Neurological disorders and inflammatory bowel diseases

Kynurenine pathway and its role in neurologic, psychiatric, and inflammatory bowel diseases

Tryptophan metabolism along the kynurenine pathway is of central importance for the immune function. It prevents hyperinflammation and induces long-term immune tolerance. Accumulating evidence also demonstrates cytoprotective and immunomodulatory properties of kynurenine pathway in conditions affecting either central or peripheral nervous system as well as other conditions such as inflammatory bowel disease (IBD). Although multilevel association exists between the inflammatory bowel disease (IBD) and various neurologic (e.g., neurodegenerative) disorders, it is believed that the kynurenine pathway plays a pivotal role in the development of both IBD and neurodegenerative disorders. In this setting, there is strong evidence linking the gut-brain axis with intestinal dysfunctions including IBD which is consistent with the fact that the risk of neurodegenerative diseases is higher in IBD patients. This review aims to highlight the role of kynurenine metabolic pathway in various neurologic and psychiatric diseases as well as relationship between IBD and neurodegenerative disorders in the light of the kynurenine metabolic pathway.

Inflammatory Bowel Disease and Neurodegenerative Diseases

A growing body of evidence has demonstrated an intricate association between inflammatory bowel disease (IBD) and neurodegenerative conditions, expanding beyond previous foci of comorbidities between IBD and mood disorders. These new discoveries stem from an improved understanding of the gut-microbiome-brain axis: specifically, the ability of the intestinal microbiota to modulate inflammation and regulate neuromodulatory compounds. Clinical retrospective studies incorporating large sample sizes and population-based cohorts have demonstrated and confirmed the relevance of IBD and chronic neurodegeneration in clinical medicine. In this review, we expound upon the current knowledge on the gut-microbiome-brain axis, highlighting several plausible mechanisms linking IBD with neurodegeneration. We also summarize the known associations between IBD with Parkinson disease, Alzheimer disease, vascular dementia and ischemic stroke, and multiple sclerosis in a clinical context. Finally, we discuss the implications of an improved understanding of the gut-microbiome-brain axis in preventing, diagnosing, and managing neurodegeneration among IBD and non-IBD patients.

Growth Failure and Primary Amenorrhea: Endocrine Dysfunction as a Late Presentation of Crohn's Disease

Crohn's disease (CD) is a chronic inflammatory bowel disease involving entire gastrointestinal tract, most commonly affecting terminal ileum and colon. It usually presents with gastrointestinal symptoms like bloody diarrhea, fever and loss of weight. The clinical course of CD includes gastrointestinal complications like fistulas, abscesses and perianal disease. Inflammatory bowel diseases (IBD) are usually diagnosed during childhood and adolescence, majority during puberty and pubertal growth spurt. Various extraintestinal manifestations may be a presentation of CD that poses a diagnostic challenge. Growth failure is an important complication of IBD rather than a manifestation. Herein we present a case of a 16-year-old Sri Lankan girl presenting with growth failure and primary amenorrhea. She had minimal gastrointestinal symptoms. She also had microcytic anemia with marginally elevated inflammatory markers and hormonal profile. She underwent colonoscopy and was diagnosed to have Crohn's disease confirmed by ileal biopsy. On initiation of treatment with immunosuppressants, she attained menarche, although no improvement in height was observed.

Mendelian randomization and genetic colocalization infer the effects of the multi-tissue proteome on 211 complex disease-related phenotypes

BACKGROUND

Human proteins are widely used as drug targets. Integration of large-scale protein-level genome-wide association studies (GWAS) and disease-related GWAS has thus connected genetic variation to disease mechanisms via protein. Previous proteome-by-phenome-wide Mendelian randomization (MR) studies have been mainly focused on plasma proteomes. Previous MR studies using the brain proteome only reported protein effects on a set of pre-selected tissue-specific diseases. No studies, however, have used high-throughput proteomics from multiple tissues to perform MR on hundreds of phenotypes.

METHODS

Here, we performed MR and colocalization analysis using multi-tissue (cerebrospinal fluid (CSF), plasma, and brain from pre- and post-meta-analysis of several disease-focus cohorts including Alzheimer disease (AD)) protein quantitative trait loci (pQTLs) as instrumental variables to infer protein effects on 211 phenotypes, covering seven broad categories: biological traits, blood traits, cancer types, neurological diseases, other diseases, personality traits, and other risk factors. We first implemented these analyses with cis pQTLs, as cis pQTLs are known for being less prone to horizontal pleiotropy. Next, we included both cis and trans conditionally independent pQTLs that passed the genome-wide significance threshold keeping only variants associated with fewer than five proteins to minimize pleiotropic effects. We compared the tissue-specific protein effects on phenotypes across different categories. Finally, we integrated the MR-prioritized proteins with the druggable genome to identify new potential targets.

RESULTS

In the MR and colocalization analysis including study-wide significant cis pQTLs as instrumental variables, we identified 33 CSF, 13 plasma, and five brain proteins to be putative causal for 37, 18, and eight phenotypes, respectively. After expanding the instrumental variables by including genome-wide significant cis and trans pQTLs, we identified a total of 58 CSF, 32 plasma, and nine brain proteins associated with 58, 44, and 16 phenotypes, respectively. For those protein-phenotype associations that were found in more than one tissue, the directions of the associations for 13 (87%) pairs were consistent across tissues. As we were unable to use methods correcting for horizontal pleiotropy given most of the proteins were only associated with one valid instrumental variable after clumping, we found that the observations of protein-phenotype associations were consistent with a causal role or horizontal pleiotropy. Between 66.7 and 86.3% of the disease-causing proteins overlapped with the druggable genome. Finally, between one and three proteins, depending on the tissue, were connected with at least one drug compound for one phenotype from both DrugBank and ChEMBL databases.

CONCLUSIONS

Integrating multi-tissue pQTLs with MR and the druggable genome may open doors to pinpoint novel interventions for complex traits with no effective treatments, such as ovarian and lung cancers.

SOX-1 antibodies in a patient with Crohn's disease: a case report

BACKGROUND

The anti-SOX-1 antibodies have been mainly associated with Lambert-Eaton Myasthenic Syndrome (LETMS) and Small-Cell Lung Cancer (SCLC). In this report, we describe the interesting case of a patient with serum anti-SOX-1 antibodies and Crohn's Disease (CD) with ensuing neurological symptoms.

CASE PRESENTATION

A Caucasian 67-year-old female was admitted to the Emergency Department with seizures, vertigo, emesis, nausea, postural instability and recurrent falls, over a period of 10 days. She had been affected by Crohn's Disease since 1991. A CT scan failed to detect any ischemic or haemorrhagic lesion. A brain MRI revealed signs of leukoencephalopathy. Western blot analysis of her serum revealed a high titre of the onconeural antibody anti-SOX1, consistent with a neurological, cerebellar type, paraneoplastic syndrome. In spite of multiple efforts to unmask a possible underlying malignancy, no neoplastic lesion cropped up during hospitalization. Her clinical conditions progressively deteriorated, up to respiratory failure; a few days later she died, due to ensuing septic shock and Multiple Organ Failure.

CONCLUSIONS

Our experience may usher and reveal a new role of anti-neural antibodies, so far reckoned an early indicator of associated malignancy, suggesting that neurological syndromes associated with such antibodies may complicate also chronic Gastrointestinal (GI) diseases. As of now, testing for anti-neuronal antibodies appeared unnecessary within the diagnostic assessment of gastroenterological disorders, which may lead to overlooking incident neurologic autoimmune diseases. Further exploration of such research hypothesis in clinical grounds appears intriguing.

Thromboembolic Events in Patients with Inflammatory Bowel Disease: A Comprehensive Overview

Inflammatory bowel disease (IBD), Crohn’s disease and ulcerative colitis are chronic inflammatory disorders of the intestines. The underlying inflammation activates the coagulation cascade leading to an increased risk of developing arterial and venous thromboembolic events such as deep vein thrombosis and pulmonary embolism. Patients with IBD are at a 2–3-fold increased risk of developing thromboembolism. This risk increases in patients with active IBD disease, flare-ups, surgery, steroid treatment, and hospitalization. These complications are associated with significant morbidity and mortality making them important in clinical practice. Clinicians should consider the increased risk of thromboembolic events in patients with IBD and manage them with appropriate prophylaxis based on the risk. In this review, we discuss the literature associated with the pathophysiology of thromboembolism in patients with IBD, summarize the studies describing the various thromboembolic events, and the management of thromboembolism in patients with IBD.

Epilepsy and the gut: Perpetrator or victim?

The brain and the gut are linked together with a complex, bi-path link known as the gut-brain axis through the central and enteric nervous systems. So, the brain directly affects and controls the gut through various neurocrine and endocrine processes, and the gut impacts the brain via different mechanisms. Epilepsy is a central nervous system (CNS) disorder with abnormal brain activity, causing repeated seizures due to a transient excessive or synchronous alteration in the brain’s electrical activity. Due to the strong relationship between the enteric and the CNS, gastrointestinal dysfunction may increase the risk of epilepsy. Meanwhile, about 2.5% of patients with epilepsy were misdiagnosed as having gastrointestinal disorders, especially in children below the age of one year. Gut dysbiosis also has a significant role in epileptogenesis. Epilepsy, in turn, affects the gastrointestinal tract in different forms, such as abdominal aura, epilepsy with abdominal pain, and the adverse effects of medications on the gut and the gut microbiota. Epilepsy with abdominal pain, a type of temporal lobe epilepsy, is an uncommon cause of abdominal pain. Epilepsy also can present with postictal states with gastrointestinal manifestations such as postictal hypersalivation, hyperphagia, or compulsive water drinking. At the same time, antiseizure medications have many gastrointestinal side effects. On the other hand, some antiseizure medications may improve some gastrointestinal diseases. Many gut manipulations were used successfully to manage epilepsy. Prebiotics, probiotics, synbiotics, postbiotics, a ketogenic diet, fecal microbiota transplantation, and vagus nerve stimulation were used successfully to treat some patients with epilepsy. Other manipulations, such as omental transposition, still need more studies. This narrative review will discuss the different ways the gut and epilepsy affect each other.

Three Different Types of β-Glucans Enhance Cognition: The Role of the Gut-Brain Axis

Background

Dietary fiber is fermented in the lower gastrointestinal tract, potentially impacting the microbial ecosystem and thus may improve elements of cognition and brain function via the gut-brain axis. β-glucans, soluble dietary fiber, have different macrostructures and may exhibit different effects on the gut-brain axis. This study aimed to compare the effects of β-glucans from mushroom, curdlan and oats bran, representing β-(1,3)/(1,6)-glucan, β-(1,3)-glucan or β-(1,3)/(1,4)-glucan, on cognition and the gut-brain axis.

Methods

C57BL/6J mice were fed with either control diet or diets supplemented with β-glucans from mushroom, curdlan and oats bran for 15 weeks. The cognitive functions were evaluated by using the temporal order memory and Y-maze tests. The parameters of the gut-brain axis were examined, including the synaptic proteins and ultrastructure and microglia status in the hippocampus and prefrontal cortex (PFC), as well as colonic immune response and mucus thickness and gut microbiota profiles.

Results

All three supplementations with β-glucans enhanced the temporal order recognition memory. Brain-derived neurotrophic factor (BDNF) and the post-synaptic protein 95 (PSD95) increased in the PFC. Furthermore, mushroom β-glucan significantly increased the post-synaptic thickness of synaptic ultrastructure in the PFC whilst the other two β-glucans had no significant effect. Three β-glucan supplementations decreased the microglia number in the PFC and hippocampus, and affected complement C3 and cytokines expression differentially. In the colon, every β-glucan supplementation increased the number of CD206 positive cells and promoted the expression of IL-10 and reduced IL-6 and TNF-α expression. The correlation analysis highlights that degree of cognitive behavior improved by β-glucan supplementations was significantly associated with microglia status in the hippocampus and PFC and the number of colonic M2 macrophages. In addition, only β-glucan from oat bran altered gut microbiota and enhanced intestinal mucus.

Conclusions

We firstly demonstrated long-term supplementation of β-glucans enhanced recognition memory. Comparing the effects of β-glucans on the gut-brain axis, we found that β-glucans with different molecular structures exhibit differentia actions on synapses, inflammation in the brain and gut, and gut microbiota. This study may shed light on how to select appropriate β-glucans as supplementation for the prevention of cognitive deficit or improving immune function clinically.

Patients With Inflammatory Bowel Diseases Are at Higher Risk for Meningitis

BACKGROUND

The epidemiology of meningitis is unknown in inflammatory bowel disease (IBD) patients.

GOALS

We aimed to determine the incidence of and risk factors for meningitis in IBD patients.

STUDY

We conducted a retrospective cohort and nested case-control study in the Quintiles IMS Legacy PharMetrics Adjudicated Claims Database from January 2001 to June 2016. We matched IBD patients to those without IBD on age, sex, enrollment, and region. Meningitis was defined as one code for meningitis associated with an emergency department visit or hospitalization. Meningitis risk was calculated with incidence rate ratios. In a nested case-control study of IBD patients, predictors for meningitis were determined with multivariable conditional logistic regression models.

RESULTS

We identified 50,029 patients with Crohn's disease (CD) and 59,830 patients with ulcerative colitis (UC) matched to 296,801 non-IBD comparators. There were 85 CD patients, 77 UC patients, and 235 comparators with meningitis. CD patients had 2.17 times the rate of meningitis and UC patients had 1.63 times the rate of meningitis as non-IBD comparators. After adjusting for relevant covariates among those with IBD, treatment with mesalamine was associated with a significantly lower odds of a meningitis claim (odds ratio: 0.40, 95% confidence interval: 0.26-0.62). Having at least one comorbidity was associated with a significantly higher odds of a meningitis claim (odds ratio: 2.21, 95% confidence interval: 1.76-2.77).

CONCLUSIONS

Although the overall rate of meningitis is low, IBD patients are at an increased risk compared with non-IBD comparators. Comorbidities are a risk factor for meningitis in IBD patients. Pneumococcal and meningococcal vaccinations should be discussed.

The Gut-Brain Axis and Its Role in Controlling Eating Behavior in Intestinal Inflammation

Malnutrition represents a major problem in the clinical management of the inflammatory bowel disease (IBD). Presently, our understanding of the cross-link between eating behavior and intestinal inflammation is still in its infancy. Crohn's disease patients with active disease exhibit strong hedonic desires for food and emotional eating patterns possibly to ameliorate feelings of low mood, anxiety, and depression. Impulsivity traits seen in IBD patients may predispose them to palatable food intake as an immediate reward rather than concerns for future health. The upregulation of enteroendocrine cells (EEC) peptide response to food intake has been described in ileal inflammation, which may lead to alterations in gut-brain signaling with implications for appetite and eating behavior. In summary, a complex interplay of gut peptides, psychological, cognitive factors, disease-related symptoms, and inflammatory burden may ultimately govern eating behavior in intestinal inflammation.

Case report of the treatment and experience of mental disorders due to chronic viral encephalitis

Viral encephalitis is a common clinical condition. Its clinical manifestations are variable and include neurological symptoms and psychiatric abnormalities, which makes clinical diagnosis and treatment difficult. To date, there are only a few reported cases on mental symptoms of chronic viral encephalitis. We present a case of a 16-year-old male patient who was previously hospitalised and diagnosed with schizophrenia and treated with aripiprazole 15 mg/day but failed to respond. The patient was then given antiviral therapy and recovered after 2 weeks. Clinicians should be aware of the possbility that chronic mental disorders could be caused by viral encephalitis. In the future, diagnosis of chronic functional mental disorders should include viral encephalitis in the differential diagnosis.

Conduct disorder and somatic health in children: a nationwide genetically sensitive study

BACKGROUND

Conduct disorder (CD), a serious behavioral and emotional disorder in childhood and adolescence, characterized by disruptive behavior and breaking societal rules. Studies have explored the overlap of CD with neurodevelopmental problems (NDP). The somatic health of children with NDP has been investigated; however, the prevalence of these problems in children with CD has not been sufficiently studied. Holistic assessment of children with CD is required for establishing effective treatment strategies.

AIMS

(1) Define the prevalence of selected neurological problems (migraine and epilepsy) and gastrointestinal problems (celiac disease, lactose intolerance, diarrhea, and constipation) in a population of twins aged 9 or 12; (2) Compare the prevalence of somatic problems in three subpopulations: (a) children without CD or NDP, (b) children with CD, and (c) children with both CD and NDP; (3) Select twin pairs where at least one child screened positive for CD but not NDP (proband) and map both children's neurological and gastrointestinal problems.

METHOD

Telephone interviews with parents of 20,302 twins in a cross-sectional, nationwide, ongoing study. According to their scores on the Autism-Tics, AD/HD, and Comorbidities inventory, screen-positive children were selected and divided into two groups: (1) children with CD Only, (2) children with CD and at least one NDP.

RESULTS

Children with CD had an increased prevalence of each neurological and gastrointestinal problem (except celiac disease), and the prevalence of somatic problems was further increased among children with comorbid CD and NDP. The presence of CD (without NDP) increased the odds of constipation for girls and the odds of epilepsy for boys. Girls with CD generally had more coexisting gastrointestinal problems than boys with CD. Female co-twins of probands with CD were strongly affected by gastrointestinal problems. Concordance analyses suggested genetic background factors in neurological and gastrointestinal problems, but no common etiology with CD could be concluded.

CONCLUSION

Co-occurring NDP could explain most of the increased prevalence of somatic problems in CD. Our results raise a new perspective on CD in children and adolescents; their CD seems to be linked to a number of other health problems, ranging from neurodevelopmental and psychiatric disorders to somatic complaints.

Constitutive Androstane Receptor: A Peripheral and a Neurovascular Stress or Environmental Sensor

Xenobiotic nuclear receptors (NR) are intracellular players involved in an increasing number of physiological processes. Examined and characterized in peripheral organs where they govern metabolic, transport and detoxification mechanisms, accumulating data suggest a functional expression of specific NR at the neurovascular unit (NVU). Here, we focus on the Constitutive Androstane Receptor (CAR), expressed in detoxifying organs such as the liver, intestines and kidneys. By direct and indirect activation, CAR is implicated in hepatic detoxification of xenobiotics, environmental contaminants, and endogenous molecules (bilirubin, bile acids). Importantly, CAR participates in physiological stress adaptation responses, hormonal and energy homeostasis due to glucose and lipid sensing. We next analyze the emerging evidence supporting a role of CAR in NVU cells including the blood-brain barrier (BBB), a key vascular interface regulating communications between the brain and the periphery. We address the emerging concept of how CAR may regulate specific P450 cytochromes at the NVU and the associated relevance to brain diseases. A clear understanding of how CAR engages during pathological conditions could enable new mechanistic, and perhaps pharmacological, entry-points within a peripheral-brain axis.

Neuroimmunogastroenterology: At the Interface of Neuroimmunology and Gastroenterology

The central nervous system (CNS) is an important regulator of the gastrointestinal tract, and CNS dysfunction can result in significant and disabling gastrointestinal symptom manifestation. For patients with neuroimmunologic and neuroinflammatory conditions, the recognition of gastrointestinal symptoms is under-appreciated, yet the gastrointestinal manifestations have a dramatic impact on quality of life. The current treatment strategies, often employed independently by the neurologist and gastroenterologist, raise the question of whether such patients are being treated optimally when siloed in one specialty. Neuroimmunogastroenterology lies at the borderlands of medical specialties, and there are few resources to guide neurologists in this area. Here, we provide an overview highlighting the potential mechanisms of crosstalk between immune-mediated neurological disorders and gastrointestinal dysfunction.

Intestinal inflammation increases convulsant activity and reduces antiepileptic drug efficacy in a mouse model of epilepsy

We studied the effects of intestinal inflammation on pentylenetetrazole (PTZ)-induced seizures in mice and the effects thereon of some antiepileptic and anti-inflammatory treatments to establish if a link may exist. The agents tested were: alpha-lactoalbumin (ALAC), a whey protein rich in tryptophan, effective in some animal models of epilepsy and on colon/intestine inflammation, valproic acid (VPA), an effective antiepileptic drug in this seizure model, mesalazine (MSZ) an effective aminosalicylate anti-inflammatory treatment against ulcerative colitis and sodium butyrate (NaB), a short chain fatty acid (SCFA) normally produced in the intestine by gut microbiota, important in maintaining gut health and reducing gut inflammation and oxidative stress. Intestinal inflammation was induced by dextran sulfate sodium (DSS) administration for 6 days. Drug treatment was started on day 3 and lasted 11 days, when seizure susceptibility to PTZ was measured along with intestinal inflammatory markers (i.e. NF-κB, Iκ-Bα, COX-2, iNOS), histological damage, disease activity index (DAI) and SCFA concentration in stools. DSS-induced colitis increased seizure susceptibility and while all treatments were able to reduce intestinal inflammation, only ALAC and NaB exhibited significant antiepileptic properties in mice with induced colitis, while they were ineffective as antiepileptics at the same doses in control mice without colitis. Interestingly, in DSS-treated mice, VPA lost part of its antiepileptic efficacy in comparison to preventing seizures in non-DSS-treated mice while MSZ remained ineffective in both groups. Our study demonstrates that reducing intestinal inflammation through ALAC or NaB administration has specific anticonvulsant effects in PTZ-treated mice. Furthermore, it appears that intestinal inflammation may reduce the antiepileptic effects of VPA, although we confirm that it decreases seizure threshold in this group. Therefore, we suggest that intestinal inflammation may represent a valid antiepileptic target which should also be considered as a participating factor to seizure incidence in susceptible patients and also could be relevant in reducing standard antiepileptic drug efficacy.

Impaired neurocognitive and psychomotor performance in patients with inflammatory bowel disease

Limited evidence exists regarding cognitive and psychomotor function in patients with inflammatory bowel disease (IBD). Therefore, we aimed to compare the neurocognitive and psychomotor function of 60 IBD patients with 60 age/sex-matched controls. Computer-based instrument Complex Reactinometer Drenovac (CRD) was used for assessment of cognitive domains: convergent thinking (simple mathematical tasks; CRD-11), perceptive abilities (light signal position discrimination; CRD-311) and sophisticated operative thinking (complex psychomotor coordination; CRD-411). The most important analyzed parameters were total test solving time (T_TTS); minimal time of particular test solving (T_MIN) and total number of wrong reactions (N_ER). Performance in all three cognitive tests showed statistically significantly longer T_TTS and T_MIN in IBD patients (P < 0.05), while there was no significant difference in N_ER. Aforementioned findings were adjusted for BMI, age and duration of education. Our study has shown impaired neurocognitive and psychomotor function in IBD patients compared to controls, especially in mental processing speed and mental endurance of perceptive abilities, convergent thinking and complex operative thinking.

Impaired neurocognitive and psychomotor performance in patients with inflammatory bowel disease

Limited evidence exists regarding cognitive and psychomotor function in patients with inflammatory bowel disease (IBD). Therefore, we aimed to compare the neurocognitive and psychomotor function of 60 IBD patients with 60 age/sex-matched controls. Computer-based instrument Complex Reactinometer Drenovac (CRD) was used for assessment of cognitive domains: convergent thinking (simple mathematical tasks; CRD-11), perceptive abilities (light signal position discrimination; CRD-311) and sophisticated operative thinking (complex psychomotor coordination; CRD-411). The most important analyzed parameters were total test solving time (T_TTS); minimal time of particular test solving (T_MIN) and total number of wrong reactions (N_ER). Performance in all three cognitive tests showed statistically significantly longer T_TTS and T_MIN in IBD patients (P < 0.05), while there was no significant difference in N_ER. Aforementioned findings were adjusted for BMI, age and duration of education. Our study has shown impaired neurocognitive and psychomotor function in IBD patients compared to controls, especially in mental processing speed and mental endurance of perceptive abilities, convergent thinking and complex operative thinking.

The intestinal barrier in multiple sclerosis: implications for pathophysiology and therapeutics

Biological barriers are essential for the maintenance of homeostasis in health and disease. Breakdown of the intestinal barrier is an essential aspect of the pathophysiology of gastrointestinal inflammatory diseases, such as inflammatory bowel disease. A wealth of recent studies has shown that the intestinal microbiome, part of the brain-gut axis, could play a role in the pathophysiology of multiple sclerosis. However, an essential component of this axis, the intestinal barrier, has received much less attention. In this review, we describe the intestinal barrier as the physical and functional zone of interaction between the luminal microbiome and the host. Besides its essential role in the regulation of homeostatic processes, the intestinal barrier contains the gut mucosal immune system, a guardian of the integrity of the intestinal tract and the whole organism. Gastrointestinal disorders with intestinal barrier breakdown show evidence of CNS demyelination, and content of the intestinal microbiome entering into the circulation can impact the functions of CNS microglia. We highlight currently available studies suggesting that there is intestinal barrier dysfunction in multiple sclerosis. Finally, we address the mechanisms by which commonly used disease-modifying drugs in multiple sclerosis could alter the intestinal barrier and the microbiome, and we discuss the potential of barrier-stabilizing strategies, including probiotics and stabilization of tight junctions, as novel therapeutic avenues in multiple sclerosis.

Cerebral Vasculitis in Ulcerative Colitis Is Predominantly Venular: Case Report and Review of the Literature

Extraintestinal complications of ulcerative colitis include isolated case reports of cerebral vasculitis. In this case report, we describe autopsy findings in a 50-year-old female who died as a result of massive multifocal cerebral hemorrhage. Microscopic examination of the left colon showed findings typical for ulcerative colitis. Examination of the brain showed an extensive vasculitis. More affected vessels were noted in grey matter than in white matter. Many showed fibrinoid necrosis, invasion by neutrophils and thrombosis. There was extensive perivascular hemorrhage with associated infarction. Vessel analysis shows most of the vessels to have been venous rather than arterial. There were no perivascular sleeves of demyelination to suggest a primary demyelinating disorder, such as acute hemorrhagic leucoencephalitis. Our analysis shows that veins are the likely target of cerebral vasculitis in ulcerative colitis. This has clinical implications because venous occlusion generally causes massive intracerebral hemorrhage with a high mortality.

Central Venous Sinus Thrombosis in a Boy With Acute Severe Ulcerative Colitis

Cerebral venous sinus thrombosis (CVST) in childhood is uncommon. Certain diseases predispose patients to CVST, such as inflammatory bowel disease (IBD), which is considered a risk factor for developing thrombosis, which in turn is considered an extraintestinal manifestation of IBD. The use of prophylaxis in certain patients is a controversial topic. We present the case of a 5-years-old child with ulcerative colitis, who presented with transverse sinus thrombosis immediately after colectomy. Considering the recent recommendations on prophylaxis in this disease, our patient and probably many others would benefit from establishing treatment with low-molecular-weight heparin. We believe that these recommendations should be known, with our case serving as an example, given that we are heading in a direction that has so far been controversial.

Cerebral granulomatosis as a manifestation of Crohn's disease

BACKGROUND

Crohn's disease (CD) is associated with a variety of extra-intestinal manifestations. Most commonly these involve the eye, skin, joints, coagulation system and liver. Cerebral manifestations of CD have been reported to a far lesser extent. The extensive detrimental impact of neurological symptoms on a patient's quality of life makes an early diagnosis and treatment particularly important. In previous case-reports, diagnosis of cerebral manifestations in CD often relied upon magnetic resonance imaging (MRI) and computed tomography (CT) alone. To our knowledge, only one case-report has documented a histologically confirmed case of cerebral lesions associated with CD so far.

CASE PRESENTATION

A 39-year-old right-handed woman with a history of CD was referred to our hospital with etiologically unexplained Gadolinium (Gd)-enhancing cortical lesions, triggering epileptic seizures. A CT-scan of the thorax and bronchoalveolar lavage found no signs of sarcoidosis. Lumbar punctures and laboratory testing found no underlying infection or coincidental autoimmune disorders and MRI-scans showed progression of lesion load. Consequently, the patient underwent stereotactic biopsy of a cortical lesion. Histological examination revealed a mixed lympho-histiocytic and tuberculoid granulomatous inflammation surrounding small vessels and no signs for infection. After exclusion of other granulomatous diseases and the typical histological findings we diagnosed a cerebral granulomatosis as a manifestation of CD. The patient was initially started on azathioprine, which had to be switched to corticosteroids and methotrexate because of an azathioprine related pancreatitis. The patient has not suffered any further epileptic seizures to date.

CONCLUSION

Cerebral manifestation of CD is a possibly underreported entity that may respond well to immunosuppressive treatment. In contrast to earlier reports of cerebral manifestations in CD, our patient showed no coincident gastrointestinal symptoms indicating an activity of CD during the progression of cortical lesion load, suggesting that similar to other extra-intestinal manifestations in CD, the activity of gastrointestinal symptoms does not necessarily reflect the activity of CD associated cerebral vasculitis. Therefore, diagnosis and therapy of cerebral manifestation may be delayed when focusing on gastrointestinal symptoms alone.

Trace Amine-Associated Receptors as Novel Therapeutic Targets for Immunomodulatory Disorders

Trace amines and their receptors (trace amine-associated receptors; TAARs) are an emerging pharmacological target for the treatment of human disorders. While most studies have focused on their therapeutic potential for neurologic and psychiatric disorders, TAARs are also expressed throughout the periphery, including prominent expression in human leukocytes. Furthermore, recent independent, unbiased metabolomic studies have consistently identified one or more TAAR ligands as potential etiologic factors in inflammatory bowel disease (IBD). The putative role of TAARs in diseases such as IBD that are associated with hyperactive immune responses has not, however, previously been systematically addressed. Here, we review the current state of the knowledge of the effects of TAARs on leukocyte function, in particular in the context of mucosal epithelial cells that interface with the environment; developing a model whereby TAARs may be considered as a novel therapeutic target for disorders associated with dysregulated immune responses to environmental factors. In this model, we hypothesize that altered trace amine homeostasis results in hyperactivity of the immune system. Such loss of homeostasis can occur through many different mechanisms including TAAR polymorphisms and altered trace amine load due to changes in host synthesis and/or degradative enzymes, diet, or microbial dysbiosis. The resulting alterations in TAAR functioning can then lead to a loss of homeostasis of leukocyte chemotaxis, differentiation, and activation, as well as an altered ability of members of the microbiota to adhere to and penetrate the epithelial cell layers. Such changes would generate a pro-inflammatory state at mucosal epithelial barrier layers that can manifest as clinical symptomatology such as that seen in IBD. These alterations may also have the potential to induce systemic effects, which could possibly contribute to immunomodulatory disorders in other systems, including neurological diseases.

Proteinase 3-antineutrophil cytoplasmic antibody-positive ulcerative colitis presenting with abducens neuropathy

A 72-year-old man with ulcerative colitis (UC) presented with complete left abducens nerve palsy. Although MRI showed no significant changes, cerebrospinal fluid analysis revealed pleocytosis and elevated protein and interleukin (IL)-6 levels. His serum proteinase 3-antineutrophil cytoplasmic antibody (PR3-ANCA) level was also elevated to 31.1 U/mL, but granulomatosis with polyangiitis was not observed. On the basis of the diagnosis of autoimmune cranial neuropathy, he was treated with steroid therapy. While tapering steroid therapy, his serum PR3-ANCA levels; cerebrospinal fluid findings, including IL-6 levels; and symptoms improved. Serum PR3-ANCA could be a useful parameter of neurological disorders associated with ANCA-positive UC.

Cognitive impairment in Crohn's disease is associated with systemic inflammation, symptom burden and sleep disturbance

BACKGROUND

Patients with Crohn's disease (CD) frequently complain of cognitive difficulties such as problems with concentration and clouding of thought, yet this has scarcely been objectively defined and underlying mechanisms remain unknown.

OBJECTIVE

The objective of this article is to objectively measure cognitive impairments in patients with CD compared with healthy controls, and if present, to identify potentially modifiable, contributing factors associated with cognitive impairment.

METHODS

CD patients and healthy age-/sex-matched controls completed surveys encompassing clinical, demographic, psychiatric, fatigue and sleep parameters. Contemporaneously, disease activity assessment with serum CRP, faecal calprotectin, Harvey-Bradshaw Index and the Subtle Cognitive Impairment test (SCIT) were performed, with the primary measure of response time (SCIT-RT) compared between groups. Multiple linear regression assessed for factors associated with slower SCIT-RT, denoting subtle cognitive impairment.

RESULTS

A total of 49 CD and 31 control individuals participated, with median age 44 years (range 22-65) and 43 years (21-63), respectively. Compared to controls, SCIT-RT was slower across all timepoints in CD patients (ANOVA p < 0.001). In multivariate analysis, serum CRP (standardised beta coefficient 0.27, 95% CI (0.02, 0.51)), abdominal pain (0.43 (0.16, 0.70)), plasma haemoglobin (1.55 (1.42, 1.68)), and concurrent fatigue (0.56 (0.25, 0.88)) were each independently associated with slower SCIT-RT in CD (each p < 0.05), with a trend for poorer sleep quality 0.54 (-0.03, 1.11) (p = 0.06), yet conversely, higher faecal calprotectin titres were associated with faster SCIT-RT (-1.77 (-1.79, -1.76), p < 0.01).

CONCLUSIONS

Patients with CD demonstrated subtle cognitive impairment utilising the objective SCIT, correlating with systemic inflammation and other disease burden measures, although higher faecal calprotectin titres were unexpectedly associated with less cognitive impairment.

Psoriasis and inflammatory bowel disease: links and risks

Psoriasis and the spectrum of inflammatory bowel diseases (IBD) are chronic, inflammatory, organotropic conditions. The epidemiologic coexistence of these diseases is corroborated by findings at the level of disease, biogeography, and intrafamilial and intrapatient coincidence. The identification of shared susceptibility loci and DNA polymorphisms has confirmed this correlation at a genetic level. The pathogenesis of both diseases implicates the innate and adaptive segments of the immune system. Increased permeability of the epidermal barrier in skin and intestine underlies the augmented interaction of allergens and pathogens with inflammatory receptors of immune cells. The immune response between psoriasis and IBD is similar and comprises phagocytic, dendritic, and natural killer cell, along with a milieu of cytokines and antimicrobial peptides that stimulate T-cells. The interplay between dendritic cells and Th17 cells appears to be the core dysregulated immune pathway in all these conditions. The distinct similarities in the pathogenesis are also reflected in the wide overlapping of their therapeutic approaches. Small-molecule pharmacologic immunomodulators have been applied, and more recently, biologic treatments that target proinflammatory interleukins have been introduced or are currently being evaluated. However, the fact that some treatments are quite selective for either skin or gut conditions also highlights their crucial pathophysiologic differences. In the present review, a comprehensive comparison of risk factors, pathogenesis links, and therapeutic strategies for psoriasis and IBD is presented. Specific emphasis is placed on the role of the immune cell species and inflammatory mediators participating in the pathogenesis of these diseases.

Structural brain lesions in inflammatory bowel disease

Central nervous system (CNS) complications or manifestations of inflammatory bowel disease deserve particular attention because symptomatic conditions can require early diagnosis and treatment, whereas unexplained manifestations might be linked with pathogenic mechanisms. This review focuses on both symptomatic and asymptomatic brain lesions detectable on imaging studies, as well as their frequency and potential mechanisms. A direct causal relationship between inflammatory bowel disease (IBD) and asymptomatic structural brain changes has not been demonstrated, but several possible explanations, including vasculitis, thromboembolism and malnutrition, have been proposed. IBD is associated with a tendency for thromboembolisms; therefore, cerebrovascular thromboembolism represents the most frequent and grave CNS complication. Vasculitis, demyelinating conditions and CNS infections are among the other CNS manifestations of the disease. Biological agents also represent a risk factor, particularly for demyelination. Identification of the nature and potential mechanisms of brain lesions detectable on imaging studies would shed further light on the disease process and could improve patient care through early diagnosis and treatment.

Differential diagnosis in inflammatory bowel disease colitis: State of the art and future perspectives

Distinction between Crohn’s disease of the colon-rectum and ulcerative colitis or inflammatory bowel disease (IBD) type unclassified can be of pivotal importance for a tailored clinical management, as each entity often involves specific therapeutic strategies and prognosis. Nonetheless, no gold standard is available and the uncertainty of diagnosis may frequently lead to misclassification or repeated examinations. Hence, we have performed a literature search to address the problem of differential diagnosis in IBD colitis, revised current and emerging diagnostic tools and refined disease classification strategies. Nowadays, the differential diagnosis is an untangled issue, and the proper diagnosis cannot be reached in up to 10% of patients presenting with IBD colitis. This topic is receiving emerging attention, as medical therapies, surgical approaches and leading prognostic outcomes require more and more disease-specific strategies in IBD patients. The optimization of standard diagnostic approaches based on clinical features, biomarkers, radiology, endoscopy and histopathology appears to provide only marginal benefits. Conversely, emerging diagnostic techniques in the field of gastrointestinal endoscopy, molecular pathology, genetics, epigenetics, metabolomics and proteomics have already shown promising results. Novel advanced endoscopic imaging techniques and biomarkers can shed new light for the differential diagnosis of IBD, better reflecting diverse disease behaviors based on specific pathogenic pathways.