Allergen-specific immunotherapy and COVID-19: What happened?

BACKGROUND: The COVID-19 infection played a key role in the discontinuation of patient treatment, such as allergen-specific immunotherapy, in chronic diseases. OBJECTIVES: We conducted a retrospective observational study at Verona University Hospital, Verona, Italy, to assess the level of adherence to sublingual immunotherapy (SLIT) in patients affected by allergic rhinitis and mild asthma. MATERIALS AND METHODS: We compared and analysed data related to first prescription and collection of 5-grass-pollen 300-index of reactivity (IR) SLIT and tablet lyophilisate, containing 75,000 standardized quality tablet units (SQ-T) allergen extract of grass-pollen from Phleum pratense L, for the five-year period 2017-2021.In particular we considered the group of naïve patients from 2017 who completed pre-COVID treatment (2017-2019) and the group of naïve patients from 2019 who completed treatment during the COVID period (2019-2021). The significance test used was Student's t-test, and P ˂ 0.05 was considered as statistically significant. RESULTS: In the three-year period 2017-2019, 264 naïve patients began treatment in 2017, of these 181 continued in 2018, 135 continued in 2019. Instead, for the period 2017-2019, there were 226 naïve patients in 2019; of these 139 continued in 2020, and 102 in 2021. CONCLUSIONS: COVID-19 did not seem to influence adherence to SLIT, which declined independently even in during the pre-pandemic 3-year period.

First use of imlifidase desensitization in a highly sensitized lung transplant candidate: a case report.

Lung transplant candidates who are highly sensitized against human leucocyte antigen present an ongoing challenge with regards to finding immunologically acceptable donors. Desensitization strategies aimed at reducing preformed donor-specific antibodies have a number of limitations. Imlifidase, an IgG-degrading enzyme derived from Streptococcus pyogenes, is a novel agent that has been used to convert positive crossmatches to negative in kidney transplant candidates, allowing transplantation to occur. We present the first case of imlifidase use for antibody depletion in a highly sensitized lung transplant candidate who went on to undergo a successful bilateral lung transplant.

[Path of a fighter]. / La désensibilisation allergénique au secours de la récidive.

Allergy is a frequent and often disabling condition for the patients. In the context of allergic rhinitis and asthma or anaphylactic shock to hymenoptera venom, allergenic desensitization can be proposed to limit the symptoms or recurrence of major reactions. Access to this treatment is made difficult by a lack of allergists, a lack of products or, more recently, by the Covid-19 crisis.

Impact of COVID-19 in allergen immunotherapy: An Italian survey.

Allergen immunotherapy (AIT) is a common treatment for patients with allergic asthma and allergic rhinoconjunctivitis. There is evidence that the COVID-19 pandemic could have altered the administration of AIT in patients in some countries, as the pandemic caused major limitations to healthcare access and delivery. The objective of this study was to evaluate the impact of the disruption imposed by the pandemic on the perceptions and administration of AIT therapies in Italy. An online survey was carried out among Italian allergists between 22 February 2021 and 12 April 2021. The results show that Italian physicians (N=66) did not consider that the COVID-19 pandemic presented an added risk to patients with allergic asthma or rhinitis receiving AIT. Although most treatments continued, there were reduced rates of AIT therapy initiations and sublingual AIT was favored over subcutaneous AIT.

Long-term adherence strategies for allergen immunotherapy.

Adherence is crucial for allergen immunotherapy (AIT) efficacy, and a long-term 3-year adherence is indispensable for the long-term benefits beyond AIT administration. Nonadherence causes should be analyzed not only at the patient level but from a broader perspective, including socioeconomic factors, health-care system factors, and disorder- and therapy-related factors. Subcutaneous immunotherapy (SCIT) adherence is ∼50% at best and, for sublingual immunotherapy, the numbers are even much worse in some regions. In this review, causes for AIT loss of adherence and strategies, published and from personal experience, to reduce nonadherence are presented. Although the broader picture of causes of nonadherence has to be taken into account, in all this, the patient-physician and patient-health care professional (AIT nurse, assistant) are still in the center, and, in SCIT, each clinic visit for a shot is an opportunity to exploit this interaction in a positive way and stimulate adherence. Patient factors of nonadherence are not so much forgetfulness but more perception of ineffectiveness and adverse effects. An explanation of what can be expected before starting AIT is crucial because most of those who drop out are seen during the first year. Adherence is especially under risk when administration is temporarily interrupted (lockdown, illness, disease flare, vacation, preseasonal AIT administration schedules). The pandemic has caused higher rates of nonadherence specifically due to a fear of getting infected with severe acute respiratory syndrome coronavirus 2, which can be mitigated with good hygiene techniques and strict sanitization protocols, which ensure the patients. Also, patient mobile discussion networks related to AIT can help encourage adherence and reduce fear of infection, even in these difficult times.

Effectiveness and safety of oral lactococci-based vaccine encoding triple common allergens to prevent airway allergy in mice.

Allergic airway disease is the most common chronic airway inflammatory disorder in developed countries. House dust mite, cockroach, and mold are the leading allergens in most tropical and subtropical countries, including Taiwan. As allergen avoidance is difficult for patients allergic to these perennial indoor allergens, allergen-specific immunotherapy (ASIT) is the only available allergen-specific and disease-modifying treatment. However, for patients sensitized to multiple allergens, ASIT using each corresponding allergen is cumbersome. In the present study, we developed a recombinant L. lactis vaccine against the three most common indoor aeroallergens and investigated its effectiveness for preventing respiratory allergy and safety in mice. Three recombinant clones of Der p 2 (mite), Per a 2 (roach), and Cla c 14 (mold) were constructed individually in pNZ8149 vector and then electroporated into host strain L.lactis NZ3900. BALB/c mice were fed with the triple vaccine 5 times per week for 4 weeks prior to sensitization. The effectiveness and safety profile were then determined. Oral administration of the triple vaccine significantly alleviated allergen-induced airway hyper-responsiveness in the vaccinated mice. The allergen-specific IgG2a was upregulated. IL-4 and IL-13 mRNA expressions as well as inflammatory cell infiltration in the lungs decreased significantly in the vaccinated groups. No body weight loss or abnormal findings in the liver and kidneys were found in any of the groups of mice. This is the first report to describe a triple-aeroallergen vaccine using a food-grade lactococcal expression system. We developed a convenient oral delivery system and intend to extend this research to develop a vaccination that can be self-administered at home by patients.

Efficacy and safety of baked milk oral immunotherapy in children with severe milk allergy: A randomized, double-blind, placebo-controlled phase 2 trial.

BACKGROUND: Cow's milk allergy is the most common food allergy in young children and has no current treatment. Oral immunotherapy studies to date have shown efficacy but high rates of adverse reactions. OBJECTIVE: We sought to evaluate the safety and efficacy of baked milk oral immunotherapy (BMOIT) in children allergic to baked milk. METHODS: Participants (3-18 years) were randomized to receive BMOIT or placebo for 12 months. Efficacy was assessed by double-blind placebo-controlled food challenge after 12 months of treatment. Safety, quality of life, and mechanistic parameters were also evaluated. RESULTS: Eleven of 15 (73%) BMOIT participants reached the primary end point, tolerating 4044 mg of baked milk protein after 12 months of oral immunotherapy, compared with 0 of 15 (0%) on placebo. The median maximum tolerated dose and median change from baseline was significantly higher in the BMOIT group than in the placebo group (median maximum tolerated dose, 4044 mg vs 144 mg; P = .001; median change in maximum tolerated dose of 3900 mg vs 0 mg, P = .0001). Dose-related reactions were common, but more than 95% in both groups were mild. There was no significant change in cow's milk- or beta lactoglobulin-IgE from baseline for either group. Cow's milk-sIgG4 did significantly increase and casein IgE decreased in the BMOIT group. For proxy-reported food allergy quality of life, there was a significant difference in the emotional impact domain only, with more improving while on placebo compared with BMOIT. Most children and adolescents in the BMOIT group directly reported improvement in at least 1 domain. CONCLUSIONS: BMOIT was well tolerated and induced a substantial level of desensitization after 12 months of treatment.

COVID-19 vaccination in patients receiving allergen immunotherapy (AIT) or biologicals-EAACI recommendations.

Immune modulation is a key therapeutic approach for allergic diseases, asthma and autoimmunity. It can be achieved in an antigen-specific manner via allergen immunotherapy (AIT) or in an endotype-driven approach using biologicals that target the major pathways of the type 2 (T2) immune response: immunoglobulin (Ig)E, interleukin (IL)-5 and IL-4/IL-13 or non-type 2 response: anti-cytokine antibodies and B-cell depletion via anti-CD20. Coronavirus disease 2019 (COVID-19) vaccination provides an excellent opportunity to tackle the global pandemics and is currently being applied in an accelerated rhythm worldwide. The vaccine exerts its effects through immune modulation, induces and amplifies the response against the severe acute respiratory syndrome coronavirus (SARS-CoV-2). Thus, as there may be a discernible interference between these treatment modalities, recommendations on how they should be applied in sequence are expected. The European Academy of Allergy and Clinical Immunology (EAACI) assembled an expert panel under its Research and Outreach Committee (ROC). This expert panel evaluated the evidence and have formulated recommendations on the administration of COVID-19 vaccine in patients with allergic diseases and asthma receiving AIT or biologicals. The panel also formulated recommendations for COVID-19 vaccine in association with biologicals targeting the type 1 or type 3 immune response. In formulating recommendations, the panel evaluated the mechanisms of COVID-19 infection, of COVID-19 vaccine, of AIT and of biologicals and considered the data published for other anti-infectious vaccines administered concurrently with AIT or biologicals.

Elevated Cow's Milk-Specific IgE Levels Prior to Oral Immunotherapy Decrease the Likelihood of Reaching the Maintenance Dose.

BACKGROUND: Food desensitization via oral immunotherapy (OIT) is gaining acceptance in clinical practice. Owing to adverse reactions, the duration of the buildup phase until a maintenance dose is achieved may be prolonged, and in a minority of cases, OIT is stopped. OBJECTIVE: We aimed to assess factors associated with the probability of reaching the maintenance dose in cow's milk (CM) OIT. METHODS: We collected data from patients undergoing CM OIT at the Montreal Children's Hospital, BC Children's Hospital, and Hospital for Sick Children. We compared univariable and multivariable Cox regressions to evaluate sociodemographic factors, comorbidities, clinical characteristics, and biomarkers at study entry associated with the likelihood of reaching a maintenance dose of 200 mL of CM. RESULTS: Among 69 children who reached 4 mL of milk, the median age was 12 years (interquartile range, 9-15 years); 59% were male. Median duration of buildup phase from 4 to 200 mL was 24.0 weeks (interquartile range, 17.7-33.4 weeks). After adjusting for age and sex, higher baseline levels of specific IgE antibodies for α-lactalbumin (hazard ratio [HR] = 0.80; 95% confidence interval [CI], 0.67-0.95), ß-lactoglobulin (HR = 0.86; 95% CI, 0.76-0.98), casein (HR = 0.82; 95% CI, 0.72-0.94), and total CM (HR = 0.79; 95% CI, 0.65-0.97) were associated with a decreased probability of reaching maintenance. In addition, for every 10-mL increase in CM tolerated at entry challenge, the probability of reaching maintenance increased by 10%. CONCLUSIONS: The data suggest that higher levels of CM-specific IgE decreased the likelihood of reaching maintenance, whereas an increased cumulative CM dose at entry challenge increased the likelihood. Assessing these factors before therapy may assist in predicting the success of CM OIT.

Nucleic acid vaccines and CpG oligodeoxynucleotides for allergen immunotherapy.

PURPOSE OF REVIEW: Molecular forms of allergen-specific immunotherapy (AIT) are continuously emerging to improve the efficacy of the treatment, to shorten the duration of protocols and to prevent any side effects. The present review covers the recent progress in the development of AIT based on nucleic acid encoding allergens or CpG oligodeoxynucleotides (CpG-ODN). RECENT FINDINGS: Therapeutic vaccinations with plasmid deoxyribonucleic acid (DNA) encoding major shrimp Met e 1 or insect For t 2 allergen were effective for the treatment of food or insect bite allergy in respective animal models. DNA expressing hypoallergenic shrimp tropomyosin activated Foxp3+ T regulatory (Treg) cells whereas DNA encoding For t 2 down-regulated the expression of pruritus-inducing IL-31. Co-administrations of major cat allergen Fel d 1 with high doses of CpG-ODN reduced Th2 airway inflammation through tolerance induction mediated by GATA3+ Foxp3hi Treg cells as well as early anti-inflammatory TNF/TNFR2 signaling cascade. Non-canonical CpG-ODN derived from Cryptococcus neoformans as well as methylated CpG sites present in the genomic DNA from Bifidobacterium infantis mediated Th1 or Treg cell differentiation respectively. SUMMARY: Recent studies on plasmid DNA encoding allergens evidenced their therapeutic potential for the treatment of food allergy and atopic dermatitis. Unmethylated or methylated CpG-ODNs were shown to activate dose-dependent Treg/Th1 responses. Large clinical trials need to be conducted to confirm these promising preclinical data. Moreover, tremendous success of messenger ribonucleic acid (mRNA) vaccines against severe acute respiratory syndrome coronavirus 2 must encourage as well the re-exploration of mRNA vaccine platform for innovative AIT.

Advances and highlights in allergic rhinitis.

Allergic rhinitis (AR) is a growing public health, medical and economic problem worldwide. The current review describes the major discoveries related to AR during the past 2 years, including risk factors for the prevalence of AR, the corresponding diagnostic strategy, precise underlying immunological mechanisms, and efficient therapies for AR during the ongoing global "coronavirus disease 2019" (COVID-19) pandemic. The review further attempts to highlight future research perspectives. Increasing evidence suggests that environmental exposures, climate changes, and lifestyle are important risk factors for AR. Consequently, detailed investigation of the exposome and the connection between environmental exposures and health in the future should provide better risk profiles instead of single predictors, and also help mitigate adverse health outcomes in allergic diseases. Although patients with dual AR, a newly defined AR phenotype, display perennial and seasonal allergens-related nasal symptoms, they are only allergic to seasonal allergens, indicating the importance of measuring inflammation at the local sites. Herein, we suggest that a combination of precise diagnosis in local sites and traditional diagnostic methods may enhance the precision medicine-based approach for management of AR; however, this awaits further investigations. Apart from traditional treatments, social distancing, washing hands, and disinfection are also required to better manage AR patients in the ongoing global COVID-19 pandemic. Despite recent advances in understanding the immune mechanisms underlying the effects of allergen immunotherapy (AIT), further understanding changes of cell profiles after AIT and accurately evaluate the efficacy of AIT are required.

One hundred and ten years of Allergen Immunotherapy: A journey from empiric observation to evidence.

One hundred and ten years after Noon's first clinical report of the subcutaneous application of allergen extracts, allergen immunotherapy (AIT) has evolved as the most important pillar of the treatment of allergic patients. It is the only disease-modifying treatment option available and the evidence for its clinical efficacy and safety is broad and undisputed. Throughout recent decades, more insights into the underlying mechanisms, in particular the modulation of innate and adaptive immune responses, have been described. AIT is acknowledged by worldwide regulatory authorities, and following the regulatory guidelines for product development, AIT products are subject to a rigorous evaluation before obtaining market authorization. Knowledge and practice are anchored in international guidelines, such as the recently published series of the European Academy of Allergy and Clinical Immunology (EAACI). Innovative approaches continue to be further developed with the focus on clinical improvement by, for example, the usage of adjuvants, peptides, recombinants, modification of allergens, new routes of administration, and the concomitant use of biologicals. In addition, real-life data provide complementary and valuable information on the effectiveness and tolerability of this treatment option in the clinical routine. New mobile health technologies and big-data approaches will improve daily treatment convenience, adherence, and efficacy of AIT. However, the current coronavirus disease 2019 (COVID-19) pandemic has also had some implications for the feasibility and practicability of AIT. Taken together, AIT as the only disease-modifying therapy in allergic diseases has been broadly investigated over the past 110 years laying the path for innovations and further improvement.

Home epinephrine-treated reactions in food allergy oral immunotherapy: Lessons from the coronavirus disease 2019 lockdown.

BACKGROUND: Oral immunotherapy (OIT) is effective in desensitizing patients with food allergy but adverse reactions limit its use. OBJECTIVE: To study the effect of the coronavirus disease 2019 lockdown in Israel between March 15, 2020, and April 30, 2020, on the incidence of home epinephrine-treated reactions. METHODS: All patients who were in the up-dosing phase of OIT for greater than or equal to 1 month during the lockdown, or a respective period in years 2015 to 2019, were studied. The incidence of home-epinephrine treated reactions during the 2020 lockdown was compared with that in the respective period in 2015 to 2019 and to periods before and after the lockdown. RESULTS: A total of 1163 OIT treatments were analyzed. Two epinephrine injections occurred during 2020 (0.7%) compared with 29 injections (3.28%) during 2015 to 2019 (P = .03). Patients treated in 2020 were older (8.1 vs 7 years, P < .01) and had a significantly lower single highest tolerated dose (12 vs 20 mg protein, P < .01). The rate of milk-OIT was lower (P = .01), but the total number of milk treatments was higher (99 vs 71 to 82) in 2020 compared with 2015 to 2019. On multivariate analysis, treatments during the 2020 lockdown were performed in older patients (P = .001), primarily for nonmilk (P = .03), began with a lower single highest tolerated dose (P = .006), and were associated with significantly less home epinephrine-treated reactions (P = .05) compared with those in 2015 to 2019. Patients treated in 2020 experienced more epinephrine-treated reactions in adjacent periods before (n = 8) and after (n = 6) the lockdown. CONCLUSION: The lower rate of home epinephrine-treated reactions during the coronavirus disease 2019 lockdown in Israel suggests that potentially avoidable triggers contribute significantly to the rate of adverse reactions during OIT.