RESUMEN
Cyclosporin A (CsA) is an effective and well-tolerated treatment for severe childhood atopic dermatitis (AD). By starting at a low dose, the therapeutic safety should be further increased. The aim of this study was to evaluate low-dose CsA in childhood AD with respect to clinical outcome and modulation of T-cell dysregulation. In an open prospective study, 10 children (age: 22-106 months) with severe AD (mean objective SCORAD score > 40 on two baseline measurements at a minimum interval of 2 weeks) were treated with CsA solution for 8 weeks. All patients received a starting dose of 2.5 mg/kg/day, which was increased stepwise in non-responders to a maximum of dose of 5 mg/kg/day. Disease activity was monitored using the SCORAD index. The frequency of cytokine-producing peripheral blood T lymphocytes was analyzed by intracellular cytokine staining, and T-cell numbers were measured by fluorescence-activated cell sorter (FACS) analysis. Twenty healthy age-matched children were included as controls for the immunological data. Nine of the 10 patients had a SCORAD reduction of at least 35%. In seven patients this was achieved with low-dose CsA at 2.5 mg/kg/day (n = 4) and 3.5 mg kg/day (n = 3). Seven of the nine responders experienced no relapse within the 4-week follow-up period. At baseline the percentage of interleukin-4 (IL-4), IL-13, and human leucocyte antigen (HLA)-DR-positive CD3(+) cells was higher in the patient group than in the controls. After CsA treatment there was a significant reduction in interferon-gamma (IFN-gamma), IL-2, IL-4, IL-13, and HLA-DR-positive CD3(+) cells. Hence, in severe pediatric AD, CsA microemulsion, when started at a low dose (2.5 mg/kg/day), improves clinical measures of disease, reduces T-lymphocyte cytokine production, and regulates T-cell activation.
Asunto(s)
Ciclosporina/uso terapéutico , Dermatitis Atópica/tratamiento farmacológico , Adolescente , Niño , Ciclosporina/administración & dosificación , Relación Dosis-Respuesta a Droga , Esquema de Medicación , Femenino , Humanos , Interleucina-13/metabolismo , Interleucina-4/metabolismo , Subgrupos Linfocitarios , Masculino , Índice de Severidad de la EnfermedadRESUMEN
BACKGROUND AND OBJECTIVE: A subset of IL-4 producing CD8+ T cells was recently identified in HIV patients. Based on these findings we examined whether IL-4 producing CD8+ T cells would also be present in allergic patients and what would be the functional relevance of this T-cell population. METHODS: We investigated the role of CD8+ T cells in IgE production of allergic diseases by analysing the cytokine profile of individual CD4+ and CD8+ T cells. RESULTS: In allergic patients about twice as many CD4+ T cells and six times as many CD8+ T cells produced IL-4 as in non-allergic controls. In contrast the frequency of IFNgamma+ T-cell subsets did not significantly differ between the allergic and non-allergic individuals. The frequency of IL4+ CD8+ T cells correlated with the level of serum IgE. Coculture experiments with T cells or purified CD8+ T cells together with autologous B cells indicated that CD8+ T cells enhanced IgE in vitro, but not IgM production, even when they were physically separated from B cells. This effect could be partially blocked by addition of an IL-4 binding protein, a soluble IL-4 receptor indicating that IL-4 is involved in CD8+ T-cell mediated IgE production. CONCLUSIONS: These data indicate a positive role of IL-4 secreting CD8+ T cells in IgE regulation in allergic patients.
Asunto(s)
Linfocitos T CD8-positivos/fisiología , Hipersensibilidad/sangre , Inmunoglobulina E/metabolismo , Interleucina-4/metabolismo , Subgrupos de Linfocitos T/fisiología , Adulto , Biomarcadores/análisis , Linfocitos T CD4-Positivos/química , Linfocitos T CD4-Positivos/citología , Linfocitos T CD8-positivos/química , Linfocitos T CD8-positivos/citología , Células Cultivadas , Humanos , Inmunoglobulina M/metabolismo , Interferón gamma/metabolismo , Leucocitos Mononucleares/química , Leucocitos Mononucleares/citología , Subgrupos de Linfocitos T/química , Subgrupos de Linfocitos T/citologíaRESUMEN
OBJECTIVE: The aim of the study was to analyse early effects of specific immunotherapy (SIT) on immune functions in cat-allergic patients. METHODS: Immunological responses of peripheral blood mononuclear cells from eight cat-allergic patients were analysed before and after SIT in comparison with 11 nonallergic controls. Cells were stimulated in vitro with either bacterial superantigen, mitogen, or cat allergen. Production of IL-12 and TH1/TH2 cytokines was analysed by ELISA and lymphocyte subset distribution was assessed by flow-cytometry. RESULTS: We found a significantly reduced secretion of IL-12 (P < 0.05) from cells of allergic individuals compared with the controls. This finding was associated with significantly lower IFN-gamma production after stimulation with allergen (P < 0.05) that did not increase during SIT. However, no significant differences were seen after stimulation with mitogen indicating an allergen specific IFN-gamma secretion response in allergic individuals. Prior to SIT IL-5 production was significantly higher in cells of allergic donors stimulated with allergen < 0.005 or mitogen (< 0.05). After reaching the maintenance dose for SIT, allergen-induced IL-5 production returned to normal levels, whereas it remained elevated after stimulation with mitogen. These changes were associated with a reduced frequency of CD45 RO T cells following SIT. CONCLUSION: These results suggest that SIT exerts early effects on allergen-specific T-cell responses with selective inhibition of the up-regulated TH2 immune response.
Asunto(s)
Alérgenos/inmunología , Gatos/inmunología , Desensibilización Inmunológica , Activación de Linfocitos , Hipersensibilidad Respiratoria/terapia , Linfocitos T/inmunología , Animales , Pruebas de Provocación Bronquial , Citocinas/biosíntesis , Ensayo de Inmunoadsorción Enzimática , Citometría de Flujo , Humanos , Memoria Inmunológica , Persona de Mediana Edad , Pruebas CutáneasRESUMEN
The role of CD45RA T cells on allergen-dependent lymphocyte functions was analyzed in atopic patients. As compared with age-matched nonatopic controls, atopic patients exhibited a significantly (p < 0.01) increased frequency of CD45RA T cells in peripheral blood. Concentration of serum IgE correlated with increases in this T cell subset. In contrast to nonatopic controls, not only CD45RO but also CD45RA T cells from atopic patients provide help for allergen-stimulated IgE and IgA production, and they act in a synergistic fashion. Transwell coculture experiments revealed that optimal production of IgE and IgA required physical contact of CD45RA T cells with B cells. Freshly prepared and in vitro-activated CD45RO and CD45RA T cells from atopic patients showed an increased expression of CD40 ligand when compared with nonatopic individuals. In addition, CD45RA (and CD45RO) T cells from atopic individuals produced IL-4, IL-5, and IFN-gamma when stimulated with mitogens. Whereas stimulation of normal lymphocytes with tetanus Ag was followed by conversion of the CD45RA to the CD45RO phenotype, T cells from atopic donors did not acquire the CD45RO isoform to the same degree despite T cell activation. In atopic patients, addition of IL-4 to anti-CD3/anti-TCR stimulated CD45RA T cell prevented the shift towards the CD45RO phenotype. These data indicate that a subset of CD45RA T cells plays a unique role as effector T cells regulating IgE and IgA production in atopic patients.
Asunto(s)
Hipersensibilidad Inmediata/inmunología , Inmunoglobulina A/biosíntesis , Inmunoglobulina E/biosíntesis , Antígenos Comunes de Leucocito/análisis , Linfocitos T Colaboradores-Inductores/metabolismo , Alérgenos/farmacología , Linfocitos B/inmunología , Comunicación Celular/inmunología , Citocinas/biosíntesis , Humanos , Inmunoglobulina A/sangre , Inmunoglobulina E/sangre , Inmunofenotipificación , Activación de Linfocitos , Cooperación Linfocítica , Recuento de Linfocitos , Linfocitos T Colaboradores-Inductores/clasificación , Linfocitos T Colaboradores-Inductores/inmunologíaRESUMEN
An estimated 100 million individuals suffer from birch pollen allergy. Specific immunotherapy, the only curative allergy treatment, can cause life-threatening anaphylactic side effects. Here, we report the genetic engineering of a recombinant trimer consisting of three covalently linked copies of the major birch pollen allergen, Bet v 1. The trimer exhibited profoundly reduced allergenic activity but contained similar secondary structures such as Bet v 1 wild type, Bet v 1-specific B cell and T-cell epitopes, and induced Th1 cytokine release. As immunogen, rBet v 1 trimer induced IgG antibodies, which blocked patients' IgE binding to Bet v 1 and related allergens. Thus, rBet v 1 trimer represents a novel hypoallergenic vaccine prototype for treatment of one of the most frequent allergy forms.