Late Cutaneous Responses Research Articles

Effect of benralizumab on inflammation in skin after intradermal allergen challenge in patients with moderate-to-severe atopic dermatitis

BackgroundAtopic dermatitis is a skin barrier dysfunction characterized by tissue eosinophilia. Objective: In patients with atopic dermatitis (AD) we evaluated the effect of eosinophil depletion with benralizumab on markers of inflammation in skin after intradermal allergen challenge. Methods20 patients with moderate to severe AD completed a randomized, double-blind, placebo-controlled parallel-group study comparing 3 doses q4wk 30 mg subcutaneous benralizumab (n=9) to placebo (n=11). Allergen and saline control intradermal challenges were conducted before and after treatment with skin biopsies collected 24 hours after challenge. Early (ECR) and late cutaneous responses (LAR) were measured by skin wheal size. Eosinophils and IL-5Rα -bearing cells including eosinophil progenitor cells (EoP), basophils and mast cells were measured in papillary dermis by immunofluorescence microscopy, and EoP, hemopoietic progenitor cells (HPC) and ILC2 were measured in blood by flow cytometry. Outcomes were compared between placebo and benralizumab treatment groups using Mann-Whitney U-test. ResultsBenralizumab reduced eosinophils in blood (p<0.0001), and allergen challenged skin as measured by H&E and EG2 (p<0.05). Benralizumab lowered levels of EoP, mast cells and basophil numbers in skin, as well as EoP, HPC and ILC2s in blood (all p<0.05). There was a trend for improvement in the ECR response (p=0.095), but no effect on the LCR. ConclusionIn patients with moderate to severe AD, benralizumab treatment significantly inhibited accumulation of eosinophils and other IL-5Rα expressing cells in the papillary dermis after intradermal allergen challenge. Targeting IL-5Rα positive cells did not modulate the size of the allergen-induced skin wheal. (ClincialTrials.gov number, NCT03563066).

Immunologic response to administration of standardized dog allergen extract at differing doses

The immunologic response to immunotherapy with dog extract is not well characterized. The purpose of this study was to examine the immunologic response to 3 doses of dog extract expressed as their Can f 1 content. Cluster immunotherapy was administered to 28 patients with dog allergy who were randomly assigned to 1 of 4 treatment arms: placebo or acetone-precipitated extract containing 0.6 mug, 3.0 mug, or 15.0 mug Can f 1 per 0.5 mL maintenance dose. Studies included titrated skin prick tests, the late cutaneous response, titrated nasal challenge with dog extract, and serum allergen-specific IgE and IgG(4). Dog allergen-stimulated lymphocyte proliferation was performed with measurement of secreted cytokines by ELISA and of intracellular cytokines by flow cytometry. There was a significant dose-dependent response in suppression of titrated skin prick tests and suppression of the late cutaneous response. There was a significant increase from baseline in dog-specific IgG(4) in both the high-dose and low-dose groups and a dose-dependent suppression of secreted TNF-alpha and increase in secreted TGF-beta. There was a dose-dependent trend in suppression of secreted IL-4 with a significant decrease from baseline in the high-dose group. There were no significant changes in symptom scores; lymphocyte proliferation; secreted IFN-gamma, IL-10, or IL-5; or intracellular cytokine production. The dose-response in immunologic parameters after immunotherapy with dog extract is similar to that previously demonstrated with cat extract. The greatest and most consistent response is seen with a dose containing 15 mug Can f 1.

Immunological Response to Administration of Standardized Dog Allergen Extract at Differing Doses

RATIONALE: The purpose of this study was to examine the immunologic response to three doses of Acetone Precipitated (AP) dog extract (Hollister Stier) expressed as Can f 1 content. METHODS: Twenty-eight dog-allergic patients were randomly assigned to one of four maintenance treatment arms: placebo, 0.6 μg, 3.0 μg, or 15.0 μg of Can f 1. Studies included the response to titrated skin prick tests, late cutaneous response to dog extract, serum allergen-specific IgE and IgG4, titrated nasal challenges, and measurement of secreted and intracellular cytokines. RESULTS: After 5 weeks of immunotherapy, there was a statistically significant dose response in suppression of prick skin tests (p=0.01) with the high-dose group exhibiting the largest change from baseline. There were statistically significant differences when the high-dose group was compared to the placebo (p=0.0003), when the medium-dose group was compared to the placebo (p= 0.006), and when the high-dose group was compared to the low-dose group (p=0.05). There was an overall significant change from baseline in suppression of the late cutaneous response (p=0.03) and significant differences from baseline when the high-dose group was compared to the placebo group (p= <0.05). There was statistically significant differences from baseline in the high and medium-dose groups (p=0.03 for both), an increase in dog-specific IgG4 in both the high and low-dose groups (p=0.03, 0.02, respectively) and suppression in secreted IL-4 in the high-dose group (p=0.05). CONCLUSIONS: The dose response to immunotherapy with dog extract displayed the greatest and most consistent response with a dose containing 15 mcg of the major allergy.

Allergen-Induced Late Cutaneous Responses Are Associated with Elevated CD3 +CCR4 + Cells and no Change in CD3 +CCR3 + or CD3 +CCR8 + Cells

Allergen-Induced Late Cutaneous Responses Are Associated with Elevated CD3 +CCR4 + Cells and no Change in CD3 +CCR3 + or CD3 +CCR8 + Cells

A Late Cutaneous Response in Actively Sensitized Rats: a New Method for Evaluating the Efficacy of Antiallergic Drugs

We established a new and facile model to investigate allergic mechanism and assess the effect of antiallergic compounds. Male Wistar rats were actively or passively sensitized. Active sensitization was performed by injection of both dinitrophenylated-ovalbumin (DNP-OA) and Bordetella pertussis. Nine days later, DNP-OA was injected into the right hind footpad. This antigen challenge induced a biphasic footpad swelling that consisted of an early-phase (EPR) and a late-phase response (LPR). In rats passively sensitized with rat anti-DNP-OA serum, DNP-OA induced only EPR. The EPR was suppressed by disodium cromoglycate, a mast cell stabilizer, but not by cyclosporin A, an immunosuppressant, while the LPR was suppressed by cyclosporin A. Furthermore, to investigate these two allergic responses determined by the interactions between the hapten and the carrier proteins, two distinct haptenated antigens were created. DNP-Ascaris (DNP-As) induced a marked EPR and LPR in DNP-As-sensitized rats. However, DNP-As induced only EPR in DNP-OA-sensitized rats, indicating that the usage of the same carrier protein in both sensitization and challenge was necessary for induction of LPR. These data suggest that this actively sensitization model in which EPR and LPR are functionally distinguishable should be useful for evaluating the efficacy of antiallergic compounds.

Inhibitory effects of low molecular weight heparin on mediator release by mast cells: preferential inhibition of cytokine production and mast cell-dependent cutaneous inflammation.

There has been substantial evidence that suggests that heparin may modulate various aspects of immune function and inflammation in addition to its well known anticoagulant activity. In this regard heparin was found to suppress cell-mediated immune responses or asthmatic reactions to allergen challenge. In the present study we analyse the effects of low molecular weight heparin (LMWH) on mast cell degranulation and cytokine production in vitro and on the elicitation of IgE-mediated mast cell-dependent late cutaneous allergic inflammation in vivo. We have established that LMWH preferentially inhibited tumour necrosis factor-alpha (TNF-alpha) and IL-4 production without having any significant effect on mast cell degranulation. These effects have been observed in mast cells derived from three different origins that were activated by either immunological or non-immunological stimuli. We have shown that there is inhibition of TNF-alpha production (and not neutralization of activity), as elimination of the drug after a short preincubation and addition of LMWH to rTNF-alpha had no effect on TNF-alpha-mediated cytotoxic activity. These results were also confirmed by ELISA. In vivo, s.c. injection of the LMWH inhibited the leucocyte infiltration associated with the late cutaneous response which followed passive cutaneous anaphylaxis (PCA) reaction, without affecting mast cell numbers or degranulation. These data suggest that LMWH may have an inhibitory role in mast cell-mediated allergic inflammation, and thus might be considered as a possible therapeutic modality.

Beyond Our Pages

Beyond Our Pages

The late asthmatic response is associated with baseline allergen-specific proliferative responsiveness of peripheral T lymphocytes in vitro and serum interleukin-5.

Increasing insights into the mechanism underlying the allergen-induced late asthmatic response (LAR) have been gained with implication of activated eosinophils and CD4+ T lymphocytes. However, the patient characteristics that indicate the individual capacity to develop a LAR are not well-defined. In 22 subjects with mild to moderate house dust mite-allergic asthma, we investigated the relationship between the LAR and two other models of late-phase allergic inflammation, i.e. the allergen-specific proliferative response of peripheral blood T lymphocytes in vitro and the late cutaneous response. Non-specific bronchial responsiveness (PC20histamine), lung function (FEV1), peripheral blood eosinophil count, early phase allergic skin sensitivity, and levels of total and specific immunoglobulin E (IgE) were determined prior to bronchial allergen challenge. Serum levels of interleukin-5 (IL-5) were measured before and at several time points after allergen inhalation. A significant correlation was found between the magnitude of the LAR and the allergen-specific proliferative response of peripheral T lymphocytes (r = 0.44, P = 0.04) but not the late cutaneous response. Stepwise-multiple linear regression of the magnitude of the LAR on the parameters analysed at baseline, resulted in a model combining PC20 histamine, early phase allergic skin sensitivity, and the allergen-specific proliferative response of peripheral T lymphocytes (R2 = 0.84, P<0.001). No contribution of the late cutaneous response to the prediction of the LAR was found. Serum levels of IL-5 increased significantly at 6 h (P = 0.01) and 24 h (P = 0.003) after bronchial allergen challenge and correlated with the allergen-specific proliferative response of peripheral T lymphocytes in vitro (rho = 0.48, P = 0.02). The findings in this study point to a role of TH2-lymphocyte responses in the development of the allergen-induced LAR. In allergic asthmatic patients, allergen-specific responsiveness of peripheral T-lymphocytes in vitro may serve as a model to determine the individual capacity to develop a LAR after allergen inhalation.

INFLUENCE OF GRASS POLLEN IMMUNOTHERAPY ON CELLULAR INFILTRATION AND CYTOKINE EXPRESSION DURING ALLERGEN-INDUCED LATE-PHASE CUTANEOUS RESPONSES

Purpose of the Study. The mechanism by which immunotherapy (IT) provides its beneficial effects are poorly understood. This study examines the effects of grass pollen IT on cellular infiltration and cytokine mRNA expression during allergen induced late phase cutaneous responses. Methods. Forty subjects were enrolled in this double blind, placebo controlled study to receive twice weekly injections of either a standardized grass pollen extract or placebo. Once maintenance was reached, injections were administered monthly for 9 months. Skin biopsies following intradermal infection with Timothy extract were performed prior to and following IT. Monoclonal antibody staining was used to detect surface markers on lymphocytes. In situ hybridization was used to identify cells expressing cytokine mRNA. Findings. Both patient groups were matched for age, disease severity, and duration. Thirty-seven patients (17 placebo, 20 active) completed the study. The treated group had a significant decrease in symptoms, medication use, and size of the immediate and late phase reaction (LPR) after intradermal allergen injection upon completion of the IT. Skin biopsy cell counts from actively treated subjects obtained after subcutaneous allergen challenge showed a significant decrease in T helper and eosinophil cell numbers compared to the placebo group. Increases in the expression of CD25 and HLA-DR (markers of T cell activation) were seen in the treatment group. No differences in amount of HA and IL5 mRNA-expressing cells (TH2) were noted, but there was an increase in IFN-γ and IL2 mRNA expressing cells (ie, TH1) in the actively treated group. A significant correlation was noted between the size of the LPR and the numbers of CD4+ cells in the placebo group.

The Pathobiology of Bronchial Asthma

Early studies of patients dying from status asthmaticus revealed marked inflammation of the bronchial tree. Subsequent histological studies of the airways and examination of bronchoalveolar lavage fluid of subjects with mild asthma have confirmed the presence of airway inflammation in life. There is epithelial edema and desquamation, subepithelial deposition of collagen and fibronectin, and an inflammatory cell infiltrate in the mucosa. There are increased numbers of activated eosinophils, CD25-positive T lymphocytes, and immature macrophages with the phenotypic characteristics of blood monocytes. An increased expression of HLA class II is present on epithelium, macrophages, and other infiltrating cells. The severity of clinical asthma correlates with several measurements of the severity of the inflammatory response, suggesting a crucial role for airway inflammation in the pathophysiology of the disease. There is considerable interest and research into the mechanisms underlying the pathogenesis and maintenance of the inflammatory response in asthma. The development and maintenance of the inflammatory response in asthma is likely to be a consequence of a complicated interaction between various cells and the mediators they generate. The characterization of an ever-increasing number of cytokines is of particular interest. Interleukin-3, interleukin-5, and granulocyte-macrophage colony-stimulating factor are hematopoietic growth factors that increase the survival of eosinophils in culture and enhance certain eosinophil functions, such as mediator generation and toxicity. Alveolar macrophages derived from asthmatic subjects produce twofold to threefold more GM-CSF than do those from normal control subjects. Using in situ hybridization, the presence of IL-5 mRNA has been demonstrated in bronchial biopsies from asthmatic subjects. Thus IL-3, IL-5, and GM-CSF influence eosinophil function and survival, and may be generated by T lymphocytes and/or alveolar macrophages within the airways in asthma. In addition to these three cytokines, IL-4 and interferon-gamma may be crucial to the regulation of IgE biosynthesis. TNF-alpha and IL-1 are potentially important in the up-regulation of endothelial adhesion molecules. An important step in the recruitment of leukocytes to an inflammatory focus is margination to the vascular endothelium. Our understanding of the molecular events involved in migration of leukocytes to an inflammatory focus has been advanced by the discovery and characterization of a variety of cell adhesion molecules. The potential role of ELAM-1 and ICAM-1 in allergic inflammation is suggested by their up-regulation on vascular endothelium in association with late cutaneous responses to allergen and by their role in certain primate models of asthma.(ABSTRACT TRUNCATED AT 400 WORDS)

Immunotherapy and allergic inflammation

A double-blind placebo-controlled trial of allergen injection immunotherapy in adult patients with severe summer hayfever. We used a partially purified biologically standardised grass pollen depot preparation (Alutard SQ, ALK Denmark Ltd.). Immunotherapy was extremely effective in reducing symptoms and medication requirements. Clinical improvement was accompanied by a decrease in both a target organ (conjunctival) and skin sensitivity. The injections were well-tolerated with minimal side effects. The results suggest that 30 minutes rather than 2 hours is an acceptable post-injection observation period. Successful immunotherapy was accompanied by suppression of the late cutaneous response to allergen. Specific immunostaining of skin biopsies revealed inhibition of the characteristic CD4+ T cell and EG2+ activated eosinophil cellular infiltrate during the late response. There was a significant relationship between CD4+ T cell and eosinophil counts after immunotherapy, i.e. the lower the number of infiltrating CD4+ cells, the lower the eosinophil counts. An unexpected finding was a prominent CD25+ (interleukin-2 receptor positive) cellular infiltrate which was only observed following Alutard SQ. Further studies involving double immunostaining methods should identify the phenotype of these activated, IL-2R+ cells. Based on murine studies Mosmann and colleagues have classified T cell responses into two types according to their profile of lymphokine production [11]. TH1 cells produce predominantly the IL-4 family of cytokines (IL-3, IL-4, IL-5) whereas TH2 cells produce predominantly interleukin-2 and interferon gamma. Insofar as the Mosmann classification may possibly be relevant to human T cell responses, the above findings would support a switch from a "TH2-" to a "TH1-" lymphocyte response following immunotherapy.(ABSTRACT TRUNCATED AT 250 WORDS)

The relationships between late cutaneous responses and specific antibody responses with outcome of immunotherapy for seasonal allergic rhinitis

Mountain cedar (MC) ( Juniperus ashei) causes a significant and isolated seasonal allergic rhinitis in south-central Texas during the winter months. Retrospective studies have indicated that patients segregate into two categories based on skin test reactions: single positive skin test to MC only and multiple positive skin tests. These two populations differed in age, personal and family history of atopy, levels of both IgE and total MC-specific IgE (sIgE), and symptomatology. It has been speculated that the subjects with only a single positive skin test may actually be nonatopic and develop an IgE response to MC because of some peculiarity of the antigen. In a prospective, randomized, controlled trial, we tested the efficacy of immunotherapy (IT) with MC extract in 51 subjects, 12 single positive skin tests and 39 multiple positive skin tests, to determine if these differences indeed exist and if IT is equally effective in both groups. We failed to demonstrate significant differences in age, sex, MC sIgE, total IgE. initial immediate cutaneous response, initial late cutaneous response, or personal or family history of atopy. IT was equally effective in both groups of subjects with no significant differences noted in repsonse to MC sIgE, MC sIgG1, MC sIgG4, or with suppression of the late cutaneous response. In addition, we found that suppression of the late cutaneous response correlated significantly with cumulative dose of MC extract, postseasonal level of MC sIgG1 and MC sIgC4, and improvement of symptomatology. Suppression of the late cutaneous response may be a clinically useful parameter to follow in monitoring patients during IT. Caution is advised because this procedure may result in systemic reactions.

The effect of theophylline and enprofylline on the late cutaneous response to antigen and compound [formula omitted

Theophylline and enprofylline have been demonstrated to reduce mast cell-mediator release, inhibit polymorphonuclear leukocyte activation, and have been reported to reduce the late bronchial response to antigen. The effects of theophylline and enprofylline on the late cutaneous response (LCR) to compound 48 80 and antigen were studied in 29 patients enrolled in a placebo-controlled, double-blind study of the effect of the xanthines in mild asthma. Skin testing to a common environmental allergen and compound 48 80 was performed during a baseline period and in the second phase of the study after stable drug levels were achieved, at least 6 weeks later. During baseline, the mean immediate wheal diameter (IWD) with antigen was 15.7 mm ± 0.5, resulting in 27 29 LCRs with a mean wheal diameter of 37.1 mm ± 5.2. The mean IWD with compound 48 80 was 16.1 mm ± 0.7, resulting in 26 29 LCRs with a mean wheal diameter of 19.6 mm ± 2.8. Repeat skin testing during treatment revealed no statistically significant changes in the LCR elicited by antigen or 48 80 in any of the treatment groups. There was little correlation between the size of the immediate wheal produced by antigen or 48 80 and the resulting size of the late response ( r = 0.174 to 0.519). However, for the same IWD, the resulting late response was smaller with 48 80 than with antigen ( p = 0.003). We conclude that (1) theophylline and enprofylline have no effect on the LCR to 48 80 and antigen and (2) for equivalent immediate wheal sizes, the resulting late response is smaller with 48 80 than with antigen.

Suppression of the late cutaneous response by immunotherapy

In a prospective, double-blind, placebo-controlled study, we examined the effect of mountain cedar (MC) immunotherapy on the MC-induced late cutaneous response (LCR). Fourteen MC-sensitive patients were intradermally skin tested before and after immunotherapy with MC extract. We measured the size of the wheal at 15 minutes and the area of tissue swelling at 6 hours. Patients were matched by the size of the LCR and started receiving either MC immunotherapy or placebo immunotherapy. MC-specific immunoglobulins (MC sIgG, MC sIgG1, MC sIgG4, and MC sIgE) were measured by ELISA. Symptom-medication scores (SMSs) were recorded on a daily basis during the MC season and tabulated at the end of the study. Comparison of the 14 paired patients revealed no significant differences beween MC-treated and placebo-treated groups in preimmunotherapy MC sIgG1 and SIgG4. However, when MC immunotherapy was compared to placebo immunotherapy, patients receiving MC immunotherapy developed significantly higher MC sIgG1 ( p < 0.04) and MC sIgG4 ( p < 0.01) after immunotherapy. Patients receiving MC immunotherapy also demonstrated significantly greater suppression of the LCR after immunotherapy ( p < 0.005) with the postimmunotherapy LCR correlating significantly with both MC sIgG4 ( r s = 0.715; p = 0.008) and cumulative dose of MC received ( r s = 0.808; p = 0.004). MC sIgE was similar in both groups after immunotherapy. The reduction in SMSs in the MC-treated group did not reach significance, nor was there a correlation of SMSs with MC sIgE, sIgG, sIgG1, or sIgG4. In conclusion, this prospective study demonstrated that the LCR in MC-sensitive patients was suppressed by MC immunotherapy and that this suppression was strongly correlated with both MC sIgG4 and cumulative dose of MC administered.

Isolated late cutaneous skin test response to ampicillin: A distinct entity

A case presentation describes a young woman with a history of two reactions to ampicillin therapy and a reproducible skin test reaction of intermediate timing that disappeared within 48 hours. The skin test response was to ampicillin only and not to other penicillin-related skin test reagents. Tests for serum IgE and IgG antibody to ampicillin were negative. The histology was that of a mononuclear and neutrophilic cellular infiltrate with neutrophil margination in the vessels. There was no immunoglobulin, complement, or fibrin deposition. The skin test reaction began and ended earlier than would be expected for a classic delayed hypersensitivity reaction. It is considered to be an isolated late cutaneous response but cannot yet be designated a late cutaneous allergic response. Reactants characteristic of an Arthus reaction were not present, and no alternative immunologic basis was confirmed.

493 Suppression of the Late Cutaneous Response (LCR) by immunotherapy (IT)

493 Suppression of the Late Cutaneous Response (LCR) by immunotherapy (IT)

45 Codeine (C) and alternaria (A) differ in ability to elicit late cutaneous responses (LCR)

45 Codeine (C) and alternaria (A) differ in ability to elicit late cutaneous responses (LCR)

Inhibition of PAF-acether induced weal and flare reaction in man by a specific PAF antagonist

It has been suggested that PAF-acether may be an important mediator in asthma and a PAF antagonist may therefore have a potentially important role. PAF-acether has been shown to induce a dual inflammatory reponse in the skin of man and we investigated the effect of BN 52063, a PAF antagonist, on this response. At a dose of 80mg, BN 52063 orally inhibited the inflammatory response to a sub-cutaneous injection of PAF-acether 400ng. A late cutaneous response was not observed in any of the subjects. BN 52063 was also demonstrated to be well tolerated at doses of 20, 40, 80 and 120mg with no significant side effects.

Comparison of the Histopathology of Immediate and Late Asthmatic and Cutaneous Responses in a Rabbit Model

The histopathologic changes in the skin and lung in the immunized rabbits are summarized in Table 1. At 30 minutes, cutaneous reaction sites and the submucosa of large airways displayed interstitial edema and vessel dilatation, while the small airways remained uninvolved. At 6 hours, both cutaneous reaction sites and the submucosa of large airways showed a moderate perivascular and interstitial cellular infiltrate with residual edema. In addition, the bronchiolar walls showed an intense, widespread mixed cellular infiltration. Similarly, there was widening of the vessel adventitia due to lymphatic dilatation and leukocyte infiltration. At 48 hours, while the edema had cleared, there was an increase in the mixed cellular infiltrate about both pulmonary and skin vessels and large and small airways. These observations showed that immunized rabbits challenged with antigen develop cutaneous and pulmonary inflammation. In conclusion, the immediate and late cutaneous responses in the rabbit model are similar to those described in the human skin. In this rabbit model, pulmonary changes are similar to those found in the skin. Thus, the pulmonary pathology in the rabbit model may be similar to the pathologic events that occur in allergic humans who have immediate and late asthmatic responses following an encounter with an antigen.

A reagin-like antibody in horse serum: 1. Occurrence and some biological properties.

The demonstration of a reagin-like antibody against Culicoides pulicaris extract in the serum of horses and ponies affected with recurrent seasonal dermatitis (sweet itch) is reported. This antibody can confer Prauznitz-Küstner (P-K) sensitivity on homologous skin for up to 5 days and, like human IgE, is thermolabile and susceptible to 2-mercaptoethanol reduction. It is eluted on diethylaminoethyl dextran-52 anion exchange chromatography independently of IgG, IgG(T) and IgM, and its elution characteristics indicate similarity in net molecular charge to human IgE. The P-K response observed in horse skin is biphasic, and is morphologically similar to the late cutaneous anaphylactic response in man. Both phases of the P-K response are dependent upon the reagin-like antibody, although other serum factors appear involved in the delayed phase of the response.