Methotrexate: new uses for an old drug

Methotrexate resistance and its regulatory mechanisms in pediatric tumors and beyond

Methotrexate (MTX) is a critical antimetabolite drug in treating various pediatric diseases, including acute lymphoblastic leukemia (ALL), non-Hodgkin lymphoma (NHL), brain tumors, osteosarcoma, inflammatory myofibroblastic tumor (IMT), juvenile scleroderma (JS), and juvenile idiopathic arthritis (JIA). MTX acts as a folate antagonist by inhibiting dihydrofolate reductase (DHFR), an enzyme essential for the synthesis of tetrahydrofolate. This disruption impairs DNA synthesis, repair, and cellular replication, particularly affecting rapidly dividing cells. Despite its efficacy, MTX resistance poses significant challenges, particularly in pediatric oncology, where it undermines the ability to achieve sustained therapeutic effects, resulting in reduced therapeutic efficacy and poor prognosis. The mechanisms of MTX resistance encompassed reduced enzyme activity pivotal for MTX metabolism, enhanced expression of efflux transporters, genetic variations, and alterations in signaling pathways. Multifaceted strategies have been explored to overcome MTX resistance. Combination therapies with ginger extract, gold nanoparticles, and arsenic trioxide (ATO) have been investigated to augment MTX's cytotoxic effects. Synergies with mTOR inhibitors and MDM2 inhibitors have demonstrated enhanced outcomes in ALL. In JIA, targeting ATP-binding cassette (ABC) transporters and modulating transforming growth factor‑β (TGF-β) signaling pathways have emerged as promising approaches. For osteosarcoma, emphasis on autophagy pathways and non-coding RNAs influencing chemotherapy sensitivity could enhance MTX effectiveness. This review delineates MTX's therapeutic roles, elucidates its resistance mechanisms, and discusses current and potential strategies for managing MTX resistance to bolster treatment effectiveness in pediatric tumors and other diseases. This knowledge base could underpin further research and development of personalized treatments to optimize MTX's clinical benefits.

Breastfeeding duration and neurodevelopment: insights into autism spectrum disorders and weaning practices

This paper examines the complex relationship between breastfeeding duration and the incidence of autism spectrum disorders (ASDs), focusing on identifying the most beneficial weaning period and its subsequent effects on child development. Breastfeeding is widely recognized for its role in promoting early health, strengthening the immune system, and supporting neurodevelopment. However, the debate over its optimal duration persists. Integrating insights from current scientific studies with interpretations of Qur'anic teachings, this study advocates for a breastfeeding duration of 21 months. This duration balances the benefits of extended breastfeeding with potential risks associated with prolonged exposure, reflecting both ancient wisdom and contemporary evidence. Key findings suggest that breastfeeding may play a preventive role in mitigating ASD symptoms and enhancing neurodevelopment through mechanisms such as immune regulation, microbiome diversity, and hormonal pathways. These insights underline the need for further specialized research to explore the long-term impacts of breastfeeding on ASD-related outcomes.

Neurotoxicity of the antineoplastic drugs: "Doxorubicin" as an example

There is an increased prevalence of cancer, and chemotherapy is widely and routinely utilized to manage the majority of cancers; however, administration of chemotherapeutic drugs has faced limitations concerning the "off-target" cytotoxicity. Chemobrain and impairment of neurocognitive functions have been observed in a significant fraction of cancer patients or survivors and reduce their life quality; this could be ascribed to the ability of chemotherapeutic drugs to alter the structure and function of the brain. Doxorubicin (DOX), an FDA-approved chemotherapeutic drug with therapeutic effectiveness, is commonly used to treat several carcinomas clinically. DOX-triggered neurotoxicity is the most serious adverse reaction after DOX-induced cardiotoxicity which greatly limits its clinical application. DOX-induced neurotoxicity is a net of multiple mechanisms that have been verified in pre-clinical and clinical studies, such as oxidative stress, neuroinflammation, mitochondrial disruption, apoptosis, autophagy, disruption of neurotransmitters, and impairment of neurogenesis. There is a massive need for developing novel therapeutics for both cancer and DOX-associated neurotoxicity; therefore investigating the implicated mechanisms of DOX-induced chemobrain will reveal multi-targets for novel curative strategies. Recently, various neuroprotective mechanisms were employed to mitigate DOX-mediated neurotoxicity. For this purpose, therapeutic interventions using pharmacological compounds were developed to protect healthy "off-target" tissues from DOX-induced toxicity. In addition, nanoplatforms were used to enable target delivery of DOX; to prevent its deposition in non-cancerous tissues. The aim of the current review is to provide some reference value for the future management of DOX-induced neurotoxicity and to summarize the underlying mechanisms of DOX-mediated neurotoxicity and the potential therapeutic interventions.

Vinpocetine mitigates methotrexate-induced duodenal intoxication by modulating NF-κB, JAK1/STAT-3, and RIPK1/RIPK3/MLKL signals

OBJECTIVES

Methotrexate (MTX) is an antimetabolite agent widely used to manage a variety of tumors and autoimmune diseases. Nonetheless, MTX-induced intestinal intoxication is a serious adverse effect limiting its clinical utility. Inflammation and oxidative stress are possible mechanisms for MTX-induced intestinal toxicity. Vinpocetine (VNP) is a derivative of the alkaloid vincamine with potent anti-inflammatory and antioxidant effects. The current study investigated the protective intestinal impact of VNP in attenuating MTX-induced intestinal intoxication in rats.

MATERIALS AND METHODS

VNP was administered orally in a dose of 20 mg/kg, while MTX was injected intraperitoneal in a dose of 20 mg/kg.

RESULTS

VNP administration attenuated drastic histological changes induced by MTX and preserved both normal villus and crypt histology. VNP significantly attenuated oxidative injury by upregulating intestinal Nrf2 and HO-1 expression. VNP attenuated inflammation by reducing MPO, NO2-, TNF-α, and IL-1β levels mediated by downregulating NF-κB, NDAPH-oxidase, IRF3, p-JAK-1, and p-STAT-3 expressions. Moreover, VNP potently counteracted intestinal necroptosis by effectively downregulating RIPK1, RIPK3, MLKL, and caspase-8 proteins.

CONCLUSION

Therefore, VNP may represent a promising approach that can attenuate intestinal toxicity in patients receiving MTX.

Connective tissue nevus misdiagnosed as juvenile localized scleroderma

BACKGROUND

Connective tissue nevi (CTN) are congenital hamartomas caused by excessive proliferation of dermis components. In children, CTN can mimic juvenile localized scleroderma (JLS), an immune mediated skin disorder that requires aggressive immunosuppression.

OBJECTIVES

Aim of our study was to describe a series of pediatric patients with CTN misdiagnosed as JLS and the discerning characteristics between the two conditions.

METHODS

Retrospective analysis of children referred to our Center during the last two decades for JLS who received a final diagnosis of CTN. Clinical, laboratory, histopathological and instrumental data (MRI and thermography) were collected and compared with those with JLS.

RESULTS

Seventeen patients with mean age at onset 4.6 years entered the study. All came to our Center with a certain diagnosis of JLS (n = 15) or suspected JLS (n = 2). The indurated skin lesions were flat and resembled either circumscribed morphea or pansclerotic morphea. In 14 patients (82.4%) they were mainly localized at the lower limbs and in three (17.6%) at the upper limbs. No patient had laboratory inflammatory changes or positive autoantibodies. Skin biopsies confirmed the diagnosis of CTN: non-familial collagenoma in eleven (64.7%), mixed CTN in four (23.5%) and familial CTN in two (11.8%). Mean age at final diagnosis was 9.5 years, with a mean diagnostic delay of 4.8 years (range 1-15 years). Sixteen patients underwent musculoskeletal MRI that was normal in all except two who showed muscle perifascial enhancement. Thermography was normal in all patients. At our first evaluation, eleven patients (64.7%) were on systemic treatment (methotrexate 11, corticosteroids 7, biologics 2), three (17.6%) on topical corticosteroids and three untreated.

CONCLUSIONS

CTN can be misdiagnosed as JLS and therefore aggressively treated with prolonged and inappropriate immunosuppression. The absence of inflammatory appearance of the skin lesions, normal instrumental and laboratory findings and the accurate evaluation of skin biopsy are crucial to address the right diagnosis.

The gut microbes in inflammatory bowel disease: Future novel target option for pharmacotherapy

Gut microbes constitute the main microbiota in the human body, which can regulate biological processes such as immunity, cell proliferation, and differentiation, hence playing a specific function in intestinal diseases. In recent years, gut microbes have become a research hotspot in the pharmaceutical field. Because of their enormous number, diversity, and functional complexity, gut microbes have essential functions in the development of many digestive diseases. Inflammatory bowel disease (IBD) is a chronic non-specific inflammatory disease with a complex etiology, the exact cause and pathogenesis are unclear. There are no medicines that can cure IBD, and more research on therapeutic drugs is urgently needed. It has been reported that gut microbes play a critical role in pathogenesis, and there is a tight and complex association between gut microbes and IBD. The dysregulation of gut microbes may be a predisposing factor for IBD, and at the same time, IBD may exacerbate gut microbes' disorders, but the mechanism of interaction between the two is still not well defined. The study of the relationship between gut microbes and IBD is not only important to elucidate the pathogenesis but also has a positive effect on the treatment based on the regimen of regulating gut microbes. This review describes the latest research progress on the functions of gut microbes and their relationship with IBD, which can provide reference and assistance for further research. It may provide a theoretical basis for the application of probiotics, fecal microbiota transplantation, and other therapeutic methods to regulate gut microbes in IBD.

The protective role of curcumin nanoparticles on the submandibular salivary gland toxicity induced by methotrexate in male rats

OBJECTIVE

To evaluate the protective role of nanocurcumin on the toxicity induced by methotrexate in the submandibular glands of rats.

DESIGN

Twenty- four healthy male Wistar albino rats were randomly distributed into 3 groups, 8 rats each. Group I-control: rats received a single intraperitoneal injection of saline; Group II-methotrexate (MTX): rats received methotrexate 20 mg/ kg day 1 of the experiment; Group III-methotrexate and nanocurcumin (MTX+NCU): rats received methotrexate 20 mg/ kg on day 1 of the experimental period in addition to nanocurcumin 100 mg/kg/day for 7 days. After euthanasia, the submandibular salivary glands of all rats were collected and prepared for histological, histomorphometric, and immunohistochemical examination (Caspase 3, Bcl2), in addition to transmission electron microscopy.

RESULTS

Histological and ultrastructural assessment revealed less salivary gland damage in the nanocurcumin group in comparison to the methotrexate group, and the percentage of acinar vacuolization showed significantly lower values in the nanocurcumin group. Group III (MTX+NCU) showed lower immunoexpression of caspase 3 than group II (MTX), while Bcl2 immunoreactivity was higher in the MTX group than in the MTX+NCU group.

CONCLUSIONS

Our results suggest that simultaneous administration of nanocurcumin reduces apoptosis in salivary glands subjected to methotrexate.

New Insights on Juvenile Psoriatic Arthritis

Juvenile psoriatic arthritis (JPsA) is a relatively rare condition in childhood as it represents approximately 5% of the whole Juvenile Idiopathic Arthritis (JIA) population. According to International League of Associations of Rheumatology (ILAR) classification, JPsA is defined by the association of arthritis and psoriasis or, in the absence of typical psoriatic lesions, with at least two of the following: dactylitis, nail pitting, onycholysis or family history of psoriasis in a first-degree relative. However, recent studies have shown that this classification system could conceal more homogeneous subgroups of patients differing by age of onset, clinical characteristics and prognosis. Little is known about genetic factors and pathogenetic mechanisms which distinguish JPsA from other JIA subtypes or from isolated psoriasis without joint involvement, especially in the pediatric population. Specific clinical trials testing the efficacy of biological agents are lacking for JPsA, while in recent years novel therapeutic agents are emerging in adults. In this review, we summarize the clinical features and the current evidence on pathogenesis and therapeutic options for JPsA in order to provide a comprehensive overview on the clinical management of this complex and overlapping entity in childhood.

What is the impact of methotrexate on liver in patients with juvenile idiopathic arthritis? Results of liver SWE performed in a single centre

OBJECTIVES

Long-term therapy with low-dose methotrexate (MTX) is widely used in treatment of rheumatic diseases, in children. The purpose of this study was to evaluate liver elasticity in patients with juvenile idiopathic arthritis (JIA) who received MTX and compare the results with control group.

METHODS

Liver elasticity was evaluated with shear wave elastography (SWE) technique in 25 patients aged 3-17 years who were followed up with JIA and received MTX and compared with 25 healthy controls of the same age and weight. Factors that had an effect on liver elasticity were examined.

RESULTS

The mean SWE value of patients was 2.64 ± 2.13 m/s and 24.10 ± 18.50 kPa, whereas 1.83 ± 0.16 m/s and 10.09 ± 1.83 kPa in control group. There was a significant difference in liver elasticity in the patient and control groups. When the patients were evaluated as Group 1 (< 1000 mg) and Group 2 (≥ 1000 mg) according to the cumulative MTX dose, no significant difference was obtained. There was positive correlation between liver elasticity and weekly MTX dose and age.

CONCLUSIONS

Our study revealed that liver elasticity significantly decreased in patients who received MTX when compared with the control group. The elastography technique will be understood better over time and used safely in many areas.

Inflammatory bowel disease and psoriasis: modernizing the multidisciplinary approach

Psoriasis and inflammatory bowel disease (IBD) are immune-mediated diseases occurring in barrier organs whose main task is to protect the organism from attack. These disorders are highly prevalent especially in northern Europe where psoriasis has a prevalence of around 3-4% and IBD around 0.3%. The prevalence of IBD in North America has been estimated at around 0.4%. The total incidence rates in northern Europe have been estimated at around 6 for Crohn's disease and 11 for ulcerative colitis per 100 000 person-years, compared with an incidence rate of around 280 per 100 000 person-years for psoriasis. Both diseases are less common in countries with a lower index of development. The rise in IBD appears to occur as populations adopt a westernized lifestyle, whereas psoriasis seems more stable and prevalence differences may derive more from variation in genetic susceptibility. The gut microbiota is clearly an important driver of IBD pathogenesis; in psoriasis, changes in gut and skin microbiota have been reported, but it is less clear whether and how these changes contribute to the pathogenesis. Large studies show that most identified genes are involved in the immune system. However, psoriasis and IBD are highly heterogeneous diseases and there is a need for more precise and deeper phenotyping to identify specific subgroups and their genetic, epigenetic and molecular signatures. Epigenetic modifications of DNA such as histone modifications, noncoding RNA effects on transcription and translation and DNA methylation are increasingly recognized as the mechanism underpinning much of the gene-environment interaction in the pathogenesis of both IBD and psoriasis. Our understanding of underlying pathogenetic mechanisms has deepened fundamentally over the past decades developing hand in hand with novel therapies targeting pathways and proinflammatory cytokines incriminated in disease. There is not only substantial overlap between psoriasis and IBD, but also there are differences with implication for therapy. In psoriasis, drugs targeting interleukin-23 and interleukin-17 have shown superior efficacy compared with anti-TNFs, whilst in IBD, drugs targeting interleukin-17 may be less beneficial. The therapeutic toolbox for psoriasis is impressive and is enlarging also for IBD. Still, there are unmet needs reflecting the heterogeneity of both diseases and there is a need for closer molecular diagnostics to allow for the development of precise therapeutics.

Protective effects of curcumin against methotrexate-induced testicular damage in rats by suppression of the p38-MAPK and nuclear factor-kappa B pathways

Objective

The present study aimed to investigate the possibility that curcumin (CMN) protects against methotrexate (MTX)-induced testicular damage by affecting the phospho-p38 (p-p38) mitogen-activated protein kinase (MAPK) and nuclear factor-kappa B (NF-κB) signaling pathways.

Methods

Eighteen male Wistar albino rats were randomly divided into three groups. The control group was given an intragastric administration of dimethyl sulfoxide (DMSO) daily for 14 days, the MTX group was given a single intraperitoneal dose of MTX (20 mg/kg) on the 11th day, and the MTX+CMN group was given intragastric CMN (100 mg/kg/day, dissolved in DMSO) for 14 days and a single intraperitoneal dose of MTX (20 mg/kg) on the 11th day. At the end of the experiment, all animals were sacrificed and the testicular tissues were removed for morphometry, histology, and immunohistochemistry. Body and testicular weights were measured.

Results

Body weights, seminiferous tubule diameter, and germinal epithelium height significantly decreased in the MTX group compared to the control group. Whereas, the number of histologically damaged seminiferous tubules and interstitial space width significantly increased in the MTX group. In addition, the number of p-p38 MAPK immunopositive cells and the immunoreactivity of NF-κB also increased in the MTX group compared to the control group. CMN improved loss of body weight, morphometric values, and histological damage due to MTX. CMN also reduced the number of p-p38 MAPK immunopositive cells and the NF-κB immunoreactivity.

Conclusion

CMN may reduce MTX-induced testicular damage by suppressing the p38 MAPK and NF-κB signaling pathways.

Distal Regions Regulate Dihydrofolate Reductase-Ligand Interactions

Protein motions play a fundamental role in enzyme catalysis and ligand binding. The relationship between protein motion and function has been extensively investigated in the model enzyme dihydrofolate reductase (DHFR). DHFR is an essential enzyme that catalyzes the reduction of dihydrofolate to tetrahydrofolate. Numerous experimental and computational methods have been used to probe the motions of DHFR through the catalytic cycle and to investigate the effect of distal mutations on DHFR motions and ligand binding. These experimental investigations have pushed forward the study of protein motions and their role in protein-ligand interactions. The introduction of mutations distal to the active site has been shown to have profound effects on ligand binding, hydride transfer rates and catalytic efficacy and these changes are captured by enzyme kinetics measurements. Distal mutations have been shown to exert their effects through a network of correlated amino acids and these effects have been investigated by NMR, protein dynamics, and analysis of coupled amino acids. The experimental methods and the findings that are reviewed here have broad implications for our understanding of enzyme mechanisms, ligand binding and for the future design and discovery of enzyme inhibitors.

Electronic properties investigation of human dihydrofolate reductase complexes with ligands

Despite the fact that there are already drugs for cancer, they still show strong toxicity to the human organism. That is why it is necessary to establish the factors affecting activity in order to develop new, more effective drugs aimed at tumor cells, minimizing harm to healthy cells. The present research is based on electronic properties calculation of the complexes using AlteQ approach. In the focus of this study are complexes of human dihydrofolate reductase (hDHFR) with a series of known inhibitors bound in the active site. Further, a statistical analysis was performed to establish the relationships between a myriad electronic characteristics and IC₅₀. The change in total volume and the change of own electrons number of hydrogen atoms in their atomic basins are identified as the descriptors correlating the most with the hDHFR inhibition potency. Additionally, two lipophilic parts of protein (Thr56, Ser59, Ile60 and Ile7, Val8, Ala9) were found, which act as a key factor in decreasing bioactivity. The depth analysis of intermolecular interactions showed that the interactions between water molecules and ligand play a crucial role in hDHFR inhibition. Furthermore, the molecular dynamics simulations were used for deeper understanding of the structural inhibition, each for 50 ns time scale in explicit water conditions. Thus, the AlteQ approach made it possible to determine the factors influencing the activity and evaluate them not only qualitatively, but also quantitatively.Communicated by Ramaswamy H. Sarma.

The effect of bee pollen on reproductive and biochemical parameters in methotrexate-induced testicular damage in adult rats

OBJECTIVES

Methotrexate (MTX) is an anticancer drug used in chemotherapy. MTX was known for its toxic effects involving most of the organs including testis. Bee pollen is healthy food for human and has antioxidant effect. We intended to determine protective effect of bee pollen against testicular injury caused by MTX in rats.

METHODS

Thirty-two adult Sprague Dawley male rats were used, and 4 groups were formed: control, MTX, pollen, and MTX + pollen. Rats were given pollen at a dose of 400 mg/kg with intragastric gavage for 10 days. On day 7, MTX was administered a single dose of 30 mg/kg ip. Serum testosterone and LH, tissue MDA level, and SOD and CAT enzyme activities were examined. In addition, spermatological parameters were evaluated.

RESULTS

MDA level and SOD activity increased while testosterone level decreased significantly in the MTX group compared to the control group. In the MTX + pollen group, MDA level and SOD activity decreased while testosterone level increased. There was no significant change in CAT activity and LH values. Abnormal sperm ratio decreased in the MTX + pollen group compared to the MTX group.

CONCLUSIONS

Our results suggest that bee pollen has a healing effect on reproductive parameters in testicular damage caused by MTX.

Methotrexate and prednisolone study in erythema nodosum leprosum (MaPs in ENL) protocol: a double-blind randomised clinical trial

INTRODUCTION

Erythema nodosum leprosum (ENL) is an immunological complication of leprosy. ENL results in morbidity and disability and if it is not treated can lead to death. The current treatment consists of thalidomide or high doses of oral corticosteroids for prolonged periods. Thalidomide is not available in many leprosy endemic countries. The use of corticosteroids is associated with morbidity and mortality. Identifying treatment regimens that reduce the use of corticosteroids in ENL is essential. Methotrexate (MTX) is used to treat many inflammatory diseases and has been used successfully to treat patients with ENL not controlled by other drugs, including prednisolone and thalidomide. We present the protocol of the 'MTX and prednisolone study in ENL' (MaPs in ENL) a randomised controlled trial (RCT) designed to test the efficacy of MTX in the management of ENL.

METHODS AND ANALYSIS

MaPs in ENL is an international multicentre RCT, which will be conducted in leprosy referral centres in Bangladesh, Brazil, Ethiopia, India, Indonesia and Nepal. Patients diagnosed with ENL who consent to participate will be randomly allocated to receive 48 weeks of weekly oral MTX plus 20 weeks of prednisolone or 48 weeks of placebo plus 20 weeks of prednisolone. Participants will be stratified by type of ENL into those with acute ENL and those with chronic and recurrent ENL. The primary objective is to determine whether MTX reduces the requirement for additional prednisolone. Patients' reported outcome measures will be used to assess the efficacy of MTX. Participants will be closely monitored for adverse events.

ETHICS AND DISSEMINATION

Results will be submitted for publication in peer-reviewed journals. Ethical approval was obtained from the Observational/Interventions Research Ethics Committee of the London School of Hygiene & Tropical Medicine (15762); The Leprosy Mission International Bangladesh Institutional Research Board (in process); AHRI-ALERT Ethical Review Committee, Ethiopia; Ethics Committee of the Managing Committee of the Bombay Leprosy Project; and The Leprosy Mission Trust India Ethics Committee; the Nepal Health and Research Council and Health Research Ethics Committee Dr. Soetomo, Indonesia. This study is registered at www.clinicaltrials.gov. This is the first RCT of MTX for ENL and will contribute to the evidence for the management of ENL.Trial registration numberNCT 03775460.

Synthesis, In Silico Prediction and In Vitro Evaluation of Antitumor Activities of Novel Pyrido[2,3-d]pyrimidine, Xanthine and Lumazine Derivatives

Ethyl 5-arylpyridopyrimidine-6-carboxylates 3a–d were prepared as a one pot three component reaction via the condensation of different aromatic aldehydes and ethyl acetoacetate with 6-amino-1-benzyluracil 1a under reflux condition in ethanol. Additionally, condensation of ethyl 2-(2-hydroxybenzylidene) acetoacetate with 6-amino-1-benzyluracil in DMF afforded 6-acetylpyridopyrimidine-7-one 3e; a facile, operationally, simple and efficient one-pot synthesis of 8-arylxanthines 6a–f is reported by refluxing 5,6-diaminouracil 4 with aromatic aldehydes in DMF. Moreover, 6-aryllumazines 7a–d was obtained via the reaction of 5,6-diaminouracil with the appropriate aromatic aldehydes in triethyl orthoformate under reflux condition. The synthesized compounds were characterized by spectral (¹H-NMR, ¹³C-NMR, IR and mass spectra) and elemental analyses. The newly synthesized compounds were screened for their anticancer activity against lung cancer A549 cell line. Furthermore, a molecular-docking study was employed to determine the possible mode of action of the synthesized compounds against a group of proteins highly implicated in cancer progression, especially lung cancer. Docking results showed that compounds 3b, 6c, 6d, 6e, 7c and 7d were the best potential docked compounds against most of the tested proteins, especially CDK2, Jak2, and DHFR proteins. These results are in agreement with cytotoxicity results, which shed a light on the promising activity of these novel six heterocyclic derivatives for further investigation as potential chemotherapeutics.

Consensus-based recommendations for the management of juvenile systemic sclerosis

Juvenile systemic sclerosis (JSSc) is a rare disease of childhood and currently no international consensus exists with regard to its assessment and treatment. This SHARE (Single Hub and Access point for paediatric Rheumatology in Europe) initiative, based on expert opinion informed by the best available evidence, provides recommendations for the assessment and treatment of patients with JSSc with a view to improving their outcome. Experts focused attention not only on the skin assessment but also on the early signs of internal organ involvement whose proper treatment can significantly affect the long-term outcome. A score for disease severity is proposed in order to perform a structured assessment of outcome over time but a validation in a wider patient population is recommended. Finally, a stepwise treatment approach is proposed in order to unify the standard of care throughout Europe with the aim to reduce morbidity and mortality in this disease.

Neurotoxicity of antineoplastic drugs: Mechanisms, susceptibility, and neuroprotective strategies

This review summarizes the adverse effects on the central and/or peripheral nervous systems that may occur in response to antineoplastic drugs. In particular, we describe the neurotoxic side effects of the most commonly used drugs, such as platinum compounds, doxorubicin, ifosfamide, 5-fluorouracil, vinca alkaloids, taxanes, methotrexate, bortezomib and thalidomide. Neurotoxicity may result from direct action of compounds on the nervous system or from metabolic alterations produced indirectly by these drugs, and either the central nervous system or the peripheral nervous system, or both, may be affected. The incidence and severity of neurotoxicity are principally related to the dose, to the duration of treatment, and to the dose intensity, though other factors, such as age, concurrent pathologies, and genetic predisposition may enhance the occurrence of side effects. To avoid or reduce the onset and severity of these neurotoxic effects, the use of neuroprotective compounds and/or strategies may be helpful, thereby enhancing the therapeutic effectiveness of antineoplastic drug.

Treatment in Juvenile Scleroderma

PURPOSE OF REVIEW

Treatment of scleroderma in children is challenging since little is known about its pathogenesis. Herein, we review the most recent evidence regarding the treatment of juvenile scleroderma.

RECENT FINDINGS

According to the recent recommendations for Pediatric Rheumatology in Europe (SHARE), systemic treatment in localized scleroderma is needed when there is a risk for disability, such as in generalized or pansclerotic morphea and progressive linear scleroderma. In juvenile systemic sclerosis, the introduction of the severity score, J4S, has standardized the assessment of the patients in the daily practice and allowed a more tailored therapeutic approach. Since, to date, no clinical trial is available in JSSc, due to its rarity, the treatment is based on adults' experience. The recent recommendations for juvenile scleroderma represent an important instrument to standardize the treatment approach, confirm the role of methotrexate, and open new windows for effective experimental treatments, such as mycophenolate mofetil and biological agents, for severe or refractory cases.

Ginkgo biloba Extract Protects against Methotrexate-Induced Hepatotoxicity: A Computational and Pharmacological Approach

Ginkgo biloba extract possess several promising biological activities; currently, it is clinically employed in the management of several diseases. This research work aimed to extrapolate the antioxidant and anti-inflammatory effects of Ginkgo biloba (Gb) in methotrexate (MTX)-induced liver toxicity model. These effects were analyzed using different in vivo experimental approaches and by bioinformatics analysis. Male SD rats were grouped as follows: saline; MTX; Gb (pretreated for seven days with 60, 120, and 180 mg/kg daily dose before MTX treatment); silymarin (followed by MTX treatment); Gb 180 mg/kg daily only; and silymarin only. Histopathological results revealed that MTX induced marked hepatic injury, associated with a substantial surge in various hepatic enzymes such as alanine transaminase (ALT), aspartate transaminase (AST), and serum alkaline phosphatase (ALP). Furthermore, MTX caused the triggering of oxidative distress associated with a depressed antioxidant system. All these injury markers contributed to a significant release of apoptotic (caspase-3 and c-Jun N-terminal kinases (JNK)) and tumor necrosis factor (TNF-α)-like inflammatory mediators. Treatment with Gb counteracts MTX-mediated apoptosis and inflammation dose-dependently along with modulating the innate antioxidative mechanisms such as glutathione (GSH) and glutathione S-transferase (GST). These results were further supplemented by in silico study to analyze drug-receptor interactions (for several Gb constituents and target proteins) stabilized by a low energy value and with a good number of hydrogen bonds. These findings demonstrated that Gb could ameliorate MTX-induced elevated liver reactive oxygen species (ROS) and inflammation, possibly by JNK and TNF-α modulation.

Incorporation of methotrexate into coconut oil nanoemulsion potentiates its antiproliferation activity and attenuates its oxidative stress

Methotrexate (MTX), a chemotherapeutic agent, has limited clinical applications due to its pulmonary and neurotoxicity. The antineoplastic activity of MTX-NE COCO, which is MTX formulated in coconut oil nanoemulsion (NE), was evaluated in A549 non-small cell lung cancer cells while its adverse side effects on the oxidative stress of the lung and brain were assessed in mice. The z-average diameter for the dispersed nanodroplet of MTX-NE COCO (79.74 ± 3.49 nm) was considerably greater than the free-NE COCO (64.80 ± 3.34 nm). In contrast, the magnitude of the negative z-potential of MTX-NE COCO (3.00 ± 0.69 mV) was markedly less than that of free-NE COCO (8.20 ± 0.76 mV). The minimum inhibitory concentration (IC₅₀) of MTX-NE COCO (18 ± 1.8 µM) was less than the IC₅₀ of free MTX (32 ± 1.2 µM) by around twofold. The in vivo evaluation of the MTX-NE COCO treatment revealed that the antioxidant enzymes activities of the brain and lung tissues, catalase, superoxide dismutase, and glutathione reductase, were relatively raised while the malondialdehyde amount was diminished when compared to the free MTX treatment. In conclusion, combining MTX with coconut oil in a NE had improved its efficacy while ameliorating its oxidative stress effect on the brain and lungs.

Efficacy of High-Dose Methotrexate in Pediatric Non-Infectious Uveitis

Purpose: To analyze the efficacy of high dose (≥ 15mg/m2/week) methotrexate (MTX) versus low dose (<15mg/m2/week) MTX in relation to time to remission on medication.Methods: Retrospective observational cohort study of pediatric patients with auto-immune uveitis with or without underlying systemic disease treated with MTX at the University Medical Center Groningen (the Netherlands) between 1990 and 2014. Primary outcome was time to remission on medication, which was defined as an observable inactive disease in the affected eye for longer than 3 months without the use of systemic corticosteroids.Results: A total of 42 patients were included. Mean age at uveitis diagnosis was 6.5 years (range 1.7 - 14.4), and 22 (52.4%) patients were male. Bilateral disease was found in 33 patients. Most patients (n=25) had anterior uveitis. JIA was the underlying systemic disease in 21 patients. Overall, 28 (66.7%) patients reached remission on medication in (median) 22.5 months (IQR 10.4- 45). Time to remission on medication in the low dose group (median 35.2, IQR 20.5 - 72.1 months) was significantly longer than in the high dose group (median 16.6, IQR 7.8 - 22.5 months) (p= 0.01). No statistically significant differences in ocular complications, steroid-sparing effect, cumulative dosage and side effects of MTX were found between the high and low dose groups.Conclusion: In this retrospective study on pediatric auto-immune uveitis, high dose MTX was associated with a shorter time to remission on medication as compared to low dose MTX, while side effects were comparable in both groups.

Therapeutic role of methotrexate in pediatric Crohn's disease

The main role of therapy in Crohn's disease (CD) is to achieve long-term clinical remission, and to allow for normal growth and development of children. The immunomodulatory drugs used for the maintenance of remission in CD include thiopurines (azathioprine and 6-mercaptopurine) and methotrexate (MTX). Development of hepatosplenic T-cell lymphoma in some patients with inflammatory bowel disease, treated with thiopurines only or in combination with anti-tumor necrosis factor agents, resulted in a growing interest in the therapeutic application of MTX in children suffering from CD. This review summarizes the literature on the therapeutic role of MTX in children with CD. MTX is often administered as a second-line immunomodulator, and 1-year clinical remission was reported in 25-69% of children with CD after excluding for the use of thiopurines. Initial data on MTX effectiveness in mucosal healing, and as a first-line immunomodulator in pediatric patients with CD, are promising. A definite conclusion, however, may only be made on the basis of additional research with a larger number of subjects.

In the Pursuit of Methotrexate Treatment Response Biomarker in Juvenile Idiopathic Arthritis-Are We Getting Closer to Personalised Medicine?

PURPOSE OF REVIEW

Methotrexate (MTX) is the most widely used disease-modifying antirheumatic drug (DMARD) in paediatric rheumatology and the mainstay in the therapy of juvenile idiopathic arthritis (JIA). Despite its common use, about 30% of children fail to respond to this medicine that results in potentially irreversible joint damage.

RECENT FINDINGS

No clinical biomarker that would predict the outcome of MTX therapy exists. Results of several studies focused on gene polymorphisms and outcome of this DMARD therapy have been published, but no reliable genetic marker useful to tailor the therapy has been discovered so far. The results of the first genome-wide association study in this field have recently revealed new genetic candidates from outside the metabolic pathway of MTX that may be associated with the efficacy of treatment. However promising, those outcomes need validation in independent prospective cohorts before we can claim that clinically useful biomarker predicting MTX treatment response is discovered.

Treatment of severe psoriasis in children: recommendations of an Italian expert group

This article provides comprehensive recommendations for the systemic treatment of severe pediatric psoriasis based on evidence obtained from a systematic review of the literature and the consensus opinion of expert dermatologists and pediatricians. For each systemic treatment, the grade of recommendation (A, B, C) based on the treatment's approval by the European Medicines Agency for childhood psoriasis and the experts' opinions is discussed. The grade of recommendation for narrow-band-ultraviolet B phototherapy, cyclosporine, and retinoids is C, while that for methotrexate is C/B. The use of adalimumab, etanercept, and ustekinumab has a grade A recommendation. No conventional systemic treatments are approved for pediatric psoriasis. Adalimumab is approved by the European Medicines Agency as a first-line treatment for severe chronic plaque psoriasis in children (≥ 4 years old) and adolescents. Etanercept and ustekinumab are approved as second-line therapy in children ≥ 6 and ≥ 12 years, respectively.

CONCLUSION

A treatment algorithm as well as practical tools (i.e., tabular summaries of differential diagnoses, treatment mechanism of actions, dosing regimens, control parameters) are provided to assist in therapeutic reasoning and decision-making for individual patients. These treatment recommendations are endorsed by major Italian Pediatric and Dermatology Societies. What is Known: • Guidelines for the treatment of severe pediatric psoriasis are lacking and most traditional systemic treatments are not approved for use in young patients. Although there has been decades of experience with some of the traditional agents such as phototherapy, acitretin, and cyclosporine in children, there are no RCTs on their pediatric use while RCTs investigating new biologic agents have been performed. What is New: • In this manuscript, an Italian multidisciplinary team of experts focused on treatment recommendations for severe forms of psoriasis in children based on an up-to-date review of the literature and experts' opinions.

Low-dose methotrexate in sickle-cell disease: a pilot study with rationale borrowed from rheumatoid arthritis

Background

Inflammation is a major feature of sickle cell disease (SCD). Low-dose methotrexate (MTX) has long been used in chronic inflammatory diseases. This pilot study examined the MTX effect on acute vaso-occlusive pain crises (VOC) in SCD patients.

Methods

Fourteen adults on hydroxyurea with severe and refractory VOC received one intramuscular injection of 10 mg of MTX per week for 12 weeks. A single weekly dose of 5 mg of leucovorin was administered orally 48 h after each MTX injection. The primary outcome was reduction in number/intensity of acute pain episodes. The secondary outcomes were improvement of quality of life (QOL) and reduction of the inflammatory status.

Results

MTX did not significantly change the median VOC frequency (12 before vs 10.5 during treatment, P = 0.6240) or the median McGill pain index (45 at week 0 vs 39.5 at week 12, P = 0.9311). However, there was a decrease of ≥50% in chronic pain resulting from avascular osteonecrosis (AVN) in 5 out of 7 patients with radiologic evidence of AVN, with the perception of longer pain-free periods. There was a 44.4% median gain in physical function in the SF-36 QOL questionnaire (P = 0.0198). MTX treatment up-regulated two C-X-C motif chemokines (CXCL), CXCL10 (P = 0.0463) and CXCL12 (P < 0.0001), without significant effect on 14 additional plasma inflammatory markers. Adverse events: One individual had fever of unknown origin. Respiratory tract infections were recorded in five patients. Among the latter, one also had dengue fever and another had a central venous line infection and died of pneumonia and septic shock. Three patients with previous history of hydroxyurea-induced hematological toxicity developed low blood platelet counts while receiving simultaneously MTX and hydroxyurea.

Conclusions

Although MTX did not reduce acute VOC frequency/intensity, it decreased chronic pain and led to QOL improvement.

Trial registrationhttp://www.who.int/ictrp/en/ and http://www.ensaiosclinicos.gov.br, RBR-2s9xvn, 19 December 2016, retrospectively registered

Electronic supplementary material

The online version of this article (doi:10.1186/s40164-017-0078-1) contains supplementary material, which is available to authorized users.

Methotrexate-induced nausea in the treatment of juvenile idiopathic arthritis

BACKGROUND

Methotrexate is the most commonly used disease modifying antirheumatic drug in the treatment of juvenile idiopathic arthritis and can be effective in controlling disease in many patients.

MAIN BODY

A significant proportion of patients experience nausea and vomiting induced by methotrexate therapy, which can lead to decreased quality of life and discontinuation of treatment with methotrexate. Many strategies have been employed in attempts to reduce methotrexate-induced nausea, including folate supplementation, switching from oral to subcutaneous methotrexate, anti-emetic therapy, behavioral therapy, and others. Anticipatory nausea can be difficult to treat, making primary prevention of nausea with anti-emetics an attractive approach.

CONCLUSION

Understanding the prevalence and impact of methotrexate-induced nausea, as well as potentially effective interventions, may help maximize the therapeutic benefits of methotrexate.

Drugs and drug-like molecules can modulate the function of mucosal-associated invariant T cells

The major-histocompatibility-complex-(MHC)-class-I-related molecule MR1 can present activating and non-activating vitamin-B-based ligands to mucosal-associated invariant T cells (MAIT cells). Whether MR1 binds other ligands is unknown. Here we identified a range of small organic molecules, drugs, drug metabolites and drug-like molecules, including salicylates and diclofenac, as MR1-binding ligands. Some of these ligands inhibited MAIT cells ex vivo and in vivo, while others, including diclofenac metabolites, were agonists. Crystal structures of a T cell antigen receptor (TCR) from a MAIT cell in complex with MR1 bound to the non-stimulatory and stimulatory compounds showed distinct ligand orientations and contacts within MR1, which highlighted the versatility of the MR1 binding pocket. The findings demonstrated that MR1 was able to capture chemically diverse structures, spanning mono- and bicyclic compounds, that either inhibited or activated MAIT cells. This indicated that drugs and drug-like molecules can modulate MAIT cell function in mammals.

A randomized controlled trial of methotrexate for patients with generalized myasthenia gravis

OBJECTIVE

To determine the steroid-sparing effect of methotrexate (MTX) in patients with symptomatic generalized myasthenia gravis (MG).

METHODS

We performed a 12-month multicenter, randomized, double-blind, placebo-controlled trial of MTX 20 mg orally every week vs placebo in 50 acetylcholine receptor antibody-positive patients with MG between April 2009 and August 2014. The primary outcome measure was the prednisone area under the dose-time curve (AUDTC) from months 4 to 12. Secondary outcome measures included 12-month changes of the Quantitative Myasthenia Gravis Score, the Myasthenia Gravis Composite Score, Manual Muscle Testing, the Myasthenia Gravis Quality of Life, and the Myasthenia Gravis Activities of Daily Living.

RESULTS

Fifty-eight patients were screened and 50 enrolled. MTX did not reduce the month 4-12 prednisone AUDTC when compared to placebo (difference MTX - placebo: -488.0 mg, 95% confidence interval -2,443.4 to 1,467.3, p = 0.26); however, the average daily prednisone dose decreased in both groups. MTX did not improve secondary measures of MG compared to placebo over 12 months. Eight participants withdrew during the course of the study (1 MTX, 7 placebo). There were no serious MTX-related adverse events. The most common adverse event was nonspecific pain (19%).

CONCLUSIONS

We found no steroid-sparing benefit of MTX in MG over 12 months of treatment, despite being well-tolerated. This study demonstrates the challenges of conducting clinical trials in MG, including difficulties with recruitment, participants improving on prednisone alone, and the need for a better understanding of outcome measure variability for future clinical trials.

CLASSIFICATION OF EVIDENCE

This study provides Class I evidence that for patients with generalized MG MTX does not significantly reduce the prednisone AUDTC over 12 months of therapy.

Rutin attenuates intestinal toxicity induced by Methotrexate linked with anti-oxidative and anti-inflammatory effects

BACKGROUND

Methotrexate (MTX) is recognized as an anti-metabolite in cancer chemotherapy and is associated with various toxicities assigned to inflammation and oxidative stress. Rutin has been reported to have significant anti-inflammatory, antioxidant along with antiulcer properties. The present study was undertaken to corroborate the effect of rutin against MTX induced intestinal toxicity in experimental animals.

METHOD

Six groups of rats (n = 6) were dosed with normal saline (3 ml/kg,i.p.); MTX (2.5 mg/kg,i.p.); rutin (50 and 100 mg/kg,i.p.); rutin + MTX (50 mg/kg + 2.5 mg/kg,i.p.); rutin + MTX (100 mg/kg + 2.5 mg/kg,i.p.) for seven consecutive days and sacrificed on eighth day. The intestinal contents were scrutinized physiologically (pH, total acidity, free acidity, CMDI), biochemically (TBARS, protein carbonyl, SOD, catalase and GSH) and for immunoregulatory cytokines (IL-2, IL-4 and IL-10).

RESULTS AND DISCUSSION

The administration of rutin demonstrated significant protection against intestinal lesions damaged by MTX. The treatment with rutin elicited noticeable inhibition of free acidity (26.20%), total acidity (22.05%) and CMDI (1.16%) in the experimental animals similar to control. In MTX treated toxic group, the levels of oxidative markers and immunoregulatory cytokines significantly increased in comparison to control, which was subsequently restored after rutin treatment. Rutin also demonstrated 75.63, 81.00 and 80.43% inhibition of cyclooxygenase-1 and 2, and 15-lipoxygenase respectively.

CONCLUSION

The positive modulation of MTX toxicity could be attributed to the free radical scavenging and anti-inflammatory (dual inhibition of arachidonic acid pathways) potential of rutin.

Kawasaki disease and hepatobiliary involvement: report of two cases

Background

Kawasaki disease (KD) without affection of the coronary artery system is rare. Optic nerve pathology together with KD has not been described earlier.

Case presentation

We present one case of KD in a 12-year-old girl predominantly with prolonged cholestasis, and a second case of multiple recurrent KD in a 9-year-old boy with hepatomegaly and ischemic optic nerve neuropathy. The coronary artery system was not involved in either case.

Conclusions

KD warrants rapid diagnosis and immediate specific treatment in order to prevent the high risk of coronary artery aneurysm and stenosis.

Methotrexate for the Management of Crohn's Disease in Children

OBJECTIVE

To review the literature evaluating methotrexate as a treatment option for Crohn's disease (CD) in pediatric patients.

DATA SOURCES

A search of PubMed electronic database (1966 to August 2015) and secondary resources was performed using the terms methotrexate, Crohn's, and inflammatory bowel disease. Other relevant articles cited within identified articles were also utilized.

STUDY SELECTION AND DATA EXTRACTION

Data sources were limited to English-language studies that included children less than 18 years of age. In total, 10 clinical studies met the criteria.

DATA SYNTHESIS

Awareness of the risk of hepatosplenic T-cell lymphoma associated with anti-tumor necrosis factor and thiopurine therapies has renewed interest in methotrexate to treat CD in children. According to data from 10 predominantly retrospective studies, children treated with oral or subcutaneous methotrexate once weekly had remission rates of 25% to 53% at 1 year. Adverse effects most often included nausea and vomiting, elevated liver function tests, headache, and hematological toxicity. The evidence to support methotrexate is limited by inconsistent study design and poorly described dosage regimens. It has been most frequently evaluated in patients with prior thiopurine exposure and has not been thoroughly evaluated as first-line therapy.

CONCLUSIONS

Based on results of retrospective studies, methotrexate is useful in the treatment of pediatric CD in those who fail thiopurine therapy. Remission rates with methotrexate are similar to those for thiopurine therapy, although no studies directly compare these agents. Although preliminary results are promising, prospective studies are needed to assess the use of methotrexate as initial first-line therapy in the pediatric CD population.

Human autoimmune diseases: a comprehensive update

There have been significant advances in our understanding of human autoimmunity that have led to improvements in classification and diagnosis and, most importantly, research advances in new therapies. The importance of autoimmunity and the mechanisms that lead to clinical disease were first recognized about 50 years ago following the pioneering studies of Macfarlane Burnett and his Nobel Prize-winning hypothesis of the 'forbidden clone'. Such pioneering efforts led to a better understanding not only of autoimmunity, but also of lymphoid cell development, thymic education, apoptosis and deletion of autoreactive cells. Contemporary theories suggest that the development of an autoimmune disease requires a genetic predisposition and environmental factors that trigger the immune pathways that lead, ultimately, to tissue destruction. Despite extensive research, there are no genetic tools that can be used clinically to predict the risk of autoimmune disease. Indeed, the concordance of autoimmune disease in identical twins is 12-67%, highlighting not only a role for environmental factors, but also the potential importance of stochastic or epigenetic phenomena. On the other hand, the identification of cytokines and chemokines, and their cognate receptors, has led to novel therapies that block pathological inflammatory responses within the target organ and have greatly improved the therapeutic effect in patients with autoimmune disease, particularly rheumatoid arthritis. Further advances involving the use of multiplex platforms for diagnosis and identification of new therapeutic agents should lead to major breakthroughs within the next decade.

Methotrexate Promotes Platelet Apoptosis via JNK-Mediated Mitochondrial Damage: Alleviation by N-Acetylcysteine and N-Acetylcysteine Amide

Thrombocytopenia in methotrexate (MTX)-treated cancer and rheumatoid arthritis (RA) patients connotes the interference of MTX with platelets. Hence, it seemed appealing to appraise the effect of MTX on platelets. Thereby, the mechanism of action of MTX on platelets was dissected. MTX (10 μM) induced activation of pro-apoptotic proteins Bid, Bax and Bad through JNK phosphorylation leading to ΔΨm dissipation, cytochrome c release and caspase activation, culminating in apoptosis. The use of specific inhibitor for JNK abrogates the MTX-induced activation of pro-apoptotic proteins and downstream events confirming JNK phosphorylation by MTX as a key event. We also demonstrate that platelet mitochondria as prime sources of ROS which plays a central role in MTX-induced apoptosis. Further, MTX induces oxidative stress by altering the levels of ROS and glutathione cycle. In parallel, the clinically approved thiol antioxidant N-acetylcysteine (NAC) and its derivative N-acetylcysteine amide (NACA) proficiently alleviate MTX-induced platelet apoptosis and oxidative damage. These findings underpin the dearth of research on interference of therapeutic drugs with platelets, despite their importance in human health and disease. Therefore, the use of antioxidants as supplementary therapy seems to be a safe bet in pathologies associated with altered platelet functions.

Overview of venous thrombosis in inflammatory bowel disease

Thrombosis in inflammatory bowel disease (IBD) is an increasingly noted extraintestinal manifestation with high morbidity and mortality. While controlling the activity of the disease with the appropriate therapy, thromboembolism prophylaxis should be applied to all patients. All common risk factors for thromboembolism are also valid for patients with IBD; however, it is clear that uncontrolled disease and hospitalization are major disease-specific risk factors for venous thromboembolism in patients with IBD. Pharmacological thromboprophylaxis with currently available anticoagulants does not increase the risk of further bleeding in patients with IBD with mild-to-moderate bleeding. In severe bleeding or with increased risk of further bleeding due to other comorbid conditions, thromboprophylaxy with mechanical methods should be the treatment option. Whether thrombosis is the cause or the result of intestinal inflammation remains to be elucidated, and other issues in the etiology, such as the role of intestinal flora in thrombosis pathogenesis, will be the subject of future studies.

Progressive hemifacial atrophy: a review

Background

Progressive Hemifacial Atrophy (PHA) is an acquired, typically unilateral, facial distortion with unknown etiology. The true incidence of this disorder has not been reported, but it is often regarded as a subtype of localized scleroderma. Historically, a debate existed whether PHA is a form of linear scleroderma, called morphea en coup de sabre (ECDS), or whether these conditions are inherently different processes or appear on a spectrum (; Adv Exp Med Biol 455:101–4, 1999; J Eur Acad Dermatol Venereol 19:403–4, 2005). Currently, it is generally accepted that both diseases exist on a spectrum of localized scleroderma and often coexist.

The pathogenesis of PHA has not been delineated, but trauma, autoimmunity, infection, and autonomic dysregulation have all been suggested. The majority of patients have initial manifestations in the first two decades of life; however, late presentations in 6th and 7th decades are also described [J Am Acad Dermatol 56:257–63, 2007; J Postgrad Med 51:135–6, 2005; Neurology 61:674–6, 2003]. The typical course of PHA is slow progression over 2-20 years and eventually reaching quiescence.

Systemic associations of PHA are protean, but neurological manifestations of seizures and headaches are common [J Am Acad Dermatol 56:257–63, 2007; Neurology 48:1013–8, 1997; Semin Arthritis Rheum 43:335–47, 2013]. As in many rare diseases, standard guidelines for imaging, treatment, and follow-up are not defined.

Methods

This review is based on a literature search using PubMed including original articles, reviews, cases and clinical guidelines. The search terms were “idiopathic hemifacial atrophy”, “Parry-Romberg syndrome”, “Romberg’s syndrome”, “progressive hemifacial atrophy”, “progressive facial hemiatrophy”, “juvenile localized scleroderma”, “linear scleroderma”, and “morphea en coup de sabre”. The goal of this review is to summarize clinical findings, theories of pathogenesis, diagnosis, clinical course, and proposed treatments of progressive hemifacial atrophy using a detailed review of literature.

Inclusion- and exclusion criteria

Review articles were used to identify primary papers of interest while retrospective cohort studies, case series, case reports, and treatment analyses in the English language literature or available translations of international literature were included.

Psoriasis in Children and Adolescents: Diagnosis, Management and Comorbidities

Psoriasis is a common chronic immune-mediated inflammatory skin disorder and begins in childhood in almost one-third of the cases. Although children present with the same clinical subtypes of psoriasis seen in adults, lesions may differ in distribution and morphology, and their clinical symptoms at presentation may vary from those reported by adult patients. Nevertheless, diagnosis of psoriasis is primarily based on clinical features. Pediatric psoriasis can have a profound long-term impact on the psychological health of affected children. Additionally, pediatric psoriasis has been associated with certain comorbidities, such as obesity, hypertension, hyperlipidemia, diabetes mellitus and rheumatoid arthritis, making early diagnosis and management essential. As guidelines are lacking and most (systemic) treatments are not approved for use in children, treatment of pediatric psoriasis remains a challenge. A prospective, multicenter, international registry is needed to evaluate these treatments in a standardized manner and ultimately to develop international guidelines on pediatric psoriasis. This article reviews current concepts in pediatric psoriasis including epidemiology, clinical features, diagnosis, the role of topical and systemic agents and the association with other morbidities in childhood.

Toward resolving the catalytic mechanism of dihydrofolate reductase using neutron and ultrahigh-resolution X-ray crystallography

Dihydrofolate reductase (DHFR) catalyzes the NADPH-dependent reduction of dihydrofolate (DHF) to tetrahydrofolate (THF). An important step in the mechanism involves proton donation to the N5 atom of DHF. The inability to determine the protonation states of active site residues and substrate has led to a lack of consensus regarding the catalytic mechanism involved. To resolve this ambiguity, we conducted neutron and ultrahigh-resolution X-ray crystallographic studies of the pseudo-Michaelis ternary complex of Escherichia coli DHFR with folate and NADP(+). The neutron data were collected to 2.0-Å resolution using a 3.6-mm(3) crystal with the quasi-Laue technique. The structure reveals that the N3 atom of folate is protonated, whereas Asp27 is negatively charged. Previous mechanisms have proposed a keto-to-enol tautomerization of the substrate to facilitate protonation of the N5 atom. The structure supports the existence of the keto tautomer owing to protonation of the N3 atom, suggesting that tautomerization is unnecessary for catalysis. In the 1.05-Å resolution X-ray structure of the ternary complex, conformational disorder of the Met20 side chain is coupled to electron density for a partially occupied water within hydrogen-bonding distance of the N5 atom of folate; this suggests direct protonation of substrate by solvent. We propose a catalytic mechanism for DHFR that involves stabilization of the keto tautomer of the substrate, elevation of the pKa value of the N5 atom of DHF by Asp27, and protonation of N5 by water that gains access to the active site through fluctuation of the Met20 side chain even though the Met20 loop is closed.

Consensus guidelines of ECCO/ESPGHAN on the medical management of pediatric Crohn's disease

Children and adolescents with Crohn's disease (CD) present often with a more complicated disease course compared to adult patients. In addition, the potential impact of CD on growth, pubertal and emotional development of patients underlines the need for a specific management strategy of pediatric-onset CD. To develop the first evidenced based and consensus driven guidelines for pediatric-onset CD an expert panel of 33 IBD specialists was formed after an open call within the European Crohn's and Colitis Organisation and the European Society of Pediatric Gastroenterolog, Hepatology and Nutrition. The aim was to base on a thorough review of existing evidence a state of the art guidance on the medical treatment and long term management of children and adolescents with CD, with individualized treatment algorithms based on a benefit-risk analysis according to different clinical scenarios. In children and adolescents who did not have finished their growth, exclusive enteral nutrition (EEN) is the induction therapy of first choice due to its excellent safety profile, preferable over corticosteroids, which are equipotential to induce remission. The majority of patients with pediatric-onset CD require immunomodulator based maintenance therapy. The experts discuss several factors potentially predictive for poor disease outcome (such as severe perianal fistulizing disease, severe stricturing/penetrating disease, severe growth retardation, panenteric disease, persistent severe disease despite adequate induction therapy), which may incite to an anti-TNF-based top down approach. These guidelines are intended to give practical (whenever possible evidence-based) answers to (pediatric) gastroenterologists who take care of children and adolescents with CD; they are not meant to be a rule or legal standard, since many different clinical scenario exist requiring treatment strategies not covered by or different from these guidelines.