Retrospective assessment of immunologic and histologic heterogeneity in granuloma annulare by cytokine staining.

BACKGROUND: Type 1 (Th1) and Type 2 (Th2) immunity have both been implicated in granuloma annulare (GA). To what extent these pathways contribute to clinical/histologic heterogeneity and/or distinct disease endotypes remains unexplored. METHODS: We retrospectively analyzed 30 GA biopsies with either palisaded or interstitial histology with and without eosinophils. We performed RNA in situ hybridization to assess how markers of Type 1 (interferon gamma), Type 2 (interleukin [IL]4, IL13, IL5), and Type 3 (IL17A) immunity in GA compared with canonical inflammatory disorders and whether markers correlated with histology. We analyzed another cohort of 14 patients who had multiple biopsies across anatomic space and time for individual conservation of histologic features. RESULTS: Interferon (IFN)G staining is highest in GA relative to other cytokines. Type 2 cytokine staining is less prominent, with IL4 increased in interstitial pattern cases. Eosinophils did not correlate with Type 2 markers. Patients with multiple biopsies display intrapatient variability in histology. CONCLUSION: Type 1 inflammation predominates over Type 2 inflammation in GA irrespective of histologic pattern. Distinct disease endotypes were not detected.

Promising Technologies in the Field of Helminth Vaccines.

Helminths contribute a larger global burden of disease than both malaria and tuberculosis. These eukaryotes have caused human infections since before our earliest recorded history (i.e.: earlier than 1200 B.C. for Schistosoma spp.). Despite the prevalence and importance of these infections, helminths are considered a neglected tropical disease for which there are no vaccines approved for human use. Similar to other parasites, helminths are complex organisms which employ a plethora of features such as: complex life cycles, chronic infections, and antigenic mimicry to name a few, making them difficult to target by conventional vaccine strategies. With novel vaccine strategies such as viral vectors and genetic elements, numerous constructs are being defined for a wide range of helminth parasites; however, it has yet to be discussed which of these approaches may be the most effective. With human trials being conducted, and a pipeline of potential anti-helminthic antigens, greater understanding of helminth vaccine-induced immunity is necessary for the development of potent vaccine platforms and their optimal design. This review outlines the conventional and the most promising approaches in clinical and preclinical helminth vaccinology.

Assessment of the pulmonary adaptive immune response to Cladosporium cladosporioides infection using an experimental mouse model.

Cladosporium cladosporioides causes asthma and superficial and deep infections, mostly in immunodeficient individuals and animals. This study aimed to investigate whether C. cladosporioides spores can enter the lungs through pulmonary circulation and influence pulmonary immune response. We intravenously injected mice with C. cladosporioides spore suspension and conducted several assays on the lungs. Pulmonary hemorrhage symptoms and congestion were most severe on days 1, 2, and 3 post-inoculation (PI). Extensive inflammatory cell infiltration occurred throughout the period of infection. More spores and hyphae colonizing the lungs were detected on days 1, 2, and 3 PI, and fewer spores and hyphae were observed within 21 d of infection. Numerous macrophages, dendritic cells, and neutrophils were observed on day 5 PI, along with upregulation of CD54, an intercellular adhesion molecule. Th1 and Th2 cells increased after infection; specifically, Th2 cells increased considerably on day 5 PI. These results suggest that days 2 and 5 PI represent the inflammatory peak in the lungs and that the Th2 and Th1 signaling pathways are potentially involved in pulmonary immune responses. In conclusion, the further adaptive immune responses played important roles in establishing effective pulmonary immunity against C. cladosporioides systemic infections based on innate immune responses.

The relationship between malnutrition and TH 2 immune markers: a study in school-aged children of different socio-economic backgrounds in Makassar, Indonesia.

OBJECTIVE: The burden of underweight remains a major problem in Indonesia, and at the same time, the prevalence of overweight is increasing. Malnutrition is a major determinant of health and has been linked to allergic disorders in children. We examined the relationship between malnutrition and TH 2 immune markers in school-aged children in Makassar, Indonesia. METHODS: A cross-sectional study was performed in five schools where socio-demographic characteristics were recorded. Children's standardised z-scores of body mass index (z-BMI) and age-standardised z-scores of height (z-HA) were assessed using WHO child growth standards. Skin prick test (SPT) reactivity was determined to house dust mite allergens. Helminth infection status, (growth) hormones including insulin-like growth factor (IGF-1) and TH 2 immune markers were measured. RESULTS: In total, 954 children were included of whom 21.6% were underweight and 14.8% overweight. After controlling for confounders, overweight was positively associated with leptin (GMR 3.55, 95% CI: 2.99-4.23) and IGF-1 (GMR 1.45, 95% CI: 1.15-1.82), whereas underweight was negatively associated (respectively GMR 0.57, 95% CI: 0.49-0.66 and GMR 0.78, 95% CI: 0.63-0.97). Underweight was associated with a lower eosinophil count (GMR 0.79, 95% CI: 0.64-0.97) but not with total IgE levels or SPT reactivity. Overweight was positively associated with SPT reactivity (adjusted OR 2.68, 95% CI: 1.50-4.78) but no relationship was found with the other TH 2 immune markers. CONCLUSION: Malnutrition is prominent in school-aged children in Makassar, with overweight associated with increased SPT reactivity. Therefore, interventions should focus on undernutrition, but also on overweight to prevent the increase of allergic disorders in Indonesia.

OBJECTIF: La charge de l'insuffisance pondérale reste un problème majeur en Indonésie et parallèlement, la prévalence du surpoids augmente. La malnutrition est un déterminant majeur de la santé et a été associée à des troubles allergiques chez les enfants. Nous avons examiné la relation entre la malnutrition et les marqueurs immunitaires TH 2 chez les enfants d'âge scolaire à Makassar, en Indonésie. MÉTHODES: Etude transversale dans cinq écoles où les caractéristiques sociodémographiques ont été enregistrées. Les scores z standardisés de l'indice de masse corporelle (z-IMC) et les scores z standardisés pour l'âge de la taille (z-HA) pour les enfants ont été évalués en utilisant les normes de croissance de l'enfant de l'OMS. La réactivité du test cutané (SPT) a été déterminée pour les allergènes d'acariens. L'état de l'infection par les helminthes, les hormones (de croissance), y compris le facteur de croissance analogue à l'insuline (IGF-1) et les marqueurs immunitaires TH 2 ont été mesurés. RÉSULTATS: Au total, 954 enfants ont été inclus, dont 21,6% en insuffisance pondérale et 14,8% en surpoids. Après contrôle des facteurs de confusion, le surpoids était positivement associé à la leptine (GMR 3,55, IC95%: 2,99-4,23) et à l'IGF-1 (GMR 1,45 ; IC95%: 1,15-1,82), tandis que l'insuffisance pondérale était associée négativement (respectivement GMR 0,57 ; IC95%: 0,49-0,66 et GMR 0,78 ; IC95%: 0,63-0,97). L'insuffisance pondérale était associée à un nombre plus faible d'éosinophiles (GMR 0,79 ; IC95%: 0,64-0,97) mais pas aux taux d'IgE totaux ou à la réactivité du SPT. Le surpoids était positivement associé à la réactivité du SPT (OR ajusté 2,68 ; IC95%: 1,50-4,78) mais aucune relation n'a été trouvée avec les autres marqueurs immunitaires T H 2. CONCLUSION: La malnutrition est importante chez les enfants d'âge scolaire à Makassar, avec un surpoids associé à une réactivité accrue du SPT. Par conséquent, les interventions devraient se concentrer sur la dénutrition, mais aussi sur le surpoids pour prévenir l'augmentation des troubles allergiques en Indonésie.

Assessment of Th1/Th2 cytokines among patients with Middle East respiratory syndrome coronavirus infection.

Middle East respiratory syndrome coronavirus (MERS-CoV) is a member of the beta-coronavirus genus of zoonotic origin that emerged in the Arabian Peninsula and is associated with significant morbidity and mortality. This study was conducted to assess the plasma levels of cytokines to evaluate the Th1/Th2 status among 46 MERS-CoV-infected patients (19 asymptomatic and 27 symptomatic) and 52 normal healthy controls using a customized luminex kit. Comparative analysis of data between MERS-CoV-infected patients and normal healthy controls revealed that although no difference was observed between asymptomatic MERS-CoV patients and controls, the mean plasma levels of interleukin (IL)-10 (44.69 ± 40.04 pg ml-1 versus 14.84 ± 6.96 pg ml-1; P < 0.0001), IL-4 (22.46 ± 8.02 pg ml-1 versus 16.01 ± 9.97 pg ml-1; P < 0.0001), IL-5 (10.78 ± 2.86 pg ml-1 versus 8.06 ± 1.41 pg ml-1; P < 0.0001) and IL-13 (14.51 ± 3.97 pg ml-1 versus 11.53 ± 4.16 pg ml-1; P < 0.003) in MERS-CoV symptomatic patients were significantly higher than the normal controls. The mean plasma levels of interferon (IFN)-γ and IL-12 were no different among the study groups. The cytokine profile among symptomatic MERS-CoV-infected patients was skewed to a Th2 type immune response.

The potential role of nicotinamide on Leishmania tropica: An assessment of inhibitory effect, cytokines gene expression and arginase profiling.

Leishmaniasis represents a major health concern worldwide which has no effective treatment modality. Nicotinamide (NAm) has been used for a wide range of applications from anticancer to antimicrobial usage. This study aimed to assess the effect of NAm combination on Leishmania tropica Inhibition, as well as on cytokines gene expression and arginase (ARG) activity in L. tropica-infected macrophages in an in vitro model. The leishmanicidal effects of NAm and Glucantime (meglumine antimoniate, MA) alone and in combination (NAm/MA) were evaluated using a colorimetric assay and macrophage model. Additionally, immunomodulatory effects and enzymatic activity were assessed by analyzing Th1 and Th2 cytokines gene expression and ARG level, respectively, in infected macrophages treated with NAm and MA, alone and in combination. Findings indicated that the NAm/MA combination demonstrated greater inhibitory effects on L. tropica promastigotes and amastigotes compared with each drug individually. Docking results proved the affinity of NAm to IFN-γ, which can affirm the increased levels of IFN-γ, IL-12p40 and TNF-α as well as reductions in IL-10 secretion with a dose-response effect, especially in the combination group. The NAm/MA combination also showed a significant reduction in the level of ARG activity at all concentrations used compared to each drug individually. These findings indicate higher effectiveness of NAm plus MA in reducing parasite growth, promoting immune response and inhibiting ARG level. This combination should be considered as a potential therapeutic regimen for treatment of volunteer patients with anthroponotic cutaneous leishmaniasis (ACL) in future control programs.

A highly polarized TH2 bladder response to infection promotes epithelial repair at the expense of preventing new infections.

Urinary tract infections (UTIs) typically evoke prompt and vigorous innate bladder immune responses, including extensive exfoliation of the epithelium. To explain the basis for the extraordinarily high recurrence rates of UTIs, we examined adaptive immune responses in mouse bladders. We found that, following each bladder infection, a highly T helper type 2 (TH2)-skewed immune response directed at bladder re-epithelialization is observed, with limited capacity to clear infection. This response is initiated by a distinct subset of CD301b+OX40L+ dendritic cells, which migrate into the bladder epithelium after infection before trafficking to lymph nodes to preferentially activate TH2 cells. The bladder epithelial repair response is cumulative and aberrant as, after multiple infections, the epithelium was markedly thickened and bladder capacity was reduced relative to controls. Thus, recurrence of UTIs and associated bladder dysfunction are the outcome of the preferential focus of the adaptive immune response on epithelial repair at the expense of bacterial clearance.

Assessment of the genes and molecular mechanisms of B cells activation through systems biology approaches.

Two classes of T helper lymphocytes, Th1 and Th2, have different roles in B cell activation based on specific cytokines. To understand the difference of molecular mechanisms of B cell activation, the microarray dataset of B cells co-cultured with type 1 and 2 T helper, Be1 and Be2, were investigated. After quality assessment, using the GEO2R tool, the GSE84948 dataset was re-analyzed. Genes with adjusted p-value ⩽ 0.05 were assumed as differentially expressed (DE). The protein-protein interaction (PPI) networks were constructed using CluePedia plugin of Cytoscape, and analyzed by NetworkAnalyzer tool and MCODE plugin. Using ClueGO plugin of Cytoscape software, gene ontology (GO) analysis was performed. The comparison of Be1 and Be2 cells with naive B cells revealed 8742 and 8748 DE genes, respectively. The topology analysis of PPI networks predicted central genes. Among these, Jak3, Actrt3, and Pik3cb genes were determined as crucial genes in Be1 network. Prkx, Smarca4, and Jak2 genes were defined as critical genes in Be2 PPI network. GO analysis with PPI networks genes resulted in the promotion of immune system activation. In conclusion, we explored holistic methods for molecular assay of the difference between B cell activation mechanisms with Th1 and Th2.

Relevance of TH2 Markers in the Assessment and Therapeutic Management of Severe Allergic Asthma: A Real-Life Perspective.

BACKGROUND: Although blood eosinophils are currently recognized as the main clinical marker of TH2-type inflammation, their relevance in identifying asthma severity remains a matter of debate. METHODS: Our retrospective real-life study on severe asthmatics included in the NEONet Italian database aimed to investigate the relevance of blood eosinophil count and fractional exhaled nitric oxide (FeNO) in the clinical assessment of severe asthma and their role as potential predictors of responsiveness to anti-IgE therapy. The cut-off values chosen were 300 eosinophils/mm3 and FeNO of 30 ppm. RESULTS: We evaluated 132 adult patients. No significant differences were observed between the groups (high and low baseline eosinophil counts) in terms of demographic data, total IgE, lung function, patient-reported outcomes, or nasal comorbidities. The Asthma Control Test score and Asthma Quality of Life Questionnaire scores were poorer in patients with FeNO ≥30 ppb than in patients with FeNO <30 ppb. In the high FeNO subgroup, more frequent hospital admissions and a higher number of working days lost in the previous year were registered. A combined score including both eosinophils and FeNO did not improve the accuracy of the individual parameters. In the high-eosinophil subgroup, the proportion of responders to omalizumab was greater and increased at each follow-up time point. CONCLUSIONS: Our findings show that blood eosinophil count is not an unequivocal marker of asthma severity, whereas a higher FeNO level is associated with more frequent hospital admissions and more working days lost. Blood eosinophils seem to act as a predictor of response to omalizumab.

The use of biologic therapies for the management of pediatric asthma.

With better understanding of the role of type 2 inflammation in allergic asthma, there has been progress made in the development of new biologic therapies targeting these specific pathways. This review will consider diagnostic criteria for using biologic therapies for pediatric asthma with special emphasis on populations that are likely to benefit the most from particular therapies. With the exception of the anti-immunoglobulin E, omalizumab, very few studies have been published on the efficacy and safety of biologic therapies in children, particularly anti-interleukin-5 (IL5) and anti-IL4/IL13 therapies. The review will highlight the scarcity of published data in pediatric-specific populations. In addition, we will consider the cost-effectiveness as well as potential long-term consequences of biologic therapies in pediatric asthma.

Histamine H4 receptor regulates Th2-cytokine profile through thymic stromal lymphopoietin in allergic rhinitis.

PURPOSE: Epithelial thymic stromal lymphopoietin (TSLP) promotes Th2 inflammatory responses through induction of OX40 ligand (OX40L) on dendritic cells in allergic rhinitis (AR). Emerging evidence supports the important role of histamine H4 receptor (H4R) in allergic inflammation. This study aimed to investigate the effects of H4R in Th2-cytokine profile mediated by TSLP in AR. METHODS: Human nasal epithelial cells (HNECs) from AR patients were stimulated with histamine in the presence or absence of H4R agonist (4-methylhistamine, 4-MH) and antagonist (NJ7777120, JNJ) or H1R agonist (2-pyridylethylamine). TSLP protein was measured by Western blotting and ELISA. To further elucidate the role of H4R in the in vivo situation of experimental AR, rats were sensitized and treated with JNJ or 4-MH. TSLP and OX40 ligand (OX40L) in the nasal mucosa were assayed by Western blotting. Th2 cytokines including interleukin-4, 5 and 13 in nasal lavage fluids were detected by ELISA. RESULTS: Histamine alone did not induce TSLP production by HNECs. The pre-incubation with 4-MH prior to histamine promoted TSLP expression, which was inhibited by the stimulation with JNJ prior to histamine and 4-MH. The pre-incubation with 2-pyridylethylamine before histamine stimulation had no impact on TSLP production. In AR rats, the levels of TSLP and OX40L protein were increased as well as Th2 cytokines, which was further up-regulated by 4-MH treatment, while JNJ treatment attenuated these effects. CONCLUSIONS: H4R activation induced TSLP production by HNECs, which up-regulated OX40L expression in the nasal mucosa of sensitized rats. These factors promoted Th2-cytokine profile in AR.

The costs of high self-control in Black and Latino youth with asthma: Divergence of mental health and inflammatory profiles.

Emerging evidence in psychology suggests a paradox whereby high levels of self-control when striving for academic success among minority youth can have physical health costs. This study tested the skin-deep resilience hypothesis in asthma- whether minority youth who are striving hard to succeed academically experience good psychological outcomes but poor asthma outcomes. Youth physician-diagnosed with asthma (N = 276, M age = 12.99; 155 = White, 121 = Black/Latino) completed interviews about school stress and a self-control questionnaire. Outcomes included mental health (anxiety/depression) and ex-vivo immunologic processes relevant to asthma (lymphocyte Th-1 and Th-2 cytokine production, and sensitivity to glucocorticoid inhibition). Physician contacts were tracked over a one-year follow-up. For minority youth experiencing high levels of school stress, greater self-control was associated with fewer mental health symptoms (beta = -0.20, p < .05), but worse asthma inflammatory profiles (larger Th-1 and Th-2 cytokine responses, lower sensitivity to glucocorticoid inhibition), and more frequent physician contacts during the one-year follow-up (beta's ranging from 0.22 to 0.43, p's < .05). These patterns were not evident in White youth. In minority youth struggling with school, high levels of self-control are detrimental to asthma inflammatory profiles and clinical outcomes. This suggests the need for health monitoring to be incorporated into academic programs to ensure that 'overcoming the odds' does not lead to heightened health risks in minority youth.

Assessment of Th1/Th2 Bias of STING Agonists Coated on Microneedles for Possible Use in Skin Allergen Immunotherapy.

Microneedle-based skin allergen-specific immunotherapy (AIT) can benefit from adjuvants that can stimulate a stronger Th1 response against the allergen. We evaluated two stimulator of interferon genes (STING) agonists, namely, cyclic diguanylate monophosphate (c-di-GMP) and cyclic diadenylate monophosphate (c-di-AMP), as skin adjuvants using coated microneedles (MNs). For comparison, the approved subcutaneous (SC) hypodermic injection containing alum was used. Ovalbumin (Ova) was used as a model allergen. Ova-specific IgG2a antibody in serum, which is a surrogate marker for Th1 type immune response was significantly higher when STING agonists were used with coated MNs as compared to SC injection of Ova+alum in mice. In contrast, IgG1 antibody, a surrogate marker for Th2 type immune response, was at comparable levels in the MN and SC groups. Restimulation of splenocytes with Ova produced higher levels of Th1 cytokines (IFN-γ and IL-2) in the STING agonists MN groups as compared to the SC group. In conclusion, delivery of STING agonists into the skin using coated MNs activated the Th1 pathway better than SC- and MN-based delivery of alum. Thus, STING agonists could fulfill the role of adjuvants for skin AIT and even for infectious disease vaccines, where stimulation of the Th1 pathway is of interest.

Development and assessment of a new cage-like particle adjuvant.

OBJECTIVES: To obtain and assess stable cage-like particles with low surface charge density, which can be prepared using a standardized, economic and scalable method. METHODS: To form these nanoparticles, the lipid composition and proportion as well the method were modified in relation to cage-like particles previously described elsewhere. Bovine albumin was used to compare ISPA performance with that of other adjuvants in mice and to assess stability. Adjuvant efficacy was analysed using a mouse model of Trypanosoma cruzi infection, which shows protection against an intracellular infection that needs a strong cellular response. KEY FINDINGS: The new particles were better in terms of level, kinetics and profile of humoral responses than Freund Adjuvant, aluminium hydroxide and Montanide TM ISA 206; they also tended to improve ISCOMATRIX™ performance. Particle size and adjuvant performance were conserved during the 6-month period assessed after preparation. In the model of Trypanosoma cruzi infection, mice immunized with ISPA and trans-sialidase developed high protection. CONCLUSIONS: The obtained nanoparticles were stable and outperformed the other assessed adjuvants in joining together the capacity of most adjuvants to enhance the immune response against specific antigen, to reduce the number of doses, to homogenize the response between individuals and to reach a balanced TH1/TH2 response.

Does Helicobacter pylori eradication therapy trigger or protect against Crohn's disease?

Helicobacter pylori (H. pylori) infection is involved in multiple gastrointestinal and extra-gastrointestinal disorders. This review focuses on possible link between H. pylori eradication and Crohn's disease (CD) which is a chronic inflammatory bowel disease (IBD). Fecal calprotectin and; to lesser extent; fecal lactoferrin are sensitive and specific markers for monitoring CD activity. Data about link between H. pylori eradication and CD are limited and inconclusive. The infection likely shifts equilibrium between T helper 1 (Th1) and Th2 immune responses to the Th2 pattern. In subjects genetically predisposed to CD (a Th1-related disease), H. pylori eradication increases Th1 proinflammatory cytokines causing development of CD. In contrast, clarithromycin and/or proton pump inhibitors that are used to eradicate H. pylori can suppress Th1 factors, and theoretically can protect against CD, but there are no data to support this supposition. This Th1/Th2 approach seems very simplistic. Another theory is that alterations in gut microbiota form "continuous antigenic stimulation" predisposing to IBD. H. pylori infection can inhibit such stimulation through activation of regulatory T cells, and thus eradication may predispose to CD. Probiotics weren't found useful in treatment of CD. The reported data about link between H. pylori eradication and CD are currently limited. Case reports, suggesting a positive association between both conditions, provide a very little evidence. On eradicating H. pylori in CD patients and/or patients with high risk for CD, patient counseling and follow-up in addition to measuring fecal calprotectin may help monitor CD activity. (Acta gastro-enterol. belg., 2016, 79, 349-354).

[New drugs for severe asthma]. / Les traitements du futur de l'asthme sévère.

Asthma is a very frequent disease with complex and heterogenous immunological and clinical features. Daily inhaled steroids are the cornerstone of the current therapeutics sometimes associated with long-acting ß2-agonist. This controller treatment is effective and allows to control asthma symptoms for the vast majority of the patients. Severe asthma is characterized by a poor level of control of symptoms, with recurrent exacerbations or a chronic airflow limitation despite an optimal management. Severe asthma remains a difficult diagnosis but we have now studies proving the clinical efficacy or promising data about monoclonal antibodies targeting IgE, IL-5, IL-4 or IL-13. Most of these monoclonal antibodies target the Th2 type eosinophilic inflammation without any treatment against non-eosinophilic or Th1 inflammation. Last, it will be essential to assess accurately the cost effectiveness of these expensive treatments, to identify and to qualify the target population for each molecule and to assess its financial impact for the community.

Development of recombinant vaccine candidate molecule against Shigella infection.

Shigellosis is an acute bacillary diarrheal disease caused by the gram negative bacillus Shigella. The existence of multiple Shigella serotypes and their growing resistance to antibiotics stress the urgent need for the development of vaccine that is protective across all serotypes. Shigella's IpaB antigen is involved in translocon pore formation, promotes bacterial invasion and induces apoptosis in macrophages. S. Typhi GroEL (Hsp 60) is the immunodominant antigen inducing both arms of immunity and has been explored as adjuvant in this study. The present study evaluates the immunogenicity and protective efficacy of recombinant IpaB domain-GroEL fusion protein in mice against lethal Shigella infection. The IpaB domain and GroEL genes were fused using overlap extension PCR and cloned in pRSETA expression vector. Fused gene was expressed in Escherichia coli BL-21 cells and the resulting 90 KDa fusion protein was purified by affinity chromatography. Intranasal (i.n.) immunization of mice with fusion protein increased the IgG and IgA antibody titers as compared to the group immunized with IpaB and GroEL and control PBS immunized group. Also IgG1 and IgG2a antibodies induced in fusion protein immunized mice were higher than co-immunized group. Significant increase in lymphocyte proliferation and cytokine levels (IFN-γ, IL-4 and IL-10), indicates induction of both Th1 and Th2 immune responses in both immunized groups. Immunization with fusion protein protected 90-95% of mice whereas 80-85% survivability was observed in co-immunized group against lethal challenge with S. flexneri, S. boydii and S. sonnei. Passive immunization conferred 60-70% protection in mice against all these Shigella species. Organ burden and histopathology studies also revealed significant decrease in lung infection as compared to the co-immunized group. Since IpaB is the conserved dominant molecule in all Shigella species, this study will lead to an ideal platform for the development of safe, efficacious and cost-effective recombinant vaccine against Shigella serotypes.

Update on Exhaled Nitric Oxide in Clinical Practice.

Asthma is characterized by chronic airway inflammation. Fractional exhaled nitric oxide (Feno) has emerged as a marker of T-helper cell type 2-mediated allergic airway inflammation. Recent studies suggest a role for Feno testing as a point-of-care tool in the management of patients with asthma. This Topics in Practice Management article reviews current coverage and reimbursement issues related to Feno testing and provides an overview of pertinent recent studies.

The Role of Type 2 Inflammation in the Pathogenesis of Asthma Exacerbations.

Asthma exacerbations are an important cause of asthma morbidity. Although viral infection of the upper airway is a common cause of asthma exacerbations, the reasons why some patients with asthma are exacerbation prone and others are exacerbation resistant are not fully understood. In this review, we examine whether Type 2 inflammation modifies airway function to make patients more susceptible to asthma exacerbations. The best data supporting a role for Type 2 inflammation in asthma exacerbations come from clinical trials of inhibitors of Type 2 inflammation in asthma. These trials include studies with omalizumab (an inhibitor of IgE) and others with inhibitors of Type 2 cytokines (IL-4, IL-5, and IL-13). All of these trials consistently show that inhibiting the Type 2 pathway causes a clinically significant reduction in asthma exacerbations. Thus, it is now clear that Type 2 inflammation is an important mechanism of susceptibility to asthma exacerbation.