Topical treatment targeting sphingosine-1-phosphate and sphingosine lyase abrogates experimental allergic rhinitis in a murine model.

BACKGROUND: Sphingosine-1-phosphate (S1P) plays a crucial role in homeostasis of the immune system by regulating lymphocyte recirculation and inflammatory cell recruitment. The levels of S1P are tightly controlled through regulated production and controlled breakdown by sphingosine-lyase (SL). The S1P analogue FTY720 has been developed as an immunosuppressant in transplantation and tested as a treatment for various inflammatory diseases. FTY720 exploits S1P biology by acting as a S1P1 and S1P 3 agonist and by inhibiting S1P breakdown by SL. OBJECTIVE: Here, we investigate interfering S1P in allergic rhinitis (AR) and its way of action. METHODS: Allergic rhinitis was induced by sensitizing mice to ovalbumin (OVA) and challenging the nose with OVA allergen. At the time of allergen challenge, mice received topical intranasal treatment with FTY720. To address the relative contribution of SL inhibition in mediating its effects, some mice were treated with the SL inhibitor 2-acetyl-4-tetrahydroxybutyl (THI). RESULTS: FTY720 treatment resulted in significantly fewer eosinophils, mast cells and dendritic cells in the nasal mucosa of AR animals, compared with diluent treatment. Levels of IL-4, IL-5, IL-10 and IL-13 produced by lymph node cells fell significantly in FTY720-treated animals. Moreover, FTY720 proved potent enough to suppress inflammation in a model of persistent AR. In vitro and in vivo experiments indicate that FTY720 impaired Th2 differentiation and proliferation important in driving eosinophilia and induced apoptosis in mast cells. CONCLUSION: Our results indicate that interfering with S1P metabolism is a powerful and feasible strategy to develop new topical agents that suppress AR.

Recombinant human serum amyloid P in healthy volunteers and patients with pulmonary fibrosis.

PRM-151, recombinant human Pentraxin-2 (PTX-2) also referred to as serum amyloid P (SAP), is under development for treatment of fibrosis. A First-in-Human (FIH) trial was performed to assess the safety, tolerability, and pharmacokinetics of single ascending intravenous doses of PRM-151 administered to healthy subjects, using a randomized, blinded, placebo controlled study design. Each cohort included three healthy subjects (PRM-151:placebo; 2:1). SAP levels were assessed using a validated ELISA method, non-discriminating between endogenous and exogenous SAP. At a dose level of 10 mg/kg, at which a physiologic plasma level of SAP was reached, two additional healthy volunteers and three pulmonary fibrosis (PF) patients were enrolled enabling comparison of the pharmacokinetic SAP profile between healthy volunteers and PF patients. In addition, the percentage of fibrocytes (CD45+/Procollagen-1+ cells) in whole blood samples was assessed to demonstrate biological activity of PRM-151 in the target population. PRM-151 administration was generally well tolerated. In two pulmonary fibrosis patients non-specific, transient skin reactions (urticaria and erythema) were observed. PRM-151 administration resulted in a 6-to 13-fold increase in mean baseline plasma SAP levels at dose levels of 5, 10, and 20 mg/kg. The estimated t1/2 of PRM-151 in healthy volunteers was 30 h. Pharmacokinetic profiles were comparable between healthy volunteers and PF patients. PRM-151 administration resulted in a 30-50% decrease in fibrocyte numbers 24 h post-dose. This suggests that administration of PRM-151 may be associated with a reduction of fibrocytes in PF patients, a population for which current pharmacotherapeutic options are limited. The pharmacological action of PRM-151 should be confirmed in future research.

Ursodeoxycholic acid suppresses eosinophilic airway inflammation by inhibiting the function of dendritic cells through the nuclear farnesoid X receptor.

BACKGROUND: Ursodeoxycholic acid (UDCA) is the only known beneficial bile acid with immunomodulatory properties. Ursodeoxycholic acid prevents eosinophilic degranulation and reduces eosinophil counts in primary biliary cirrhosis. It is unknown whether UDCA would also modulate eosinophilic inflammation outside the gastrointestinal (GI) tract, such as eosinophilic airway inflammation seen in asthma. The working mechanism for its immunomodulatory effect is unknown. METHODS: The immunosuppressive features of UDCA were studied in vivo, in mice, in an ovalbumin (OVA)-driven eosinophilic airway inflammation model. To study the mechanism of action of UDCA, we analyzed the effect of UDCA on eosinophils, T cells, and dendritic cell (DCs). DC function was studied in greater detail, focussing on migration and T-cell stimulatory strength in vivo and interaction with T cells in vitro as measured by time-lapse image analysis. Finally, we studied the capacity of UDCA to influence DC/T cell interaction. RESULTS: Ursodeoxycholic acid treatment of OVA-sensitized mice prior to OVA aerosol challenge significantly reduced eosinophilic airway inflammation compared with control animals. DCs expressed the farnesoid X receptor for UDCA. Ursodeoxycholic acid strongly promoted interleukin (IL)-12 production and enhanced the migration in DCs. The time of interaction between DCs and T cells was sharply reduced in vitro by UDCA treatment of the DCs resulting in a remarkable T-cell cytokine production. Ursodeoxycholic acid-treated DCs have less capacity than saline-treated DCs to induce eosinophilic inflammation in vivo in Balb/c mice. CONCLUSION: Ursodeoxycholic acid has the potency to suppress eosinophilic inflammation outside the GI tract. This potential comprises to alter critical function of DCs, in essence, the effect of UDCA on DCs through the modulation of the DC/T cell interaction.

United airways: circulating Th2 effector cells in an allergic rhinitis model are responsible for promoting lower airways inflammation.

BACKGROUND: Allergic rhinitis (AR) and asthma often coexist and are referred to as 'united airways' disease. However, the molecular and cellular pathways that are crucially involved in the interaction between upper and lower airways remain to be identified. OBJECTIVE: We sought to assess whether and how AR exacerbates lower airway inflammation upon allergen challenge in mice. METHODS: We previously developed an intranasal ovalbumin (OVA)-driven AR model, characterized by nasal eosinophilic inflammation, enhanced serum levels of OVA-specific IgE and Th2 cytokine production in cervical lymph nodes. In OVA-sensitized mice with or without AR, a lower airway challenge was given, and after 24 h, lower airway inflammation was analysed. RESULTS: We found that AR mice were more susceptible to eosinophilic inflammation following a lower airway OVA challenge than OVA-sensitized controls. AR mice manifested increased numbers of eosinophils in bronchoalveolar lavage fluid and increased inter-cellular adhesion molecule-1 (ICAM-1) expression on lung endothelium, when compared with OVA-sensitized controls. Depletion of T cells in OVA-challenged AR mice completely abrogated all hallmarks of lower airway inflammation, including enhanced IL-5 and tissue eosinophilia. Conversely, adoptive transfer of Th2 effector cells in naïve animals induced lower airway eosinophilic inflammation after challenge with OVA. Blocking T cell recirculation during AR development by the spingosine-1 analogue FTY720 also prevented lower airway inflammation including ICAM-1 expression in AR mice upon a single lower airway challenge. CONCLUSION: Our mouse model of 'united airways' disease supports epidemiological and clinical data that AR has a significant impact on lower airway inflammation. Circulating Th2 effector cells are responsible for lung priming in AR mice, most likely through up-regulation of ICAM-1.

Allogeneic chondrogenically differentiated human bone marrow stromal cells do not induce dendritic cell maturation.

Bone marrow stromal cell (BMSC)-mediated endochondral bone formation may be a promising alternative to the current gold standards of autologous bone transplantation, in the development of novel methods for bone repair. Implantation of chondrogenically differentiated BMSCs leads to bone formation in vivo via endochondral ossification. The success of this bone formation in an allogeneic system depends upon the interaction between the implanted constructs and the host immune system. The current study investigated the effect of chondrogenically differentiated human bone marrow stromal cell (hBMSC) pellets on the maturation and function of dendritic cells (DCs) by directly coculturing bone forming chondrogenic hBMSC pellets and immature or lipopolysaccharide (LPS)-matured DCs in vitro. Allogeneic chondrogenic hBMSC pellets did not affect the expression of CD80, CD86, or HLADR on immature or LPS-matured DCs following 24, 48, or 72 hr of coculture. Furthermore, they did not induce or inhibit antigen uptake or migration of the DCs over time. IL-6 was secreted by allogeneic chondrogenic hBMSC pellets in response to LPS-matured DCs. Overall, this study has demonstrated that maturation of immature DCs was not influenced by allogeneic chondrogenic hBMSC pellets. This suggests that allogeneic chondrogenic hBMSC pellets do not stimulate immunogenic responses from DCs in vitro and are not expected to indirectly activate T cells via DCs. For this reason, allogeneic chondrogenic bone marrow stromal cell pellets are promising candidates for future tissue engineering strategies utilising allogeneic cells for bone repair.

Improving the diagnostic management of upper extremity deep vein thrombosis.

Essentials The Constans score and D-dimer can rule out upper extremity deep vein thrombosis without imaging. We evaluated the performance of an extended Constans score and an age-adjusted D-dimer threshold. The extended Constans score did not increase the efficiency compared to the original score. Age-adjusted D-dimer testing safely increased the efficiency by 4%, but this needs validation. SUMMARY: Background Among patients with clinically suspected upper extremity deep vein thrombosis (UEDVT), a clinical decision rule based on the Constans score combined with D-dimer testing can safely rule out the diagnosis without imaging in approximately one-fifth of patients. Objectives To evaluate the performance of the original Constans score, an extended Constans score and an age-adjusted D-dimer positivity threshold. Methods Data of 406 patients with suspected UEDVT previously enrolled in a multinational diagnostic management study were used. The discriminatory performance, calibration and diagnostic accuracy of the Constans score were evaluated. The Constans score was extended by selecting clinical variables that may have incremental value in detecting UEDVT, conditional on the original Constans score items. The performance of the Constans rule was evaluated in combination with fixed and age-adjusted D-dimer thresholds. Results The original Constans score showed good discriminatory performance (c-statistic, 0.81; 95% confidence interval [CI], 0.76-0.85). An extended Constans score with five additional clinical items improved discriminatory performance and calibration, but this did not translate into a higher efficiency in avoiding imaging tests. Compared with a fixed threshold, age-adjusted D-dimer testing increased the proportion of patients for whom imaging and anticoagulation could be withheld from 21% to 25% (gain, 3.7%; 95% CI, 2.3-6.0%). Conclusions The Constans score has good discriminatory performance in the diagnosis of UEDVT. Age-adjusted D-dimer testing is likely to safely increase the efficiency of the diagnostic algorithm, but this approach needs prospective validation.

ADAMTS-13 and von Willebrand factor predict venous thromboembolism in patients with cancer.

UNLABELLED: ESSENTIALS: Cancer patients are at high risk of venous thromboembolism (VTE). In this study, cases and controls were cancer patients who did or did not develop VTE. von Willebrand factor (VWF) levels were higher if compared with controls and correlated with cancer stage. VWF and ADAMTS-13 are associated with the occurrence of VTE in cancer. BACKGROUND: Patients with cancer are at high risk of venous thromboembolism (VTE). ADAMTS-13 regulates von Willebrand factor (VWF) activity, which plays a role in the development of cancer and in VTE. OBJECTIVES: The aim of this study was to search for an association between the levels of VWF and ADAMTS-13 and VTE in patients with cancer and to compare current scoring systems for prediction of VTE before and after addition of these parameters. PATIENTS/METHODS: In a case-control study, in which patients with recently diagnosed cancer were followed-up for 6 months, we compared 20 patients who developed VTE (cases) and 140 patients with cancer without VTE (controls), matched for sex, age, and type and stage of cancer. We measured VWF, ADAMTS-13 (activity and antigen), P-selectin, D-dimer and F1 + 2 levels at baseline, and calculated both the Khorana score and the Khorana score expanded after addition of P-selectin and D-dimer levels. RESULTS: VWF levels were significantly higher in cases when compared with controls (326 ± 185% vs. 242 ± 158%) and correlated with advanced stage of cancer: localized, 185 [142; 222]; locally advanced, 240 [146; 257]; metastatic, 267 [153; 324] (mean [interquartile range]). The addition of two biomarkers, ADAMTS-13 activity and F1 + 2 levels, to the Khorana score improved receiver operating curves. CONCLUSIONS: von Willebrand factor and ADAMTS-13 are associated with the occurrence of VTE in patients with cancer. Moreover, addition of ADAMTS-13 and F1 + 2 levels to the Khorana score considerably increases the predictive value for VTE.

Current management strategies and long-term clinical outcomes of upper extremity venous thrombosis.

UNLABELLED: Essentials Few data exist on outcome of upper extremity deep and superficial vein thrombosis (UEDVT and UESVT). We followed 102 and 55 patients with UEDVT or UESVT, respectively, for a median of 3.5 years. Risk of recurrent venous thromboembolism was low in both diseases, and the mortality high. Postthrombotic symptoms were infrequent and cancer patients had a higher risk of recurrent VTE. SUMMARY: Background There is scant information on the optimal management and clinical outcome of deep and superficial vein thrombosis of the upper extremity (UEDVT and UESVT). Objectives To explore treatment strategies and the incidence of recurrent venous thromboembolism (VTE), mortality, postthrombotic symptoms, and bleeding in patients with UEDVT and UESVT and to assess the prognosis of cancer patients with UEDVT. Patients/methods Follow-up of patients with UEDVT or UESVT, who were enrolled previously in a diagnostic management study. Results We followed 102 and 55 patients with UEDVT and UESVT, respectively, both for a median of 3.5 years. Anticoagulant treatment was started in 100 patients with UEDVT (98%) and in 40 (73%) with UESVT. Nine patients with UEDVT (9%) developed recurrent VTE, 26 (26%) died, 6 (8%) of 72 patients had moderate postthrombotic symptoms, and 5 (5%) experienced major bleeding. One patient with UESVT had a recurrent VTE, 18 (33%) died, none had moderate postthrombotic symptoms, and none had major bleeding. Of the cancer patients with UEDVT, 18% had recurrent VTE vs. 7.5% in non-cancer patients (adjusted hazard ratio 2.2, 95%CI 0.6-8.2). The survival rate was 50% in cancer patients with UEDVT vs. 60% in those without (adjusted HR 0.8, 95%CI 0.4-1.4). Conclusions The risk of recurrent VTE was low in patients with UEDVT, and negligible for UESVT. Mortality was high for both diseases. Postthrombotic symptoms were infrequent and mild. Anticoagulant therapy of UEDVT carried a substantial risk of major bleeding. Cancer patients had a significant risk of recurrent VTE.

Passive smoking causes an 'allergic' cell infiltrate in the nasal mucosa of non-atopic children.

Environmental tobacco smoke (ETS) is one of the most common indoor pollutants to which many children are exposed. This study was set up to determine possible effects on cellular infiltrates in the nasal mucosa of children exposed to ETS. The research population consisted of a group of ten children exposed to more then 15 cigarettes/day and a control group of ten children without exposure. The groups were matched for age and gender. None of the children had an atopic constitution. Immunohistochemical staining techniques were used to determine the number of Langerhans cells, T cells, B cells, granulocytes, macrophages, mast cells and eosinophils in the nasal mucosa. IgE+ cells and eosinophils were seen in significantly higher cell numbers in the nasal mucosa of children exposed to ETS (Mann-Whitney U-test). IgE+ mast cells were not found to be more numerous in the ETS-exposed group. We can conclude that exposure to ETS causes changes in cellular infiltrates which partly resemble those seen in the nasal mucosa of allergic children. However, no sign of allergic sensitisation can be found in the nasal mucosa. Children with a genetic predisposition to allergic disease will probably suffer most from the 'unstable' nasal mucosa due to ETS.

Inflammatory cells seem not to be involved in idiopathic rhinitis.

Mucosal inflammatory cellular infiltrates are correlated with nasal complaints in symptomatic allergic rhinitis. Some authors suggest inflammation of a neurogenic or immunogenic nature as an underlying disorder for idiopathic rhinitis (IR). We looked at the possible involvement of inflammatory cells in the pathogenesis of IR. Nasal biopsies were taken from sixty-five IR patients with significant nasal complaints and from twenty healthy controls with no nasal complaints. Inflammatory cells were quantified using monoclonal antibodies directed against lymphocytes, antigen-presenting cells, eosinophils, macrophages, monocytes, mast cells and other IgE-positive cells. No significant differences were found, for any cell, between IR patients and controls. We conclude that inflammatory cells do not seem to play an important role in this meticulously characterised group of IR patients.

Anticoagulant treatment of cancer patients with pulmonary embolism in the real world. Actual use of low-molecular-weight heparin in cancer.

BACKGROUND: Since 2004, guidelines recommend long-term treatment with low-molecular-weight heparin (LMWH) in patients with cancer and pulmonary embolism (PE). We assessed the proportion of cancer patients with PE actually treated with LMWH and the duration of anticoagulant treatment in the Netherlands. METHODS: A retrospective cohort study in patients that were hospitalised for PE between 1998-2008. Patients with PE were selected from national hospital discharge records, after linkage to a national pharmacy database. Cancer patients with PE were matched for age, sex and year of diagnosis of PE to subjects with PE without cancer. RESULTS: 600 cancer patients with PE were matched to 1200 patients with PE without cancer. Long-term LMWH was prescribed in 82 (13.7%) of the cancer patients and in eight (0.7%) of the cancer-free patients (p < 0.001); all the other patients received vitamin K antagonists (VKA). From 1998-2008, there was an increase in the use of LMWH in cancer patients: in 2007-2008, LMWH was prescribed in 42 (32%) cases, compared with one (1.7%) of the cancer patients with PE in 1998-1999. Median duration of treatment was 5.8 months (interquartile range 3.1-8.8) in cancer patients, compared with 7.0 months (4.9-11) in patients without cancer (p < 0.001), a difference that persisted after adjustment for mortality. CONCLUSIONS: Although the use of LMWH in patients with cancer and PE is increasing, in 2008, patients in the Netherlands are still mostly treated with VKA, and not with LMWH as recommended by guidelines. Cancer patients with PE on average receive shorter treatment than matched patients without cancer.

A worldwide survey to assess the current approach to the treatment of patients with cancer and venous thromboembolism.

Low-molecular-weight heparin (LWMH) is recommended as the preferred anticoagulant treatment over vitamin K antagonists (VKA) for venous thromboembolism (VTE) in patients with cancer. However, there is uncertainty about the duration and dose of LMWH treatment. Therefore, we designed this multinational survey to assess the current approach to the treatment of patients with cancer and VTE. An electronic survey tool was used to disseminate a survey containing 49 questions on different aspects of the treatment of patients with cancer and VTE, among both thrombosis and non-thrombosis specialists. A total of 229 invitations were sent, and 141 completed the survey (60% of the total). Fifty-eight percent of the respondents were from Europe, 35% from the US and the remaining 7% from other countries. Respondent's specialties included haematology (23%), oncology (18%), pulmonology (15%) and general internal medicine (15%). LMWH was indicated as the first choice for the long-term treatment by 82% of the respondents, of whom 60% used full therapeutic doses and 40% chose a dose reduction. When continuing anticoagulants after the long-term treatment period, 44% of respondents preferred LMWH, 10% VKA, while the remaining 45% chose per individual patient for either LMWH or VKA. In conclusion, we observed a relatively high observance rate of the guidelines with respect to the use of LMWH for the long-term treatment of VTE in cancer. In contrast, the dose of LMWH and the type of anticoagulant chosen after the initial 3-12 months varied substantially, probably reflecting the limited available evidence.

Limitations of screening for occult cancer in patients with idiopathic venous thromboembolism.

BACKGROUND: Idiopathic venous thrombosis (IVT) is associated with occult malignancy in 10% of patients. The Trousseau study investigated whether extensive screening using abdominal and chest computed tomography (CT) scans and mammography in women would decrease mortality, compared with limited screening. Here, the costs and test characteristics of these screening strategies are presented, including true- and false-positive findings, sensitivity and specificity. METHODS: All investigations performed because of a suspicion of malignancy in the limited or extensive screening groups were collected. Costs were calculated using Dutch healthcare tariffs. RESULTS: A total of 342 and 288 patients with IVT were included in the extensive and the limited screening group, respectively. The prevalences of malignancy and mortality were comparable between these two groups, as were the abnormal findings during routine screening. In 30% of the extensively screened patients, the CT scans or mammography showed abnormalities necessitating further diagnostic work-up; this yielded six malignancies and resulted in a positive predictive value of 6.6%, sensitivity of 33% and specificity of 70%. Mean costs per patient were €165.17 for the routine and €530.92 for the extensive screening. CONCLUSION: Screening using CT scans and mammography results in extra costs due to the high percentage of false-positive findings for which a further diagnostic work-up is indicated.

Cell-derived microvesicles and cancer.

Blood and other body f luids contain cell-derived microvesicles. The presence of microvesicles in cancer patients was already noticed in the late 1970s. Since then, the prothrombotic state in cancer patients has invariably been associated with the presence of such microvesicles. More recently, a growing body of evidence supports an important contribution of microvesicles to cancer cell survival, invasiveness and metastases. Here, we will present an overview of the many contributions of microvesicles to cancer development and progression. In addition, their role in risk stratification and treatment of cancer patients is discussed.

A novel method for isolating dendritic cells from human bronchoalveolar lavage fluid.

BACKGROUND: Dendritic cells (DCs) play a pivotal role in linking the innate and adaptive immune response and have been implicated in a variety of pulmonary diseases. Currently, studies on the role of DCs are limited by difficulties in isolating DCs from the lung. Surgical lung specimens are not readily available and purification of DCs from digested lung tissue is likely to induce phenotypical and functional changes. DCs obtained from the alveolar spaces are thought to represent the local microenvironment and can be obtained using minimally invasive techniques. We developed a novel method of isolating DCs from bronchoalveolar lavage (BAL) fluid. METHODS: After removal of macrophages, the remaining BAL cells were stained with a lineage mix (CD3-, CD14-, CD16-, CD19-, CD56-FITC), CD11c and HLA-DR and sorted with a FACS ARIA. DAPI was used as a dead-live marker. mDCs were low autofluorescent, lineage mix negative, CD11c+ and HLA-DR+ cells. pDCs were CD11c(-) but CD123+. Morphological assessment of sorted mDCs and pDCs was performed. Sorted mDCs were tested in a mixed leukocyte reaction (MLR) with naive CD4+ T cells and evaluated for T cell differentiation and cytokine production. With confocal microscopy DC-T cell interaction was assessed. RESULTS: Using our sorting strategy, mDCs and pDCs, with a high purity upon FACS analysis of the sorted fraction, were obtained. These cells showed the morphological characteristics of DCs. Most importantly, mDCs were able to induce T cell proliferation and differentiation in a MLR, and interact with T cells as assessed by confocal microscopy. These results indicate the presence of functional DCs. Freezing and thawing of the BAL cells did not affect phenotype or T cell stimulatory capacity of the isolated DCs. CONCLUSION: Using a novel sorting strategy, functional mDCs can be isolated from BAL fluid, enabling a detailed study in pulmonary disease.

Desloratadine reduces systemic allergic inflammation following nasal provocation in allergic rhinitis and asthma patients.

BACKGROUND: Preclinical studies have demonstrated that some second-generation antihistamines have anti-inflammatory effects. It is not known whether these effects are also demonstrable in vivo. In this study we investigated the effect of treatment with desloratadine (DL) on systemic inflammation and on nasal and bronchial mucosal inflammation after nasal allergen provocation (NP) in subjects with grass-pollen-allergic rhinitis and asthma. METHODS: Twenty-six subjects with grass-pollen-allergic rhinitis and asthma were randomly allocated to 8 days of treatment with DL (n = 13) or placebo (n = 13) outside the grass pollen season. On day 7 they underwent nasal provocation with grass pollen allergen. Nasal and bronchial biopsies were taken for immunohistochemical evaluation, and blood samples were analysed. Rhinitis and asthma symptoms, peak nasal inspiratory flow and peak expiratory flow, were also measured at specified times. RESULTS: The number of circulating eosinophils decreased during DL treatment, and there was a reduced increase in circulating eosinophils after NP in these subjects. There was also a significant reduction in early bronchial clinical response. There was no significant lessening in the severity of the nasal symptoms. Nasal and bronchial mucosal inflammation parameters did not alter under DL treatment. CONCLUSION: These data suggest that treatment with DL reduces systemic eosinophilia and prevents the increase in circulating eosinophils after NP. DL also significantly reduces the early bronchial clinical response to NP. However, airway mucosal inflammation is not altered by 1 week of treatment.

Evaluation of an intranasal house dust mite provocation model as a tool in clinical research.

BACKGROUND: As a result of the all-year-round exposure to house dust mite (HDM), perennial rhinitis patients never have a clear symptom-free period. In this study, we investigated whether, despite these symptoms, we can still use nasal HDM provocations to study perennial allergic rhinitis and the effects of treatment. METHODS: In a parallel-group study, after 1 week treatment with either fluticasone propionate aqueous nasal spray (FPANS) or placebo, 20 patients, allergic to HDM, registered symptoms (nasal obstruction, rhinorrhoea, sneezing, pruritus and eye symptoms) using three different scoring methods [Lebel, categorical and visual analogue scale (VAS)] and peak nasal inspiratory flow (PNIF) after HDM provocations. Provocations were performed with 1000 biological units/ml and 24 h later with 10,000 biological units/ml of HDM. Before and after the provocations, nasal mucosa biopsies were taken for immunohistochemical staining to determine the number of eosinophils. RESULTS: House dust mite provocations resulted in an increase in symptoms and a decrease in PNIF. Even at high-dose provocation, the FPANS group registered significantly lower symptoms than the placebo group for nasal blockage, sneezing, eye symptoms, and PNIF in both early and late phases. FPANS also suppressed rhinorrhoea during the late phase and the influx of eosinophils in the lamina propria. CONCLUSION: Despite the high background of symptoms, allergic responses can be induced in this perennial rhinitis model. The VAS score seems most suited to detect these changes and the suppression of symptoms by 7 days of FPANS treatment. Epithelial eosinophilia at baseline was correlated positively with the severity of the reaction after the first provocation.

Local IgE production in the nasal mucosa: a review.

IgE is one of the most important markers for allergy. The presence of specific IgE on skin mast cells (skin test) and/or the existence of specific IgE in serum (RAST) indicates sensitization, but not necessarily clinical allergy, in the target organ. Discrepancies between sensitization and disease could be explained by local IgE production. The nasal mucosa contains all the cell types necessary for a local IgE immune response. Moreover, it has been shown that this local IgE is specific for the specific allergen to which the patient is allergic. The availability of IL-4 and IL-13 produced in the nasal mucosa creates the possibility for isotype switching of B cells to IgE-positive B cells, and proliferation and maturation of B cells to IgE-producing plasma cells. The IgE positivity of B cells and plasma cells implies that IgE production occurs in the nasal mucosa. The observation of the presence of allergen-positive plasma cells and the finding that all allergen-positive cells were also IgE-positive indicates that this local IgE production is allergen-specific. Data discussed in this review provide strong evidence for the local production of specific IgE in the nasal mucosa.

Allergen binding to specific IgE in the nasal mucosa of allergic patients.

BACKGROUND: Until now, it has not been possible to identify specific IgE locally in the airway mucosa. In this study we investigated the possibility of determining specific allergen binding locally in the nasal mucosa. METHODS: Nasal mucosal biopsy specimens were taken from 11 patients with symptoms of an isolated grass pollen allergy, 10 patients with symptoms of perennial allergic rhinitis in response to house dust mite allergen, and 10 nonallergic control subjects. Sections of these biopsy specimens were stained by using commercially available biotinylated allergens (AlaSTAT, Diagnostic Products Corp.). RESULTS: Staining with biotinylated grass pollen (GP1) demonstrated positive cells only in patients with grass pollen allergy. Biotinylated Dermatophagoides pteronyssinus (D1) only stained cells in patients with perennial allergy. Specific binding of allergen to cells of patients with allergy and the blocking experiments proved the method to be highly specific. Allergen-positive cells stained double with IgE, the high-affinity receptor for IgE (Fc epsilon RI), CD1, HLA-DR, tryptase, and chymase. Most allergen-positive cells proved to be mast cells. CONCLUSION: This immunohistochemical study shows the presence of specific IgE against grass pollen and house dust mite allergens locally on cells in the airway mucosa.