Fumaric acid esters suppress peripheral CD4- and CD8-positive lymphocytes in psoriasis

Nuclear Factor Erythroid 2 Related Factor 2 and Mitochondria Form a Mutually Regulating Circuit in the Prevention and Treatment of Metabolic Syndrome

Significance: Metabolic syndrome (MetS) has become a major global public health problem and there is an urgent need to elucidate its pathogenesis and find more effective targets and modalities for intervention. Recent Advances: Oxidative stress and inflammation are two of the major causes of MetS-related symptoms such as insulin resistance and obesity. Nuclear factor erythroid 2 related factor 2 (Nrf2) is one of the important systems responding to oxidative stress and inflammation. As cells undergo stress, cysteines within Kelch-like ECH-associated protein 1 (Keap1) are oxidized or electrophilically modified, allowing Nrf2 to escape ubiquitination and be translocated from the cytoplasm to the nucleus, facilitating the initiation of the antioxidant transcriptional program. Meanwhile, a growing body of evidence points out a specific modulation of mitochondrial homeostasis by Nrf2. After nuclear translocation, Nrf2 activates downstream genes involved in various aspects of mitochondrial homeostasis, including mitochondrial biogenesis and dynamics, mitophagy, aerobic respiration, and energy metabolism. In turn, mitochondria reciprocally activate Nrf2 by releasing reactive oxygen species and regulating antioxidant enzymes. Critical Issues: In this review, we first summarize the interactions between Nrf2 and mitochondria in the modulation of oxidative stress and inflammation to ameliorate MetS, then propose that Nrf2 and mitochondria form a mutually regulating circuit critical to maintaining homeostasis during MetS. Future Directions: Targeting the Nrf2-mitochondrial circuit may be a promising strategy to ameliorate MetS, such as obesity, diabetes, and cardiovascular diseases.

Nrf2 Signaling Pathway: a Potential Therapeutic Target in Combating Oxidative Stress and Neurotoxicity in Chemotherapy-Induced Cognitive Impairment

Chemotherapy-induced cognitive impairment (CICI) is one of the major adverse effects of antineoplastic drugs, which decrease the quality of life in cancer survivors. Extensive experimental and clinical research suggests that chemotherapeutic drugs generate an enormous amount of reactive oxygen species (ROS), contributing to oxidative stress, neuroinflammation, blood-brain barrier (BBB) disruption, and neuronal death, eventually leading to CICI. Despite the progress in exploring different pathological mechanisms of CICI, effective treatment to prevent CICI progression has not been developed yet. Nrf2 is the principal transcription factor that regulates cellular redox balance and inflammation-related gene expression. Emerging evidence suggests that upregulation of Nrf2 and its target genes could suppress oxidative stress, and neuroinflammation, restore BBB integrity, and increase neurogenesis. This review discusses the role of Nrf2 in CICI, how it responds to oxidative stress, inflammation, neurotoxicity, and potential Nrf2 activators that could be used to enhance Nrf2 activation in CICI.

Exploring Psoriasis Inflammatory Microenvironment by NanoString Technologies

Psoriasis is a chronic inflammatory skin disease whose molecular mechanisms and microenvironment are poorly understood. We performed gene expression analysis through the nCounter® PanCancer Immune Profiling Panel (NanoString Technologies, Seattle, WA, USA) on 22 FFPE punch biopsies from 19 psoriasis-affected patients. A subset of five cases was analyzed before (T0) and after 6 months (T6) of treatment with dimethyl fumarate (DMF) to address immune microenvironment changes. Molecular comparisons according to biopsy site and age of onset showed a different distribution of innate immune cells (mast cells, macrophages, NK cells, and DC cells) and pathways (complement regulation and transporter functions). The analysis according to PASI (Psoriasis Area and Severity Index) led to non-significant results, suggesting no link between molecular expression profile and clinical amount of skin disease. In DMF-treated patients, we observed a strong immunomodulatory effect after treatment: A subversion of exhausted CD8 T cells, NK CD56dim cells, Tregs, neutrophils, CD45+ cells, T cells, B cells, and macrophages was reported between the two analyzed time-points, as well as the reduction in pro-inflammatory pathways and molecules, including cytotoxicity, pathogen defense, antigen processing, adhesion, cell cycle, chemokines, cytokines, and interleukins. The inflammatory psoriatic microenvironment can be modulated using DMF with encouraging results, achieving an immune-tolerant and non-inflammatory condition through the regulation of both innate and adaptive immunity.

Biochemical and cellular basis of oxidative stress: Implications for disease onset

Cellular oxidation-reduction (redox) systems, which encompass pro- and antioxidant molecules, are integral components of a plethora of essential cellular processes. Any dysregulation of these systems can cause molecular imbalances between the pro- and antioxidant moieties, leading to a state of oxidative stress. Long-lasting oxidative stress can manifest clinically as a variety of chronic illnesses including cancers, neurodegenerative disorders, cardiovascular disease, and metabolic diseases like diabetes. As such, this review investigates the impact of oxidative stress on the human body with emphasis on the underlying oxidants, mechanisms, and pathways. It also discusses the available antioxidant defense mechanisms. The cellular monitoring and regulatory systems that ensure a balanced oxidative cellular environment are detailed. We critically discuss the notion of oxidants as a double-edged sword, being signaling messengers at low physiological concentrations but causative agents of oxidative stress when overproduced. In this regard, the review also presents strategies employed by oxidants including redox signaling and activation of transcriptional programs such as those mediated by the Nrf2/Keap1 and NFk signaling. Likewise, redox molecular switches of peroxiredoxin and DJ-1 and the proteins they regulate are presented. The review concludes that a thorough comprehension of cellular redox systems is essential to develop the evolving field of redox medicine.

An inhibitor of interaction between the transcription factor NRF2 and the E3 ubiquitin ligase adapter β-TrCP delivers anti-inflammatory responses in mouse liver

It is widely accepted that activating the transcription factor NRF2 will blast the physiological anti-inflammatory mechanisms, which will help combat pathologic inflammation. Much effort is being put in inhibiting the main NRF2 repressor, KEAP1, with either electrophilic small molecules or disrupters of the KEAP1/NRF2 interaction. However, targeting β-TrCP, the non-canonical repressor of NRF2, has not been considered yet. After in silico screening of ∼1 million compounds, we now describe a novel small molecule, PHAR, that selectively inhibits the interaction between β-TrCP and the phosphodegron in transcription factor NRF2. PHAR upregulates NRF2-target genes such as Hmox1, Nqo1, Gclc, Gclm and Aox1, in a KEAP1-independent, but β-TrCP dependent manner, breaks the β-TrCP/NRF2 interaction in the cell nucleus, and inhibits the β-TrCP-mediated in vitro ubiquitination of NRF2. PHAR attenuates hydrogen peroxide induced oxidative stress and, in lipopolysaccharide-treated macrophages, it downregulates the expression of inflammatory genes Il1b, Il6, Cox2, Nos2. In mice, PHAR selectively targets the liver and greatly attenuates LPS-induced liver inflammation as indicated by a reduction in the gene expression of the inflammatory cytokines Il1b, TNf, and Il6, and in F4/80-stained liver resident macrophages. Thus, PHAR offers a still unexplored alternative to current NRF2 activators by acting as a β-TrCP/NRF2 interaction inhibitor that may have a therapeutic value against undesirable inflammation.

In Vitro Efficacy and Molecular Mechanism of Curcumin Analog in Pathological Regulation of Spinocerebellar Ataxia Type 3

Unlike other nuclear factor erythroid-2-related factor 2 (Nrf2) activators, the mechanism of action of curcumin analog, ASC-JM17 (JM17), in regulating oxidative homeostasis remains unknown. Spinocerebellar ataxia type 3 (SCA3) is an inherited polyglutamine neurodegenerative disease caused mainly by polyglutamine neurotoxicity and oxidative stress. Presently, we compared actions of JM17 with those of known Nrf2 activators, omaveloxolone (RTA-408) and dimethyl fumarate (DMF), using human neuroblastoma SK-N-SH cells with stable transfection of full-length ataxin-3 protein with 78 CAG repeats (MJD78) to clarify the resulting pathological mechanism by assaying mitochondrial function, mutant ataxin-3 protein toxicity, and oxidative stress. JM17, 1 μM, comprehensively restored mitochondrial function, decreased mutant protein aggregates, and attenuated intracellular/mitochondrial reactive oxygen species (ROS) levels. Although JM17 induced dose-dependent Nrf2 activation, a low dose of JM17 (less than 5 μM) still had a better antioxidant ability compared to the other Nrf2 activators and specifically increased mitochondrial superoxide dismutase 2 in an Nrf2-dependent manner as shown by knockdown experiments with siRNA. It showed that activation of Nrf2 in response to ROS generated in mitochondria could play an import role in the benefit of JM17. This study presents the diversified regulation of JM17 in a pathological process and helped develop more effective therapeutic strategies for SCA3.

Dimethyl fumarate titration for the systemic treatment of moderate-to-severe plaque psoriasis

Background

Dimethyl fumarate (DMF) is an oral systemic agent approved for the treatment of moderate-to-severe psoriasis vulgaris. It has a favourable tolerability profile, but it is associated with a high incidence of mild and reversible adverse events. The aim of the article is to describe a clinical experience aimed at increasing tolerability.

Patients and methods

A group of patients was treated with DMF with a titration schedule, according to clinical practice, although a personalization of the step-up timing was allowed. The highest dose was the minimal effective dose or the maximal tolerated doses.

Results

DMF treatment was effective in reducing the disease severity and improving the quality of life. DMF was well tolerated as only mild, mainly gastrointestinal, adverse events occurred in these patients. In addition, the up-titration schedule seemed to provide a reduced incidence of adverse events compared with the fixed dose.

Conclusion

Our experience suggested that the recommended up-titration schedule of DMF, adjusted and personalized according to patient needs and physician opinion, provided a relevant clinical benefit and was well tolerated.

Cross-sectional analysis of peripheral blood mononuclear cells in lymphopenic and non-lymphopenic relapsing-remitting multiple sclerosis patients treated with dimethyl fumarate

BACKGROUND

Relapsing-remitting multiple sclerosis (RRMS) is an autoimmune disorder of the central nervous system. Dimethyl Fumarate is a disease-modifying medication used to treat RRMS patients that can induce lymphopenia. We aimed to immunophenotype peripheral blood mononuclear cells (PBMC) in RRMS patients cross-sectionally and examine the characteristics and modifications of lymphopenia over time.

METHODS

Characterization of PBMC was done by multiparametric flow cytometry. Patients had been on treatment for up to 4 years and were grouped into lymphopenic (DMF-L) and non-lymphopenic (DMF-N) patients.

RESULTS

Lymphopenia affected the cell population changes over time, with other patient characteristics (gender, age, and previous treatment status) also having significant effects. In both lymphopenic and non-lymphopenic patients, PBMC percentages were reduced over time. While overall T and B cells frequencies were not affected, males, older patients and untreated patients had significant changes in B cell subpopulations over time. CD4⁺ to CD8⁺T cell ratio increased significantly in lymphopenic patients over time. CD4^-CD8^-T cell population was similarly reduced in both lymphopenic and non-lymphopenic patients, over time. While the monocyte and NK overall populations were not changed, non-classical monocyte subpopulation decreased over time in lymphopenic patients. We also found CD56^-CD16⁺ and CD56^-CD16^- NK cells frequencies changed over time in lymphopenic patients. Immune populations showed correlations with clinical outcomes measured by EDSS and relapse rate. Analysis of the overall immunophenotype showed that, while groups divided by other patient characteristics showed differences, the lymphopenia status overrode these differences, resulting in similar immunophenotype within DMF-L.

CONCLUSIONS

Our data provide evidence that under the same therapy, lymphopenia affects how the immunophenotype changes over time and can override the differences associated with other patient characteristics and possibly mask other significant changes in the immune profile of patients.

The antioxidant response in Barrett's tumorigenesis: A double-edged sword

Esophageal adenocarcinoma (EAC) is the dominant form of esophageal malignancies in the United States and other industrialized countries. The incidence of EAC has been rising rapidly during the past four decades. Barrett's esophagus (BE) is the main precancerous condition for EAC, where a metaplastic columnar epithelium replaces normal squamous mucosa of the lower esophagus. The primary risk factor for BE and EAC are chronic gastroesophageal reflux disease (GERD), obesity and smoking. During the BE-dysplasia-EAC sequence, esophageal cells are under a tremendous burden of accumulating reactive oxygen species (ROS) and oxidative stress. While normal cells have intact antioxidant machinery to maintain a balanced anti-tumorigenic physiological response, the antioxidant capacity is compromised in neoplastic cells with a pro-tumorigenic development antioxidant response. The accumulation of ROS, during the neoplastic progression of the GERD-BE-EAC sequence, induces DNA damage, lipid peroxidation and protein oxidation. Neoplastic cells adapt to oxidative stress by developing a pro-tumorigenic antioxidant response that keeps oxidative damage below lethal levels while promoting tumorigenesis, progression, and resistance to therapy. In this review, we will summarize the recent findings on oxidative stress in tumorigenesis in the context of the GERD-BE-EAC process. We will discuss how EAC cells adapt to increased ROS. We will review APE1 and NRF2 signaling mechanisms in the context of EAC. Finally, we will discuss the potential clinical significance of applying antioxidants or NRF2 activators as chemoprevention and NRF2 inhibitors in treating EAC patients.

Oral dimethyl fumarate induces changes within the peripheral neutrophil compartment of patients with psoriasis that are linked with skin improvement

BACKGROUND

Dimethyl fumarate (DMF) is a treatment for moderate-to-severe psoriasis and multiple sclerosis. DMF therapy typically improves skin inflammation within the first 3 months of treatment. DMF is a prodrug that generates the hydroxycarboxylic acid receptor 2 (HCA2) agonist, monomethyl fumarate (MMF). Despite widespread clinical use, DMF's mechanism of action is not fully understood.

OBJECTIVES

We wished to characterize the changes induced by DMF in peripheral neutrophils within the first 3 months of treatment to better understand its early antipsoriatic effects.

METHODS

Flow cytometry was used to assess T-cell and neutrophil frequencies, apoptosis and activation phenotype. In vitro culture of neutrophils with DMF and MMF was used to evaluate apoptosis and HCA2 internalization. Serum levels of neutrophil degranulation products were measured by enzyme-linked immunosorbent assay.

RESULTS

Patients with psoriasis had significantly higher leucocyte counts at baseline compared with controls, with a large population of pro-inflammatory CD62L^lo  CD11b^bright neutrophils. Analysis revealed that DMF treatment reduced the frequency of CD62L^lo  CD11b^bright neutrophils and serum levels of neutrophil activation markers. This reduction was not linked to increased apoptosis.

CONCLUSIONS

Our results reveal a novel in vivo effect of DMF therapy on pro-inflammatory neutrophils that likely contributes to this treatment's antipsoriatic efficacy.

Perspectives on the Clinical Development of NRF2-Targeting Drugs

The transcription factor NRF2 (nuclear factor erythroid 2-related factor 2) triggers homeostatic responses against a plethora of environmental or endogenous deviations in redox metabolism, inflammation, proteostasis, etc. Therefore, pharmacological activation of NRF2 is a promising therapeutic strategy for several chronic diseases that are underlined by low-grade oxidative inflammation and dysregulation of redox metabolism, such as neurodegenerative, cardiovascular, and metabolic diseases. While NRF2 activation is useful in inhibiting carcinogenesis, its inhibition is needed in constituted tumors where NRF2 provides a survival advantage in the challenging tumor niche. This review describes the electrophilic and non-electrophilic NRF2 activators with clinical projection in various chronic diseases. We also analyze the status of NRF2 inhibitors, which are for the moment in a proof-of-concept stage. Advanced in silico screening and medicinal chemistry are expected to provide new or repurposing small molecules with increased potential for fostering the development of targeted NRF2 modulators. The nuclear factor erythroid 2 (NFE2)-related factor 2 (NRF2) is rapidly degraded by proteasomes under a basal condition in a Keap1-dependent manner. ROS oxidatively modifies Keap1 to release NRF2 and allow its nuclear translocation. Here it binds to the antioxidant response element to regulate gene transcription. An alternative mechanism controlling NRF2 stability is glycogen synthase kinase 3 (GSK-3)-induced phosphorylation. Indicated in blue are NRF2-activating and NRF2-inhibiting drugs.

Friend or Foe: Xenobiotic Activation of Nrf2 in Disease Control and Cardioprotection

Nuclear factor erythroid 2-related factor 2 (Nrf2) is a transcription factor that governs a highly conserved pathway central to the protection of cells against various oxidative stresses. However, the biological impact of xenobiotic intervention of Nrf2 in physiological and pathophysiological conditions remains debatable. Activation of Nrf2 in cancer cells has been shown to elevate drug resistance and increase cell survival and proliferation, while inhibition of Nrf2 sensitizes cancer cells to drug treatment. On the other hand, activation of Nrf2 in normal healthy cells has been explored as a rather successful strategy for cancer chemoprevention. Selective activation of Nrf2 in off-target cells has recently been investigated as an approach for protecting off-target tissues from untoward drug toxicity. Specifically, induction of antioxidant response element genes via Nrf2 activation in cardiac cells is being explored as a means to limit the well-documented cardiotoxicity accompanied by cancer treatment with commonly prescribed anthracycline drugs. In addition to cancers, Nrf2 has been implicated in many other diseases including Alzheimer's and Parkinson's Diseases, diabetes, and cardiovascular disease. In this review, we discuss the roles of Nrf2 and its downstream target genes in the treatment of various diseases, and its recently explored potential for increasing the benefit: risk ratio of commonly utilized cancer treatments.

Different Fumaric Acid Esters Elicit Distinct Pharmacologic Responses

Objective

To test the hypothesis that dimethyl fumarate (DMF, Tecfidera) elicits different biological changes from DMF combined with monoethyl fumarate (MEF) (Fumaderm, a psoriasis therapy), we investigated DMF and MEF in rodents and cynomolgus monkeys. Possible translatability of findings was explored with lymphocyte counts from a retrospective cohort of patients with MS.

Methods

In rodents, we evaluated pharmacokinetic and pharmacodynamic effects induced by DMF and MEF monotherapies or in combination (DMF/MEF). Clinical implications were investigated in a retrospective, observational analysis of patients with MS treated with DMF/MEF (n = 36).

Results

In rodents and cynomolgus monkeys, monomethyl fumarate (MMF, the primary metabolite of DMF) exhibited higher brain penetration, whereas MEF was preferentially partitioned into the kidney. In mice, transcriptional profiling for DMF and MEF alone identified both common and distinct pharmacodynamic responses, with almost no overlap between DMF- and MEF-induced differentially expressed gene profiles in immune tissues. The nuclear factor (erythroid-derived 2)-like 2 (Nrf2)-mediated oxidative stress response pathway was exclusively regulated by DMF, whereas apoptosis pathways were activated by MEF. DMF/MEF treatment demonstrated that DMF and MEF functionally interact to modify DMF- and MEF-specific responses in unpredictable ways. In patients with MS, DMF/MEF treatment led to early and pronounced suppression of lymphocytes, predominantly CD8⁺ T cells. In a multivariate regression analysis, the absolute lymphocyte count (ALC) was associated with age at therapy start, baseline ALC, and DMF/MEF dosage but not with previous immunosuppressive medication and sex. Furthermore, the ALC increased in a small cohort of patients with MS (n = 6/7) after switching from DMF/MEF to DMF monotherapy.

Conclusions

Fumaric acid esters exhibit different biodistribution and may elicit different biological responses; furthermore, pharmacodynamic effects of combinations differ unpredictably from monotherapy. The strong potential to induce lymphopenia in patients with MS may be a result of activation of apoptosis pathways by MEF compared with DMF.

Dimethyl fumarate induced lymphopenia in multiple sclerosis: A review of the literature

Dimethyl fumarate (DMF) is a first line medication for multiple sclerosis. It has a favourable safety profile, however, there is concern regarding the occurrence of moderate-severe and sustained lymphopenia and the associated risk of progressive multifocal leukoencephalopathy. We carried out an extensive literature review to understand the molecular mechanisms underlying this adverse reaction. Dynamic changes in certain components of the immune system are likely to be important for the therapeutic effects of DMF, including depletion of memory T cells and decrease in activated T cells together with expansion of naïve T cells. Similar modifications were reported for the B cell components. CD8⁺ T cells are particularly susceptible to DMF-induced cell death, with marked reductions observed in lymphopenic subjects. The reasons underlying such increased sensitivity are not known, nor it is known how expansion of other lymphocyte subsets occurs. Understanding the molecular mechanisms underlying DMF action is challenging: in vivo DMF is rapidly metabolized to monomethyl fumarate (MMF), a less potent immunomodulator in vitro. Pharmacokinetics indicate that MMF is the main active species in vivo. However, the relative importance of DMF and MMF in toxicity remains unclear, with evidence presented in favour of either of the compounds as toxic species. Pharmacogenetic studies to identify genetic predictors of DMF-induced lymphopenia are limited, with inconclusive results. A role of the gut microbiome in the pharmacological effects of DMF is emerging. It is clear that further investigations are necessary to understand the mechanisms of DMF-induced lymphopenia and devise preventive strategies. Periodic monitoring of absolute lymphocyte counts, currently performed in clinical practise, allows for the early detection of lymphopenia as a risk-minimization strategy.

Nrf2 in Neoplastic and Non-Neoplastic Liver Diseases

Simple Summary

Although the Keap1-Nrf2 pathway represents a powerful cell defense mechanism against a variety of toxic insults, its role in acute or chronic liver damage and tumor development is not completely understood. This review addresses how Nrf2 is involved in liver pathophysiology and critically discusses the contrasting results emerging from the literature. The aim of the present report is to stimulate further investigation on the role of Nrf2 that could lead to define the best strategies to therapeutically target this pathway.

Abstract

Activation of the Keap1/Nrf2 pathway, the most important cell defense signal, triggered to neutralize the harmful effects of electrophilic and oxidative stress, plays a crucial role in cell survival. Therefore, its ability to attenuate acute and chronic liver damage, where oxidative stress represents the key player, is not surprising. On the other hand, while Nrf2 promotes proliferation in cancer cells, its role in non-neoplastic hepatocytes is a matter of debate. Another topic of uncertainty concerns the nature of the mechanisms of Nrf2 activation in hepatocarcinogenesis. Indeed, it remains unclear what is the main mechanism behind the sustained activation of the Keap1/Nrf2 pathway in hepatocarcinogenesis. This raises doubts about the best strategies to therapeutically target this pathway. In this review, we will analyze and discuss our present knowledge concerning the role of Nrf2 in hepatic physiology and pathology, including hepatocellular carcinoma. In particular, we will critically examine and discuss some findings originating from animal models that raise questions that still need to be adequately answered.

NRF2 Regulation Processes as a Source of Potential Drug Targets against Neurodegenerative Diseases

NRF2 acts by controlling gene expression, being the master regulator of the Phase II antioxidant response, and also being key to the control of neuroinflammation. NRF2 activity is regulated at several levels, including protein degradation by the proteasome, transcription, and post-transcription. The purpose of this review is to offer a concise and critical overview of the main mechanisms of NRF2 regulation and their actual or potential use as targets for the treatment of neurodegenerative diseases.

A safety evaluation of dimethyl fumarate in moderate-to-severe psoriasis

Introduction: Psoriasis is a chronic inflammatory disorder affecting skin, nails and joints. Systemic therapy of psoriasis is based upon several drugs which include fumaric acid esters (FAEs), initially introduced in 1959. Since 2017, one of the key substances among FAE spectrum (dimethyl fumarate; DMF) was registered by the European Medicines Agency (EMA) for the treatment of moderate-to-severe psoriasis vulgaris.Areas covered: This article covers the basic concepts underlying usefulness of DMF in psoriasis and extensively reviews the studies, which included its use in monotherapy of this dermatosis, with a particular emphasis on safety aspects and adverse events (AEs).Expert opinion: DMF monotherapy is a valuable systemic modality in the management of moderate-to-severe psoriasis as proved by a recent phase III study. AEs associated with DMF therapy are frequent, usually of mild severity, with a dose-independent manner. Occasionally they are burdensome and require drug discontinuation. The most common AEs comprise gastrointestinal symptoms, flushing and white blood cell count abnormalities. The latter require strict monitoring to prevent serious complications. Acknowledging the possibility of AEs, the use of DMF in moderate-to-severe psoriasis is encouraged while the need of further studies still remains.

In MS: Immunosuppression is passé

IMPORTANCE

Prolonged and significant alterations of the immune system by immunosuppression makes multiple sclerosis (MS) patients susceptible to opportunistic infections and malignancies over long periods of treatment.

OBSERVATIONS

A reasonable clinical and practical definition of immunosuppression is a temporary or permanent alteration of the body's immune system and subsequent lack of ability to fight infections and malignancies. Immunosurveillance is the sine qua non of the immune system. Immunosurveillance is the constant process by which the immune system looks for and recognizes foreign pathogens such as bacteria and viruses or pre-cancerous or cancerous cells in the body. Immunomodulation (a decrease or increase in pitch or tone - in this case a decrease) maintains immunosurveillance. Immunosuppression (quashing, stamping out) impedes immunosurveillance by one mechanism or another. Immunosuppressive agents need to be administered continually in order to maintain effectiveness. In contrast, immune reconstitution therapies (IRTs) are short course agents that are initially immunosuppressive but ultimately immunomodulatory and can provide significant decreased disease activity over time without retreatment.

CONCLUSIONS AND RELEVANCE

The goal of disease modifying therapies in MS is effectiveness over long periods of time with minimal risk. The preservation, reduction or elimination of immunosurveillance should be an important consideration in deciding on the optimal disease modifying treatments (DMT) for an individual MS patient. IRTs have the advantage of providing long term control of disease activity with short term immunosuppression followed by long term immunomodulation without retreatment. For most MS patients with mild or modest disease activity, initial immunomodulation followed by IRT for breakthrough disease may be the best option. In MS, immunosuppression may be passé.

Risk factors for lymphopenia in patients with relapsing-remitting multiple sclerosis treated with dimethyl fumarate

OBJECTIVES

To identify risk factors for DMF-induced lymphopenia and characterize its impact on T lymphocyte subsets in MS patients.

METHODS

We performed a retrospective analysis of 194 RRMS patients treated with DMF at the Beth Israel Deaconess Medical Center (BIDMC) over a median of 17 months. We reviewed demographics, ethnic background, prior medication history, complete blood counts and T lymphocyte subsets. Possible lymphopenia risk factors examined included age, prior natalizumab exposure, vitamin D levels, and concomitant exposure to carbamazepine, opiates, tobacco, or steroids. Lymphopenia was defined as grade 1: absolute lymphocytes count (ALC) 800-999/μl; grade 2: ALC 500-799/μl; grade 3: ALC 200-499/μl; and grade 4: ALC < 200/μl.

RESULTS

Of 194 DMF-treated patients, 73 (38%) developed lymphopenia and reached an ALC nadir after a median of 504 days (range 82-932). Risk of developing DMF-induced lymphopenia increased with BMI 25-30, older age, white ethnicity, non-smoking status, and lowest quartile baseline ALC. Prior exposure to natalizumab or concomitant steroid, opiates or carbamazepine/oxcarbamazepine use was not associated with lymphopenia. Compared to baseline levels, CD8 T cells were significantly more reduced than CD4 cells. CD8 counts were more commonly reduced with age or white ethnicity. Subjects with BMI 25-30 was associated with a higher risk of abnormal CD4 cell count reductions. In contrast, non-smokers were more likely to experience reductions in both CD4 and CD8 counts while on DMF.

CONCLUSIONS

Patients with low baseline lymphocyte counts, with intermediate BMI, with white ethnicity, with advanced age, or with no tobacco use, had a significantly higher incidence of lymphopenia on DMF. Intermediate BMI or lowest quartile baseline ALC predicted low CD4 levels, while advanced age or white ethnicity predicted low CD8 levels from DMF exposure.

Risk factors for lymphopenia in patients with relapsing-remitting multiple sclerosis treated with dimethyl fumarate

OBJECTIVES

To identify risk factors for DMF-induced lymphopenia and characterize its impact on T lymphocyte subsets in MS patients.

METHODS

We performed a retrospective analysis of 194 RRMS patients treated with DMF at the Beth Israel Deaconess Medical Center (BIDMC) over a median of 17 months. We reviewed demographics, ethnic background, prior medication history, complete blood counts and T lymphocyte subsets. Possible lymphopenia risk factors examined included age, prior natalizumab exposure, vitamin D levels, and concomitant exposure to carbamazepine, opiates, tobacco, or steroids. Lymphopenia was defined as grade 1: absolute lymphocytes count (ALC) 800-999/μl; grade 2: ALC 500-799/μl; grade 3: ALC 200-499/μl; and grade 4: ALC < 200/μl.

RESULTS

Of 194 DMF-treated patients, 73 (38%) developed lymphopenia and reached an ALC nadir after a median of 504 days (range 82-932). Risk of developing DMF-induced lymphopenia increased with BMI 25-30, older age, white ethnicity, non-smoking status, and lowest quartile baseline ALC. Prior exposure to natalizumab or concomitant steroid, opiates or carbamazepine/oxcarbamazepine use was not associated with lymphopenia. Compared to baseline levels, CD8 T cells were significantly more reduced than CD4 cells. CD8 counts were more commonly reduced with age or white ethnicity. Subjects with BMI 25-30 was associated with a higher risk of abnormal CD4 cell count reductions. In contrast, non-smokers were more likely to experience reductions in both CD4 and CD8 counts while on DMF.

CONCLUSIONS

Patients with low baseline lymphocyte counts, with intermediate BMI, with white ethnicity, with advanced age, or with no tobacco use, had a significantly higher incidence of lymphopenia on DMF. Intermediate BMI or lowest quartile baseline ALC predicted low CD4 levels, while advanced age or white ethnicity predicted low CD8 levels from DMF exposure.

Activators and Inhibitors of NRF2: A Review of Their Potential for Clinical Development

The transcription factor NRF2 (nuclear factor erythroid 2-related factor 2) triggers the first line of homeostatic responses against a plethora of environmental or endogenous deviations in redox metabolism, proteostasis, inflammation, etc. Therefore, pharmacological activation of NRF2 is a promising therapeutic approach for several chronic diseases that are underlined by oxidative stress and inflammation, such as neurodegenerative, cardiovascular, and metabolic diseases. A particular case is cancer, where NRF2 confers a survival advantage to constituted tumors, and therefore, NRF2 inhibition is desired. This review describes the electrophilic and nonelectrophilic NRF2 activators with clinical projection in various chronic diseases. We also analyze the status of NRF2 inhibitors, which at this time provide proof of concept for blocking NRF2 activity in cancer therapy.

ARE ANTIBIOTICS OF ANY USE IN THE MANAGEMENT OF GRANULOMA ANNULARE IN CHILDREN?

Background:

Granuloma annulare (GA) is a benign inflammatory dermatosis of unknown cause, of which generalised granuloma annulare (GGA) is a subtype that tends to be resistant to treatment. Various antibiotics have been used to treat GGA, the most recent being combination therapy with rifampicin, ofloxacin and minocycline (ROM). This study aims to explore the efficacy of antibiotics in treating GGA, and whether antibiotics may be useful in children with GGA.

Materials and Methods:

A systematic review of literature published from 1947 to 2017 was undertaken in order to evaluate the use of antibiotics in treating GGA. Data on characteristics of children with GGA were extracted and eligible studies were then qualitatively analysed.

Results:

Seven hundred and ninety (790) potential studies were identified, of which 16 were eligible for inclusion in the final analysis. Of these 16 studies, majority were case studies (n=9, 56.3%), with 2 case series (12.5%), 2 retrospective studies (12.5%) and 3 open-label prospective studies (18.8%). Main antibiotic treatments reported were either monthly combination therapy of rifampicin, ofloxacin and minocycline (ROM), or monotherapy with dapsone or doxycycline. Out of a total of 158 patients with GA, 72 patients (45.6%) were treated with antibiotics. Of the 72, 48.6% (n=35) of these patients had GGA while 4 were children; two with GA (2 with GGA), all of whom were treated with dapsone.

Conclusion:

There is paucity of evidence to support the use of antibiotics in the treatment of GGA in children. Although ROM has shown promising results in adults, more studies are needed to validate these findings in children.

Dimethyl fumarate impairs differentiated B cells and fosters central nervous system integrity in treatment of multiple sclerosis

In multiple sclerosis (MS), the effect of dimethyl fumarate (DMF) treatment is primarily attributed to its capacity to dampen pathogenic T cells. Here, we tested whether DMF also modulates B cells, which are newly recognized key players in MS, and to which extent DMF restricts ongoing loss of oligodendrocytes and axons in the central nervous system (CNS). Therefore, blood samples and brain tissue from DMF-treated MS patients were analyzed by flow cytometry or histopathological examination, respectively. Complementary mechanistic studies were conducted in inflammatory as well as non-inflammatory CNS demyelinating mouse models. In this study, DMF reduced the frequency of antigen-experienced and memory B cells and rendered remaining B cells less prone to activation and production of pro-inflammatory cytokines. Dissecting the functional consequences of these alterations, we found that DMF ameliorated a B cell-accentuated experimental autoimmune encephalomyelitis model by diminishing the capacity of B cells to act as antigen-presenting cells for T cells. In a non-inflammatory model of toxic demyelination, DMF limited oligodendrocyte apoptosis, promoted maturation of oligodendrocyte precursors and reduced axonal damage. In a CNS biopsy of a DMF-treated MS patient, we equivalently observed higher numbers of mature oligodendrocytes as well as a reduced extent of axonal damage when compared to a cohort of treatment-naïve patients. In conclusion, we showed that besides suppressing T cells, DMF dampens pathogenic B cell functions, which probably contributes to its clinical effectiveness in relapsing MS. DMF treatment may furthermore limit chronically ongoing CNS tissue damage, which may reduce long-term disability in MS apart from its relapse-reducing capacity.

Identification of Novel Protein Targets of Dimethyl Fumarate Modification in Neurons and Astrocytes Reveals Actions Independent of Nrf2 Stabilization

The fumarate ester dimethyl fumarate (DMF) has been introduced recently as a treatment for relapsing remitting multiple sclerosis (RRMS), a chronic inflammatory condition that results in neuronal demyelination and axonal loss. DMF is known to act by depleting intracellular glutathione and modifying thiols on Keap1 protein, resulting in the stabilization of the transcription factor Nrf2, which in turn induces the expression of antioxidant response element genes. We have previously shown that DMF reacts with a wide range of protein thiols, suggesting that the complete mechanisms of action of DMF are unknown. Here, we investigated other intracellular thiol residues that may also be irreversibly modified by DMF in neurons and astrocytes. Using mass spectrometry, we identified 24 novel proteins that were modified by DMF in neurons and astrocytes, including cofilin-1, tubulin and collapsin response mediator protein 2 (CRMP2). Using an in vitro functional assay, we demonstrated that DMF-modified cofilin-1 loses its activity and generates less monomeric actin, potentially inhibiting its cytoskeletal remodeling activity, which could be beneficial in the modulation of myelination during RRMS. DMF modification of tubulin did not significantly impact axonal lysosomal trafficking. We found that the oxygen consumption rate of N1E-115 neurons and the levels of proteins related to mitochondrial energy production were only slightly affected by the highest doses of DMF, confirming that DMF treatment does not impair cellular respiratory function. In summary, our work provides new insights into the mechanisms supporting the neuroprotective and remyelination benefits associated with DMF treatment in addition to the antioxidant response by Nrf2.

Fumaric acid ester-induced T-cell lymphopenia in the real-life treatment of psoriasis

Background

Fumaric acid esters (FAEs) are used to treat psoriasis and are known to cause lymphopenia in roughly 60% of the patients. Much remains to be elucidated about the biological effects of FAEs on lymphocytes.

Objective

To evaluate the influence of long‐term FAE (Fumaderm^®) treatment on peripheral blood CD4⁺ and CD8⁺ T cells, CD19⁺ B cells and CD56⁺ natural killer (NK) cells in psoriasis.

Methods

In this single‐centre retrospective observational subcohort study, we obtained leucocyte and lymphocyte subset counts before initiating FAE therapy in 371 psoriasis patients (mean age, 47.8 years; 63.3% males) and monitored them during treatment (mean treatment duration, 2.9 years). Multiparametric flow cytometry was used for immunophenotyping.

Results

FAEs significantly reduced the numbers of CD4⁺ T, CD8⁺ T, CD19⁺ B and CD56⁺NK cells. Among lymphocyte subsets, the mean percentage reduction from baseline was always highest for CD8⁺ T cells, with a peak of 55.7% after 2 years of therapy. The risk of T‐cell lymphopenia increased significantly with the age of the psoriasis patients at the time that FAE therapy was initiated. It was significantly decreased for the combination therapy with methotrexate and folic acid (vitamin B9) supplementation. Supporting evidence was found suggesting that T‐cell lymphopenia enhances the effectiveness of FAE therapy.

Conclusions

Monitoring distinct T‐cell subsets rather than just absolute lymphocyte counts may provide more meaningful insights into both the FAE treatment safety and efficacy. We therefore suggest optimizing pharmacovigilance by additionally monitoring CD4⁺ and CD8⁺ T‐cell counts at regular intervals, especially in patients of middle to older age. Thus, further prospective studies are needed to establish evidence‐based recommendations to guide dermatologists in the management of psoriasis patients who are taking FAEs and who develop low absolute T‐cell counts.

Dimethyl fumarate (DMF) vs. monoethyl fumarate (MEF) salts for the treatment of plaque psoriasis: a review of clinical data

Fumarates (fumaric acid esters, FAEs) are orally administered systemic agents used for the treatment of psoriasis and multiple sclerosis. In 1994, a proprietary combination of FAEs was licensed for psoriasis by the German Drug Administration for use within Germany. Since then, fumarates have been established as one of the most commonly used treatments for moderate-to-severe psoriasis in Germany and other countries. The licensed FAE formulation contains dimethyl fumarate (DMF), as well as calcium, zinc, and magnesium salts of monoethyl fumarate (MEF). While the clinical efficacy of this FAE mixture is well established, the combination of esters on which it is based, and its dosing regimen, was determined empirically. Since the mid-1990s, the modes of action and contribution of the different FAEs to their overall therapeutic effect in psoriasis, as well as their adverse event profile, have been investigated in more detail. In this article, the available clinical data for DMF are reviewed and compared with data for the other FAEs. The current evidence substantiates that DMF is the main active compound, via its metabolic transformation to monomethyl fumarate (MMF). A recent phase III randomized and placebo-controlled trial including more than 700 patients demonstrated therapeutic equivalence when comparing the licensed FAE combination with DMF alone, in terms of psoriasis clearance according to the Psoriasis Area and Severity Index (PASI) and Physician's Global Assessment (PGA). Thus, DMF as monotherapy for the treatment of psoriasis is as efficacious as in combination with MEF, making the addition of such fumarate derivatives unnecessary.

Emerging Understanding of the Mechanism of Action for Dimethyl Fumarate in the Treatment of Multiple Sclerosis

Dimethyl fumarate (DMF) is an effective treatment option for relapsing-remitting multiple sclerosis (MS), but its therapeutic mechanism of action has not been fully elucidated. A better understanding of its mechanism will allow for the development of assays to monitor its clinical efficacy and safety in patients, as well as guide the development of the next generation of therapies for MS. In order to build the foundation for determining its mechanism, we reviewed the manner in which DMF alters lymphocyte subsets in MS patients, its impact on clinical efficacy and safety, as well as its molecular effects in cellular and animal models. DMF decreases absolute lymphocyte counts, but does not affect all subsets uniformly. CD8⁺ T-cells are the most profoundly affected, but reduction also occurs in the CD4⁺ population, particularly within the pro-inflammatory T-helper Th1 and Th17 subsets, creating a bias toward more anti-inflammatory Th2 and regulatory subsets. Similarly, B-lymphocyte, myeloid, and natural killer populations are also shifted toward a more anti-inflammatory state. In vitro and animal models demonstrate a role for DMF within the central nervous system (CNS) in promoting neuronal survival in an Nrf2 pathway-dependent manner. However, the impact of DMF directly within the CNS of MS patients remains largely unknown.

Characterization of lymphopenia in patients with MS treated with dimethyl fumarate and fingolimod

Objective:

Lymphopenia is a common occurrence of disease-modifying therapies (DMTs) for relapsing-remitting MS (RRMS). The aim of this study was to dissect the prevalence of various lymphocyte subsets in patients with RRMS treated with 2 DMTs commonly associated with lymphopenia, dimethyl fumarate (DMF), and fingolimod (FTY).

Methods:

Multicolor flow cytometry and multiplex assays were used to identify up to 50 lymphocyte subpopulations and to examine the expression of multiple cytokines in selected patients. We compared patients untreated (NT) or treated with FTY or DMF who did (DMF-L) or did not (DMF-N) develop lymphopenia.

Results:

All FTY patients developed lymphopenia in both T-cell and B-cell compartments. CD41 T cells were more affected by this treatment than CD81 cells. In the B-cell compartment, the CD271IgD2 subpopulation was reduced. T cells but not B cells were significantly reduced in DMF-L. However, within the B cells, CD271 cells were significantly lower. Both CD41 and CD81 subpopulations were reduced in DMF-L. Within the remaining CD41 and CD81 compartments, there was an expansion of the naive subpopulation and a reduction of the effector memory subpopulation. Unactivated lymphocyte from DMF-L patients had significantly higher levels of interferon-γ, interleukin (IL)-12, IL-2, IL-4, IL-6, and IL-1β compared with DMF-N. In plasma, TNFβ was significantly higher in DMF-N and DMF-L compared with NT, whereas CCL17 was significantly higher in DMF-L compared with NT and DMF-N.

Conclusions:

This study shows that different treatments can target different lymphocyte compartments and suggests that lymphopenia can induce compensatory mechanisms to maintain immune homeostasis.

Progressive multifocal leukoencephalopathy associated with fumaric acid esters treatment in psoriasis patients

BACKGROUND

Fumaric acid esters (FAEs) are a systemic treatment for psoriasis considered to have a favourable long-term safety profile without an increased risk for immunosuppression. However, progressive multifocal leukoencephalopathy (PML), a rare, opportunistic viral infection of the central nervous system, has been linked anecdotally to FAE treatment.

OBJECTIVE

To assess clinical features and outcomes of FAE-associated PML cases.

METHODS

Systematic literature search in multiple databases up to 25th February 2016 for reports of PML in psoriasis patients treated with FAEs.

RESULTS

Eight cases (four male, four female) of FAE-associated PML were identified. Median age was 64 years (range 42-74 years); median FAE treatment duration was 3 years (range 1.5-5 years). Six patients were treated with a formulation containing dimethyl fumarate (DMF) and monoethyl fumarates, and two patients with a DMF formulation. Patients exhibited neurological symptoms, such as aphasia, hemiparesis and dysarthria. PML diagnosis was based on MRI findings and presence of JC virus in cerebrospinal fluid and/or brain tissue. All cases were linked to moderate-to-severe reductions in absolute lymphocyte counts, with nadirs ranging from 200 to 792 cells per mm³ . Median exposure to lymphocytopenia was 2 years (range 1-5 years). In all cases, FAE treatment was discontinued; PML was treated with mefloquine plus mirtazapine. Three patients improved, two had stable disease, two had residual symptoms, and one patient died to an immune reconstitution inflammatory syndrome.

CONCLUSION

Progressive multifocal leukoencephalopathy is infrequently linked to FAE treatment, but underreporting cannot be excluded. Physicians treating patients with FAEs should be vigilant for the occurrence of PML, and both clinicians and patients should be alert for onset of new neurological symptoms. Periodic monitoring of lymphocyte counts and FAE discontinuation in case of moderate-to-severe lymphocytopenia is recommended to minimize the risk for PML.

Treatment response to dimethyl fumarate is characterized by disproportionate CD8+ T cell reduction in MS

BACKGROUND

The effect of dimethyl fumarate (DMF) on circulating lymphocyte subsets and their contribution as predictors of clinical efficacy have not yet been investigated in multiple sclerosis (MS).

OBJECTIVE

To evaluate lymphocytes and lymphocyte subsets (analyzed 6 months after DMF start) in MS patients with and without disease activity after 1 year of treatment in a retrospective study.

METHODS

Peripheral blood lymphocyte subsets were analyzed by flow cytometry. Untreated MS patients ( n = 40) were compared to those 6 months after onset of DMF treatment ( n = 51). Clinical and magnetic resonance imaging (MRI) disease activity of DMF-treated patients were assessed in the first year under treatment.

RESULTS

Stable patients showed significantly lower lymphocytes, CD4+ and CD8+ T cells as well as CD19+ B cells compared to active patients under DMF treatment. Furthermore, an increased CD4/CD8 ratio ( p < 0.025) in stable patients indicated a disproportionate reduction of CD8+ T cells relative to CD4+ T cells. Reduced lymphocytes, CD8+ T cells, and CD19+ B cells 6 months after DMF start allowed prediction of the treatment response in the first year.

CONCLUSION

DMF treatment response is reflected by lower circulating lymphocytes and specific lymphocyte subsets. Changes in the cellular immune profiles under DMF treatment are clinically relevant and might serve as a surrogate marker of treatment response.

What's new about oral treatments in Multiple Sclerosis? Immunogenetics still under question

Multiple Sclerosis (MS) is a chronic pathology affecting the Central Nervous System characterized by inflammatory processes that lead to demyelination and neurodegeneration. In MS treatment, disease modifying therapies (DMTs) are essential to reduce disease progression by suppressing the inflammatory response responsible for promoting lesion formation. Recently, in addition to the classical injectable DMTs like Interferons and Glatiramer acetate, new orally administered drugs have been approved for MS therapy: dimethyl fumarate, teriflunomide and fingolimod. These drugs act with different mechanisms on the immune system, in order to suppress the harmful inflammatory process. An additional layer of complexity is introduced by the influence of polymorphic gene variants in the Human Leukocyte Antigen region on the risk of developing MS and its progression. To date, pharmacogenomic studies have mainly focused on the patient's response following admission of injectable drugs. Therefore, greater consideration must be made to pharmacogenomics with a view to developing more effective and personalized therapies. This review aims to shed light on the mechanism of action of the new oral drugs dimethyl fumarate, teriflunomide and fingolimod, taking into account both the importance of immunogenetics in drug response and pharmacogenomic studies.

Mechanism of action of three newly registered drugs for multiple sclerosis treatment

Multiple sclerosis (MS) is a disease of suspected autoimmune origin leading to neurodegeneration. The disease pathomechanism is considered to be primarily based on neuroinflammation directed against myelin antigens caused by autoreactive T cells. MS etiology remains still unknown, which makes it difficult to create an efficient therapy, therefore, MS treatment targets mechanisms involved in disease pathology. In this review, we present the mechanism of action of three newly registered drugs for MS. Dimethyl fumarate (DMF) is an agent presenting a broad spectrum of action. Its main activity is based on activating the nuclear factor E2 dependent pathway leading to antioxidant enzyme synthesis. DMF in general suppresses the pro-inflammatory immune activity and exerts a neuroprotective action. Teriflunomide is a more focused drug, acting as an inhibitor of pyrimidines synthesis, important for rapidly dividing cells such as activated lymphocytes. Similarly, alemtuzumab, an anti-CD52 antibody, causes depletion of mainly lymphocytes. Since in MS pathology, T and B cells are involved, this mode of action is promising.

Dimethyl fumarate in multiple sclerosis: latest developments, evidence and place in therapy

Dimethyl fumarate (DMF) is one of the newer additions to the armamentarium of potent immunomodulators for the treatment of relapsing-remitting multiple sclerosis (RRMS). After more than 2 years of real-world experience and more than 190,000 patients currently treated with DMF worldwide, it is a good timepoint to review the experience gathered so far and to re-evaluate the potential of this first-line oral multiple sclerosis (MS) drug. Post-hoc analyses of clinical and magnetic resonance imaging (MRI) data, some comprising more than 6 years of drug exposure including patients from the clinical trials, and the overall notion in clinical practice widely confirm the good efficacy of DMF in RRMS. Despite an overall good safety profile, it became also clear that the necessary clinical vigilance while using DMF may not be neglected. So far, four reported cases of progressive multifocal leukoencephalopathy (PML), a towering shadow over many MS therapies, warrant proper attention in newly-updated risk management plans. This review recapitulates efficacy and safety aspects of DMF therapy in relation to reported data from the pivotal clinical trials. In addition, we summarize recent insights into DMF mechanisms of action drawn from the field of basic research which may have important implications for clinical practice.

Fumaric acid esters promote neuronal survival upon ischemic stress through activation of the Nrf2 but not HIF-1 signaling pathway

Oxidative stress is a hallmark of ischemic stroke pathogenesis causing neuronal malfunction and cell death. Up-regulation of anti-oxidative genes through activation of the NF-E2-related transcription factor 2 (Nrf2) is one of the key mechanisms in cellular defense against oxidative stress. Fumaric acid esters (FAEs) represent a class of anti-oxidative and anti-inflammatory molecules that are already in clinical use for multiple sclerosis therapy. Purpose of this study was to investigate whether FAEs promote neuronal survival upon ischemia, and analyze putative underlying molecular mechanisms in neurons. Murine organotypic hippocampal slice cultures, and two neuronal cell lines were treated with dimethyl fumarate (DMF) and monomethyl fumarate (MMF). Ischemic conditions were generated by exposing cells and slice cultures to oxygen-glucose deprivation (OGD), and cell death was determined through propidium iodide staining. Treatment with both DMF and MMF immediately after OGD during reoxygenation strongly reduced cell death in hippocampal cultures ex vivo. Both DMF and MMF promoted neuronal survival in HT-22 and SH-SY5Y cell lines exposed to ischemic stress. DMF but not MMF activated the anti-oxidative Nrf2 pathway in neurons. Accordingly, Nrf2 knockdown in murine neurons abrogated the protective effect of DMF but not MMF. Moreover, FAEs did not activate the hypoxia-inducible factor (HIF) pathway suggesting that this pathway may not significantly contribute to FAE mediated neuroprotection. Our results may provide the basis for a new therapeutic approach to treat ischemic pathologies such as stroke with a drug that already has a broad safety record in humans.

Mutually enhancing anti-inflammatory activities of dimethyl fumarate and NF-κB inhibitors--implications for dose-sparing combination therapies

Fumaric acid esters, dimethyl fumarate (DMF) in particular, have been established for the therapy of psoriasis and, more recently, multiple sclerosis. In the light of therapy-limiting dose-dependent side effects, such as gastrointestinal irritation, reducing the effective doses of FAE is a worthwhile goal. In search of strategies to maintain the anti-inflammatory activity of DMF at reduced concentrations, we found that NF-κB inhibition augmented key anti-inflammatory effects of DMF in two complementary experimental settings in vitro. At non-toxic concentrations, both proteasome inhibition with bortezomib as well as blocking NF-κB activation through KINK-1, a small molecule inhibitor of IKKβ-profoundly enhanced DMF-dependent inhibition of nuclear NF-κB translocation in TNFα-stimulated human endothelial cells. This resulted in significant and selective co-operative down-regulation of endothelial adhesion molecules crucial for leucocyte extravasation, namely E-selectin (CD62E), VCAM-1 (CD106) and ICAM-1 (CD54), on both mRNA and protein levels. Functionally, these molecular changes led to synergistically decreased rolling and firm adhesion of human lymphocytes on TNF-activated endothelial cells, as demonstrated in a dynamic flow chamber system. If our in vitro findings can be translated into clinical settings, it is conceivable that anti-inflammatory effects of DMF can be achieved with lower doses than currently used, thus potentially reducing unwanted side effects.

Dimethyl fumarate-associated lymphopenia: Risk factors and clinical significance

BACKGROUND

Dimethyl fumarate (DMF), a disease-modifying therapy for multiple sclerosis (MS), causes lymphopenia in a fraction of patients. The clinical significance of this is unknown. Several cases of progressive multifocal leukoencephalopathy in lymphopenic fumarate-treated patients have raised concerns about drug safety. Since lymphocytes contribute to MS pathology, lymphopenia may also be a biomarker for response to the drug.

OBJECTIVE

The objective of this manuscript is to evaluate risk factors for DMF-induced lymphopenia and drug failure in a real-world population of MS patients.

METHODS

We conducted a retrospective cohort study of 221 patients prescribed DMF at a single academic medical center between March 2013 and February 2015.

RESULTS

Grade 2-3 lymphopenia developed in 17% of the total cohort and did not resolve during DMF treatment. Older age (>55), lower baseline absolute lymphocyte count and recent natalizumab exposure increased the risk of developing moderate to severe lymphopenia while on DMF. Lymphopenia was not predictive of good clinical response or of breakthrough MS activity on DMF.

CONCLUSIONS

Lymphopenia develops in a significant minority of DMF-treated patients, and if grade 2 or worse, is unlikely to resolve while on the drug. Increased vigilance in lymphocyte monitoring and infection awareness is particularly warranted in older patients and those switching from natalizumab.

Dimethyl fumarate-associated lymphopenia: Risk factors and clinical significance

BACKGROUND

Dimethyl fumarate (DMF), a disease-modifying therapy for multiple sclerosis (MS), causes lymphopenia in a fraction of patients. The clinical significance of this is unknown. Several cases of progressive multifocal leukoencephalopathy in lymphopenic fumarate-treated patients have raised concerns about drug safety. Since lymphocytes contribute to MS pathology, lymphopenia may also be a biomarker for response to the drug.

OBJECTIVE

The objective of this manuscript is to evaluate risk factors for DMF-induced lymphopenia and drug failure in a real-world population of MS patients.

METHODS

We conducted a retrospective cohort study of 221 patients prescribed DMF at a single academic medical center between March 2013 and February 2015.

RESULTS

Grade 2-3 lymphopenia developed in 17% of the total cohort and did not resolve during DMF treatment. Older age (>55), lower baseline absolute lymphocyte count and recent natalizumab exposure increased the risk of developing moderate to severe lymphopenia while on DMF. Lymphopenia was not predictive of good clinical response or of breakthrough MS activity on DMF.

CONCLUSIONS

Lymphopenia develops in a significant minority of DMF-treated patients, and if grade 2 or worse, is unlikely to resolve while on the drug. Increased vigilance in lymphocyte monitoring and infection awareness is particularly warranted in older patients and those switching from natalizumab.

Progressive neurologic dysfunction in a psoriasis patient treated with dimethyl fumarate

Progressive multifocal leukoencephalopathy (PML) has recently been described in psoriasis or multiple sclerosis patients treated with fumaric acid esters (fumarates), who had developed severe and long-standing lymphocytopenia (<500/mm(3) ). We report a psoriasis patient who presented with progressive neurologic dysfunction and seizures after 2.5 years of fumarate therapy. Despite absolute lymphocyte counts remaining between 500-1000/mm(3) , his CD4(+) and CD8(+) T-cell counts were markedly low. MRI showed right hemispheric and brainstem lesions and JC virus DNA was undetectable in his cerebrospinal fluid. Brain biopsy revealed typical features of PML as well as JC virus-infected neurons. Clinicians should consider PML in the differential diagnosis of fumarate-treated patients presenting with brain lesions or seizures even in the absence of severe lymphocytopenia.

Reduction of CD8(+) T lymphocytes in multiple sclerosis patients treated with dimethyl fumarate

Objective:

To evaluate the influence of dimethyl fumarate (DMF, Tecfidera) treatment of multiple sclerosis (MS) on leukocyte and lymphocyte subsets.

Methods:

Peripheral blood leukocyte and lymphocyte subsets, including CD3⁺, CD4⁺, and CD8⁺ T cells; CD19⁺ B cells; and CD56⁺ natural killer (NK) cells, were obtained at baseline and monitored at 3 months, 6 months, and 12 months after initiation of DMF treatment.

Results:

Total leukocyte and lymphocyte counts diminished after 6 months of DMF therapy. At 12 months, lymphocyte counts had decreased by 50.1% (p < 0.0001) and were below the lower limit of normal (LLN) in one-half of patients. CD3⁺ T lymphocyte counts fell by 44.2% (p < 0.0001). Among subsets, CD8⁺ T cell counts declined by 54.6% (p < 0.0001), whereas CD4⁺ T cell counts decreased by 39.2% (p = 0.0006). This disproportionate reduction of CD8⁺ T cells relative to CD4⁺ T cells was significant (p = 0.007) and was reflected by a 35.5% increase in the CD4/CD8 ratio (p = 0.007). A majority of CD8⁺ T cell counts, but not CD4⁺ T cell counts, were below the LLN even when total lymphocyte counts were greater than 500 cells/μL. CD19⁺ B cell counts were reduced by 37.5% (p = 0.035). Eosinophil levels decreased by 54.1% (p = 0.006), whereas levels of neutrophils, monocytes, basophils, and NK cells were not significantly altered.

Conclusion:

Subsets of peripheral blood leukocytes and lymphocytes are differentially affected by DMF treatment of MS. Reduction of CD8⁺ T cells is more pronounced than that of CD4⁺ T cells. These findings may have implications for cell-mediated antiviral immunity during DMF treatment.

Fumaric acid esters in the management of psoriasis

Fumaric acid esters (FAE) are small molecules with immunomodulating, anti-inflammatory, and anti-oxidative effects. FAE were introduced as a systemic psoriasis treatment in 1959 and empirically developed further between 1970 and 1990 in Germany, Switzerland, and the Netherlands. The development of FAE as psoriasis treatment did not follow the traditional drug development phases. Nonetheless, in 1994 FAE were approved in Germany for the treatment of severe plaque psoriasis. FAE are currently one of the most commonly used treatments in Germany, and FAE are increasingly being used as an unlicensed treatment in several other European countries. To date, six randomized controlled trials and 29 observational studies have evaluated FAE in a combined total of 3,439 patients. The efficacy and safety profile of FAE is favorable. About 50%–70% of patients achieve at least 75% improvement in psoriasis severity after 16 weeks of treatment. Common adverse events of FAE include gastrointestinal complaints and flushing symptoms, which lead to treatment discontinuation in up to 40% of patients. Lymphocytopenia, eosinophilia, and proteinuria are commonly observed during FAE treatment, but rarely require treatment discontinuation. The long-term safety profile of continuous FAE treatment is favorable without an increased risk for infections, malignancies, or other serious adverse events. There are no known drug-interactions for FAE. The 2009 European evidence-based S3-guidelines on psoriasis treatment recommend FAE and suggest it as a first-line systemic treatment for moderate-to-severe plaque psoriasis. This review is aimed to give an overview of FAE treatment in the management of psoriasis.

Dimethyl fumarate for treatment of multiple sclerosis: mechanism of action, effectiveness, and side effects

Dimethyl fumarate is an orally available treatment option for relapsing-remitting multiple sclerosis (MS) in a new formulation with improved gastroenteric coating. The mode of action comprises immunomodulatory effects and an activation of nuclear (erythroid-derived 2) related factor mediated antioxidative response pathways leading to additional cytoprotective effects. In two pivotal phase III trials, dimethyl fumarate, 240 mg twice daily, reduced relapse rates by about 50 % as compared with placebo. In the DEFINE trial, progression of disability was also significantly reduced. Both trials demonstrated a significant reduction of gadolinium-enhanced lesions as well as T2 lesions on cranial MRI. The studies revealed a beneficial safety profile of dimethyl fumarate. The most prevalent side effects were transient flushing and gastrointestinal tract irritation. Dimethyl fumarate has recently been approved in the USA for the treatment of relapsing-remitting MS. The compound is a welcome addition to the immunomodulatory treatment armamentarium for MS patients and physicians alike.

Mode of action and clinical studies with fumarates in multiple sclerosis

Multiple sclerosis (MS) as a chronic neuro-inflammatory and neurodegenerative disease of the central nervous system is frequently associated with severe disability and impairment in quality of life. Early disease-modifying treatment options have mainly focused on inflammatory aspects of the disease. Recently, the neurodegenerative features have received more attention in experimental models, paraclinical assessments and the evaluation of drug effects. Fumaric acid esters (FAEs) as orally available immunomodulatory and neuroprotective compounds have thus advanced to a highly interesting MS treatment option. Here, we will review the pharmaceutical history of FAEs, their immunomodulatory and putative neuroprotective mechanisms of action and clinical trial data in relapsing MS.

A review of safety-related pregnancy data surrounding the oral disease-modifying drugs for multiple sclerosis

The recent approval of several oral disease-modifying drugs (DMDs) for multiple sclerosis (MS) brings promise of improved clinical effectiveness as well as greater drug compliance compared to the existing non-oral DMDs, and substantially increases patient choice and therapeutic options in the effective management of MS. However, for men and women with MS of childbearing age, concerns about the effect of oral DMDs on pregnancy and the fetus may arise. Some limited data from animal reproductive studies of oral DMDs suggest a potential increased risk of early pregnancy loss, impaired growth and birth defects. Although active surveillance mechanisms exist, there is limited data to inform clinical practice. Using existing information from published clinical trials and drug monographs, as well as recent conference proceedings, this review summarizes the mechanism of action (in relation to embryogenesis and pregnancy) and existing animal or human pregnancy-related data for approved (fingolimod, teriflunomide and dimethyl fumarate) and investigational (laquinimod and firategrast) oral DMDs for MS.