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Dr. Karl-Christian Bergmann presented on SLIT at #CSACI15.
Dr Bergmann points out that the dendritic cells that are felt to be stimulated by SLIT are also plentiful between the lip and gums. Mechanisms of SCIT and SLIT are similar. Over last 30 yrs there is large increase in SLIT knowledge. SLIT often used with patients who refuse injections, don't want or have uncontrolled symptoms w long term pharmacotherapy.
A recent Dust mite SLIT trial has chosen similar "units" to grass SLIT trials (300 IR vs 500 IR vs placebo).
Sensitization vs. clinical symptoms
Dr Bergmann points out skin test positivity to dust mite may only be sensitization, esp in older pts who have non-allergic rhinitis. Dr. Bergmann advocating for the diagnostic value of nasal allergen challenge. Only 3 of 10 of patients w symp. and +ve SPT will react.
A reason for "failure" of any form of dust mite immunotherapy can be non-allergic/vasomotor rhinitis with previous sensitization. Participants had to have a specific IgE to dust mite of at least 0.7 kU/L for inclusion in the HDM SLIT trial.
20% of dust mite exposure is at night. Have to protect the whole day as 80% exposure throughout day.
Dr Bergmann - "First study to demonstrate efficacy in adults with house dust mite allergic rhinitis."
Onset of action of the HDM SLIT tablet appears to be at 4 months of treatment in this study - 20 % improvement compared to placebo. Dr Bergmann: The therapeutic benefit of DM SLIT took about 4 months to show up with no difference between 300 and 500 IR tablets. Bergmann: SLIT works much faster; after 3-4 months. It takes SCIT mites therapy 2-3 yrs for best result.
Side effects
Main side effects of DM SLIT were throat & mouth irritation/swelling esp with 500 IR. You are putting DM in your mouth…Oral itching usually only 1st week & in most cases this will decrease or disappear long term.
The first dose of SLIT tablets (grass, ragweed or eventually dust mite) MUST be taken under medical supervision. Other doses at home. Dr Bergmann: No fatalities reported with the use of SLIT in the past 25 years. Only 2 cases of anaphylaxis. Systemic side effects occur less than 5% in patients with SLIT. Most common side effects with SLIT use are oral itch and edema, mostly occur in the 1st few days.
Comment from Dr. Scadding - look in the patient's mouth before first dose of SLIT - if any open lesions do not give dose. Dr. Scadding also pre-treats with antihistamines to improve tolerability of SLIT (reduces oral itch). Dr Scadding recommends using antihistamine before starting SLIT as well as examining the mouth for injury before start. Dr G Scadding from England points out that the oral symptoms from SLIT may be prevented by antihistamine use the night before.
Question from audience about development of eosinophilic esophagitis following SLIT Bergmann hasn't seen it but some have.
Dr Bergmann - patients with oral allergy syndrome appear to tolerate SLIT just as well as those patients without.
SLIT should only be prescribed by those with allergy training. In Germany, MD's can prescribe SLIT.
Efficacy
Recent @CochraneAirways meta-analysis of SLIT confirmed efficacy. Data bank on SLIT - shown that SLIT is very effective. SLIT-Tablet almost as effective of SCIT - SLIT Drops half as much. SLIT Tabs may be more efficacious than drops but is essentially the same as shots based on Cochrane.
Persistent effect of SLIT is key although how long is unpredictable.
Dr Bergmann: Dust mite SLIT tablets have *just* started use in Germany but is not available in North America at this time.
Dr Bergmann: In one study, only 34% of patients started on SCIT still taking it 3 years later compared to 50% with SLIT.
How can we be sure patient takes SLIT regularly, compliance at home?
Future SLIT
Future developments in SLIT - birch tablet, cow's milk, peanut, peach, and hazelnut. Dr Bergmann: The future of SLIT is in food allergy IT, with favourable results so far.