Hydrocortisone enhances allergen-specific IgE production by peripheral blood mononuclear cells from atopic patients with high serum allergen-specificIgE levels
Yj. Cho et al., Hydrocortisone enhances allergen-specific IgE production by peripheral blood mononuclear cells from atopic patients with high serum allergen-specificIgE levels, CLIN EXP AL, 30(11), 2000, pp. 1576-1581
Background Although there is convincing evidence that human B cells can be
induced to produce IgE by a combination of interleukin 4 (IL-4) and hydroco
rtisone (HC) in atopic subjects, it is still uncertain if this performs the
same functions in allergen-specific IgE synthesis.
Objective This study was designed to investigate the differences of IgE reg
ulation between atopics and nonatopics, interactions of HC with IL-4, and t
he correlation between in vitro total IgE, allergen-specific IgE synthesis
and serum IgE levels.
Methods Peripheral blood mononuclear cells (PBMCs) from 16 atopic asthma pa
tients sensitive to Dermatophagoides farinae and seven nonatopic controls w
ere cultured with IL-4 and/or HC. Total IgE and D. farinae-specific IgE in
culture supernatant were measured by ELISA and FAST.
Results IL-4 increased total IgE synthesis in PBMCs from both atopics and n
onatopics, whereas, HC had this effect only in some atopics who showed spon
taneous IgE production in vitro. HC acted synergistically with IL-4 in tota
l IgE synthesis, Their effects were more remarkable in cases with lower tot
al serum IgE levels. PBMCs from eight of 16 atopics produced D. farinae-spe
cific IgE in vitro either spontaneously or by IL-4 and/or HC. HC had more p
rofound effects than IL-4 in these patients. They also showed higher total
IgE synthesis by HC, and higher specific serum IgE levels than the others.
IL-4 and/or HC did not induce any D. farinae-specific IgE synthesis by PBMC
s from nonatopics.
Conclusion HC had a more profound effect than IL-4 on the induction of D. f
arinae-specific IgE synthesis in atopic patients with high serum allergen s
pecific IgE levels, Further studies to determine the causes of these effect
s, such as the presence of long lived allergen specific B cells as the resu
lt of the priming effect of IL-4 in vivo, may be needed.