic pulmonary fibrosis as a model of lung disease. As a proof of concept, we dissected the evidence that several treatments used to treat RA and ILD such as glucocorticoids, pirfenidone, disease modifying antirheumatic drugs, targeted biologics such as tumor necrosis factor (TNF)-inhibitors, rituximab, tocilizumab, and nintedanib may act indirectly on the CS, suggesting that the CS might represent a potential therapeutic target in these complex diseases.

Antirheumatic therapy is associated with reduced complement activation in rheumatoid arthritis

Background

The complement system plays an important role in pathophysiology of cardiovascular disease (CVD), and might be involved in accelerated atherogenesis in rheumatoid arthritis (RA). The role of complement activation in response to treatment, and in development of premature CVD in RA, is limited. Therefore, we examined the effects of methotrexate (MTX) and tumor necrosis factor inhibitors (TNFi) on complement activation using soluble terminal complement complex (TCC) levels in RA; and assessed associations between TCC and inflammatory and cardiovascular biomarkers.

Methods

We assessed 64 RA patients starting with MTX monotherapy (n = 34) or TNFi with or without MTX co-medication (TNFi±MTX, n = 30). ELISA was used to measure TCC in EDTA plasma. The patients were examined at baseline, after 6 weeks and 6 months of treatment.

Results

Median TCC was 1.10 CAU/mL, and 57 (89%) patients had TCC above the estimated upper reference limit (<0.70). Compared to baseline, TCC levels were significantly lower at 6-week visit (0.85 CAU/mL, p<0.0001), without significant differences between the two treatment regimens. Notably, sustained reduction in TCC was only achieved after 6 months on TNFi±MTX (0.80 CAU/mL, p = 0.006). Reductions in TCC after treatment were related to decreased C-reactive protein (CRP), erythrocyte sedimentation rate (ESR) and interleukin 6, and increased levels of total, high and low-density lipoprotein cholesterol. Similarly, baseline TCC was significantly related to baseline CRP, ESR and interleukin 6. Patients with endothelial dysfunction had higher baseline TCC than those without (median 1.4 versus 1.0 CAU/mL, p = 0.023).

Conclusions

Patients with active RA had elevated TCC, indicating increased complement activation. TCC decreased with antirheumatic treatment already after 6 weeks. However, only treatment with TNFi±MTX led to sustained reduction in TCC during the 6-month follow-up period. RA patients with endothelial dysfunction had higher baseline TCC compared to those without, possibly reflecting involvement of complement in the atherosclerotic process in RA.

A pragmatic non-invasive assessment of liver fibrosis in patients with psoriasis, rheumatoid arthritis or Crohn's disease receiving methotrexate therapy

BACKGROUND AND AIMS

The reported hepatotoxicity of methotrexate underlines the need for a repeated non-invasive and reliable evaluation of liver fibrosis. We estimated, using a non-invasive strategy, the prevalence of significant liver fibrosis in patients treated by methotrexate and the predictors of significant fibrosis (fibrosis≥F2).

METHODS

Fibrosis was prospectively evaluated using 9 non-invasive tests in consecutive patients with psoriasis, rheumatoid arthritis, or Crohn's disease. Significant fibrosis was assessed without liver biopsy by defining a "specific method" (result given by the majority of the tests) and a "sensitive method" (at least one test indicating a stage≥F2).

RESULTS

One hundred and thirty-one patients (66 Psoriasis, 40 rheumatoid arthritis, and 25 Crohn's disease) were enrolled, including 83 receiving methotrexate. Seven tests were performed on average per patient, with a complete concordance in 75% of cases. Fibroscan® was interpretable in only 61% of patients. The best performances (AUROC>0.9) for predicting significant fibrosis were obtained by tests dedicated to steatohepatitis (FibroMeter NAFLD, NFS and FPI). The prevalence of fibrosis≥F2 according to the "specific" or the "sensitive" assessment of fibrosis was 10% and 28%, respectively. Methotrexate exposure did not influence the fibrosis stage. Factors independently associated with significant fibrosis according our "sensitive method" were age, male gender, and metabolic syndrome.

CONCLUSION

We provided a non-invasive approach for identifying liver fibrosis≥F2 by using 8 biochemical tests and Fibroscan®. In this population, the risk of significant fibrosis was related to age, male gender, and presence of metabolic syndrome, but was not influenced by methotrexate.

Incidence and Risk Factors of Hepatic Fibrosis in Psoriatic Patients Receiving Methotrexate with Concomitant Acitretin Therapy and Methotrexate Monotherapy

Background

The use of methotrexate-acitretin (MTX-ACI) combination therapy in treating psoriasis has been limited due to concerns related to hepatic fibrosis. However, in vitro evidence revealed a protective effect of acitretin in methotrexate (MTX)-induced liver fibrosis.

Objective

This study aimed to compare the real-life incidence of hepatic fibrosis in patients with psoriasis receiving MTX-ACI and MTX monotherapy and to investigate factors associated with hepatic fibrosis in MTX-exposed patients.

Methods

A retrospective cohort study was conducted based on a real-life registry containing data on patients with psoriasis who were administered MTX-ACI or MTX between 2008 and 2019 and underwent transient elastography according to cumulative MTX dose of 1.0–1.5 g and/or 3.5–4.0 g. Time-to-event analysis was performed to determine the cumulative incidence, incidence rate, and factors potentially affecting the occurrence of hepatic fibrosis.

Results

Of the 160 patients, 32 (20%) were treated with MTX-ACI, and 128 (80%) with MTX alone. Four patients (12.5%) in MTX-ACI group and 21 (16.4%) in MTX group developed hepatic fibrosis (p = 0.59). There was no statistically significant difference in cumulative incidence (16% in MTX-ACI vs 17% in MTX, p = 0.89) and incidence rate (37 cases per 1000 person-year in MTX-ACI vs 23 cases per 1000 person-year in MTX; hazard ratio [HR] = 1.07; p = 0.90) of hepatic fibrosis between the two groups. Diabetes and obesity were identified as significant factors associated with hepatic fibrosis (adjusted HR = 2.40, 95% confidence interval [CI]: 1.05–5.51; p = 0.04 and adjusted HR = 3.28, 95% CI: 1.18–9.16; p = 0.02, respectively) regardless of the cumulative MTX dose.

Conclusion

The incidence of hepatic fibrosis in a real-life clinical situation, determined by transient elastography in patients with psoriasis receiving MTX-ACI, was not increased compared to those receiving MTX monotherapy. Type 2 diabetes mellitus and obesity were identified as risk factors of hepatic fibrosis; hence, patients with these factors receiving long-term MTX therapy should be regularly monitored for this particular event.

Assessment of Liver Fibrosis Markers in People with Rheumatoid Arthritis on Methotrexate

BACKGROUND

Up to 3% of methotrexate (MTX)-treated rheumatoid arthritis (RA) patients may develop liver fibrosis or cirrhosis, requiring effective screening algorithms.

AIMS

To assess the utility of non-invasive liver fibrosis assessment in RA patients on MTX.

METHODS

56 patients were recruited from rheumatology outpatient clinics in a public tertiary centre from July 2017 to October 2018. Clinical data was collected. Screening for hepatic fibrosis was performed utilising transient elastography (TE), aminoaspartate transaminase to platelet ratio index (APRI), Hepascore, and Fibrosis-4 index (FIB-4). Those with suspected significant liver fibrosis based on these screening tests were assessed by a hepatologist.

RESULTS

27 patients were suspected to have liver fibrosis on screening, including 10/56 (18%) by TE, 20/56 (36%) by Hepascore, 2/56 by APRI (4%) and 1/56 by FIB-4 (2%). Of these 27 patients, 11 were reviewed by a hepatologist and 1 diagnosed with significant liver fibrosis. TE, but not APRI, Hepascore or FIB-4, was found to have 100% sensitivity and 84% specificity (p=0.029) for hepatologist-diagnosed liver fibrosis.

CONCLUSION

Liver fibrosis develops in a minority of MTX-treated RA patients. This study suggests that TE is a more sensitive screening test than APRI, FIB-4 or Hepascore in the identification of people with RA at risk of hepatic fibrosis. This article is protected by copyright. All rights reserved.

Role of nonalcoholic fatty liver disease as risk factor for drug-induced hepatotoxicity

BACKGROUND

Obesity is often associated with nonalcoholic fatty liver disease (NAFLD), which refers to a large spectrum of hepatic lesions including fatty liver, nonalcoholic steatohepatitis (NASH) and cirrhosis. Different investigations showed or suggested that obesity and NAFLD are able to increase the risk of hepatotoxicity of different drugs. Some of these drugs could induce more frequently an acute hepatitis in obese individuals whereas others could worsen pre-existing NAFLD.

AIM

The main objective of the present review was to collect the available information regarding the role of NAFLD as risk factor for drug-induced hepatotoxicity. For this purpose, we performed a data-mining analysis using different queries including drug-induced liver injury (or DILI), drug-induced hepatotoxicity, fatty liver, nonalcoholic fatty liver disease (or NAFLD), steatosis and obesity. The main data from the collected articles are reported in this review and when available, some pathophysiological hypotheses are put forward.

RELEVANCE FOR PATIENTS

Drugs that could pose a potential risk in obese patients include compounds belonging to different pharmacological classes such as acetaminophen, halothane, methotrexate, rosiglitazone, stavudine and tamoxifen. For some of these drugs, experimental investigations in obese rodents confirmed the clinical observations and unveiled different pathophysiological mechanisms which could explain why these pharmaceuticals are particularly hepatotoxic in obesity and NAFLD. Other drugs such as pentoxifylline, phenobarbital and omeprazole might also pose a risk but more investigations are required to determine whether this risk is significant or not. Because obese people often take several drugs for the treatment of different obesity-related diseases such as type 2 diabetes, hyperlipidemia and coronary heart disease, it is urgent to identify the main pharmaceuticals that can cause acute hepatitis on a fatty liver background or induce NAFLD worsening.

The Role of ANK in Calcium Pyrophosphate Deposition Disease

The protein product of the progressive ankylosis gene, known as ANK, is a 492-amino acid multi-pass transmembrane protein. This protein is critical for the regulation of pyrophosphate, and gain of function ANK mutations is associated with calcium pyrophosphate deposition disease. Much about the structure, function, and regulation of ANK remain unstudied. This review of the current literature examines recent contributions to our understanding of ANK. We focus on new work on the function, binding partners, and regulators of ANK. A more complete understanding of this important protein may help to identify future therapeutic targets for the treatment of calcium pyrophosphate deposition disease.

Complement 5a is an indicator of significant fibrosis and earlier cirrhosis in patients chronically infected with hepatitis B virus

Purpose

To investigate the association between serum complement 5a (C5a) concentration and liver fibrosis and cirrhosis in a large cohort of patients chronically infected with hepatitis B virus (HBV).

Methods

Five hundred and eight patients with chronic HBV infection undergoing liver biopsy were included. Serum concentrations of C5a was measured by Luminex screening system. Ishak histological system was obtained.

Results

C5a levels were negatively associated with liver fibrosis stages and significantly declined in patients with severe fibrosis and cirrhosis (P < 0.001). Multiple analysis showed C5a, AST, laminin, Co-IV, platelet count, albumin, HBsAg associated with liver fibrosis independently. Based on the markers above, we created two scores, Fib-model for significant fibrosis and Cirrh-model for earlier cirrhosis. Fib-model was performing better to differentiate from significant fibrosis, with an AUROC of 0.82 (95 % CI 0.78, 0.86), in comparison to existed models APRI, FIB-4 and Forns’ index with AUROCs of 0.71 (95 % CI 0.66, 0.76), 0.72 (95 % CI 0.67, 0.77), 0.77 (95 % CI 0.72, 0.81), respectively. Although, Cirrh-model showed AUROC of 0.85 (95 % CI 0.80, 0.91) for evaluation of earlier cirrhosis, superior to APRI, and Forns’ index, C5a + FIB-4 performed best with an AUROC of 0.94 (95 % CI 0.90, 0.97).

Conclusion

In patients with chronic HBV infection, serum C5a concentration significantly decreased in severe fibrosis stages and earlier cirrhosis. Fib-model and C5a + FIB-4 performed better than existed models for assessment of significant fibrosis and earlier cirrhosis, respectively.

Electronic supplementary material

The online version of this article (doi:10.1007/s15010-016-0942-7) contains supplementary material, which is available to authorized users.

Genomic characterization of remission in juvenile idiopathic arthritis

Introduction

The attainment of remission has become an important end point for clinical trials in juvenile idiopathic arthritis (JIA), although we do not yet have a full understanding of what remission is at the cell and molecular level.

Methods

Two independent cohorts of patients with JIA and healthy child controls were studied. RNA was prepared separately from peripheral blood mononuclear cells (PBMC) and granulocytes to identify differentially expressed genes using whole genome microarrays. Expression profiling results for selected genes were confirmed by quantitative, real-time polymerase chain reaction (RT-PCR).

Results

We found that remission in JIA induced by either methotrexate (MTX) or MTX plus a TNF inhibitor (etanercept, Et) (MTX + Et) is characterized by numerous differences in gene expression in peripheral blood mononuclear cells and in granulocytes compared with healthy control children; that is, remission is not a restoration of immunologic normalcy. Network analysis of the differentially expressed genes demonstrated that the steroid hormone receptor superfamily member hepatocyte nuclear factor 4 alpha (HNF4α) is a hub in several of the gene networks that distinguished children with arthritis from controls. Confocal microscopy revealed that HNF4a is present in both T lymphocytes and granulocytes, suggesting a previously unsuspected role for this transcription factor in regulating leukocyte function and therapeutic response in JIA.

Conclusions

These findings provide a framework from which to understand therapeutic response in JIA and, furthermore, may be used to develop strategies to increase the frequency with which remission is achieved in adult forms of rheumatoid arthritis.

In silico pathway analysis: the final frontier towards completely rational drug design

Pathway and network analyses are rapidly becoming the mainstream tools for functional interpretation of high-throughput data and for drug discovery. Current scientific literature has plenty of examples on how pathway analysis tools are used across all steps of drug development pipeline. Pathway and network analyses already enable rational selection of drug targets based on the knowledge about disease biology. Pathway analysis tools are also popular for the analysis of drug action and validation of drug efficacy and toxicity. This article overviews current achievements of pathway analysis and suggests future directions for its application in drug development such as rational design of combinatorial therapy and personalized medicine.

Identification of novel compounds that enhance colon cancer cell sensitivity to inflammatory apoptotic ligands

Immune and inflammatory death ligands expressed within neoplastic tissue could potentially target apoptosis to transformed cells. To develop approaches that accentuate the anti-cancer potential of the inflammatory response, the Chembridge DIVERSet (TM) library was screened for compounds that accentuated apoptosis in a strictly TNF-dependent manner. We identified a number of novel compounds with this activity, the most active of these, AK3 and AK10, sensitized colon cancer cells to TNF at 0.5 μM and 2 μM, respectively, without inducing apoptosis on their own. The activity of these compounds was structure-dependent and general, as they accentuated cell death by TNF or Fas ligation in multiple colon cancer cell lines. Both AK3 and AK10 arrested cells in mitosis, with live cell imaging indicating that mitotically arrested cells were the source of apoptotic bodies. AK3 accentuated caspase-8 and caspase-9 activation with little effect on NFκB target gene activation. Enhanced caspase activation corresponded to an increased expression of TNFR1 on the cell surface. To determine the general interplay between mitotic arrest and TNF sensitivity, Aurora kinase (MLN8054 and MLN8237) and PLK1 (BI2536) inhibitors were tested for their ability to sensitize cells to TNF. PLK1 inhibition was particularly effective and influenced TNFR1 surface presentation and caspase cleavage like AK3, even though it arrested mitosis at an earlier stage. We propose that AK3 and AK10 represent a new class of mitotic inhibitor and that selected mitotic inhibitors may be useful for treating colon cancers or earlier lesions that have a high level of inflammatory cell infiltrate.

Liver stiffness correlates with methotrexate cumulative dose in patients with rheumatoid arthritis

BACKGROUND

Liver stiffness values were recently proposed to identify patients with methotrexate-induced liver fibrosis. Aim of this study was to assess the clinical and laboratory determinants of the association between liver stiffness, measured by transient elastography, and methotrexate treatment in patients with rheumatoid arthritis in the absence of other factors contributing to liver damage and fibrosis.

METHODS

100 patients with rheumatoid arthritis, with a cumulative methotrexate dose ranging from 1530 to 13,000 mg over a mean period of 7.07±3.89 yrs, were retrospectively evaluated.

RESULTS

The average liver stiffness value in the whole population was 4.93±1.8 kPa, excluding the presence of significant fibrosis. At univariate analysis, a significant correlation was found between liver stiffness and methotrexate cumulative dose, duration of treatment, alanine transaminases levels, body mass index, gamma glutamyl-transpeptidase and the presence of steatosis. At multivariate analysis, a significant association was detected only between liver stiffness and methotrexate cumulative dose. Out of 11 patients with liver stiffness >7.0 kPa, five were subjected to liver biopsy and mild or moderate perisinusoidal fibrosis was detected in two patients with a cumulative dose >4000 mg and liver stiffness >9 kPa.

CONCLUSIONS

Chronic methotrexate treatment induces a progressive increase in liver stiffness corresponding to mild or moderate perisinusoidal fibrosis for values >9 kPa.

Extracellular matrix molecules: potential targets in pharmacotherapy

The extracellular matrix (ECM) consists of numerous macromolecules classified traditionally into collagens, elastin, and microfibrillar proteins, proteoglycans including hyaluronan, and noncollagenous glycoproteins. In addition to being necessary structural components, ECM molecules exhibit important functional roles in the control of key cellular events such as adhesion, migration, proliferation, differentiation, and survival. Any structural inherited or acquired defect and/or metabolic disturbance in the ECM may cause cellular and tissue alterations that can lead to the development or progression of disease. Consequently, ECM molecules are important targets for pharmacotherapy. Specific agents that prevent the excess accumulation of ECM molecules in the vascular system, liver, kidney, skin, and lung; alternatively, agents that inhibit the degradation of the ECM in degenerative diseases such as osteoarthritis would be clinically beneficial. Unfortunately, until recently, the ECM in drug discovery has been largely ignored. However, several of today's drugs that act on various primary targets affect the ECM as a byproduct of the drugs' actions, and this activity may in part be beneficial to the drugs' disease-modifying properties. In the future, agents and compounds targeting directly the ECM will significantly advance the treatment of various human diseases, even those for which efficient therapies are not yet available.