PEGylated Recombinant Adenosine Deaminase Maintains Detoxification and Lymphocyte Counts in Patients with ADA-SCID

PURPOSE

Metabolic detoxification with enzyme replacement therapy (ERT) promotes immune recovery in patients with adenosine deaminase (ADA)-deficient severe combined immunodeficiency (ADA-SCID). Elapegademase is a PEGylated recombinant bovine ADA ERT developed to replace the now-discontinued bovine-derived pegademase. This study was a 1-way crossover from pegademase to elapegademase in 7 patients with ADA-SCID to assess efficacy and safety outcomes for elapegademase.

METHODS

After once-weekly pegademase dosage was adjusted to achieve therapeutic metabolic detoxification and trough ADA activity, patients transitioned to a bioequivalent dose of elapegademase. Maintenance of metabolic detoxification and adequate ADA activity were evaluated periodically.

RESULTS

One patient withdrew after 2 doses of an early elapegademase formulation due to injection-site pain caused by EDTA. The 6 remaining patients completed 71-216 weeks of elapegademase therapy with a formulation that did not contain EDTA. In these patients, elapegademase improved ADA activity compared with pegademase and maintained metabolic detoxification. Total lymphocyte counts increased for all completer patients from between 1.2- and 2.1-fold at the end of study compared with baseline. Elapegademase had a comparable safety profile to pegademase; no patient developed a severe infectious complication. Three patients had transient, non-neutralizing antibodies to pegademase, elapegademase, and/or polyethylene glycol ≤ 47 weeks of treatment without effect on trough plasma ADA activity or trough erythrocyte deoxyadenosine nucleotide levels.

CONCLUSION

Elapegademase was safe, well tolerated, achieved stable trough plasma ADA activity with weekly dosing, was effective in maintaining metabolic detoxification, and was associated with maintenance or improvements in lymphocyte counts compared with pegademase therapy in patients with ADA-SCID.

Conducting an Oral Food Challenge: An Update to the 2009 Adverse Reactions to Foods Committee Work Group Report

Oral food challenges are an integral part of an allergist's practice and are used to evaluate the presence or absence of allergic reactivity to foods. A work group within the Adverse Reactions to Foods Committee of the American Academy of Allergy, Asthma & Immunology was formed to update a previously published oral food challenge report. The intention of this document was to supplement the previous publication with additional focus on safety, treatment of IgE-mediated allergic reactions, guidance for challenges in infants and adults, psychosocial considerations for children and families participating in an oral food challenge, specific guidance for baked milk or baked egg challenges, masking agents and validated blinding recipes for common food allergens, and recommendations for conducting and interpreting challenges in patients with suspected food protein-induced enterocolitis syndrome. Tables and figures within the report and an extensive online appendix detail age-specific portion sizes, appropriate timing for antihistamine discontinuation, serum and skin test result interpretation, written consents, and instructional handouts that may be used in clinical practice.

Allergic Reaction Caused by a Lip Balm–Flavored Facemask Used During Inhalational Induction

Flavoring a facemask with a lip balm for inhalational induction in children is a common practice. However, most anesthesia providers are unaware of potential complications and the management of allergic reactions caused by lip balm. We describe the occurrence of allergic reaction to lip balm–flavored facemask in a child who underwent an inhalational anesthetic induction. The facial rash resolved completely without complications after administration of an antihistamine and steroid.

Degree of anxiety in food allergic children in a tertiary care center

BACKGROUND

The link between internalizing psychiatric disorders, such as anxiety and depression, and allergic diseases has attracted a high level of interest from psychiatrists and immunologists. Recent studies have found increased anxiety in children with asthma, but findings in children with food allergy (FA) have been inconsistent.

OBJECTIVE

It was hypothesized that children with FA would score significantly higher on a standardized anxiety screen than general pediatric (GP) patients but not as high as patients with diagnosed anxiety disorders.

METHODS

A total of 114 patients aged 8 to 16 years (37 with confirmed anxiety disorder from a pediatric psychiatry clinic, 40 with confirmed FA from a pediatric allergy clinic, and 43 well-care patients from a GP clinic) and their mothers completed the Screen for Child Anxiety Related Emotional Disorders (SCARED).

RESULTS

Children and mothers in the allergy group did not report increased levels of anxiety in children on total SCARED scores or subscales compared with children and mothers from the GP group. There was a trend toward increased panic disorder symptoms reported in children by mothers of children in the allergy group, but this finding did not reach statistical significance.

CONCLUSION

Children with FA did not have increased anxiety; however, there was a trend for mothers of children with allergies to report more symptoms of panic disorder in their children. It remains important to screen families for anxiety-related symptoms and refer them to mental health services when indicated.

The associations of triclosan and paraben exposure with allergen sensitization and wheeze in children

Triclosan and parabens are chemicals used in personal care and medical products as microbicides and preservatives. Triclosan and paraben exposure may be associated with allergy (atopy), but these associations have not been evaluated with respect to other atopic states such as eczema (atopic dermatitis). This study examines the associations of urinary triclosan and paraben concentrations with allergic sensitization and asthma in children according to eczema history. We performed a cross-sectional analysis of U.S. children aged 6-18 years who participated in the National Health and Nutrition Examination Survey (2005-2006). Triclosan and paraben concentrations were measured in urine. We assessed associations of triclosan and parabens with allergic sensitization and asthma using multivariable logistic regression in 837 children with complete data and stratified our results by eczema status. After covariate adjustment, triclosan and methyl and propyl paraben concentrations were positively associated with the odds of aeroallergen sensitization. Eczema did not significantly modify the association between triclosan or paraben levels and aeroallergen sensitization, asthma, or wheeze. The odds of parent-reported atopic asthma increased 34% (95% CI, 0, 81) across triclosan concentration quartiles. Increasing triclosan concentrations (quartiles) were associated with 2.3 times the odds of food sensitization (95% CI, 1.14, 4.44) among children with eczema, but not among children without eczema (OR, 1.25; 95% CI 0.93, 1.68; effect measure modification, p = 0.04). Triclosan and paraben exposures may increase the risk of atopic asthma and aeroallergen sensitization. Prospective studies are necessary to confirm these findings and determine if these chemicals pose a risk to children's health.

A retrospective chart review to identify perinatal factors associated with food allergies

Background

Gut flora are important immunomodulators that may be disrupted in individuals with atopic conditions. Probiotic bacteria have been suggested as therapeutic modalities to mitigate or prevent food allergic manifestations. We wished to investigate whether perinatal factors known to disrupt gut flora increase the risk of IgE-mediated food allergies.

Methods

Birth records obtained from 192 healthy children and 99 children diagnosed with food allergies were reviewed retrospectively. Data pertaining to delivery method, perinatal antibiotic exposure, neonatal nursery environment, and maternal variables were recorded. Logistic regression analysis was used to assess the association between variables of interest and subsequent food allergy diagnosis.

Results

Retrospective investigation did not find perinatal antibiotics, NICU admission, or cesarean section to be associated with increased risk of food allergy diagnosis. However, associations between food allergy diagnosis and male gender (66 vs. 33; p=0.02) were apparent in this cohort. Additionally, increasing maternal age at delivery was significantly associated with food allergy diagnosis during childhood (OR, 1.05; 95% CI, 1.017 to 1.105; p=0.005).

Conclusions

Gut flora are potent immunomodulators, but their overall contribution to immune maturation remains to be elucidated. Additional understanding of the interplay between immunologic, genetic, and environmental factors underlying food allergy development need to be clarified before probiotic therapeutic interventions can routinely be recommended for prevention or mitigation of food allergies. Such interventions may be well-suited in male infants and in infants born to older mothers.

Hypersensitivity to total parenteral nutrition fat-emulsion component in an egg-allergic child

Immunoglobulin E (IgE)-mediated food allergies affect 6% to 8% of children in the United States with symptoms ranging from localized hives to life-threatening anaphylaxis. Intravenous fat emulsions (IFEs) are a vital component of total parental nutrition, because they provide essential fatty acids. IFE is a sterile fat emulsion that contains egg-yolk phospholipids. Although egg allergy is listed as a contraindication, adverse reactions are uncommon. We report here the case of a hypersensitivity to IFE in a 2-year-old patient with previously undocumented egg allergy. Our patient was placed on total parental nutrition and a 20% IFE postoperatively and developed diffuse pruritus 14 days after initiation of therapy. She showed transient improvement with intravenous antihistamine, but her symptoms did not resolve until the IFE was stopped. On the basis of clinical history, including aversion to egg, we performed skin-prick testing, the results of which were positive for egg white allergy. Serum testing confirmed allergy to both egg yolk and egg white. To our knowledge, this is the first reported case of a pediatric patient with a history suggestive of egg allergy, positive skin-prick and serum testing to egg, and reaction to IFE infusion. Although ingestion of egg lecithin in cooked food is generally tolerated by egg-allergic people, administration of intravenous egg-containing lipid emulsions may cause significant adverse reactions.

Effect of tetanus immunization on t-helper cytokine production in adults with and without allergic rhinitis

Epidemiological evidence links T-helper type 2 (Th2) cytokine responses to the pathogenesis of atopy/asthma. It is hypothesized that certain immunizations may induce/amplify Th2 cytokine responses. The objective of this study was to determine whether Th cytokine responses to immunization with tetanus toxoid differ in adults with and without allergic rhinitis (AR). Thirty subjects were enrolled (15 AR and 15 non-AR subjects as confirmed by history and allergy skin testing). Blood was collected before (day 0) and on days 3, 7, 14, and 28 after immunization with tetanus toxoid. Peripheral blood mononuclear cells (PMNCs) were purified and cultured with either PHA or tetanus toxoid for 2 or 6 days, respectively. Supernatants were harvested and assayed for IFN-gamma and IL-13 levels (pg/mL) by EIA. Results were normalized by log transformation and analyzed by stepwise regression. Baseline (day 0) cytokine values were similar in both groups. PHA and tetanus-induced IFN-gamma were increased (p < 0.05) in non-AR (3.2 +/- 0.3 and 1.4 +/- 0.3 on day 7, and 3.5 +/- 0.2 and 1.9 +/- 0.2 on day 14, respectively) compared with AR subjects (2.3 +/- 0.3 and 0.9 +/- 0.3 on day 7, and 2.7 +/- 0.3 and 1.2 +/- 0.3 on day 14, respectively). PHA-induced, but not tetanus-induced, IL-13 production was increased (p < 0.05) in non-AR compared with AR subjects on day 7 (p < 0.05). PHA-induced IL-13 production was 3.1 +/- 0.2 in non-AR and 2.6 +/- 0.3 in AR subjects on day 7. These results indicate differential Th cytokine responses in AR and non-AR subjects after immunization with tetanus toxoid. Future studies are warranted and may result in the identification of potential prevention/treatment strategies for atopy/asthma.