ABSTRACT
Patients with atopic dermatitis (AD) commonly develop antibodies of subclasses IgG and IgE to house dust mites, such as Dermatophagoides pteronyssinus and D. farinae. The domestic mite Blomia tropicalis is prevalent in Brazil and can cause the exacerbation of AD. The objectives of this study were to assess skin reactivity to B. tropicalis extracts of AD patients and a control group of nonallergic subjects, and to determine the in vitro reactivity of anti-B. tropicalis IgG and IgE in the serum of AD patients and a control group of nonallergic individuals. Subjects were 36 patients with confirmed AD and the controls were 25 nonallergic individuals. Skin sensitivity to B. tropicalis extracts was tested by the prick-test, and anti-B. tropicalis IgG reactivity in the serum was detected by the Western blot. Anti-B. tropicalis IgE reactivity in the serum was measured by RAST. Patients with AD reacted 7.12 times more often to extracts from B. tropicalis than the control group. A positive association was observed between the presence of anti-B. tropicalis IgG and IgE and AD. AD patients showed a high degree of sensitization to B. tropicalis; it can thus be considered a risk factor for the development of AD exacerbations in patients exposed to this mite species.
Subject(s)
Dermatitis, Atopic/immunology , Immunoglobulin E/immunology , Immunoglobulin G/immunology , Mite Infestations/immunology , Mites/immunology , Adolescent , Adult , Animals , Blotting, Western , Brazil , Child , Child, Preschool , Dust , Female , Humans , Infant , Male , Middle AgedABSTRACT
BACKGROUND: To verify the importance of Blomia tropicalis in atopic dermatitis (AD), we determined the cutaneous reactivity and the serum level of B. tropicalis-specific IgE and IgG subclasses in AD patients. METHODS: B. tropicalis-specific IgE and IgG subclasses were determined in AD patients and compared with bronchial asthma (BA) patients and a control group (CG) of nonatopic subjects. Specific IgE was obtained by skin prick test and RAST. B. tropicalis-specific IgG subclasses were determined by ELISA. The data were statistically analyzed by chi-square test (Mantel-Haenszel) and odds ratio (OR). RESULTS: We detected positive skin prick tests in 61.76% of AD and 83.33% of BA patients, and in 12.5% of the CG. RAST was positive in 44.12% of AD and in 61.90% of BA patients, but not in the CG. B. tropicalis-specific IgG1 and IgG2 subclasses showed no significant differences between the three groups. IgG3 subclass positivity was statistically significant in AD patients (41.17%) when compared to BA patients (14.29%) and the CG (16.67%). The determination of B. tropicalis-specific IgG4 was positive in 32.35% of AD patients, 21.43% of BA patients, and 8.33% of the CG. CONCLUSIONS: These results confirm that the storage mite B. tropicalis is an important allergen in AD. It is possible that IgG3 activates the complement in AD patients, releasing vasoactive amines that further amplify the allergic reaction. The positive results of the B. tropicalis-specific IgG4 found in AD and BA were probably due to chronic exposure to this storage mite in the home environment.
Subject(s)
Dermatitis, Contact/immunology , Immunoglobulin E/analysis , Immunoglobulin G/analysis , Mites/immunology , Adolescent , Adult , Aged , Animals , Asthma/immunology , Child , Child, Preschool , Enzyme-Linked Immunosorbent Assay , Female , Humans , Immunoglobulin E/classification , Immunoglobulin G/classification , Infant , Male , Middle Aged , Radioallergosorbent Test , Reference Values , Skin TestsABSTRACT
O estudo teve como objetivo avaliar a tolerabilidade, a eficácia clínica e a segurança do uso da cetirizina (CTZ) no tratamento da rinite alérgica perene. O estudo foi comparativo contra placebo (PLB), duplo-cego, randomizado, cruzado. Os pacientes receberam um período de 15 dias com CTZ (10 mg em dose única di ria), seguido de outro período de 15 dias com PLB, ou vice-versa de acordo com lista de aleatorizaçäo. Setenta e dois pacientes foram admitidos e 52 deles completaram os dois períodos de tratamento previstos. A CTZ mostrou superioridade nos seguintes sintomas de rinite alérgica: coriza, obstruçäo nasal, crises de espirro, prurido nasal e conjuntivite. O sintoma tosse näo foi modificado por qualquer dos tratamentos. Os sinais físicos de rinite alérgica, como coloraçäo da mucosa, hipertrofia de cornetos, secreçäo nasal e inflamaçäo faríngea, mantiveram-se inalterados com os dois tratamentos. O mesmo ocorreu com os sinais vitais: pressäo arterial, frequência cardíaca, frequência respiratória e peso. Durante o período de tratamento com a CTZ foram observados eventos adversos em sete pacientes (12,3 por cento) e no período PLB foram observados eventos adversos em oito pacientes (14 por cento). Os eventos adversos mais frequentes no período de tratamento com CTZ foram sonolência e aumento subjetivo de peso (nÝo confirmado ao exame físico); no período PLB foram tontura, aumento de apetite e cefaléia. Durante o período de tratamento com a CTZ nove pacientes interromperam o tratamento, sendo oito pacientes por abandono ou falta de colaboraçäo do paciente e um por evento adverso (urticária ao frio näo controlada). Durante o período PLB 11 pacientes interromperam o tratamento, sendo dez pacientes por abandono ou falta de colaboraçäo do paciente e um por evento adverso (tontura e calafrios). Concluímos que a CTZ se mostrou clinicamente superior ao PLB em efic cia, proporcionando alívio dos sintomas da rinite alérgica perene e sintomas conjuntivais. A incidência de eventos adversos com CTZ nÝo diferiu da observada com PLB. A cetirizina é um anti-histamínico eficaz e bem tolerado, com posologia cômoda em relaçäo aos anti-histamínicos clássicos, podendo ser utilizada para tratamento da rinite alérgica.
