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Background:
The clinical
efficacy of allergen
immunotherapy using
therapeutic vaccines
containing modified
allergen extracts
has been previously
shown.
Objective: To
evaluate the
clinical efficacy of
a vaccine containing
depigmented,
polymerized extract
of Dermatophagoides
pteronyssinus in
asthmatic children,
monosensitized to
mites, after 4
months of treatment.
Material and
Methods: A total
of 30 mite-allergic,
asthmatic children (age
range, 8-16 years)
were entered in the
study; 15 were
treated with the
modified allergen
extract (active
group) and 15
received only
pharmacologic
treatment (control
group). The study
was open, controlled
and parallel with
random allocation of
the patients to each
of the groups.
Efficacy was
evaluated using
allergen-specific
bronchial challenge
tests, dose-response
skinprick tests, and
symptom and
medication scores.
The results of the
bronchial challenges
and dose-response
skinprick tests were
compared at baseline
and after 4 months
of treatment. The
build up phase
consisted of 4
injections in 2 days,
followed by 4
injections of the
maintenance dose.
Results: All
patients of the
active group
concluded the study,
whereas 2 of the
control group did
not. In the active
group, there was a
significant
difference in the
PC20FEV1 (P < .01)
after 4 months. The
mean allergen
quantity needed was
26 μg at baseline vs
309 μg after 4
months (a 12.8-fold
increase). There was
no difference in the
control group (5 μg
at baseline vs 8 μg
at the end). A
significant
reduction in the
number of cases with
dual
bronchial response
was observed in the
treated group (P <
.05). Two treated
patients of this
group experienced a
negative bronchial
challenge after 4
months of treatment.
The group of active
patients also
experienced
significant
improvement in skin
reactivity and
symptom and
medication scores.
Conclusions:
Vaccines containing
depigmented
polymerized extracts
of D pteronyssinus
are safe and
effective in the
treatment of mite
allergic asthmatic
children, and
provide clinical
benefit after 4
months of treatment.
Key words:
Immunotherapy.
Dermatophagoides
pteronyssinus.
Asthma.
Hyperreactivity.
Modified allergens.
Allergoids. |
