Long-term immunologic effects of broad-spectrum aeroallergen immunotherapy.
BACKGROUND
Limited data exist regarding extended, long-term immunologic effects of immunotherapy in polysensitized individuals. To study possible long-term effects, skin tests and specific IgE levels were obtained from subjects who had previously received broad-spectrum aeroallergen immunotherapy years before.


METHODS
Eighty-two subjects (78% male, mean age 23 years) previously enrolled in a randomized, placebo-controlled trial of immunotherapy for treatment of childhood allergic asthma were reevaluated in adulthood (mean follow-up interval, 10.8 years) by puncture skin tests and CAP-RAST levels for major aeroallergens. All completed at least 18 months (median 27 months) of maintenance active treatment or placebo injections without subsequent immunotherapy.


RESULTS
At adult follow-up, 36% of all skin tests to treatment allergens among subjects who received immunotherapy (n = 41) had significantly reduced intensity versus 26% of skin tests among placebo recipients (n = 41; p = 0.03). No significant differences were noted for individual treatment allergens. No significant differences were observed in the long-term changes of serum-specific IgE antibody levels for all treatment allergens between immunotherapy treatment and placebo groups (p = 0.43). The treatment and placebo groups had a similar acquisition of new skin test sensitivities from time of randomization in the original childhood trial to debriefing (15 vs. 20%; p = 0.28) and to adult follow-up (30 vs. 31%; p = 0.75).


CONCLUSIONS
Immunotherapy suppresses skin test sensitivity 8-16 years after discontinuation of treatment, but long-term effects on specific IgE levels in serum are not observed. Broad-spectrum immunotherapy does not appear to affect the acquisition of new inhalant sensitivities.
Limb
Susan L
SL
Division of Allergy and Clinical Immunology, Johns Hopkins University School of Medicine, Baltimore, Md. 21224, USA.
Brown
Kathryn C
KC
Wood
Robert A
RA
Eggleston
Peyton A
PA
Hamilton
Robert G
RG
Adkinson
N Franklin
NF
D000293:Adolescent; D000328:Adult; D000485:Allergens / Q000276:immunology*; D001249:Asthma / Q000276:immunology / Q000628:therapy*; D015331:Cohort Studies; D003888:Desensitization, Immunologic / Q000379:methods*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007073:Immunoglobulin E / Q000097:blood; D008297:Male; D011852:Radioallergosorbent Test; D012882:Skin Tests; D018709:Statistics, Nonparametric
D000485:Allergens; D007073:Immunoglobulin E