Mecanismos da imunoterapia alérgeno-específica / Mechanisms of allergen-specific immunotherapy

A imunoterapia alérgeno-específica tem sido usada há mais de 100 anos como um tratamento de dessensibilização para doenças alérgicas, representando um método potencialmente curativo e específico. O presente estudo tem como objetivo revisar os mecanismos da imunoterapia alérgeno-específica, através de revisão bibliográfica com base em artigos publicados entre 1998 e 2016, disponíveis no banco de dados PubMed. Os mecanismos de ação da imunoterapia incluem modulação de linfócitos T e B, produção de IgG4 alérgeno-específica e redução de IgE alérgenoespecífica, migração de eosinófilos, basófilos e mastócitos nos tecidos, bem como a liberação de seus mediadores. As células T reguladoras (Treg) suprimem as células dendríticas responsáveis pela geração de células T efetoras, inibindo TH1, TH2 e TH17. As células Treg foram identificadas como peças-chave no processo de indução de tolerância periférica aos alérgenos.

Allergen-specific immunotherapy has been used for more than 100 years as a desensitizing therapy for allergic diseases, representing a potentially curative and specific method. The aim of the present study was to review the mechanisms of allergenspecific immunotherapy based on papers published between 1998 and 2016 and available in the PubMed database. The mechanisms of action of immunotherapy include modulation of T-and B-cell responses, induction of allergen-specific IgG4 and suppression of allergen-specific IgE production, migration of eosinophils, basophils, and mast cells to tissues, as well as release of their mediators. Regulatory T cells (Treg) suppress dendritic cells that support the generation of effector T cells, inhibiting TH1, TH2, and TH17 cells. Treg cells have been identified as key regulators of the induction process of peripheral allergen tolerance.

Regulatory B Cells Are Inversely Associated with Disease Activity in Rheumatoid Arthritis

PURPOSE: The function of regulatory B lymphocytes is known to be abnormal in inflammatory diseases. However, a recent study indicates that IL-10+ B cells seem to be expanded in rheumatoid arthritis (RA). Therefore, the state of IL-10+ B cells in the peripheral blood from RA patients and healthy controls were investigated. MATERIALS AND METHODS: CD19+ cells in peripheral blood mononuclear cells were purified from blood samples of RA patients and age and gender-matched healthy controls, and stimulated with CD40 ligand and CpG for 48 hours. Then, intracellular IL-10 in CD19+ cells was analyzed using flow cytometry. RESULTS: There was no significant difference in the proportion of IL-10+ B cells between 10 RA patients and 10 healthy controls (RA, 0.300+/-0.07 vs. healthy control 0.459+/-0.07, p=0.114). The proportion of induced IL-10+ B cells to total B cells in RA patients was significantly higher than those in controls (RA, 4.44+/-3.44% vs. healthy control 2.44+/-1.64%, p=0.033). However, the proportion of IL-10+ B cells to total B cells correlated negatively with disease activity in RA patients (r=-0.398, p=0.040). Erythrocyte sedimentation rate or C-reactive protein or medication was not associated with the proportion of IL-10+ B cells. CONCLUSION: The proportion of induced IL-10+ B cell increased in RA patients compared to healthy control, however, negatively correlated with disease activity in RA.