Immunotherapy and allergic inflammation.
A double-blind placebo-controlled trial of allergen injection immunotherapy in adult patients with severe summer hayfever. We used a partially purified biologically standardised grass pollen depot preparation (Alutard SQ, ALK Denmark Ltd.). Immunotherapy was extremely effective in reducing symptoms and medication requirements. Clinical improvement was accompanied by a decrease in both a target organ (conjunctival) and skin sensitivity. The injections were well-tolerated with minimal side effects. The results suggest that 30 minutes rather than 2 hours is an acceptable post-injection observation period. Successful immunotherapy was accompanied by suppression of the late cutaneous response to allergen. Specific immunostaining of skin biopsies revealed inhibition of the characteristic CD4+ T cell and EG2+ activated eosinophil cellular infiltrate during the late response. There was a significant relationship between CD4+ T cell and eosinophil counts after immunotherapy, i.e. the lower the number of infiltrating CD4+ cells, the lower the eosinophil counts. An unexpected finding was a prominent CD25+ (interleukin-2 receptor positive) cellular infiltrate which was only observed following Alutard SQ. Further studies involving double immunostaining methods should identify the phenotype of these activated, IL-2R+ cells. Based on murine studies Mosmann and colleagues have classified T cell responses into two types according to their profile of lymphokine production [11]. TH1 cells produce predominantly the IL-4 family of cytokines (IL-3, IL-4, IL-5) whereas TH2 cells produce predominantly interleukin-2 and interferon gamma. Insofar as the Mosmann classification may possibly be relevant to human T cell responses, the above findings would support a switch from a "TH2-" to a "TH1-" lymphocyte response following immunotherapy.(ABSTRACT TRUNCATED AT 250 WORDS)
Durham
S R
SR
Department of Allergy and Clinical Immunology, National Heart & Lung Institute, London.
Varney
V
V
Gaga
M
M
Frew
A J
AJ
Jacobson
M
M
Kay
A B
AB
D000328:Adult; D003888:Desensitization, Immunologic / Q000009:adverse effects; D004311:Double-Blind Method; D006801:Humans; D008222:Lymphokines / Q000096:biosynthesis; D011058:Pollen / Q000276:immunology; D006255:Rhinitis, Allergic, Seasonal / Q000276:immunology / Q000473:pathology / Q000628:therapy*; D012867:Skin / Q000276:immunology / Q000473:pathology; D016176:T-Lymphocyte Subsets / Q000276:immunology
D008222:Lymphokines