A Recombinant Fragment of Human Surfactant Protein D Suppresses Basophil Activation, Th2 and B Cell Responses in Grass Pollen-induced Allergic Inflammation

Rationale: rfhSP-D has been shown to suppress house dust mite and Aspergillus 74 fumigatus-induced allergic inflammation in murine models. 75 Objectives: We sought to elucidate the effect of rfhSP-D on FcεRI and CD23- 76 mediated grass pollen induced allergic inflammatory responses. 77 Methods: rfhSP-D, containing homotrimeric neck and lectin domains, was 78 expressed in Escherichia coli BL21 (λDE3) pLysS. PBMCs and sera were obtained 79 from grass pollen allergic individuals (n=27). The effect of rfhSP-D on basophil 80 activation and histamine release was measured by flow cytometry. IgE-facilitated 81 allergen binding and presentation was assessed by flow cytometry. Th2 cytokines 82 were measured in cell culture supernatants. The effect of rfhSP-D on IgE production 83 by B cells when stimulated with CD40L, IL-4 and IL-21 was also determined. 84 Results: rfhSP-D bound to Phleum pratense in a dose- and calcium-dependent 85 manner. Allergen-induced basophil responsiveness and histamine release was 86 inhibited in the presence of rfhSP-D, as measured by CD63, CD203c 87 (P=0.0086,P=0.04205), and intracellular-labelled DAO (P=0.0003,P=0.0148). The 88 binding of allergen-IgE complexes to B cells was reduced by 51%(P=0.002) in the 89 presence of rfhSP-D. This decrease was concomitant with reduction in CD23 90 expression on B cells (P<0.001). rfhSP-D suppressed allergen-driven CD27- 91 CD4+CRTH2+ T cell proliferation (P<0.01), IL-4 and IL-5 levels (all, P<0.01). 92 Moreover, rfhSP-D inhibited CD40L/IL-4 and IL-21-mediated IgE production(77.12%; 93 P=0.02) by B cells. 94 Conclusion: For the first time, we show that rfhSP-D inhibited allergen-induced 95 basophil responses at a single cell, level and suppressed CD23-mediated facilitated 5 allergen presentation and Th2 cytokine production. 96 In addition, rfhSP-D inhibited IgE 97 synthesis by B cells, which is also a novel observation.This research was funded by Royal Brompton Hospital charity research funds

Passive Prophylactic Administration with a Single Dose of Anti-Fel d 1 Monoclonal Antibodies REGN1908-1909 in Cat Allergen-Induced Allergic Rhinitis: A Randomized, Double-blind, Placebo Controlled Trial

RATIONALE: Sensitization to Felis domesticus allergen 1 (Fel d 1) contributes to persistent allergic rhinitis and asthma. Existing treatment options for cat allergy, including allergen immunotherapy (AIT) are only moderately effective, and AIT has limited use due to safety concerns. OBJECTIVES: To explore the relationship among the pharmaokinteic, clinical, and immunological effects of REGN1908-1909 (anti-Fel d 1 monoclonal antibodies) in patients after treatment. METHODS: Patients received REGN1908-1909 (n=36) or placebo (n=37) in a phase 1b study. Fel d 1-induced basophil and IgE-facilitated allergen binding responses were evaluated at baseline and days 8, 29 and 85. Cytokine and chemokine levels in nasal fluids were measured. REGN1908-1909 inhibition of allergen-IgE binding in patient serum was evaluated. MEASUREMENTS AND MAIN RESULTS: Peak serum drug concentrations were concordant with maximal observed clinical response. The anti-Fel d 1 IgE/cat-dander IgE ratio in pretreatment serum correlated with Total Nasal Symptom Score improvement. The allergen neutralizing capacity of REGN1908-1909 was observed in serum and nasal fluid, and was detected in an inhibition assay. Type-2 cytokines (IL-4, IL-5 and IL-13) and chemokines (CCL17/TARC, CCL5/RANTES) in nasal fluid were inhibited in REGN1908-1909-treated patients compared to placebo (all P < 0.05); IL-13 and IL-5 levels correlated with TNSS improvement. Ex vivo assays demonstrated that REGN1908 and REGN1909 combined was more potent than each alone for inhibiting FcεRI- and FcεRII (CD23)-mediated allergic responses and subsequent T-cell activation. CONCLUSION: Single passive dose administration of Fel d 1-neutralizing IgG antibodies improved nasal symptoms in cat-allergic patients, and was underscored by suppression of FcεRI-, FcεRII- and Th2-mediated allergic responses. Clinical trial registration available at www.clinicaltrials.gov, ID: NCT02127801

Allergen-specific IgG+ memory B cells are temporally linked to IgE memory responses

BACKGROUND: Immunoglobulin E (IgE) are least abundant, tightly regulated and IgE producing B cells are rare. The cellular origin and evolution of IgE responses are poorly understood. OBJECTIVE: To investigate the cellular and clonal origin of IgE memory responses following mucosal allergen exposure by sublingual immunotherapy (SLIT). METHODS: In a randomized double-blind, placebo-controlled, time-course SLIT study, peripheral blood mononuclear cells (PBMCs) and nasal biopsies were collected from forty adults with seasonal allergic rhinitis at baseline, 4, 8, 16, 28 and 52 weeks. RNA was extracted from PBMCs, sorted B cells and nasal biopsies for VH repertoire sequencing. Moreover, monoclonal antibodies were derived from single B cell transcriptomes. RESULTS: Combining VH repertoire sequencing and single cell transcriptomics yielded direct evidence of a parallel boost of two clonally and functionally related B cell subsets of short-lived IgE+ plasmablasts and IgG+ memory B cells (termed IgGE). Mucosal grass pollen allergen exposure by SLIT resulted in highly diverse IgE and IgGE repertoires. These were extensively mutated and appeared relative stable as per heavy chain isotype, somatic hypermutations and clonal composition. Single IgGE + memory B cell and IgE+ pre-plasmablast transcriptomes encoded antibodies that were specific for major grass pollen allergens and were able to elicit basophil activation at very low allergen concentrations. CONCLUSION: For the first time, we have shown that upon mucosal allergen exposure, human IgE memory resides in allergen-specific IgG+ memory B cells. These rapidly switch isotype and expand into short-lived IgE+ plasmablasts and serve as a potential target for therapeutic intervention

Approach to diagnosis and pathological examination in bronchial Dieulafoy disease: a case series

<p>Abstract</p> <p>Background</p> <p>There are limited series concerning Dieulafoy disease of the bronchus. We describe the clinical presentation of a series of 7 patients diagnosed with Dieulafoy disease of the bronchus and provide information about the pathological diagnosis approach.</p> <p>Patients and methods</p> <p>A retrospective review of patients who underwent surgery for massive and unexplained recurrent hemoptysis in a referral center during a 11-year period.</p> <p>Results</p> <p>Seven heavy smoker (49 pack years) patients (5 males) mean aged 54 years experienced a massive hemoptysis (350–1000 ml) unrelated to a known lung disease and frequently recurrent. Bronchial contrast extravasation was observed in 3 patients, combining both CT scan and bronchial arteriography. Efficacy of bronchial artery embolization was achieved in 40% of cases before surgery. Pathological examination demonstrated a minute defect in 3 cases and a large and dysplasic superficial bronchial artery in the submucosa in all cases.</p> <p>Conclusion</p> <p>Dieulafoy disease should be suspected in patients with massive and unexplained episodes of recurrent hemoptysis, in order to avoid hazardous endoscopic biopsies and to alert the pathologist if surgery is performed.</p

The Effect of Rush Immunotherapy with House Dust Mite in the Production of IL-5 and IFN-γ from the Peripheral Blood T Cells of Asthmatic Children

Although the mechanisms are unclear, rush immunotherapy (RIT) may be effective to treat allergic diseases. We investigated the long-term modifications of cellular immunity as a mechanism of RIT. The RIT group, included 15 house dust mite (HDM)-sensitized asthmatic children, received RIT only with Dermatophagoides farinae (Der f) and Dermatophagoides pteronyssinus (Der p), whereas the control group, consisted of 10 HDM-sensitized asthmatic children, did not receive RIT. The asthma symptom scores and the skin reactivities to Der f were measured. The cellular proliferative responses and intracellular interleukin (IL)-5 and interferon (IFN)-γ productions from peripheral blood T cells were also measured before, 8 weeks and 1 yr after RIT. The symptom scores, skin reactivity to Der f and cellular proliferative responses to Der f were decreased significantly after 8 weeks and maintained until 1 yr of RIT. The IFN-γ/IL-5 ratio of the CD3(+) and CD4(+) cells were increased significantly after 8 weeks and maintained until 1 yr of RIT, while there were no changes in the control group. These data indicate that the continuous functional modification from Th2 to Th1 phenotype of the CD4(+) T cells are developed after RIT in the asthmatic children sensitized with HDM

Human Platelet-Rich Plasma- and Extracellular Matrix-Derived Peptides Promote Impaired Cutaneous Wound Healing In Vivo

Previous work in our laboratory has described several pro-angiogenic short peptides derived from endothelial extracellular matrices degraded by bacterial collagenase. Here we tested whether these peptides could stimulate wound healing in vivo. Our experiments demonstrated that a peptide created as combination of fragments of tenascin X and fibrillin 1 (comb1) applied into cranial dermal wounds created in mice treated with cyclophosphamide to impair wound healing, can improve the rate of wound closure. Furthermore, we identify and characterize a novel peptide (UN3) created and modified from two naturally-occurring peptides, which are present in human platelet-rich plasma. In vitro testing of UN3 demonstrates that it causes a 50% increase in endothelial proliferation, 250% increase in angiogenic response and a tripling of epithelial cell migration in response to injury. Results of in vivo experiments where comb1 and UN3 peptides were added together to cranial wounds in cyclophosphamide-treated mice leads to improvement of wound vascularization as shown by an increase of the number of blood vessels present in the wound beds. Application of the peptides markedly promotes cellular responses to injury and essentially restores wound healing dynamics to those of normal, acute wounds in the absence of cyclophosphamide impairment. Our current work is aimed at understanding the mechanisms underlying the stimulatory effects of these peptides as well as identification of the cellular receptors mediating these effects.National Institutes of Health (U.S.) (Grant EY15125)National Institutes of Health (U.S.) (Grant EY19533)Wound Care Partners, LL

Early efficacy of CABG care delivery in a low procedure-volume community hospital: operative and midterm results

BACKGROUND: The Leapfrog Group recommended that coronary artery bypass grafting (CABG) surgery should be done at high volume hospitals (>450 per year) without corresponding surgeon-volume criteria. The latter confounds procedure-volume effects substantially, and it is suggested that high surgeon-volume (>125 per year) rather than hospital-volume may be a more appropriate indicator of CABG quality. METHODS: We assessed 3-year isolated CABG morbidity and mortality outcomes at a low-volume hospital (LVH: 504 cases) and compared them to the corresponding Society of Thoracic Surgeons (STS) national data over the same period (2001–2003). All CABGs were performed by 5 high-volume surgeons (161–285 per year). "Best practice" care at LVH – including effective practice guidelines, protocols, data acquisition capabilities, case review process, dedicated facilities and support personnel – were closely modeled after a high-volume hospital served by the same surgeon-team. RESULTS: Operative mortality was similar for LVH and STS (OM: 2.38% vs. 2.53%), and the corresponding LVH observed-to-expected mortality (O/E = 0.81) indicated good quality relative to the STS risk model (O/E<1). Also, these results were consistent irrespective of risk category: O/E was 0, 0.9 and 1.03 for very-low risk (<1%), low risk (1–3%) and moderate-to-high risk category (>3%), respectively. Postoperative leg wound infections, ventilator hours, renal dysfunction (no dialysis), and atrial fibrillation were higher for LVH, but hospital stay was not. The unadjusted Kaplan-Meier survival for the LVH cohort was 96%, 94%, and 92% at one, two, and three years, respectively. CONCLUSION: Our results demonstrated that high quality CABG care can be achieved at LVH programs if 1) served by high volume surgeons and 2) patient care procedures similar to those of large programs are implemented. This approach may prove a useful paradigm to ensure high quality CABG care and early efficacy at low volume institutions that wish to comply with the Leapfrog standards