The clinical implications of thalidomide in inflammatory bowel diseases

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.

Recent advances in the treatment of IBD: Targets, mechanisms and related therapies

Inflammatory bowel disease (IBD), as a representative inflammatory disease, currently has multiple effective treatment options available and new therapeutic strategies are being actively explored to further increase the treatment options for patients with IBD. Furthermore, biologic agents and small molecule drugs developed for ulcerative colitis (UC) and Crohn's disease (CD) have evolved toward fewer side effects and more accurate targeting. Novel inhibitors that target cytokines (such as IL-12/23 inhibitors, PDE4 inhibitors), integrins (such as integrin inhibitors), cytokine signaling pathways (such as JAK inhibitors, SMAD7 blocker) and cell signaling receptors (such as S1P receptor modulator) have become the preferred treatment choice for many IBD patients. Conventional therapies such as 5-aminosalicylic acid, corticosteroids, immunomodulators and anti-tumor necrosis factor agents continue to demonstrate therapeutic efficacy, particularly in combination with drug therapy. This review integrates research from chemical, biological and adjuvant therapies to evaluate current and future IBD therapies, highlighting the mechanism of action of each therapy and emphasizing the potential of development prospects.

Optimising management strategies of inflammatory bowel disease in resource-limited settings in Asia

Over the 21st century, inflammatory bowel disease (IBD) has become a global disease with increasing prevalence reported in the Asian subcontinent as a result of rapid urbanisation, industrialisation, and westernisation of lifestyles. Although rates of surgery have shown a temporal decrease globally because of the increasing availability of new drugs and early initiation of effective therapy, health-care costs associated with IBD have continued to rise. The increase in IBD prevalence in resource-limited countries poses a substantial health-care burden. Drugs are not universally accessible or available. An optimised and practical management strategy of IBD in resource-limited countries in Asia is urgently needed. Special consideration should be made to balance the risk of undertreatment (and suboptimal disease control) because of financial constraints with the risk of overtreatment, which is associated with side-effects and costly therapeutics. In this Series paper, we summarise the current approach in optimising conventional therapies, use of other therapies, and de-escalation of biologics in low-resource settings in Asia. The long-term objective is to strive for more effective and affordable therapies with sustained durability of benefit.

Inhibition of colitis by ring-modified analogues of 6-acetamido-2,4,5-trimethylpyridin-3-ol

6-Aminopyridin-3-ol scaffold has shown an excellent anti-inflammatory bowel disease activity. Various analogues with the scaffold were synthesized in pursuit of the diversity of side chains tethering on the C(6)-position. Structure-activity relationship among the analogues was investigated to understand the effects of the side chains and their linkers on their anti-inflammatory activities. In this study, structural modification moved beyond side chains on the C(6)-position and reached to pyridine ring itself. It expedited us to synthesize diverse ring-modified analogues of a representative pyridine-3-ol, 6-acetamido-2,4,5-trimethylpyridin-3-ol (9). In the evaluation of compounds on their inhibitory actions against TNF-α-induced adhesion of monocytic cells to colonic epithelial cells, an in vitro model mimicking colon inflammation, the effects of compounds 9, 17, and 19 were greater than tofacitinib, an orally available anti-colitis drug, and compound 17 showed the greatest activity. In addition, TNF-α-induced angiogenesis, which permits more inflammatory cell migration into inflamed tissues, was significantly blocked by compounds 17 and 19 in a concentration-dependent manner. In the comparison of in vivo therapeutic effects of compounds 9, 17, and 19 on dextran sulfate sodium (DSS)-induced colitis in mice, compound 17 was the most potent and efficacious, and compound 19 was better than compound 9 which showed a similar degree of inhibitory effect to tofacitinib. Taken together, it seems that either the trimethyl system or the hydroxyl group on the pyridinol ring is essential to the activity. This finding might become a new milestone in the development of pyridinol-based anti-inflammatory bowel disease agents.

Overcoming cancer therapeutic bottleneck by drug repurposing

Ever present hurdles for the discovery of new drugs for cancer therapy have necessitated the development of the alternative strategy of drug repurposing, the development of old drugs for new therapeutic purposes. This strategy with a cost-effective way offers a rare opportunity for the treatment of human neoplastic disease, facilitating rapid clinical translation. With an increased understanding of the hallmarks of cancer and the development of various data-driven approaches, drug repurposing further promotes the holistic productivity of drug discovery and reasonably focuses on target-defined antineoplastic compounds. The "treasure trove" of non-oncology drugs should not be ignored since they could target not only known but also hitherto unknown vulnerabilities of cancer. Indeed, different from targeted drugs, these old generic drugs, usually used in a multi-target strategy may bring benefit to patients. In this review, aiming to demonstrate the full potential of drug repurposing, we present various promising repurposed non-oncology drugs for clinical cancer management and classify these candidates into their proposed administration for either mono- or drug combination therapy. We also summarize approaches used for drug repurposing and discuss the main barriers to its uptake.

Perianal Disease and Granulomas: Think Out of the Box…

BACKGROUND

Chronic granulomatous disease (CGD) is a primary immunodeficiency due to a malfunction of NADPH oxidase. It is characterized by recurrent and severe infections caused by catalase-positive microorganisms and autoinflammatory manifestations. Recently, there has been described an NCF4 gene variant that causes a deficiency of p40^phox, a subunit of NADPH oxidase. Patients with this deficiency appear to have a less severe clinical form as compared to classic CGD.

CASE

A 15-year-old girl with vulvar lichen planus since she was 2 years old and suspected Crohn's disease (CD) was first seen at our hospital. At the age of 12 years, she had been submitted to sacrococcygeal cyst exeresis, without cicatrization of the surgical wound and extension of the lesion to the perianal area. The diagnosis of CD was questioned, and the patient underwent an endoscopic and radiologic assessment, which was normal. A skin biopsy from the perianal area revealed a granuloma; thus, CD with isolated perianal disease was assumed. After several different treatments including antibiotics, infliximab, and adalimumab, the perianal lesion persisted, with no associated gastrointestinal symptoms. Therefore, the hypothesis of an immunodeficiency was considered. An immunologic and genetic study revealed reduced oxidative burst in the phorbol myristate acetate test, with diminished reactive oxygen species production and a homozygous mutation in the NCF4 gene. The adolescent started prophylactic trimethoprim-sulfamethoxazole and became asymptomatic.

CONCLUSIONS

The present case highlights that alternative diagnoses to CD must be considered in the presence of isolated perianal disease with granulomatous inflammation, especially when the disease is refractory to conventional CD therapy.

Peripheral neuropathy and gastroenterologic disorders: an overview on an underrecognized association

BACKGROUND AND AIM OF THE WORK

Although peripheral neuropathies in children are often of genetic origin, acquired causes should be carefully looked for and ruled out also in the pediatric age. Gastroenterological disorders can be complicated by peripheral neuropathy as a result of micronutrients deficiency, drug toxicity or because of shared pathophysiological mechanisms.

METHODS

In this descriptive review we sought to give an overview on the most relevant clinical conditions in which peripheral neuropathies are associated with gastro-intestinal disorders or symptoms.

RESULTS

We describe the clinical, demographic, and electrophysiological features of peripheral neuropathy in three main clinical scenarios: in the context of common gastroenterological disorders (inflammatory bowel and celiac disease), in the context of micronutrients deficiencies arising from malabsorption irrespective of etiology, and in a rare degenerative mitochondrial disorder, mitochondrial neurogastrointestinal encephalomyopathy (MNGIE) disorder.

CONCLUSIONS

The association between gastrointestinal and peripheral nervous system symptoms is probably still underrecognized but has to be actively sought, in order to provide prompt diagnosis resulting in optimal care and long-term management with the aim to improve quality of life and, at least in some conditions, try to impact on prognosis.

A Brighter Side to Thalidomide: Its Potential Use in Immunological Disorders

Thalidomide and its derivatives are immunomodulatory drugs (IMiDs) known for their sedative, teratogenic, anti-angiogenic, and anti-inflammatory properties. Commonly used in the treatment of cancers such as multiple myeloma and myelodysplastic syndrome (MDS), IMiDs have also been used in the treatment of an inflammatory skin pathology associated with Hansen's disease/leprosy. They have also shown promise in the treatment of autoimmune disorders including systemic lupus erythmatosus (SLE) and inflammatory bowel disease (IBD). Recent structural and experimental observations have revolutionized our understanding of these properties by revealing the fundamental molecular events underpinning IMiD activity. We review these findings, their relevance to IMiD therapy in immunological disorders, and discuss how further research might unlock the vast clinical potential of these compounds.

Thalidomide is a therapeutic agent that is effective in inducing and maintaining endoscopic remission in adult CD patients

BACKGROUND AND AIMS

Previous studies have indicated that thalidomide may be effective in achieving clinical remission and response; however, there is a lack of studies on its effect in endoscopic remission. The aim of this study was to assess the efficacy and safety of thalidomide in inducing and maintaining endoscopic remission.

METHODS

A retrospective study was conducted in adult Crohn's disease (CD) patients treated with thalidomide. Patients were assessed based on their medical records. Endoscopy was performed after 4-6 months of thalidomide administration, and the simple endoscopic score for CD (SES-CD) was obtained.

RESULTS

Twenty of the 21 (95.2%) eligible patients were recruited. Endoscopic remission was achieved in 7 of the 14 (50%) endoscopy active patients who received thalidomide treatment, whereas 10 (71.4%) patients showed an endoscopy response. The other 6 patients in endoscopic remission still maintained remission after thalidomide treatment. The SES-CD in endoscopy active patients was significantly reduced after thalidomide treatment (P<0.05). A total of 32 adverse events occurred in 17 of the 21 (81.0%) patients. Adverse events resolved spontaneously in 11 (64.7%) patients and resulted in treatment discontinuation and dose reduction in 4 (19.1%) and 2 (9.5%) patients, respectively.

CONCLUSIONS

Thalidomide therapy is effective in inducing and maintaining endoscopic remission in adult CD patients. However, side effects may limit its clinical use in CD treatment.

A Novel Green Synthesis of Thalidomide and Analogs

Thalidomide and its derivatives are currently under investigation for their antiangiogenic, immunomodulative, and anticancer properties. Current methods used to synthesize these compounds involve multiple steps and extensive workup procedures. Described herein is an efficient microwave irradiation green synthesis method that allows preparation of thalidomide and its analogs in a one-pot multicomponent synthesis system. The multicomponent synthesis system developed involves an array of cyclic anhydrides, glutamic acid, and ammonium chloride in the presence of catalytic amounts of 4-N,N-dimethylaminopyridine (DMAP) to produce thalidomide and structurally related compounds within minutes in good isolated yields.

Successful treatment of ileal ulcers caused by immunosuppressants in two organ transplant recipients

Although gastroduodenal ulcers are common in solid organ transplant patients, there are few reports on multiple giant ulcers in the distal ileum and ileocecal valve caused by immunosuppressants Herein, we report on a liver transplant recipient and a renal transplant recipient with multiple large ulcers in the distal ileum and ileocecal valve who rapidly achieved ulcer healing upon withdrawal of sirolimus or tacrolimus and administration of thalidomide. In case 1, a 56-year-old man with primary hepatocellular carcinoma had received a liver transplantation. Tacrolimus combined with sirolimus and prednisolone was used as the anti-rejection regimen. Colonoscopy was performed because of severe abdominal pain and diarrhea at post-operative month 10. Multiple giant ulcers were found at the ileocecal valve and distal ileum. The ulcers healed rapidly with withdrawal of sirolimus and treatment with thalidomide. There was no recurrence during 2 years of follow-up. In case 2, a 34-year-old man with end-stage kidney disease received kidney transplantation and was put on tacrolimus combined with mycophenolate mofetil and prednisolone as the anti-rejection regimen. Twelve weeks after the operation, the patient presented with hematochezia and severe anemia. Colonoscopy revealed multiple large ulcers in the ileocecal valve and distal ileum, with massive accumulation of fresh blood. The bleeding ceased after treatment with intravenous somatostatin and oral thalidomide. Tacrolimus was withdrawn at the same time. Colonoscopy at week 4 of follow-up revealed remarkable healing of the ulcers, and there was no recurrence of bleeding during 1 year of follow-up. No lymphoma, tuberculosis, or infection of cytomegalovirus, Epstein-Barr virus, or fungus was found in either patient. In post-transplantation cases with ulcers in the distal ileum and ileocecal valve, sirolimus or tacrolimus should be considered a possible risk factor, and withdrawing them or switching to another immunosuppressant might be effective to treat these ulcers.

Angiogenesis in Inflammatory Bowel Disease

Angiogenesis is an important component of pathogenesis of inflammatory bowel disease (IBD). Chronic inflammation and angiogenesis are two closely related processes. Chronic intestinal inflammation is dependent on angiogenesis and this angiogenesis is modulated by immune system in IBD. Angiogenesis is a very complex process which includes multiple cell types, growth factors, cytokines, adhesion molecules, and signal transduction. Lymphangiogenesis is a new research area in the pathogenesis of IBD. While angiogenesis supports inflammation via leukocyte migration, carrying oxygen and nutrients, on the other hand, it has a major role in wound healing. Angiogenic molecules look like perfect targets for the treatment of IBD, but they have risk for serious side effects because of their nature.

Peripheral neuropathy: an underreported neurologic manifestation of inflammatory bowel disease

BACKGROUND AND AIMS

One of the most frequent neurologic complications reported in inflammatory bowel disease population is peripheral neuropathy; however, clinical aspects of peripheral nerve damage are not well characterized. The aim of the review is to present the existing literature on peripheral neuropathy in inflammatory bowel disease patients.

METHODS

A literature search identified the publications reporting on epidemiology, clinical features, underlying mechanisms and management of ulcerative colitis and Crohn's disease patients with peripheral nerve involvement.

RESULTS

The pathogenesis of peripheral nervous system damage in inflammatory bowel disease has yet to be elucidated, although it seems to be related to immune mechanisms; therefore, treatment with immunotherapy is recommended. In addition, peripheral neuropathy may appear as iatrogenic-related disorders associated with several drugs used in controlling inflammatory bowel disease activity; finally, peripheral neuropathy may also be caused by micronutrient deficiencies secondary to malabsorption-related disorders.

CONCLUSIONS

Although peripheral nervous nerve damage associated with inflammatory bowel disease is rarely reported, clinicians should be aware of the peripheral neuropathy clinical manifestations in order to recognize it and provide early treatment, which is crucial for preventing major neurologic morbidity. Heightened awareness is necessary for the successful management of these patients.