LAUSR

BACKGROUND The purpose of this study is to examine the changes in B lymphocyte subsets in patients receiving allergen immunotherapy. METHODS B lymphocyte subsets of patients before immunotherapy and one year after immunotherapy began were examined using the flow cytometric method. Age-matched healthy children served as the control group. RESULTS Twenty-two patients with asthma and/or allergic rhinitis and 14 healthy, age-matched controls were included in the study. The median age of the patients was 13 years old (range: 6-20 years), and eleven (50.0%) were male. The median age of the healthy controls was also 13 years old (range: 7-17), and seven (50.0%) were male. In the age group from 11 to 15 years; the patients' relative and absolute counts of active and mature sensitive B cells were higher than those of the healthy children (p=0.027-0.012 and p=0.032-0.010, respectively) before immunotherapy. The relative and absolute counts of active B cells before immunotherapy were also significantly higher than those of after immunotherapy (p=0.001-0.001, p=0.025-0.037, and p=0.029-0.035, respectively). Before immunotherapy, the relative and absolute counts of mature sensitive B cells were significantly higher than those obtained after immunotherapy (p=0.024-0.006) in the 11-15-year-old age group. CONCLUSIONS Allergen immunotherapy directly influences B cell differentiation and causes a decrease in the count of active B cells. This finding is relevant because the B cell count can be used as a guide in the assessment of an individual patient's treatment response and also when determining whether to continue the immunotherapy.