Sublingual immunotherapy: a double‐blind, placebo‐controlled trial with <i>Parietaria judaica </i>extract standardized in mass units in patients with rhinoconjunctivitis, asthma, or both

Background: Recent work indicates that subcutaneous specific immunotherapy induces specific T-cell anergy, a shift in the TH1/TH2 ratio, and antibody production in favor of IgG4. There are few data on sublingual immunotherapy (SLIT), especially in children. Methods: We assessed the proliferation of peripheral blood mononuclear cells (³H-thymidine incorporation) and secretion of interleukin (IL)-4, interferon (IFN)γ and IL-5 (ELISA) after in vitro stimulation with allergen or phytohemagglutinin (PHA) in 29 children with allergic rhinoconjunctivitis receiving SLIT with grass pollen before, and after 1 and 2 years of treatment in a multicenter placebo-controlled study on the efficacy of the treatment. Further, non-specific intracellular production of IL-4, IL-13, IFNγ, IL-2, IL-10 and IL-5 (FACS) and serum total and specific IgE and IgG4 (ELISA) were analyzed. Results: Proliferation and IL-4 and IL-5 secretion after stimulation with allergen or PHA did not differ between the groups. In addition, we observed no effect of SLIT on intracellular cytokine production. IFNγ secretion after allergen coculture was comparable between the groups. Following PHA stimulation, IFNγ secretion was significantly higher in the SLIT group after 1 year, and a trend was observable already before and after 2 years of treatment, probably due to the inhomogeneity in the groups despite randomization (for age and asthma). No significant changes were observed for sIgE/sIgG4 ratios over time either in or between the groups. Conclusion: During 2 years of SLIT in children with a positive effect on rescue medication use, we observed no significant effects on in vitro T-cell immune responses or immunoglobulins. So far, pediatric studies demonstrating stable effects of SLIT on such reactions are missing, probably due to limited effects of SLIT on systemic immunologic reactions.

Section: Discussionmentioning

confidence: 99%

Lack of Detectable Alterations in Immune Responses during Sublingual Immunotherapy in Children with Seasonal Allergic Rhinoconjunctivitis to Grass Pollen

Rolinck-Werninghaus

Kopp

Liebke

et al. 2005

“…The study of La Rosa et al [36] showed that the most adverse events were gastrointestinal complaints with a cumulative dose of Par j 1 = 52.25 mg administered over 2 years. Previously, Purello-D’Ambrosio et al [37] did not report systemic adverse reactions in 31 patients submitted to SLIT with P. judaica extract, but the cumulative dose administered to each patient was equal to 12.77 µg of Par j 1. Di Rienzo et al [38] followed up 268 children receiving SLIT and reported that the overall incidence of systemic adverse reactions was 3% in the patients, but the authors did not indicate the allergen responsible of systemic effects.…”

Section: Discussionmentioning

confidence: 99%

Possible Relationship between Systemic Side Effects and Sensitization to rPar j 2 in Allergic Patients Submitted to an Ultra-Rush (20 min) Sublingual Immunotherapy and Selected by Component Resolved Diagnosis

Rossi

Monasterolo²,

Coco³

et al. 2005

Background: The pollen of Parietaria spp., a weed of the Urticaceae family, is a major cause of respiratory allergy in the Mediterranean area, where the most common species are Parietaria judaica and Parietaria officinalis. In this study, we evaluated the specific serum IgE-binding profiles to individual P. judaica pollen recombinant major allergen, and Phleum pratense cytoskeletal profilin and a 2-EF-hand calcium-binding allergen homologous to cross-reactive Parietaria pollen allergens, in patients allergic to pollen with positive skin test towards Parietaria spp. extract. Methods: The present observation included 220 patients from the province of Cuneo, north-west Italy, all suffering from rhino-conjunctivitis and/or asthma selected on the basis of skin test positive to P. judaica extract. The sera were evaluated for specific IgE reactivity to P. judaica pollen major recombinant(r) allergen Par j 2, Phleum pratense pollen allergens rPhl p 7 (2-EF-hand calcium binding protein) and rPhl p 12 (profilin), both identified as cross-reactive Parietaria spp. allergens, using Pharmacia CAP System. Out of 220 patients, 37 patients with IgE reactivity to rPar j 2 and 105 patients sensitized to at least one timothy pollen major allergen (i. e. rPhl p 1, rPhl p 2, natural Phl p 4 and rPhl p 6) were submitted to an ultra-rush protocol of sublingual immunotherapy (SLIT). The occurrence of adverse reactions were evaluated in both groups. Results: All 220 patients with pollinosis and positive in vivo skin prick tests had in vitro positive CAP results to P. judaica natural extract. On the contrary, in these patients the prevalence of Par j 2-specific IgE was only 33.2% (73/220). In fact, 116/220 (52.7%) patients with serum specific IgE to crude Parietaria pollen extract had specific IgE to Phl p 12, 18/220 (8.1%) subjects with specific IgE to rPhl p 12 also exhibited specific IgE to Phl p 7 and 26/220 (11.8%) subjects had specific IgE against rPhl p 7. Particularly, geometric mean (25th–75th percentile) of specific IgE to rPar j 2 were as follows: 2.87 kUA/l (1.005–7.465). Out of 73 patients with specific IgE to rPar j 2, 7 subjects (9.6%) had also specific IgE to rPhl p 7, 12 (16.4%) had specific IgE to rPhl p 12 and 4 (4.1%) patients had specific IgE to both recombinant allergens. Of 37 patients under an ultra-rush protocol of SLIT, 3 subjects (8.1%) experienced generalized urticaria, and 1 of them also had diarrhea 3 h after the last dose of Parietaria judaica extract oral-vaccine administration. On the contrary, no systemic reactions were observed in 105 patients after Phleum pratense extract oral intake after a similar ultra-rush SLIT protocol (p = 0.0046). Conclusions: In the light of present findings, allergen extract-based diagnosis, in vivo and in vitro, cannot discriminate allergic patients that are genuinely sensitized to Parietaria spp. major allergens or to other major allergens to which current immunotherapeutic allergy extracts are standardized. Therefore, in vitro component resolved diagnosis is the unique tool t...

“…The same applies for the study by Bahceciler et al [34]: patients did not actually suffer from asthma, asthma scores were near zero at baseline and lung function tests were normal. Other publications do not even mention their data in the results section [35] making it impossible to analyze them. Pajno et al [36] compared SLIT versus symptomatic therapy studying pediatric patients allergic to Parietaria pollen treated either with SLIT plus inhaled fluticasone or placebo plus fluticasone and a control group receiving rescue medication only.…”

Section: Resultsmentioning

confidence: 99%

Sublingual Immunotherapy for Allergic Rhinoconjunctivitis – The Seeming and the Real

Reider¹

2005

Background: Subcutaneous specific immunotherapy (SIT) has been shown to be a causal treatment with long-term efficacy for allergic rhinoconjunctivitis and asthma, and a preventive measure against the development of asthma and new sensitizations. As it is associated with several inconveniences and serious side effects, sublingual immunotherapy (SLIT) has been developed to evade these problems. Methods: The present review of previously published studies on allergic rhinoconjunctivitis aimed to determine the efficacy of SLIT in comparison with subcutaneous treatment and to summarize long-term results of immunotherapy and its effects on the prevention and treatment of asthma and the prevention of new sensitizations. Results: The effect of SLIT on allergic rhinoconjunctivitis is low to moderate, depends on the allergen used and is more pronounced in adults than in children, in whom a consistent effect has not been demonstrated. Direct comparison with SIT shows conflicting and inconsistent results. Detailed studies on the prevention of asthma and new sensitizations are not available. Consistent effects of asthma treatment on both symptom and medication scores and lung function have not been reported. A quantitative evaluation is not possible due to indistinct inclusion criteria and different outcome criteria. In summary, currently SLIT plays no significant role in the treatment of asthma, apart from children monosensitized to house dust mites in whom it may have low-moderate effects. Only one study deals with the long-term efficacy of SLIT, which demonstrated a persistent positive effect on asthma, whereas data on rhinoconjunctivitis are completely lacking. Conclusions: Primary and secondary targets of specific immunotherapy have not been answered satisfactorily for the sublingual route. To date, SLIT cannot be recommended as an adequate alternative to the subcutaneous form. Questions regarding the cumulative dose, duration of therapy and immunological mechanisms have also not been answered. The indication should thus be limited to adult patients with pollen-induced rhinoconjunctivitis being unable to perform SIT, e.g. due to significant side effects.