A three‐year double‐blind placebo‐controlled study with specific oral immunotherapy to Dermatophagoides: evidence of safety and efficacy in paediatric patients

Abstract

Very few double-blind trials of oral immunotherapy have been reported. The majority of these have been performed with pollen extracts and the results have often been equivocal. The major weaknesses of these studies have been the short periods of the trials, the low doses of allergen employed and inadequate evaluation of efficacy. The present study has involved a placebo-controlled double-blind trial of oral immunotherapy for three years with Dermatophagoides pteronyssinus at relatively high doses in 18 paediatric patients. Throughout the trial clinical parameters (symptom and medication scores) and immunological parameters (specific IgE, IgG1 and IgG4 levels) were monitored in order to assess the safety and efficacy of the treatment. The treatment was well tolerated by all patients and no side-effects were experienced. Clinical improvement was evident after the second year of therapy and this was confirmed by a significant reduction in conjunctival reactivity assessed by a specific conjunctival provocation test. In addition, there were significant changes in the immunological parameters with a reduction in specific IgE and increased levels of IgG4 and IgG1, results in keeping with previous studies of oral and subcutaneous immunotherapy. Although the results do not provide an explanation of the basis of successful oral immunotherapy, they clearly demonstrate the efficacy and safety of the treatment and suggest that it may be a useful and more acceptable alternative for patients than the traditional subcutaneous immunotherapy.

Allergen-Specific Conjunctival Challenge in Asthma

“…ASCC provides a useful tool to confirm the diagnosis of sensitization to a specific allergen, to evaluate the grade of specific sensitization, to study the pathophysiology o f al lergic reactions considering signs and symptons, cells and mediators of the inflammatory response [3,4], to define the most correct and precise diagnosis in polysensitized allergic patients (particularly when specific immunotherapy is pro posed), to evaluate the effectiveness of specific immuno therapy (monitoring allergen threshold dose or clinical and inflammatory parameters) [6][7][8] and to evaluate the anti allergic activity of antiallergic drugs [3,13]. In this context, ASCC has always been proposed in allergic subjects suf fering from conjunctivitis with or without rhinitis.…”

“…This tipic is of particular interest from a diag nostic viewpoint, especially when specific immunotherapy is warranted, and from a prognostic one. The evaluation of the grade of specific conjunctival reactivity has been con sidered as a predictive marker of successful immunotherapy [6][7][8], Since it has recently been demonstrated that ASCC may be performed also in children with allergic asthma on ly, ASCC has been suggested as a suitable diagnostic tool in asthmatic children [9].…”

Construction of a Der p2-transgenic plant for the alleviation of airway inflammation

“…10 The traditional subcutaneous route has a risk of severe adverse events; therefore, safer routes of administration, such as the sublingual route, have been tested in numerous controlled trials and have shown show long-lasting efficacy in asthma and rhinitis in adults and children. [11][12][13][14] Sublingual immunotherapy is now accepted by the World Health Organization as a valid alternative to the subcutaneous route of administration in asthmatic children. 15,16 However, sublingual immunotherapy has limitations because the duration of allergen administration is long and its costs are considerable.…”

Oral Immunotherapy May Induce T Cell Anergy

“…Discussion Although a number of open trials of oral immunotherapy with pollens and house dust mite reported good results, dou ble-blind studies have shown inconsistent results [2^1], Studies using high doses of allergens seemed to obtain good results [5,6].…”

“…Recently, two placebo-controlled double-blind trials of oral immunotherapy with house dust mite using relatively high doses of allergen demonstrated good results in reducing allergic symptoms [5,6], Several mechanisms have been postulated to account for the efficacy of conventional immunotherapy. They include (1) increased allergen-specific IgG antibody which com petes with cell-bound IgE for circulating allergen, (2) de creased total serum IgE levels and blunted seasonal rises of allergen-specific IgE antibody, and (3) diminished mediator release from basophils and mast cells after allergen expo sure.…”