Tobacco Exposure and Efficacy of Biologic Therapy in Patients With Severe Asthma: A Nationwide Study From the Danish Severe Asthma Register.

BACKGROUND: Randomized trials of biologics in severe, uncontrolled asthma have excluded patients with a cumulative tobacco exposure of more than 10 pack-years. Therefore, our knowledge of the impact of smoking exposure on the clinical effects of biologics in severe asthma remains incomplete. However, because many patients with asthma are current or former smokers, investigating the potential impacts of tobacco exposure on the effects of biologic treatment is clinically important. OBJECTIVE: To investigate the impact of smoking history and tobacco exposure on the effectiveness of biologic therapy in real-life patients with severe asthma. METHODS: We used data from a complete nationwide cohort of patients with severe asthma who were receiving biologics, the Danish Severe Asthma Register. We divided patients according to smoking history and cumulative tobacco exposure and analyzed data at baseline and after 12 months of biologic treatment. RESULTS: A total of 724 bio-naive patients were identified in the Danish Severe Asthma Register, 398 of whom had never been smokers (55%), 316 were previous smokers (44%), and 10 were current smokers (1%). Within the group of current and former smokers, 37% had 1 to 9 pack-years of tobacco exposure, 26% had 10 to 19 pack-years, and 37% had 20 or more pack-years of tobacco exposure. Patients with tobacco exposure had similar reductions in the number of exacerbations, reductions in maintenance oral corticosteroid use, and improvements in asthma symptoms compared with patients with 0 pack-years. CONCLUSION: Former smoking history and lifetime tobacco exposure do not have an impact on the efficacy of biologics in patients with severe asthma.

Intralymphatic immunotherapy improves grass pollen allergic rhinoconjunctivitis: A 3-year randomized placebo-controlled trial.

BACKGROUND: Allergic rhinoconjunctivitis is a global health problem. Different allergen immunotherapy regimes are marketed but have low adherence because they are expensive, complex, and time-consuming. New allergen immunotherapy forms are needed. OBJECTIVE: In a 3-year follow-up double-blind randomized placebo-controlled trial, we aimed to investigate the effect of intralymphatic allergen immunotherapy (ILIT). METHODS: Patients with grass pollen rhinoconjunctivitis were treated with 3 ILIT injections and an ILIT booster 1 year later, 3 ILIT injections and a placebo booster, or 3 placebo injections and a placebo booster. Primary outcome was improvement in a combined symptom and medication score (cSMS). A novel evaluation tool with a linear regression model of cSMS and grass pollen counts was developed. Secondary outcomes were changes in grass specific immunoglobulins and skin and nasal provocation tests to grass pollen. RESULTS: A total of 36 patients were included. Log10-transformed cSMS was reduced by 0.30 (95% CI, 0.11-0.49; P = .002), equaling 48.5% (95% CI, 24.5%-62%), in the entire 3-year follow-up period, significant only in the first follow-up season but not in the second and third seasons. The regression model showed a 37% (P < .001) reduction in cSMS. The booster injection 1 year later had no additional effect. Secondary, repeated measures of IgE and IgG4 to grass showed significant between-group difference and within-group change in the ILIT groups. No change in provocation test results was found. CONCLUSIONS: ILIT gives a substantial reduction in grass pollen allergy symptoms and use of rescue medication, significant in the first season after treatment. A booster injection had no additional effect.

Pretreatment IgE sensitization patterns determine the molecular profile of the IgG4 response during updosing of subcutaneous immunotherapy with timothy grass pollen extract.

BACKGROUND: Allergen immunotherapy is an effective treatment of allergic rhinoconjunctivitis. Clinical efficacy is associated with improvement of basophil sensitivity and an increase in allergen-specific immunoglobulin concentration. OBJECTIVE: We sought to determine whether changes in allergen component-specific serum IgE and IgG4 levels during the updosing phase of subcutaneous immunotherapy (SCIT) are biomarkers of the immunologic changes that can lead to treatment efficacy. METHODS: Twenty-four subjects with grass pollen-induced allergic rhinoconjunctivitis were randomized 3:1 to receive SCIT (Alutard SQ) or to an open control group. IgE and IgG4 concentrations were determined for the major allergens Phl p 1 or Phl p 5 by using ImmunoCAP and for 8 grass pollen molecules by using Immuno Solid-phase Allergy Chip (ISAC) before treatment and after updosing. RESULTS: Levels of specific IgE against the dominant major allergens Phl p 1 and Phl p 5 increased from a mean of 23.0 to 48.8 kU/L (P = .01, n = 18) during the updosing phase in ImmunoCAP measurements but decreased from a median of 4.6 ISAC specific units (ISU) to 2.14 ISU (P < .0001, n = 102) when measured by using ISAC against 8 grass allergen components. The updosing phase induced a specific IgG4 level increase from a median of 0 ISU before treatment to 0.83 ISU after 12 weeks (P < .0001, n = 102) but only for allergen molecules to which pretreatment-specific IgE antibodies were detected (Spearman σ = 0.72, P < .0001, n = 102). CONCLUSION: Pretreatment allergen component-specific IgE appears to determine the induction of IgG4 in the updosing phase. Induced IgG4 seems to suppress IgE levels on ISAC, resulting in a marked decrease in ISAC-measured specific IgE levels after updosing of SCIT. Thus this decrease in ISAC IgE levels can be used to monitor the blocking effect of allergen-specific immunotherapy-induced non-IgE antibodies.