Cryptococcus-Related Immune Reconstitution Inflammatory Syndrome (IRIS): Pathogenesis and its Clinical Implications

This review provides an overview of Cryptococcus neoformans immunology and focuses on the pathogenesis of Cryptococcus-related paradoxical immune reconstitution inflammatory syndrome (IRIS). Cryptococcal IRIS has three phases: (1) before antiretroviral therapy (ART), with a paucity of cerebrospinal fluid (CSF) inflammation and defects in antigen clearance; (2) during initial ART immune recovery, with pro-inflammatory signaling by antigen-presenting cells without an effector response; and (3) at IRIS, a cytokine storm with a predominant type-1 helper T-cell (Th₁) interferon-gamma (IFN-γ) response. Understanding IRIS pathogenesis allows for risk stratification and customization of HIV/AIDS care. In brief, persons at high IRIS risk may benefit from enhancing microbiologic clearance by use of adjunctive agents in combination with amphotericin, prolonging initial induction therapy, and/or increasing the initial consolidation antifungal therapy dose to at least 800 mg of fluconazole daily until the 2-week CSF culture is known to be sterile. Prophylactic anti-inflammatory therapies or undue delay of ART initiation in an attempt to prevent IRIS is unwarranted and may be dangerous.     

The Role of HMGB1 in the Pathogenesis of Inflammatory and Autoimmune Diseases

High-mobility group box 1 (HMGB1) protein is a highly abundant protein that can promote the pathogenesis of inflammatory and autoimmune diseases once it is in an extracellular location. This translocation can occur with immune cell activation as well as cell death, with the conditions for release associated with the expression of different isoforms. These isoforms result from post-translational modifications, with the redox states of three cysteines at positions 23, 45 and 106 critical for activity. Depending on the redox states of these residues, HMGB1 can induce cytokine production via toll-like receptor 4 (TLR4) or promote chemotaxis by binding the chemokine CXCL12 for stimulation via CXCR4. Fully oxidized HMGB1 is inactive. During the course of inflammatory disease, HMGB1 can therefore play a dynamic role depending on its redox state. As a mechanism to generate alarmins, cell death is an important source of HMGB1, although each major cell death form (necrosis, apoptosis, pyroptosis and NETosis) can lead to different isoforms of HMGB1 and variable levels of association of HMGB1 with nucleosomes. The association of HMGB1 with nucleosomes may contribute to the pathogenesis of systemic lupus erythematosus by producing nuclear material whose immunological properties are enhanced by the presence of an alarmin. Since HMGB1 levels in blood or tissue are elevated in many inflammatory and autoimmune diseases, this molecule can serve as a unique biomarker as well as represent a target of novel therapies to block its various activities.     

Endothelial Fas-Ligand in Inflammatory Bowel Diseases and in Acute Appendicitis

Fas-mediated induction of apoptosis is a major factor in the selection of lymphocytes and downregulation of immunological processes. In the present study, we have assessed endothelial Fas-ligand (FasL) expression in normal human ileum, appendix, and colon, and compared the expression levels with that in inflammatory bowel disease and in acute appendicitis. In a normal appendix, endothelial FasL levels were constant in almost half of the mucosal vessels; but, in the normal ileum and colon, endothelial FasL was practically restricted to areas in close proximity to lymphatic follicles, and was expressed mainly in the submucosal aspect of the follicles in the vessels with high endothelium. In samples from subjects with either Crohn’s disease or ulcerative colitis, the extent of endothelial FasL expression was elevated in the submucosa and associated with an elevated number of lymphoid follicles. In inflammatory bowel disease, ulcers and areas with a high density of mononuclear cells expressing FasL also showed an elevated density of blood vessels with endothelial FasL expression. Although the function of endothelial FasL remains unclear, such a specific expression pattern suggests that endothelial FasL expression has a role in the regulation of lymphocyte access to the peripheral lymphoid tissues, including the intestinal mucosa.     

Comprehensive Analysis of Inflammatory Immune Mediators in Vitreoretinal Diseases

Inflammation affects the formation and the progression of various vitreoretinal diseases. We performed a comprehensive analysis of inflammatory immune mediators in the vitreous fluids from total of 345 patients with diabetic macular edema (DME, n = 92), proliferative diabetic retinopathy (PDR, n = 147), branch retinal vein occlusion (BRVO, n = 30), central retinal vein occlusion (CRVO, n = 13) and rhegmatogenous retinal detachment (RRD, n = 63). As a control, we selected a total of 83 patients with either idiopathic macular hole (MH) or idiopathic epiretinal membrane (ERM) that were free of major pathogenic intraocular changes, such as ischemic retina and proliferative membranes. The concentrations of 20 soluble factors (nine cytokines, six chemokines, and five growth factors) were measured simultaneously by multiplex bead analysis system. Out of 20 soluble factors, three factors: interleukin-6 (IL-6), interleukin-8 (IL-8), and monocyte chemoattractant protein-1 (MCP-1) were significantly elevated in all groups of vitreoretinal diseases (DME, PDR, BRVO, CRVO, and RRD) compared with control group. According to the correlation analysis in the individual patient''s level, these three factors that were simultaneously increased, did not show any independent upregulation in all the examined diseases. Vascular endothelial growth factor (VEGF) was significantly elevated in patients with PDR and CRVO. In PDR patients, the elevation of VEGF was significantly correlated with the three factors: IL-6, IL-8, and MCP-1, while no significant correlation was observed in CRVO patients. In conclusion, multiplex bead system enabled a comprehensive soluble factor analysis in vitreous fluid derived from variety of patients. Major three factors: IL-6, IL-8, and MCP-1 were strongly correlated with each other indicating a common pathway involved in inflammation process in vitreoretinal diseases.     

Microbiota: A Missing Link in The Pathogenesis of Chronic Lung Inflammatory Diseases

Chronic respiratory diseases account for high morbidity and mortality, with asthma, chronic obstructive pulmonary disease (COPD), and cystic fibrosis (CF) being the most prevalent globally. Even though the diseases increase in prevalence, the exact underlying mechanisms have still not been fully understood. Despite their differences in nature, pathophysiologies, and clinical phenotypes, a growing body of evidence indicates that the presence of lung microbiota can shape the pathogenic processes underlying chronic inflammation, typically observed in the course of the diseases. Therefore, the characterization of the lung microbiota may shed new light on the pathogenesis of these diseases. Specifically, in chronic respiratory tract diseases, the human microbiota may contribute to the disease’s development and severity. The present review explores the role of the microbiota in the area of chronic pulmonary diseases, especially COPD, asthma, and CF.     

硫化氢在心血管保护过程中免疫炎症调节研究进展

硫化氢(hydrogen sulfide,H_2S)是一种无色、具有臭鸡蛋气味的气体,过去认为只是一种有毒的气体。近年来大量研究证实H_2S是继一氧化氮(nitric oxide,NO)和一氧化碳(carbon oxide,CO)后第三种内源性气体信号分子,同时,H_2S在心血管系统疾病发生、发展过程中起关键的调控作用,但其机制还不明确,已有报道主要通过抗凋亡、抗氧化、调节内皮一氧化氮合酶活性、促进血管新生等;而本文总结了H_2S在缺血性心脏病、动脉粥样硬化等心血管疾病中免疫炎症调节作用及其机制,从而为H_2S生物学功能以及相关心血管疾病的防治提供新的思路。     

间充质干细胞来源的外泌体治疗炎症性肠病研究进展*

间充质干细胞主要通过免疫调控和旁分泌在炎症性疾病的治疗中发挥功能。MSC的旁分泌效应是通过分泌可溶性因子并释放外泌体而发挥作用。外泌体将DNA、蛋白质/肽、mRNA、microRNA、脂质和细胞器等成分转移到受体细胞中直接发挥功能。MSC-Exo替代MSC为炎症性肠病的治疗提供了一种新策略。总结不同组织(骨髓、脐带和脂肪)来源的MSC- Exo用于治疗炎症性肠病的研究进展。     

A Systematic Review of the Cost-Effectiveness of Biologics for the Treatment of Inflammatory Bowel Diseases

Background

Biologics are used for the treatment of inflammatory bowel diseases, Crohn´s disease and ulcerative colitis refractory to conventional treatment. In order to allocate healthcare spending efficiently, costly biologics for inflammatory bowel diseases are an important target for cost-effectiveness analyses. The aim of this study was to systemically review all published literature on the cost-effectiveness of biologics for inflammatory bowel diseases and to evaluate the methodological quality of cost-effectiveness analyses.

Methods

A literature search was performed using Medline (Ovid), Cochrane Library, and SCOPUS. All cost-utility analyses comparing biologics with conventional medical treatment, another biologic treatment, placebo, or surgery for the treatment of inflammatory bowel diseases in adults were included in this review. All costs were converted to the 2014 euro. The methodological quality of the included studies was assessed by Drummond’s, Philips’, and the Consolidated Health Economic Evaluation Reporting Standards checklist.

Results

Altogether, 25 studies were included in the review. Among the patients refractory to conventional medical treatment, the incremental cost-effectiveness ratio ranged from dominance to 549,335 €/Quality-Adjusted Life Year compared to the incremental cost-effectiveness ratio associated with conventional medical treatment. When comparing biologics with another biologic treatment, the incremental cost-effectiveness ratio ranged from dominance to 24,012,483 €/Quality-Adjusted Life Year. A study including both direct and indirect costs produced more favorable incremental cost-effectiveness ratios than those produced by studies including only direct costs.

Conclusions

With a threshold of 35,000 €/Quality-Adjusted Life Year, biologics seem to be cost-effective for the induction treatment of active and severe inflammatory bowel disease. Between biologics, the cost-effectiveness remains unclear.     

Serological Investigation of Food Specific Immunoglobulin G Antibodies in Patients with Inflammatory Bowel Diseases

Objective

Dietary factors have been indicated to influence the pathogenesis and nature course of inflammatory bowel diseases (IBD) with their wide variances. The aim of the study was to assess the prevalence and clinical significance of 14 serum food specific immunoglobulin G (sIgG) antibodies in patients with IBD.

Methods

This retrospective study comprised a total of 112 patients with IBD, including 79 with Crohn''s disease (CD) and 33 with ulcerative colitis (UC). Medical records, clinical data and laboratory results were collected for analysis. Serum IgG antibodies against 14 unique food allergens were detected by semi-quantitative enzyme linked immunosorbent assay (ELISA).

Results

Food sIgG antibodies were detected in 75.9% (60/79) of CD patients, 63.6% (21/33) of UC patients and 33.1% (88/266) of healthy controls (HC). IBD patients showed the significantly higher antibodies prevalence than healthy controls (CD vs. HC, P = 0.000; UC vs. HC, P = 0.001). However no marked difference was observed between CD and UC groups (P = 0.184). More subjects were found with sensitivity to multiple antigens (≥3) in IBD than in HC group (33.9% vs.0.8%, P = 0.000). Egg was the most prevalent food allergen. There was a remarkable difference in the levels of general serum IgM (P = 0.045) and IgG (P = 0.041) between patients with positive and negative sIgG antibodies. Patients with multiple positive allergens (≥3) were especially found with significant higher total IgG levels compared with sIgG-negative patients (P = 0.003). Age was suggested as a protective factor against the occurrence of sIgG antibodies (P = 0.002).

Conclusions

The study demonstrates a high prevalence of serum IgG antibodies to specific food allergens in patients with IBD. sIgG antibodies may potentially indicate disease status in clinical and be utilized to guide diets for patients.     

Carcinoembryonic antigen (CEACAM) family members and Inflammatory Bowel Disease

Inflammatory bowel disease (IBD), encompassing Crohn’s disease (CD) and ulcerative colitis (UC), is a chronic intestinal inflammatory condition with increasing incidence worldwide and whose pathogenesis remains largely unknown. The collected evidence indicates that genetic, environmental and microbial factors and a dysregulated immune response are responsible for the disease. IBD has an early onset and long term sufferers present a higher risk of developing colitis associated cancer (CAC). The carcinoembryonic antigen-related adhesion molecules (CEACAM) are a subgroup of the CEA family, found in a range of different cell types and organs including epithelial cells in the intestine. They can act as intercellular adhesions molecules for e.g. bacteria and soluble antigens. CEACAMs are involved in a number of different processes including cell adhesion, proliferation, differentiation and tumour suppression. Some CEACAMs such as CEACAM1, CEACAM5 and CEACAM6 are highly associated with cancer and are even recognised as valid clinical markers for certain cancer forms. However, their role in IBD pathogenesis is less understood. The purpose of this review is to provide a comprehensive summary of published literature on CEACAMs and intestinal inflammation (IBD). The interactions between CEACAMs and bacteria adhesion in relation to IBD pathophysiology will be addressed and potential new therapeutic and diagnostic opportunities will be identified.     

The Vitamin D Status in Inflammatory Bowel Disease

Context

There is no consensus on the vitamin D status of children and adolescents with inflammatory bowel disease (IBD).

Aim

To determine the vitamin D status of patients with IBD by comparing their serum 25(OH)D concentration to that of healthy controls.

Hypothesis

Serum 25(OH)D concentration will be lower in patients with IBD compared to controls.

Subjects and Methods

A case-controlled retrospective study of subjects with IBD (n = 58) of 2–20 years (male n = 31, age 16.38±2.21 years; female n = 27, age16.56±2.08 years) and healthy controls (n = 116; male n = 49, age 13.90±4.59 years; female n = 67, age 15.04±4.12years). Study subject inclusion criteria: diagnosis of Crohn’s disease (CD) or ulcerative colitis (UC). Vitamin D deficiency was defined as 25(OH)D of (<20 ng/mL) (<50 nmol/L), overweight as BMI of ≥85^th but <95^th percentile, and obesity as BMI ≥95^th percentile. Data were expressed as mean ± SD.

Results

Patients with CD, UC, and their controls had mean serum 25(OH)D concentrations of 61.69±24.43 nmol/L, 53.26±25.51, and 65.32±27.97 respectively (ANOVA, p = 0.196). The overweight/obese controls had significantly lower 25(OH)D concentration compared to the normal-weight controls (p = 0.031); whereas 25(OH)D concentration was similar between the normal-weight and overweight/obese IBD patients (p = 0.883). There was no difference in 25(OH)D between patients with UC and CD, or between subjects with active IBD and controls. However, IBD subjects with elevated ESR had significantly lower 25(OH)D than IBD subjects with normal ESR (p = 0.025), as well as controls (65.3±28.0 nmol/L vs. 49.5±25.23, p = 0.045).

Conclusion

There is no difference in mean serum 25(OH)D concentration between children and adolescents with IBD and controls. However, IBD subjects with elevated ESR have significantly lower 25(OH)D than controls. Therefore, IBD subjects with elevated ESR should be monitored for vitamin D deficiency.     

血管生成素与炎症性疾病

血管生成素（angiogenin,ANG）是首个被发现来源于肿瘤的具有血管生成能力的蛋白质,但其在炎症中的作用机制尚未完全阐明. 研究表明, ANG在炎症性疾病的发生发展中起重要作用,并与炎症的调控密切相关,而慢性炎症正是导致肿瘤形成、生长和转移的因素之一. 本文以ANG与炎症的关联为基础,结合我们的工作阐述ANG在炎症性疾病特别是肿瘤中的作用和调控机制,明确ANG与蛋白质的相互作用、对信号通路的调控及核内作用是其发挥功能的重要机制,也可能是调控肿瘤炎症的重要机制. 因而,深入研究ANG与炎症的关系不仅可加深我们对ANG兼具抗炎、抗新生血管双重功能的认识,更可为炎症性疾病的治疗提供潜在的作用靶点和新的思路和方法.     

IL-21/IL-21R信号在IBD病变形成机制中作用的研究进展

炎症性肠病(Inflammatory bowel disease,IBD)的发病机制至今尚不明确,普遍认为是由肠黏膜免疫调节异常、持续性肠道感染、肠黏膜屏障缺损、遗传和环境等多种因素相互作用导致的。近年来,研究发现IBD患者血清中IL-21水平异常升高,提示IL-21/IL-21R信号可能在IBD的病变形成中发挥重要作用。IL-21是一种重要的具有多重生物学功能的细胞因子,通过对CD4+T细胞、CD8+T细胞、Th17细胞、B细胞、巨噬细胞、树突状细胞等多种细胞产生影响,从而参与IBD的发生发展。本文就IL-21/IL-21R信号在炎症性肠病发病机制中的研究进展进行综述。     

人脐带间充质干细胞对炎症性肠病小鼠模型的治疗作用

目的:探讨2种方式移植人脐带间充质干细胞(UCMSC)对TNBS诱导的炎症性肠病小鼠模型的治疗作用。方法:分离培养人UCMSC,并通过一次性腹腔注射TNBS制备炎症性肠病动物模型,采用尾静脉注射和腹腔注射2种方式移植人UCMSC进行治疗,4周后处死,观察动物的死亡率、体重改变及结肠炎症变化,并进行大体和病理评分。结果:与对照组相比,尾静脉和腹腔注射移植UCMSC组动物死亡率下降,体重恢复较早,结肠病变大体评分和病理评分均显著改善;2种方式移植组之间的评分无显著差异。结论:尾静脉和腹腔移植人UCMSC对TNBS诱导的炎症性肠病小鼠模型均有治疗作用。     

前列腺素E2对免疫细胞及炎症相关疾病的调控作用

前列腺素E2(prostaglandin E2,PGE2)是一种极其重要的脂质代谢产物,在受到生理或病理的各种刺激,尤其是有害刺激时被释放,在发热、炎症和血压调节中均发挥着重要作用.PGE2通过4种功能相互拮抗的的受体(E-prostanoid receptors,EP1、EP2、EP3和EP4)而广泛参与机体及细胞代谢过程.一直以来,人们都认为前列腺素在免疫过程中发挥的作用相当有限,部分原因是因为抑制类前列腺素合成的非甾体类抗炎药在机体免疫过程中没有发挥明显作用.但近来的研究表明,PGE2很可能在免疫细胞的发育分化及免疫应答过程中也起重要作用.本文主要对前列腺素与免疫系统的关系进行分析和总结,并重点讨论相关研究的新近进展.