Repeated low-dose intradermal allergen injection suppresses allergen-induced
cutaneous late responses.
Author(s): Rotiroti G, Shamji M, Durham SR, Till SJ.
Affiliation(s): Allergy and Clinical Immunology, National Heart and Lung Institute, Imperial
College London, London, United Kingdom.
Publication date & source: 2012, J Allergy Clin Immunol. , 130(4):918-24
BACKGROUND: Subcutaneous immunotherapy with high-dose grass pollen was first
described more than 100 years ago. This treatment suppresses allergen-induced
cutaneous late responses, with lesser effects on early responses. In contrast,
low-dose subcutaneous immunotherapy has not shown clinical benefit. Uncontrolled
reports from the early 20th century describe low-dose allergen inoculation
directly into the dermis, an immunologically active area containing abundant
dendritic cells and lymphatics.
OBJECTIVE: We sought to investigate the effect of low-dose intradermal grass
pollen administration on cutaneous reactivity to allergen.
METHODS: Thirty adults sensitized to grass and tree pollens were randomized to
receive (1) 6 repeat intradermal injections at 2-week intervals of grass pollen
extract (estimated 7 ng of the major grass allergen Phl p 5 per injection), (2) 2
intradermal injections separated by 10 weeks, or (3) a single intradermal
injection at 10 weeks. At the end of the study, cutaneous early and late
responses were measured after double-blind intradermal injection with grass and
birch pollen.
RESULTS: Participants who received 6 fortnightly intradermal grass pollen
injections had markedly smaller cutaneous late responses to grass pollen than
control subjects who received 2 injections separated by 10 weeks (P < .01) or a
single injection (P < .001) and showed induction of grass pollen-specific IgG
antibodies. Suppression was observed whether late responses were measured on the
arms or the back. However, early responses were equivalent in all groups.
CONCLUSION: Low-dose intradermal allergen, like conventional subcutaneous
high-dose immmunotherapy, suppresses allergen-induced cutaneous late responses in
a manner that is allergen specific, systemic, and associated with induction of
IgG antibodies.
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