Subcutaneous and sublingual immunotherapy in children: complete update on controversies, dosing, and efficacy

Comparison of rush-subcutaneous and sublingual immunotherapy with house dust mite extract for pediatric allergic rhinitis: A prospective cohort study

BACKGROUND

We aimed to compare the effectiveness and safety of subcutaneous immunotherapy (SCIT) and sublingual immunotherapy (SLIT) with standardized house dust mite (HDM) extract for allergic rhinitis.

METHODS

Participants with allergic rhinitis selected their treatment between HDM SCIT or HDM SLIT, according to their wishes. We prospectively followed symptoms of allergic rhinitis using the allergic rhinitis symptom medication score (ARSMS), along with adverse reactions, during the dose escalation and maintenance phases for two years. We compared the outcomes between propensity score-matched groups to adjust the confounding factors.

RESULTS

After propensity score matching, 88 patients in the HDM SCIT (n = 44) and HDM SLIT groups (n = 44) remained for analysis. The HDM SCIT group showed significantly earlier effectiveness than the HDM SLIT group (median time to decrease in ARSMS [≥2 points]: 5.5 vs. 18.0 months, p < 0.001). The incidence of systemic reactions was not significantly different between the two groups in the dose escalation phase (68.2% vs. 56.8%, p = 0.379). In the maintenance phase, the incidence of systemic reactions was higher in the HDM SCIT group than in the HDM SLIT group (18.2% vs. 0%, p < 0.006). All 44 patients in the HDM SCIT group completed two years of treatment, while nine patients in the HDM SLIT group discontinued treatment.

CONCLUSIONS

The HDM SCIT group showed an earlier onset of therapeutic effect and a lower discontinuation rate than the HDM SLIT group, although more severe systemic reactions were observed during the maintenance phase.

Clinical Applications of Sublingual Immunotherapy

Sublingual immunotherapy (SLIT) is effective for the treatment of allergic rhinitis and allergic asthma in adults and children. In a limited number of studies, SLIT efficacy has been demonstrated for the treatment of food allergy. SLIT has a higher safety profile versus subcutaneous immunotherapy, although some systemic reactions have been reported. Appropriate patient selection, meticulous patient education, and routine follow-up are key for the safe and effective administration of SLIT. With organization and attention to detail, adding SLIT to one's practice can provide a highly valued patient service.

Systemic Reactions in Pediatric Patients Receiving Standardized Allergen Subcutaneous Immunotherapy with and without Seasonal Dose Adjustment

BACKGROUND

The 2003 Joint Task Force on Practice Parameters recommended standardizing allergen subcutaneous immunotherapy (SCIT). Data from longitudinal surveillance survey in North America reported a systemic reaction (SR) rate of 0.1% to 0.2% of injection visits. The rate of SR to standardized SCIT in pediatric patients has not been well evaluated.

OBJECTIVE

The objective of this study was to evaluate the rate of SRs to standardized SCIT in pediatric patients aged 5 to 18 years in a single tertiary care center in the United States.

METHODS

A retrospective chart review was conducted in 2 groups: group 1 started SCIT within a period extending from January 2009 to June 2012, whereas group 2 started SCIT within a period extending from January 2013 to June 2016. The protocol was modified in group 2 such that updosing and maintenance doses were adjusted in the spring for tree and grass pollen and in the fall for weed pollen.

RESULTS

There were a total of 128 patients in group 1 and 118 patients in group 2. The rate of SR was 0.429% in group 1 and 0.364% in group 2, which was not significant. There was no difference in the severity of SR in the 2 groups with no-fatal or near-fatal SR noted. Asthma was a significant risk factor in the younger age subgroup aged 5 to 11 years.

CONCLUSIONS

Standardized SCIT appears to be associated with an SR rate of 0.429% to 0.364% of visits in pediatric patients. Protocol modification did not lead to a significant drop in SR. Larger multicenter studies are required to further evaluate the rate of SRs from standardized SCIT.

Comparison of Pediatric and Adult Systemic Reactions to Subcutaneous Immunotherapy

BACKGROUND

Subcutaneous immunotherapy (SCIT) has been used to treat allergic rhinitis for over a century, and current regimens have wide variability with an array of practice styles and dosing strategies. Although there are some statements about contraindications and cautions, no specific formal age- or weight-based dosing guidelines are utilized when administering SCIT.

OBJECTIVE

The primary objective of this study was to estimate the overall incidence rate of any reaction to SCIT and to consider the severity of the reaction by grade in children and adults.

METHODS

A retrospective chart review was conducted to document the number and severity of episodes of systemic reactions (SRs) in pediatric and adult subjects. Crude incidence rates were estimated as the number of SRs relative to the total injections administered. Adjusted incidence rate ratios were generated using a generalized estimating equation approach, which accounted for multiple visits within subjects.

RESULTS

The incidence rate for any SR was 0.2%. The unadjusted incidence rate of any SR was significantly higher in children compared with adults (P < .001), although not significant when adjusted for asthma, gender, and phase of SCIT (P < .054). However, the incidence rate for grade 1 and 2 SRs in children was 1.89 times the incidence rate for adults, adjusting for these variables (P < .015).

CONCLUSIONS

These results suggest that current SCIT practices are associated with a higher rate of SRs, specifically of grade 1 and 2 SRs, in children than adults. Further studies are necessary to evaluate if changes in dosing strategies for children, such as a lower starting dose, a decrease in target maintenance dose, or a slower build-up phase, are warranted.

The risk and management of anaphylaxis in the setting of immunotherapy

BACKGROUND

Anaphylactic events due to immunotherapy are probably not completely preventable. There is always an inherent risk surrounding the administration of an allergen to an individual who is sensitized to the substance administered.

METHODS

There are, however, effective measures to reduce the risk of these events, and to optimize the assurance of a good outcome in the face of such an event.

RESULTS

Of prime importance in preventing these episodes is the regular assessment of the patient's health status, especially in regard to asthma, and the careful attention to the prevention of dosing errors.

CONCLUSION

Of equal importance, in regard to assuring a good outcome should such an event occur, are the rapid recognition of symptoms and the immediate injection of epinephrine, the drug of choice for the treatment of any episode of anaphylaxis.

Sublingual immunotherapy

Sublingual immunotherapy (SLIT) has been shown to be safe and efficacious in treating allergic rhinitis. It has been used in Europe for more than 20 years, and interest in the United States is increasing. SLIT has been shown to elicit immunologic changes similar to subcutaneous injection immunotherapy. SLIT may prevent new sensitizations, improve asthma control, and decrease asthma development in allergic individuals. Although differences in antigen quantification and standardization make European dosing schemes difficult to translate in the United States, several new studies suggest the range for effective dosing. Further studies will help clarify optimal dosing.

Evidence of effect of subcutaneous immunotherapy in children: complete and updated review from 2006 onward

OBJECTIVE

To update the scientific evidence of subcutaneous immunotherapy (SCIT) in children.

DATA SOURCES

PubMed, EMBASE, and known articles.

STUDY SELECTION

All publications on SCIT in pediatric patients from January 2006 to April 2011. Study design was not a restriction. The articles were analyzed according to their outcomes and evaluated on their scientific quality using the Grading of Recommendations Assessment, Development, and Evaluation and Jadad tools. Clinical, safety, and immunologic data were gathered.

RESULTS

The scientific evidence produced by the 31 articles analyzed showed that there is high-quality evidence that grass pollen SCIT causes a reduction in the combined symptom-medication score and increases the threshold of the conjunctival provocation test, immediately and 7 years after termination of SCIT, as well as the threshold of the specific bronchial provocation test and the skin prick test reactivity. Alternaria SCIT improves medication scores, combined symptom-medication scores, and quality of life. It augments the threshold in the nasal provocation test. High-quality evidence of house dust mite SCIT shows that asthma symptom and medication scores improve and emergency department visits and skin reactivity are reduced; moderate evidence indicates improvement in pulmonary function tests. Pollen SCIT prevents asthma (moderate evidence); evidence for long-term benefit of pollen SCIT (7-12 years after termination) is low to moderate. There is inconclusive evidence for SCIT reducing new sensitizations.

CONCLUSION

There is acceptable evidence that shows that grass pollen, Alternaria, and house dust mite SCIT is beneficial in allergic children.

Sublingual immunotherapy in children with allergic rhinitis: quality of systematic reviews

Systematic reviews have gained popularity as a way to combine the increasing amount of research information. This study assessed the quality of systematic reviews and meta-analyses of sublingual immunotherapy (SLIT) for allergic rhinitis in children, published since 2000. Eligible reviews were identified by searching Medline/Pubmed, Embase, and the Cochrane Library, from 2000 through 2008. Methodological quality was assessed using the assessment of multiple systematic reviews instrument. Ten systematic reviews were included, one of which was published in the Cochrane Library. Eight reviews gave some details about the search strategy. None of the reviews included measures to avoid selection bias. In 60% of the reviews, the methodological quality of the included studies was (partly) assessed. Four reviews pooled the results of individual studies, neglecting clinical heterogeneity. Three of the 10 reviews provided information about sources of funding or grants from industry. Of the 10 reviews, the six reviews with the highest overall score scored 5-8 points, indicating moderate quality. Systematic reviews are useful to evaluate the efficacy of SLIT in children. Although more reviews have become available, the methodological quality could be improved. SLIT for children could be promising, but methodological flaws in the reviews and individual studies are too serious to draw definite conclusions.

Immunotherapy in asthma

Asthma is a chronic inflammatory disorder of the airways in which many cells and cellular elements play a role. Chronic inflammation is associated with airway hyper-responsiveness that leads to recurrent episodes of wheezing, breathlessness, chest tightness and coughing, as well as variable airflow obstruction within the lung. With time, such airflow obstruction may become permanent due to remodeling. It has been treated for more than 100 years by subcutaneous immunotherapy with allergen extracts but in recent years, other forms and types of immunotherapy have been introduced. Perhaps the most successful of these to date, is sublingual immunotherapy, which has attained significant usage in European countries but has yet to make inroads into clinical practice in North America. Other mechanisms to modify the inflammatory responses of asthma have included immunotherapy with recombinant allergens, the use of allergen peptides targeting antigen-specific T cells and the administration of Toll-like receptor agonists coupled to allergen proteins. As the inflammatory responses in asthma frequently involve IgE, a modified monoclonal antibody to IgE and interfering with its binding to the IgE receptor have gained acceptance for treating severe allergic asthma. Other monoclonal antibodies or recombinant receptor antagonists are being assessed for their ability to block other contributors to the inflammatory response. Finally, attempts have been made to generate autoantibody responses to cytokines implicated in asthma. Most of these therapies aim to modify or inhibit the so-called Th 2 immune response, which is implicated in many forms of asthma, or to inhibit cytokines involved in these responses. However, an added benefit of classical immunotherapy seems to be the ability to prevent the allergic progression to new sensitivities and new forms of allergic disease.

Tolerability and clinical efficacy of oral immunotherapy with house dust mites in a model of canine atopic dermatitis: a pilot study

Atopic dermatitis (AD) is a chronic, life-long disease. In humans, immunotherapy (IT) is the only treatment that can alter the course of AD. Oral IT is appealing owing to the ease of administration and the potential for increased compliance. The purposes of this study were to investigate the tolerability, clinical efficacy and effects on allergen-specific IgE of oral IT using a canine AD model. Thirteen atopic beagles sensitized to house dust mites (HDMs) were randomly divided into two groups. One group received daily oral doses of HDMs while the other group received vehicle only for 7 months. The investigator evaluating the dogs was blinded to the allocation of treatments. Prior to and after 2 and 7 months of IT, dogs were challenged daily with HDMs for 3 days concurrently, and clinical signs were scored using a modified Canine Atopic Dermatitis Extent and Severity Index (CADESI). Prior to and at completion of oral IT, serum was collected for measurement of allergen-specific IgE. Oral IT was well tolerated, and no adverse effects were noted. Analysis of variance showed no significant effect of time, group and group × time interaction for CADESI scores. In addition, there were no significant differences in allergen-specific IgE levels. In conclusion, it appears that oral administration of HDMs is well tolerated in these atopic beagles but that this protocol was not sufficient to induce clinical improvement. Further, longer-term studies will be necessary to explore the potential of oral IT in veterinary medicine.

Specific immunotherapy by the sublingual route for respiratory allergy

Specific immunotherapy is the only treatment able to act on the causes and not only on the symptoms of respiratory allergy. Sublingual immunotherapy (SLIT) was introduced as an option to subcutaneous immunotherapy (SCIT), the clinical effectiveness of which is partly counterbalanced by the issue of adverse systemic reactions, which occur at a frequency of about 0.2% of injections and 2-5% of the patients and may also be life-threatening. A large number of trials, globally evaluated by several meta-analyses, demonstrated that SLIT is an effective and safe treatment for allergic rhinitis and allergic asthma, severe reactions being extremely rare. The application of SLIT is favored by a good compliance, higher than that reported for SCIT, in which the injections are a major factor for noncompliance because of inconvenience, and by its cost-effectiveness. In fact, a number of studies showed that SLIT may be very beneficial to the healthcare system, especially when its effectiveness persists after treatment withdrawal because of the induced immunologic changes.

Certainties and doubts about sublingual and oral immunotherapy in children

PURPOSE OF REVIEW

Sublingual (SLIT) and oral immunotherapy (OIT) are two variants of immunotherapy that might be especially of interest for children. After adult studies, lately many trials in children are published. However, the quality of published material varies. In the present review we analyze paediatric SLIT publications from the past 2 years in the light of a new system of evaluation of quality of evidence, the grading of recommendations assessment, development and evaluation system.

RECENT FINDINGS

High quality evidence in children: high-dose daily grass SLIT reduces symptoms and medication use; low-dose pollen SLIT reduces the development of new sensitizations. Low-dose SLIT reduces symptoms and medication in mild-moderate atopic dermatitis. Latex SLIT for 3 years results in a negative glove test. The evidence for the effectiveness of SLIT for seasonal and perennial asthma is still of moderate-low quality, as is the evidence for asthma prevention. Too high dose of mite SLIT seems ineffective for asthma. Oral allergen immunotherapy is promising for some food allergies. Some definite immunological changes are seen with SLIT; facilitated antibody presentation and IL-17 might correlate with efficacy.

SUMMARY

Even after a hundred years of immunotherapy, it is still an ever changing field with SLIT and OIT making fast progress.

Sublingual immunotherapy in children: complete and updated review supporting evidence of effect

PURPOSE OF REVIEW

The interest in sublingual immunotherapy (SLIT) is still growing worldwide and especially for the pediatric age group, this modality is appealing. Lately, some negative systematic review articles have been published on SLIT in children. However, high quality articles published from 2007 onward had not been included.

RECENT FINDINGS

Explanations are sought for the negative outcomes in these reviews and shortcomings are discussed. New pediatric studies - not included in the previous reviews -designed taking into account the golden rules for SLIT (high daily dose, starting at least 4 months before pollen season) do show statistically significant improvement in symptom and medication scores for rhinitis and asthma in pollen allergy. New house dust mite studies still show inconsistent data.

SUMMARY

Evidence of effect is confirmed for SLIT in children with allergic rhinitis or asthma caused by pollen exposure. For house dust mite asthma, evidence is still nonconcordant. New techniques to improve SLIT efficacy are under investigation.