Non-alcoholic fatty liver disease in 2015

There is worldwide epidemic of non-alcoholic fatty liver disease(NAFLD). NAFLD is a clinical entity related to metabolic syndrome. Majority of the patients are obese but the disease can affect non-obese individuals as well. Metabolic factors and genetics play important roles in the pathogenesis of this disorder. The spectrum of disorders included in NAFLD are benign macrovesicular hepatic steatosis, non-alcoholic steatohepatitis, hepatic fibrosis, cirrhosis of liver and hepatocellular carcinoma. Although the disease remains asymptomatic most of the time, it can slowly progress to end stage liver disease. It will be the most common indication of liver transplantation in the future. It is diagnosed by abnormal liver chemistry, imaging studies and liver biopsy. As there are risks of potential complications during liver biopsy, many patients do not opt for liver biopsy. There are some noninvasive scoring systems to find out whether patients have advanced hepatic fibrosis. At the present time, there are limited treatment options which include lifestyle modification to loose weight, vitamin E and thioglitazones. Different therapeutic agents are being investigated for optimal management of this entity. There are some studies done on incretin based therapies in patients with NAFLD. Other potential agents will be silent information regulator protein Sirtuin and antifibrotic monoclonal antibody Simtuzumab against lysyl oxidase like molecule 2. But they are still in the investigational phase.

Gastrointestinal neuroendocrine tumors in 2020

Gastrointestinal neuroendocrine tumors are rare slow-growing tumors with distinct histological,biological,and clinical characteristics that have increased in incidence and prevalence within the last few decades.They contain chromogranin A,synaptophysin and neuron-specific enolase which are necessary for making a diagnosis of neuroendocrine tumor.Ki-67 index and mitotic index correlate with cellular proliferation.Serum chromogranin A is the most commonly used biomarker to assess the bulk of disease and monitor treatment and is raised in both functioning and non-functioning neuroendocrine tumors.Most of the gastrointestinal neuroendocrine tumors are non-functional.World Health Organization updated the classification of neuroendocrine tumors in 2017 and renamed mixed adenoneuroendocrine carcinoma into mixed neuroendocrine neoplasm.Gastric neuroendocrine tumors arise from enterochromaffin like cells.They are classified into 4 types.Only type I and type II are gastrin dependent.Small intestinal neuroendocrine tumor is the most common small bowel malignancy.More than two-third of them occur in the terminal ileum within 60 cm of ileocecal valve.Patients with small intestinal neuroendrocrine tumors frequently show clinical symptoms and develop distant metastases more often than those with neuroendocrine tumors of other organs.Duodenal and jejunoileal neuroendocrine tumors are distinct biologically and clinically.Carcinoid syndrome generally occurs when jejuno-ileal neuroendocrine tumors metastasize to the liver.Appendiceal neuroendocrine tumors are generally detected after appendectomy.Colonic neuroendocrine tumors generally present as a large tumor with local or distant metastasis at the time of diagnosis.Rectal neuroendocrine tumors are increasingly being diagnosed since the implementation of screening colonoscopy in 2000.Gastrointestinal neuroendocrine tumors are diagnosed and staged by endoscopy with biopsy,endoscopic ultrasound,serology of biomarkers,imaging studies and functional somatostatin scans.Various treatment options are available for curative and palliative treatment of gastrointestinal neuroendocrine tumors.

Ischemic bowel disease in 2021

Ischemic bowel disease(ISBODI)includes colon ischemia,acute mesenteric ischemia(AMI)and chronic mesenteric ischemia(CMI).Epidemiologically,colon ischemia is the most common type followed by AMI and CMI.There are various risk factors for the development of ISBODI.Abdominal pain is the common presenting symptom of each type.High clinical suspicion is essential in ordering appropriate tests.Imaging studies and colonoscopy with biopsy are the main diagnostic tests.Treatment varies from conservative measures to surgical resection and revascularization.Involvement of multidisciplinary team is essential in managing ISBODI.Although open surgery with revascularization plays an important role,recently there is an increasing interest in percutaneous endovascular treatment.

Recent advances in the management of gastrointestinal stromal tumor

Gastrointestinal stromal tumor(GIST)is a rare but an important clinical entity seen in our clinical practice.It is the most common mesenchymal tumor of the gastrointestinal tract and most common malignancy of the small intestine.Although the exact prevalence of GIST is not known,the incidence of GIST has been increasing.GISTs arise from interstitial cells of Cajal.Most of the GISTs occur due to mutation in c-kit gene or platelet derived growth factor receptor alpha gene.15%of GISTs do not have these mutations and they are called wildtype GISTs.Almost all GISTs express KIT receptor tyrosine kinase.Histologically,GISTs look like spindle cell tumors most of the time but they can be epitheloid or mixed type.The median size of GISTs varies from 2.7 cm to 8.9 cm.Clinically,patients with small GISTs remain asymptomatic but as the GIST size increases,patients present with various symptoms depending on the location of the GIST.Most of GISTs are located in the stomach or small bowel.Diagnosis is suspected on imaging and endoscopic studies,and confirmed by tissue acquisition with immunohistochemical staining.The aggressiveness of GISTs depends on the size,mitotic index and location.Surgical resection is the treatment of choice.But various endoscopic modalities of resection are increasingly being tried.Tyrosine kinase inhibitors are extremely useful in the management of large GISTs,unresectable GISTs and metastatic GISTs.Treatment options for metastatic GISTs also include radiotherapy,chemotherapy,hepatic artery embolization,chemoembolization and radiofrequency ablation.

Acute cholangitis-an update

Acute cholangitis is bacterial infection of the extrahepatic biliary system. As it is caused by gallstones blocking the common bile duct in most of the cases, its prevalence is greater in ethnicities with high prevalence of gallstones. Biliary obstruction of any cause is the main predisposing factor. Diagnosis is established by the presence of clinical features, laboratory results and imaging studies. The treatment modalities include administration of intravenous fluid, antibiotics, and drainage of the bile duct. The outcome is good if the treatment is started early, otherwise it could be grave.

Era of direct acting anti-viral agents for the treatment of hepatitis C

Hepatitis C infection is universal and the most common indication of liver transplantation in the United States. The period of less effective interferon therapy with intolerable side effects has gone. Now we have stepped into the era of direct acting anti-viral agents(DAAs) against hepatitis C virus. Treatment of hepatitis C is now extremely effective, tolerable and requires a short duration of intake of oral agents. Less monitoring is required with the current therapy and drug-drug interactions are less than the previous regimen. The current treatment options of chronic hepatitis C with various DAAs are discussed in this article.

Checkpoint inhibitors: What gastroenterologists need to know

Checkpoint inhibitors are increasingly being used in clinical practice. They can cause various gastrointestinal,hepatic and pancreatic side effects. As these side effects can be serious, appropriate management is essential. The different checkpoint inhibitors with their mechanisms of action and indications, as well as evaluation and management of gastrointestinal, hepatic and pancreatic side effects, are discussed in this article.

Blood thinners and gastrointestinal endoscopy

As the number of diagnostic and therapeutic gastrointestinal endoscopies is increasing, and there is an increase in number of patients taking blood thinners, we are seeing more and more patients on blood thinners prior to endoscopic procedures. Gastrointestinal bleeding or thromboembolism can occur in this category of patients in the periendoscopic period. To better manage these patients, endoscopists should have a clear concept about the various blood thinners in the market. Patients’ risk of thromboembolism off anticoagulation, and the risk of bleeding from endoscopic procedures should be assessed prior to endoscopy. The endoscopic procedure should be done when it is safe to do it.

Eosinophilic esophagitis in adults: An update

Eosinophilic esophagitis is a worldwide chronic allergic disease of the esophagus.In the last decade,there is an epidemic of this entity in the western world.Mostly seen in children and young adults,patients present with dysphagia or food impaction in the emergency room.Characteristic endoscopic findings,esophageal eosinophilia and non-responsiveness to proton pump inhibitors help make the diagnosis.Avoidance of foodallergens,administration of steroidal anti-inflammatory medications and dilation of the esophagus are the mainstays of treatment.Investigations are ongoing for mucosal healing and optimum maintenance treatment.

Myeloid-derived suppressor cells in gastrointestinal cancers:A systemic review

Gastrointestinal(GI)cancers are one of the most common malignancies worldwide,with high rates of morbidity and mortality.Myeloid-derived suppressor cells(MDSCs)are major components of the tumor microenvironment(TME).MDSCs facilitate the transformation of premalignant cells and play roles in tumor growth and metastasis.Moreover,in patients with GI malignancies,MDSCs can lead to the suppression of T cells and natural killer cells.Accordingly,a better understanding of the role and mechanism of action of MDSCs in the TME will aid in the development of novel immune-targeted therapies.