SELECTED ARTICLES FROM THE RECENT LITERATURE 2004

11/3/04

Co-seasonal sublingual immunotherapy reduces asthma development in children with seasonal allergic rhinitis

Summary
Background - Allergy immunotherapy (IT) administered by the traditional subcutaneous route has been shown to reduce the extent/severity of seasonal allergic rhinitis (SAR) and seasonal asthma. However, such IT has generally been given by multiple injections before the onset of the season when the offending allergen becomes airborne. Previous attempts at co-seasonal injection IT have not yielded very impressive benefit and/or were limited by adverse reactions to this injection IT.

Findings - Novembre et al investigated whether co-seasonal IT administered by the sublingual route (SLIT) was effective in reducing SAR symptoms and decreasing the frequency of asthma occurrence. One hundred thirteen children ages 4-14 years, sensitive to grass alone were randomized to receive SLIT or standards symptomatic therapy (control group) during the offending pollinating season.

The authors found a less frequent use of rescue medication for SAR in those who were receiving SLIT than in the control group during the 2nd-3rd year of the study. Development of asthma after 3 years was 3.5 times as frequent in the control group than in the SLIT treated group.

Conclusions- Co-seasonal SLIT reduces SAR symptoms and the development of seasonal allergic asthma.

Reference
J Allergy Clin Immunol 2004;114851-7

Editor's Comments
The study described above has the advantage of being carried out in 6 different Pediatric Allergy clinics in Italy, thus getting around any potential problems due to findings unique to one investigative site. However, there are some study design problems that may limit interpretation of the findings: 1) the randomization was on an open basis; 2) there was no sublingual-placebo study group raising possibilities of "intervention/suggestion" bias with a placebo effect; 3) the major SAR outcome measurement was the use of rescue medications.

Nevertheless the findings, particularly reduced seasonal asthma, warrant further investigation. However, it should be noted that impressive improvement was apparently not seen during the first year of SLIT, a situation commonly seen with traditional subcutaneous IT as well.

 

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