J. Pene et al., IMMUNOTHERAPY WITH FEL-D-1 PEPTIDES DECREASES IL-4 RELEASE BY PERIPHERAL-BLOOD T-CELLS OF PATIENTS ALLERGIC TO CATS, Journal of allergy and clinical immunology, 102(4), 1998, pp. 571-578
Background: Cells producing a T-H2-cytokine profile play an important
role in the onset and maintenance of atopic diseases, and therefore sp
ecific immunotherapy is aimed to induce a switch to cells producing a
T-H1- or T-H0-cytokine profile. Recently, a novel form of immunotherap
y making use of synthetic peptides from the major cat allergen Fel d 1
has been developed, but its mechanisms of action are unknown. Objecti
ves: We examined the effects of immunotherapy with Fel dl peptides on
the response to bronchial provocation tests (PD20FEV1) with a standard
ized Fel d 1 cat extract on Fel d 1-specific serum IgE and IgG Levels
and in vitro IL-4 and IFN-gamma production. Methods: Patients allergic
to cats received 6 weekly injections of 7.5 mu g (Low dose), 75 mu g
(medium dose), or 750 mu g (high dose) of Fel d 1 peptides (25 patient
s) or a placebo (6 patients). Results: Six weeks after ending immunoth
erapy, posttreatment PD20FEV1 was not significantly different between
the treated and placebo groups. However, in the medium- and high-dose
groups there was a significant improvement between baseline and posttr
eatment days. IL-4 release was significantly reduced in the high dose-
treated group (P < .005, Wilcoxon W test), whereas it was unchanged in
the low or medium dose- and in the placebo-treated groups. In all gro
ups, IFN-gamma, IgE, and IgG levels remained unchanged. Conclusion: Th
ere was no correlation between the improvement of PD20FEV1 and the dec
rease in IL-4 production, These data suggest that peptide immunotherap
y may act by shifting, the Fel d 1-induced response of PBMCs in vitro
from the T-H2-like to the T-H0-like phenotype.