Background:  Sublingual immunotherapy (SLIT) is effective and safe in the treatment of allergic rhinitis. However, there is no meta‐analysis in asthma treatment. Methods:  The clinical efficacy of SLIT for asthma was evaluated through a systematic review with meta‐analysis. MEDLINE (1966–2005), EMBASE (1974–2005), LILACS (1982–2005), and the Cochrane Library were searched for related literature in any language. Randomized‐controlled clinical trials (RCT) on SLIT in asthma treatment for adults and children were selected. From 119 citations, 25 studies with 1706 patients were included in this meta‐analysis. For each report, quality scores were assigned and data were extracted in relation to the outcomes analyzed: asthmatic symptoms, use of asthma medications, lung function, and bronchial provocation. Results:  According to the Jadad quality method, 64% of the studies were assigned scores of 4 or 5. Immunotherapy was seen to significantly reduce asthma severity when parameter compositions were all analyzed by categorical outcomes. There was a nonsignificant reduction in asthma symptoms when analyzed using standardized mean differences. No severe reactions were observed. Conclusions:  This meta‐analysis found that SLIT is beneficial for asthma treatment albeit the magnitude of the effect is not very large. Moreover, it is a safe alternative to the subcutaneous route. More RCT with standardization of symptom scores and medications are needed in order to contribute further to this subject.

BACKGROUND: An association between class I and II alleles of the major histocompatibility complex and idiopathic chronic urticaria has previously been observed in different populations, but there are still no studies on Brazilian populations in this regard. OBJECTIVE: The involvement of the major histocompatibility complex classes I and II (loci A, B and DR) in Brazilian patients with idiopathic chronic urticaria and a positive autologous serum skin test was investigated and compared with a healthy population group. METHODS: DNA was extracted from the blood of 42 patients with idiopathic chronic urticaria and major histocompatibility complex classes I and II alleles were determined using the polymerase chain reaction and a laboratory test for oligonucleotide hybridization using a single-filament probe. The frequencies of these alleles in patients with chronic urticaria were compared with the frequencies in 1000 genetically unrelated voluntary blood donors from the same region of Brazil. The diagnosis of idiopathic chronic urticaria was based on the patients' clinical history and routine laboratory tests. Only the patients with positive autologous serum skin test were selected. The allele distribution resulted from the patient and control groups were analyzed using odds ratios and 95% confidence intervals. RESULTS: No statistically significant differences were found between the positive autologous serum skin test patients with chronic urticaria and the control group. CONCLUSIONS: We found that in this population group, there was no specific association between the HLA alleles studied and chronic urticaria. We believe that further population studies are needed in order to investigate the possible existence of this association. Keywords: Genes, MHC class I; Genes, MHC class II; HLA antigens; Skin tests; Urticaria Resumo: FUNDAMENTOS: A associação entre os alelos do MHC classe I e II e a urticária crônica idiopática tem sido previamente constatada em diferentes populações, sendo que na população brasileira ainda não existem estudos a este respeito. OBJETIVOS: Foi estudado o envolvimento do MHC classe I e II (locci A, B e DR) em pacientes brasileiros com urticária crônica idiopá-tica e teste cutâneo do soro autólogo positivo, comparando-se com um grupo populacional saudável. MÉTODOS: O DNA foi extraído do sangue de 42 pacientes com urticária crônica idiopática e o MHC classe I e II determinado por reação em cadeia da polimerase e teste laboratorial de hibridização de oligonucleotídeo com sonda de filamento único. A freqüência destes alelos em pacientes com urticária crônica idiopática foi comparada com a de 1000 doadores de sangue voluntários e geneticamente não relacionados, da mesma região do Brasil. O diagnóstico de urticária crônica idiopática foi baseado na história clínica do paciente e exames laboratoriais de rotina; foram selecionados apenas os pacientes com teste cutâneo do soro autólogo positivo. O resultado da distribuição alélica entre o grupo de pacientes e o grupo controle foi analisado atravé...