EAU-ESMO consensus statements on the management of advanced and variant bladder cancer-an international collaborative multi-stakeholder effort: under the auspices of the EAU and ESMO Guidelines Committees†.

BACKGROUND: Although guidelines exist for advanced and variant bladder cancer management, evidence is limited/conflicting in some areas and the optimal approach remains controversial. OBJECTIVE: To bring together a large multidisciplinary group of experts to develop consensus statements on controversial topics in bladder cancer management. DESIGN: A steering committee compiled proposed statements regarding advanced and variant bladder cancer management which were assessed by 113 experts in a Delphi survey. Statements not reaching consensus were reviewed; those prioritised were revised by a panel of 45 experts before voting during a consensus conference. SETTING: Online Delphi survey and consensus conference. PARTICIPANTS: The European Association of Urology (EAU), the European Society for Medical Oncology (ESMO), experts in bladder cancer management. OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS: Statements were ranked by experts according to their level of agreement: 1-3 (disagree), 4-6 (equivocal), 7-9 (agree). A priori (level 1) consensus was defined as ≥70% agreement and ≤15% disagreement, or vice versa. In the Delphi survey, a second analysis was restricted to stakeholder group(s) considered to have adequate expertise relating to each statement (to achieve level 2 consensus). RESULTS AND LIMITATIONS: Overall, 116 statements were included in the Delphi survey. Of these, 33 (28%) statements achieved level 1 consensus and 49 (42%) statements achieved level 1 or 2 consensus. At the consensus conference, 22 of 27 (81%) statements achieved consensus. These consensus statements provide further guidance across a broad range of topics, including the management of variant histologies, the role/limitations of prognostic biomarkers in clinical decision making, bladder preservation strategies, modern radiotherapy techniques, the management of oligometastatic disease and the evolving role of checkpoint inhibitor therapy in metastatic disease. CONCLUSIONS: These consensus statements provide further guidance on controversial topics in advanced and variant bladder cancer management until a time where further evidence is available to guide our approach.

Commentary on "DNA damage response and repair gene alterations are associated with improved survival in patients with platinum-treated advanced urothelial carcinoma."

PURPOSE: Platinum-based chemotherapy remains the standard treatment for advanced urothelial carcinoma by inducing DNA damage. We hypothesize that somatic alterations in DNA damage response and repair (DDR) genes are associated with improved sensitivity to platinum-based chemotherapy. EXPERIMENTAL DESIGN: Patients with diagnosis of locally advanced and metastatic urothelial carcinoma treated with platinum-based chemotherapy who had exon sequencing with the Memorial Sloan Kettering-Integrated Mutation Profiling of Actionable Cancer Targets (MSK-IMPACT) assay were identified. Patients were dichotomized based on the presence/absence of alterations in a panel of 34 DDR genes. DDR alteration status was correlated with clinical outcomes and disease features. RESULTS: One hundred patients were identified, of which 47 harbored alterations in DDR genes. Patients with DDR alterations had improved progression-free survival (9.3 vs. 6.0 months, log-rank P = 0.007) and overall survival (23.7 vs. 13.0 months, log-rank P = 0.006). DDR alterations were also associated with higher number mutations and copy-number alterations. A trend toward positive correlation between DDR status and nodal metastases and inverse correlation with visceral metastases were observed. Different DDR pathways also suggested variable effect on clinical outcomes. CONCLUSIONS: Somatic DDR alteration is associated with improved clinical outcomes in platinum-treated patients with advanced urothelial carcinoma. Once validated, it can improve patient selection for clinical practice and future study enrollment.

Enhanced antigen presenting and T cell functions during late-phase allergic responses in the lung.

BACKGROUND: Allergic inflammation is a common feature of asthma and may contribute to both development and perpetuation of disease. The interaction of antigen-presenting cells (APC) with sensitized helper T lymphocytes (TC) producing Th2 cytokines may determine the inflammatory response. Recruitment of APC and TC to the lung during allergic responses has been demonstrated, but functional studies in humans have been limited. OBJECTIVE: This study examined the function of APC and TC accumulating at sites of inflammation after segmental allergen challenge (SAC). METHODS: Fifteen allergic patients underwent SAC, and cells from bronchoalveolar lavage (BAL) were collected after 24 hours. APC and TC from the blood and BAL were purified based on expression of the monocyte marker, CD14; the plasmacytoid dendritic cell (pDC) marker, BDCA4, identifying neuropilin-1 (NRP1); and the helper T cell marker, CD4. Functional activity was assessed using allergen-induced T cell proliferation. Flow cytometry identified cells expressing CD14 and NRP1. RESULTS: SAC resulted in a 12-fold increase in mononuclear cells having the morphologic appearance of blood monocytes. Most of these cells co-expressed CD14 and NRP1. After saline challenge, BAL mononuclear cells demonstrated little APC function. Following SAC, BAL mononuclear cells showed function equal to pDC from blood and greater than blood monocytes. Purified NRP1+ cells from BAL had even greater function than pDC cells from blood (P = .008). Using consistent sources of APC, enhanced proliferation of TC from lung compared to blood was also demonstrated (P = .002). CONCLUSIONS: The marked increase in APC function for allergen-specific TC proliferation during allergic inflammation is largely due to the recruitment of monocytes and dendritic cells. There is also an enhanced response in the lung TC population, consistent with recruitment of allergen-specific T cells. Interactions between recruited APC and TC may occur as an early event promoting allergic airway inflammation.

BCL-2 protects human and mouse Th17 cells from glucocorticoid-induced apoptosis.

BACKGROUND: Glucocorticoid resistance has been associated with Th17-driven inflammation, the mechanisms of which are not clear. We determined whether human and mouse Th17 cells are resistant to glucocorticoid-induced apoptosis. METHODS: Freshly isolated human blood Th17 cells and in vitro differentiated Th17 cells from IL-17F red fluorescent protein reporter mice were treated with dexamethasone, a potent glucocorticoid. Apoptosis was measured using annexin V and DAPI staining. Screening of apoptosis genes was performed using the apoptosis PCR array. Levels of molecules involved in apoptosis were measured using quantitative RT-PCR, flow cytometry, and Western blotting. Knockdown of BCL-2 in murine Th17 cells was performed via retroviral transduction. Cytokines were measured using ELISA. A murine Th17-driven severe asthma model was examined for Th17 glucocorticoid sensitivity in vivo. RESULTS: Human and mouse Th17 cells and mouse Th2 cells were resistant to glucocorticoid-induced apoptosis. Th17 cells had glucocorticoid receptors levels comparable to those in other T effectors cells. Th17 cells had high levels of BCL-2, knockdown of which sensitized Th17 cells to dexamethasone-induced apoptosis. Production of IL-22, but not IL-17A and IL-17F, was suppressed by glucocorticoids. STAT3 phosphorylation in Th17 cells was insensitive to glucocorticoid inhibition. Lung Th17 cells in the murine severe asthma model were enhanced, rather than suppressed, by glucocorticoids. CONCLUSION: Th17 cells are resistant to glucocorticoid-induced apoptosis and cytokine suppression, at least in part due to high levels of BCL-2. These findings support a role of Th17 cells in glucocorticoid-resistant inflammatory conditions such as certain endotypes of asthma.

Gender is a determinative factor in the initial clinical presentation of eosinophilic esophagitis.

Eosinophilic esophagitis (EoE) is a chronic, immune-mediated disease resulting in symptoms of esophageal dysmotility. Abnormalities include dysphagia, food impaction and reflux. Although men appear to comprise a majority of the EoE population, few studies have directly assessed gender-associated clinical differences. The aim of this study is to identify the effect of gender on the initial clinical presentation of adult-onset EoE patients. We reviewed our electronic medical record database from January 2008 to December 2011 for adults diagnosed with EoE per the 2011 updated consensus guidelines. Patient demographics, presenting symptoms, endoscopy findings and complications were recorded. Proportions were compared using chi-squared analysis, and means were compared using the Student's t-test. A total of 162 patients met the inclusion criteria and 71 (44%) were women. Women were more likely to report chest pain (P = 0.03) and heartburn (P = 0.06), whereas men more commonly reported dysphagia (P = 0.04) and a history of food impaction (P = 0.05). Endoscopic findings were similar between groups. No patients suffered esophageal perforations. These data suggest that men report more fibrostenotic symptoms and women report more inflammatory symptoms at the time of diagnosis. There was no difference in endoscopic findings between genders. This is one of the only reviews comparing differences in clinical presentation, endoscopic findings and complications between gender for EoE. The current recommended guidelines state that any patient with symptoms of esophageal dysfunction should be biopsied for EoE. Our findings support biopsying patients with typical and atypical symptoms of dysmotility including heartburn and chest pain.

Neoadjuvant chemotherapy use in bladder cancer: a survey of current practice and opinions.

Objectives. Level 1 evidence supports the use of neoadjuvant chemotherapy (NAC) to improve overall survival in muscle invasive bladder cancer; however utilization rates remain low. The aims of our study were to determine factors associated with NAC use, to more clearly define reasons for low utilization, and to determine the current rate of NAC use among urologic oncologists. Materials and Methods. Active members of the Society for Urologic Oncology were provided a 20-question survey. Descriptive statistical analysis was conducted for each question and univariate analysis was performed. Results. We achieved a response rate of 21%. Clinical T3/T4 disease was the most often selected reason for recommending NAC (87%). Concerns with recommending NAC were age and comorbidities (54%) followed by delay in surgery (35%). An association was identified between urologic oncologists who discussed NAC with >90% of their patients and medical oncologists "always" recommending NAC (P = 0.0009). NAC utilization rate was between 30 and 57%. Conclusions. Amongst this highly specialized group of respondents, clinical T3-T4 disease was the most common reason for implementation of NAC. Respondents who frequently discussed NAC were more likely to report their medical oncologist always recommending NAC. Reported NAC use was higher in this surveyed group (30-57%) compared with recently published rates.

Radical cystectomy and orthotopic urinary reconstruction in patients with bladder cancer after renal transplantation: clinical outcomes and description of technique.

OBJECTIVES: Radical cystectomy (RC) with pelvic lymph node dissection and urinary diversion is the standard treatment for muscle-invasive bladder cancer. In the setting of prior renal transplantation, surgical treatment remains the mainstay but is technically challenging. We report our patient outcomes in this unique population with a description of the technique. METHODS: We identified five patients with a history of renal transplantation who underwent RC and orthotopic urinary diversion. Preoperative clinical and demographic features were compiled and disease-specific and functional outcomes were assessed. Intraoperative technical challenges and maneuvers for avoiding complications are highlighted. RESULTS: Four patients were male and one was female, with a median age of 64 years. Gross hematuria was the most common sign at presentation. Clinical staging was T2, T2 with carcinoma in situ (CIS), high-grade (HG) Ta with CIS, T2 with squamous differentiation, and HG T1, and pathologic tumor stage was pTisN1, pT3N0, pTisN0, pT3N0, and pT0N0, respectively. One patient received a Studer-type diversion and four underwent Hautmann diversion. Median follow-up after cystectomy was 12.9 months. Graft ureteral identification was aided by the use of intravenous dye in all patients. Ipsilateral pelvic lymph node dissection was not possible in any patient. All patients are alive at follow-up, with two experiencing recurrence at 7.2 months and 66.8 months. No patient experienced a significant decrease in estimated creatinine clearance postoperatively. Postoperative daytime control was reported by all patients whereas two noted complete nighttime control. CONCLUSIONS: RC with orthotopic diversion is a technically demanding procedure in patients with a history renal transplantation. Meticulous technique and careful attention to the altered anatomy are required for successful outcomes.

Prospective evaluation of MRI, ¹¹C-acetate PET/CT and contrast-enhanced CT for staging of bladder cancer.

PURPOSE: To prospectively evaluate the diagnostic performance of magnetic resonance imaging (MRI), (11)C-acetate positron emission tomography/computed tomography (PET/CT) and contrast-enhanced CT for bladder cancer staging, using whole-mount pathologic review of radical cystectomy and pelvic lymph node specimens as the reference standard. MATERIALS AND METHODS: The institutional review board approved this prospective study, which was compliant with the Health Insurance Portability and Accountability Act. Written informed consent was obtained from 16 patients with histologically confirmed bladder cancer who underwent MRI, (11)C-acetate PET/CT and contrast-enhanced CT before radical cystectomy and pelvic lymph node dissection. Before imaging 4/16 patients had received intravesical Bacillus Calmette-Guérin treatment, 6 had received systemic chemotherapy, 3 had received both and 3 had received neither. Measures of diagnostic performance including accuracy, sensitivity and specificity were estimated separately for each imaging modality. RESULTS: MRI correctly staged 56% of patients (9/16), overstaged 38% (6/16) and understaged 6% (1/16). CT correctly staged 50% of patients (8/16), overstaged 44% (7/16) and understaged 6% (1/16). In 9 patients, (11)C-acetate PET/CT showed uptake within the bladder wall; the uptake was true-positive in 7 patients and false-positive in 2 patients. Of the remaining 7 patients, 5 had true-negative and 2 had false-negative PET/CT results for cancer in the bladder wall. For all modalities, staging accuracy was reduced in patients with a history of prior intravesical and/or systemic chemotherapy. CONCLUSION: In staging bladder cancer, MRI, (11)C-acetate PET/CT and CT displayed similar levels of accuracy. For all modalities, a history of intravesical and/or systemic chemotherapy affected staging accuracy.

Anterior pelvic exenteration with total vaginectomy for recurrent or persistent genitourinary malignancies: review of surgical technique, complications, and outcome.

OBJECTIVE: To describe the surgical technique, complications, and outcomes after anterior pelvic exenteration with total vaginectomy (AETV) for recurrent or persistent genitourinary malignancies. METHODS: We reviewed the medical records of all patients who underwent AETV between 12/2002 and 07/2011. Relevant demographic, clinical, and pathological information was collected. Postoperative complications and rates of readmission and reoperation (up to 180 days after surgery) were examined, and preliminary survival data were obtained. RESULTS: We identified 11 patients who underwent AETV. The median age at the time of the surgery was 55 years (range, 36-71). The median tumor size was 0.9 cm (range, microscopic - 4). Primary tumor sites included: cervix, 6; uterus, 3; vagina, 1; and urethra, 1. Complete surgical resection with negative pathologic margins was achieved in all 11 patients. Major postoperative complications occurred in 4 patients (36%). Six patients (55%) required readmission to the hospital. No operative mortalities were observed, and none of the patients required a re-operation. With a median follow-up after the procedure of 25 months (range, 6-95), none of the patients developed a pelvic recurrence. Ten patients (91%) were alive without evidence of disease and one patient (9%) developed a pancreatic recurrence. CONCLUSION: AETV sparing the rectosigmoid and anus is feasible in highly selected patients with central pelvic recurrences. Compared to previously reported studies on total pelvic exenteration, data from this case series suggest that AETV may be associated with a lower rate of complications without compromising the oncologic outcome, while also preserving rectal function.

Extended pelvic resections for recurrent or persistent uterine and cervical malignancies: an update on out of the box surgery.

OBJECTIVE: To update our report on the outcome of patients who underwent extended pelvic resection (EPR) for recurrent or persistent uterine and cervical malignancies. METHODS: We reviewed the records of all patients who underwent EPR between 6/2000 and 07/2011. EPR was defined as an en-bloc resection of a pelvic tumor with sidewall muscle, bone, major nerve, and/or major vascular structure. Complications up to 180 days post surgery were analyzed. Survivals were estimated using the Kaplan-Meier method. RESULTS: We identified 22 patients. Median age at the time of EPR was 58 years (range, 36-74). Median tumor diameter was 5.4 cm (range, 1.5-11.2). Primary tumor sites included: uterus, 13; cervix, 7; synchronous uterus/cervix, 1; and synchronous uterus/ovary, 1. The EPR structures were: muscle, 13; nerve, 10; bone, 8; vessel, 5. Complete gross resection with microscopically negative margins (R0 resection) was achieved in 17 patients (77%). There were no perioperative mortalities. Major postoperative complications occurred in 14 patients (64%). The two most common morbidities were pelvic abscesses and peripheral neuropathies. Median follow-up time was 28 months (range, 6-99). The 5-year overall survival (OS) for the entire cohort was 34% (95% CI, 13-57). For the 17 patients who had an R0 resection, the 5-year OS was 48% (95% CI, 19-73). In patients with positive pathologic margins (n=5), the 5-year OS was 0%. CONCLUSION: EPR was associated with prolonged survival when an R0 resection was achieved. The high rate of postoperative complications remains a hallmark of these procedures and properly selected patients should be extensively counseled preoperatively.

MRI at the completion of chemoradiotherapy can accurately evaluate the extent of disease in women with advanced urethral carcinoma undergoing anterior pelvic exenteration.

AIM: To demonstrate the value of pelvic magnetic resonance imaging (MRI) in mapping tumour extension after chemoradiotherapy and before anterior pelvic exenteration in patients with primary carcinoma of the urethra. MATERIALS AND METHODS: The Institutional Review Board approved and issued a waiver of informed consent for this retrospective study, which was compliant with the Health Insurance Portability and Accountability Act. Six women (median age 51 years, range 39-63 years) with histopathology-proven urethral carcinoma who underwent neoadjuvant chemoradiotherapy before anterior pelvic exenteration were included in the study. All had MRI performed at first presentation and after completion of chemoradiotherapy. MRI images were analysed by an experienced reader, who was blinded to the clinical data. The tumour location, signal intensity, size, local extension, and presence of enlarged lymph nodes were recorded for each patient at baseline and after chemoradiotherapy. Surgical histopathology constituted the reference standard. RESULTS: All tumours were locally advanced (stage T3) at baseline MRI. The mean maximum diameter of the tumour at baseline MRI was 3.7 cm (range 2.4-5 cm). After chemoradiotherapy, the mean reduction in maximum tumour diameter on MRI was 44% (range 13-67%), but only three cases were down-staged. MRI was accurate in the evaluation of tumour extension after completion of chemoradiotherapy in all cases. Persistence of bladder neck and anterior vaginal wall invasion was correctly identified in three cases. CONCLUSION: In women with advanced primary urethral cancer, MRI is an excellent tool for monitoring neo-adjuvant chemoradiotherapy changes and evaluating the extent of disease before exenterative surgery.

Cat allergen-induced blood basophil reactivity in vitro predicts acute human nasal allergen challenge responses in vivo.

BACKGROUND: Basophil histamine release (BHR) to allergen has been used as a confirmatory test to support the clinical diagnosis of allergic disease. OBJECTIVE: Among subjects reporting respiratory cat allergy, we hypothesized that cat-induced BHR in vitro would predict nasal allergen challenge (NAC) response in that same individual. We therefore compared the magnitude of cat allergen-induced BHR to NAC outcome and serological measures of cat-specific IgE and the ratio of cat-specific IgE to total IgE. METHODS: Forty-two subjects with a history of cat allergy, positive cat puncture skin test (PST) and detectable cat-specific IgE (> 0.1 kAU/L, ImmunoCap) participated with consent. Subjects were grouped as positive or negative cat allergen-induced BHR, with a positive result defined as the release of ≥ 20% of the total cellular histamine content. The majority of subjects also underwent a NAC with a positive result defined as ≥ 5 total sneezes. RESULTS: Subjects with a positive compared with a negative cat allergen BHR had higher cat-specific IgE levels at 5.40 ± 1.24 kAU/L (n=25) vs. 1.55 ± 0.73 kAU/L (n=17, P=0.01) as well as a higher cat-specific IgE/total IgE ratio [6.1 ± 1.4% (n=25) vs. 1.6 ± 0.9% (n=17, P=0.01)]. Of the 31 subjects who underwent a NAC, a positive NAC was observed in 78% (18/23) with a positive cat allergen BHR compared with 37% (3/8) with a negative cat allergen BHR, giving a positive predictive value of 78% and a negative predictive value of 63%. The diagnostic sensitivity and specificity of a positive BHR to predict a positive NAC was 86% and 50%, respectively. CONCLUSIONS AND CLINICAL RELEVANCE: A positive cat allergen-induced BHR is associated with higher cat-specific IgE levels, a higher cat-specific to total IgE ratio and is predictive of a positive cat-induced NAC [ClinicalTrials.gov NCT00604786].

A critical role for choline kinase-alpha in the aggressiveness of bladder carcinomas.

Bladder cancer is one of the most common causes of death in industrialized countries. New tumor markers and therapeutic approaches are still needed to improve the management of bladder cancer patients. Choline kinase-alpha (ChoKalpha) is a metabolic enzyme that has a role in cell proliferation and transformation. Inhibitors of ChoKalpha show antitumoral activity and are expected to be introduced soon in clinical trials. This study aims to assess whether ChoKalpha plays a role in the aggressiveness of bladder tumors and constitutes a new approach for bladder cancer treatment. We show here that ChoKalpha is constitutively altered in human bladder tumor cells. Furthermore, in vivo murine models, including an orthotopic model to mimic as much as possible the physiological conditions, revealed that increased levels of ChoKalpha potentiate both tumor formation (P< or =0.0001) and aggressiveness of the disease on different end points (P=0.011). Accordingly, increased levels of ChoKalpha significantly reduce survival of mice with bladder cancer (P=0.05). Finally, treatment with a ChoKalpha-specific inhibitor resulted in a significant inhibition of tumor growth (P=0.02) and in a relevant increase in survival (P=0.03).

Siglec-8 on human eosinophils and mast cells, and Siglec-F on murine eosinophils, are functionally related inhibitory receptors.

Siglecs (sialic acid-binding, Ig-like lectins) are a family of single-pass transmembrane cell surface proteins found predominantly on leucocytes. Their unique structural characteristics include an N-terminal carbohydrate-binding ('lectin') domain that binds sialic acid, followed by a variable number of Ig-like domains, hence these structures are a subset of the Ig gene superfamily. Another unique feature of Siglecs is that most, but not all, possess so-called immunoreceptor tyrosine-based inhibitory motifs in their cytoplasmic domains, suggesting that these molecules function in an inhibitory capacity. Siglec-8, the eighth member identified at the time, was discovered as part of an effort initiated almost a decade ago to identify novel human eosinophil and mast cell proteins. Since that time, its selective expression on human eosinophils and mast cells has been confirmed. On eosinophils, Siglec-8 engagement results in apoptosis, whereas on mast cells, inhibition of FcepsilonRI-dependent mediator release, without apoptosis, is seen. It has subsequently been determined that the closest functional paralog in the mouse is Siglec-F, selectively expressed by eosinophils but not expressed on mast cells. Despite only modest homology, both Siglec-8 and Siglec-F preferentially recognize a sulphated glycan ligand closely related to sialyl Lewis X, a common ligand for the selectin family of adhesion molecules. Murine experiments in normal, Siglec-F-deficient mice and hypereosinophilic mice have resulted in similar conclusions that Siglec-F, like Siglec-8, plays a distinctive and important role in regulating eosinophil accumulation and survival in vivo. Given the resurgent interest in eosinophil-directed therapies for a variety of disorders, plus its unique additional ability to also target the mast cell, therapies focusing on Siglec-8 could some day prove to be a useful adjunct to our current armamentarium for the treatment of asthma, allergies and related disorders where overproduction and overactivity of eosinophils and mast cells is occurring.

Clara cell 10-kDa protein expression in chronic rhinosinusitis and its cytokine-driven regulation in sinonasal mucosa.

BACKGROUND: Clara cell 10-kDa protein (CC10) is a multifunction protein with anti-inflammatory and immunomodulatory effects; hence we compared the CC10 expression between chronic rhinosinusitis (CRS) patients with and without nasal polyps (NPs), analyzed its association with disease severity and response to surgery, and explored its regulation via cytokines. METHODS: The plasma and tissue CC10 levels were compared between controls and CRS patients with and without NPs by means of quantitative RT-PCR, ELISA, and immunohistochemistry. Computed tomography (CT) scan and endoscopy findings and symptoms were scored. Nasal explant culture was used to explore the effect of TNF-alpha, IL-1beta, IL-4, INF-gamma, and IL-10 on CC10 gene regulation. RESULTS: Compared with controls, the CC10 expression in sinonasal mucosa was significantly inhibited in both CRS patients with and without NPs. There was a significant further decrease of CC10 expression in patients with NPs and asthma. No difference in CC10 plasma levels was found between controls and patients. CC10 levels inversely correlated with preoperative CT scores, and postoperative endoscopy and symptom scores. TNF-alpha, IL-1beta and IL-4 inhibited, whereas INF-gamma and IL-10 promoted CC10 production in nasal mucosa. A significantly faster decay of CC10 transcripts was seen after IL-1beta treatment. IL-1beta and IL-10 induced thyroid transcription factor-1 expression. INF-gamma increased, whereas IL-4 inhibited hepatocyte nuclear factor-3alpha expression. CONCLUSION: CC10 may take part in the pathogenesis of CRS and correlates with disease severity and response to surgery. Different cytokines can regulate CC10 expression in nasal mucosa differentially through modulating mRNA stability and certain transcriptional factors expression.

Siglec-F antibody administration to mice selectively reduces blood and tissue eosinophils.

BACKGROUND: Sialic acid-binding immunoglobulin-like lectins (Siglecs) are a family of receptors that bind sialic acid and mostly contain immunoreceptor tyrosine-based inhibitory motifs, suggesting that these molecules possess inhibitory functions. We have recently identified Siglec-8 as an eosinophil-prominent Siglec, and cross-linking of Siglec-8 on human eosinophils induces apoptosis. In this article, we address the in vivo consequences of Siglec engagement. We and others have identified mouse Siglec-F as the closest functional paralog of human Siglec-8, based on shared ligand-binding and expression pattern. We therefore hypothesized that Siglec-F engagement would affect levels and viability of eosinophils in vivo. METHODS: Wild type and hypereosinophilic mice were administered Siglec-F antibody and levels of eosinophils in peripheral blood and tissue were measured. Eosinophil apoptosis (in vivo and in vitro) was determined by binding of Annexin-V. RESULTS: Studies in IL-5 transgenic mice, displaying hypereosinophilia, show that administration of a single dose of Siglec-F antibody results in rapid reductions in quantum of eosinophils in the blood. This decrease was accompanied by reductions in tissue eosinophils. Quantum of eosinophils in blood was decreased using two separate antibodies, as well as in other mouse models (wild type mice and in a mouse model of chronic eosinophilic leukemia). Mechanistic studies demonstrated that Siglec-F antibody administration induced apoptosis of eosinophils in vivo and in vitro. CONCLUSION: These data demonstrate that activation of innate immune receptors, like Siglec-F, can significantly reduce mouse eosinophil viability. As such, targeting Siglec-8/F may be a therapeutic approach for eosinophilic disorders.

Practical allergy (PRACTALL) report: risk assessment in anaphylaxis.

Effector mechanisms in anaphylaxis were reviewed. Current approaches to confirmation of the clinical diagnosis were discussed. Improved methods for distinguishing between allergen sensitization (which is common in the general population) and clinical risk of anaphylaxis (which is uncommon) were deliberated. Innovative techniques that will improve risk assessment in anaphylaxis in the future were described.