Influence of B lymphocyte stimulator on the production of anti-FcεRI and anti-IgE antibodies by B lymphocytes from patients with chronic idiopathic urticaria

Objective To explore if B lymphocyte stimulator （BlyS） stimulates B lymphocytes from patients with chronic idiopathic urticaria （CIU） to produce anti-high affinity IgE receptor （FceRI） or anti-IgE antibodies. Methods Totally, 300 CIU patients and 300 health controls were enrolled in this study. Blood samples were obtained from these subjects. Peripheral blood B lymphocytes were isolated and cultured in vitro for 72 hours. Then, BlyS of various concentrations （2, 4, 8, 16 ng/ml） was added to the culture medium of B lymphocytes followed by another 72-hour culture. Enzyme-linked immunosorbent assay was performed to determine the serum levels of BIyS, anti-FceRl and anti-IgE antibodies, as well as the supernatant levels of anti-FceRI and anti-IgE antibodies. The relationship between BlyS and anti-FceRI and anti-IgE antibody production was assessed. SPSS software version 16.0 was used for statistical analysis. Chi-square test was performed to compare the positivity rate of antibodies, and analysis of variance and least significance difference-t test to assess numerical data. Results The CIU patients showed higher levels of serum BlyS （t = 3.04, P 〈 0.01）, anti-FceRI antibodies （t = 3.51, P 〈 0.01 ）, and anti-IgE antibodies （t = 3.29, P 〈 0.01 ） compared with the health controls. The serum level of BlyS was positively correlated with that of anti-FceRI antibodies （r = 0.93, P 〈 0.01 ） and anti-IgE antibodies （r = 0.91, P 〈 0.01 ）. The levels of anti-FceRI antibodies and anti-IgE antibodies were significantly increased in the culture supernatant of patient-derived B lymphocytes treated with BlyS compared with those remaining untreated （ t = 3.67, 3.56, respectively, both P 〈 0.01 ）, and the concentration of BIyS was positively correlated with the levels of both anti-FeeRI antibodies and anti-IgE antibodies （r = 0.96, 0.91, respectively, both P 〈 0.01 ）. The coincidence rate between the serum and supernatant was 94.76% and 87.84% in the detection of anti-FeeRI antibodies and anti-IgE antibodies respectively. Conclusions BlyS level is upregulated in the serum of patients with CIU, which may play an important role in the pathogenesis of CIU by stimulating B lymphocytes to produce anti-FceRI antibodies or anti-IgE antibodies. Key words: Urticaria;  B cell activating factor;  Antibodies, FeeRI;  Antibodies, IgE;  B-lymphocytes