Profound loss of esophageal tissue differentiation in patients with eosinophilic esophagitis.

BACKGROUND: A key question in the allergy field is to understand how tissue-specific disease is manifested. Eosinophilic esophagitis (EoE) is an emerging tissue-specific allergic disease with an unclear pathogenesis. OBJECTIVE: Herein we tested the hypothesis that a defect in tissue-specific esophageal genes is an integral part of EoE pathogenesis. METHODS: We interrogated the pattern of expression of esophagus-specific signature genes derived from the Human Protein Atlas in the EoE transcriptome and in EPC2 esophageal epithelial cells. Western blotting and immunofluorescence were used for evaluating expression of esophageal proteins in biopsy specimens from control subjects and patients with active EoE. Whole-exome sequencing was performed to identify mutations in esophagus-specific genes. RESULTS: We found that approximately 39% of the esophagus-specific transcripts were altered in patients with EoE, with approximately 90% being downregulated. The majority of transcriptional changes observed in esophagus-specific genes were reproduced in vitro in esophageal epithelial cells differentiated in the presence of IL-13. Functional enrichment analysis revealed keratinization and differentiation as the most affected biological processes and identified IL-1 cytokines and serine peptidase inhibitors as the most dysregulated esophagus-specific protein families in patients with EoE. Accordingly, biopsy specimens from patients with EoE evidenced a profound loss of tissue differentiation, decreased expression of keratin 4 (KRT4) and cornulin (CRNN), and increased expression of KRT5 and KRT14. Whole-exome sequencing of 33 unrelated patients with EoE revealed 39 rare mutations in 18 esophagus-specific differentially expressed genes. CONCLUSIONS: A tissue-centered analysis has revealed a profound loss of esophageal tissue differentiation (identity) as an integral and specific part of the pathophysiology of EoE and implicated protease- and IL-1-related activities as putative central pathways in disease pathogenesis.

Anesthetic Management of a Patient with Wolff-Parkinson-White Syndrome for Laparoscopic Cholecystectomy: A Case Report.

Wolff-Parkinson-White syndrome, an electrophysiological disorder of heart caused by preexcitation of an abnormal accessory pathway,can either be asymptomatic or may present with palpitation or exertional dyspnea. We report a case of an asymptomatic 45-year-old male with incidental finding of Wolff-Parkinson-White syndrome posted for laparoscopic cholecystectomy under general anesthesia. The anesthetic management of these patients is challenging as they are prone to develop life-threatening tachyarrhythmia. Taking all the necessary precautions to prevent tachyarrhythmia, balanced anesthesia, rigorous monitoring and preparedness with necessary drugs and equipment to treat any complications is the cornerstone for positive outcome. Keywords: accessory pathway; tachyarrhythmia; WPW syndrome.

Lamotrigine induced toxic epidermal necrolysis: A case report.

INTRODUCTION: A wide spectrum of cutaneous adverse reactions ranging from simple maculopapular rashes to more severe and life-threatening reactions like Stevens-Johnson syndrome (SJS) and toxic epidermal necrolysis(TEN) have been described after exposure to many antiepileptic drugs. Although the adverse effect following lamotrigine has been reported after a low initial dosage, the risk of developing TEN is relatively rare. CASE REPORT: We present a 23-year-old female, 6 months post-partum, a case of complex partial seizure, who developed TEN after 14 days of monotherapy with lamotrigine. She was put on steroids and other supportive management. After a tempestuous course of 9 days in ICU, she made an eventful recovery. DISCUSSION: Lamotrigine, a chemically different newer antiepileptic, if rapidly titrated and used in conjunction with valproate can cause exfoliative dermatitis-like TEN, but at lower doses and as a monotherapy, female, post-partum, probably due to hormonal factors and strong association between HLA-B*1502 and AED (Antiepileptic drug)-induced SJS/TEN in patients of Asian ethnicity could be other contributing cause. Also, lesser use of lamotrigine in developing nations might have led to a lesser incidence of serious cutaneous adverse reactions. The SCORTEN (Severity-of-illness score for toxic epidermal necrolysis) is the most widely used system to standardize the evaluation of risk and prognosis in patients with TEN. CONCLUSION: Though rare but TEN can occur following lamotrigine monotherapy. Prompt diagnosis, withdrawal of offending agent, and timely proper supportive care might help in lowering the mortality.

Single-cell RNA sequencing identifies inflammatory tissue T cells in eosinophilic esophagitis.

T cell heterogeneity is highly relevant to allergic disorders. We resolved the heterogeneity of human tissue CD3+ T cells during allergic inflammation, focusing on a tissue-specific allergic disease, eosinophilic esophagitis (EoE). We investigated 1088 single T cells derived from patients with a spectrum of disease activity. Eight disparate tissue T cell subtypes (designated T1-T8) were identified, with T7 and T8 enriched in the diseased tissue. The phenotypes of T7 and T8 resemble putative Treg (FOXP3+) and effector Th2-like (GATA3+) cells, respectively. Prodigious levels of IL-5 and IL-13 were confined to HPGDS+ CRTH2+IL-17RB+FFAR3+CD4+ T8 effector Th2 cells. EoE severity closely paralleled a lipid/fatty acid-induced activation node highlighted by the expression of the short-chain fatty acid receptor FFAR3. Ligands for FFAR3 induced Th2 cytokine production from human and murine T cells, including in an in vivo allergy model. Therefore, we elucidated the defining characteristics of tissue-residing CD3+ T cells in EoE, a specific enrichment of CD4+ Treg and effector Th2 cells, confinement of type 2 cytokine production to the CD4+ effector population, a highly likely role for FFAR3 in amplifying local Th2 responses in EoE, and a resource to further dissect tissue lymphocytes and allergic responses.

Whole-exome sequencing uncovers oxidoreductases DHTKD1 and OGDHL as linkers between mitochondrial dysfunction and eosinophilic esophagitis.

Eosinophilic esophagitis (EoE) is an allergic inflammatory esophageal disorder with a complex underlying genetic etiology often associated with other comorbidities. Using whole-exome sequencing (WES) of 63 patients with EoE and 60 unaffected family members and family-based trio analysis, we sought to uncover rare coding variants. WES analysis identified 5 rare, damaging variants in dehydrogenase E1 and transketolase domain-containing 1 (DHTKD1). Rare variant burden analysis revealed an overabundance of putative, potentially damaging DHTKD1 mutations in EoE (P = 0.01). Interestingly, we also identified 7 variants in the DHTKD1 homolog oxoglutarate dehydrogenase-like (OGDHL). Using shRNA-transduced esophageal epithelial cells and/or patient fibroblasts, we further showed that disruption of normal DHTKD1 or OGDHL expression blunts mitochondrial function. Finally, we demonstrated that the loss of DHTKD1 expression increased ROS production and induced the expression of viperin, a gene previously shown to be involved in production of Th2 cytokines in T cells. Viperin had increased expression in esophageal biopsies of EoE patients compared with control individuals and was upregulated by IL-13 in esophageal epithelial cells. These data identify a series of rare genetic variants implicating DHTKD1 and OGDHL in the genetic etiology of EoE and underscore a potential pathogenic role for mitochondrial dysfunction in EoE.

In vitro model for studying esophageal epithelial differentiation and allergic inflammatory responses identifies keratin involvement in eosinophilic esophagitis.

Epithelial differentiation is an essential physiological process that imparts mechanical strength and barrier function to squamous epithelia. Perturbation of this process can give rise to numerous human diseases, such as atopic dermatitis, in which antigenic stimuli can penetrate the weakened epithelial barrier to initiate the allergic inflammatory cascade. We recently described a simplified air-liquid interface (ALI) culture system that facilitates the study of differentiated squamous epithelia in vitro. Herein, we use RNA sequencing to define the genome-wide transcriptional changes that occur within the ALI system during epithelial differentiation and in response to allergic inflammation. We identified 2,191 and 781 genes that were significantly altered upon epithelial differentiation or dysregulated in the presence of interleukin 13 (IL-13), respectively. Notably, 286 genes that were modified by IL-13 in the ALI system overlapped with the gene signature present within the inflamed esophageal tissue from patients with eosinophilic esophagitis (EoE), an allergic inflammatory disorder of the esophagus that is characterized by elevated IL-13 levels, altered epithelial differentiation, and pro-inflammatory gene expression. Pathway analysis of these overlapping genes indicated enrichment in keratin genes; for example, the gene encoding keratin 78, an uncharacterized type II keratin, was upregulated during epithelial differentiation (45-fold) yet downregulated in response to IL-13 and in inflamed esophageal tissue from patients. Thus, our findings delineate an in vitro experimental system that models epithelial differentiation that is dynamically regulated by IL-13. Using this system and analyses of patient tissues, we identify an altered expression profile of novel keratin differentiation markers in response to IL-13 and disease activity, substantiating the potential of this combined approach to identify relevant molecular processes that contribute to human allergic inflammatory disease.