Allergy, Asthma, and Clinical Immunology : Official Journal of the Canadian Society of Allergy and Clinical Immunology最新文献

The novel coronavirus disease of 2019 (COVID-19) pandemic has severely impacted the training of health care professional students because of concerns of potential asymptomatic transmission to colleagues and vulnerable patients. From May 27th, 2020, to June 23rd 2021; at a time when B.1.1.7 (alpha) and B.1.617.2 (delta) were the dominant circulating variants, PCR testing was conducted on 1,237 nasopharyngeal swabs collected from 454 asymptomatic health care professional students as they returned to their studies from across Canada to Kingston, ON, a low prevalence area during that period for COVID-19. Despite 46.7% of COVID-19 infections occurring in the 18-29 age group in Kingston, severe-acute-respiratory coronavirus-2 was not detected in any of the samples suggesting that negligible asymptomatic infection occurred in this group and that PCR testing in this setting may not be warranted as a screening tool.

Background: Cases of food allergy after hematopoietic stem cell and solid organ transplantation in previously nonallergic transplant recipients were reported as transplant-acquired food allergy (TAFA), but information about its long-term outcome is still limited. A phenomenon where patients reacquire food allergy by resuming daily consumption after a negative oral food challenge has not yet been reported.

Case presentation: We report two cases of TAFA after liver transplantation and cord blood transplantation. In each case, the threshold of daily consumption to cause allergic symptoms decreased when a negative oral food challenge was obtained.

Conclusions: Our cases show an importance of gastrointestinal tract as a route of food sensitization because thresholds that caused allergic reactions decreased during their resuming process. We need to be careful with possible resensitization once a negative substantial dose was confirmed.

Background: Selective IgA deficiency (SIgAD) is the most prevalent inborn errors of immunity with almost unknown etiology. This study aimed to investigate the clinical diagnostic and prognostic values of lymphocyte subsets and function in symptomatic SIgAD patients.

Methods: A total of 30 available SIgAD patients from the Iranian registry and 30 age-sex-matched healthy controls were included in the present study. We analyzed B and T cell peripheral subsets and T cell proliferation assay by flow cytometry in SIgAD patients with mild and severe clinical phenotypes.

Results: Our results indicated a significant increase in naïve and transitional B cells and a strong decrease in marginal zone-like and switched memory B-cells in SIgAD patients. We found that naïve and central memory CD4⁺ T cell subsets, as well as Th1, Th2 and regulatory T cells, have significantly decreased. On the other hand, there was a significant reduction in central and effector memory CD8⁺ T cell subsets, whereas proportions of both (CD4⁺ and CD8⁺) terminally differentiated effector memory T cells (T_EMRA) were significantly elevated in our patients. Although some T cell subsets in severe SIgAD were similar, a decrease in marginal-zone and switched memory B cells and an increase in CD21^low B cell of severe SIgAD patients were slightly prominent. Moreover, the proliferation activity of CD4⁺ T cells was strongly impaired in SIgAD patients with a severe phenotype.

Conclusion: SIgAD patients have varied cellular and humoral deficiencies. Therefore, T cell and B cell assessment might help in better understanding the heterogeneous pathogenesis and prognosis estimation of the disease.

Background: Patients widely use medical identification (ID) to indicate their food and drug allergies, and chronic medical conditions. One chronic condition for which patients are recommended to use a form of medical ID is Aspirin-Exacerbated Respiratory Disease (AERD), a disease characterized by the presence of asthma, chronic rhinosinusitis with nasal polyps and sensitivity to aspirin and other COX-1 inhibitors, including nonsteroidal anti-inflammatory drugs (NSAIDs). The uptake of medical ID use in AERD is unknown and has not been widely studied in this population.

Methods: We conducted a cross-sectional survey study to measure the perception of the need to use a medical ID and its use by patients with AERD internationally.

Results: 245 members of an online AERD support group completed an online survey. The majority (80%, n = 198) of the participants did not use any form of medical ID. The participants reported that the lack of knowledge and awareness about the importance of using a medical ID was the most common reason for not using it.

Conclusion: This international survey found that the majority of the AERD patient respondents did not use a medical ID. The most common reasons for nonuse were not knowing that it is recommended for their condition and that the patients did not consider it necessary. The results highlight the need for further patient and health care provider education.

Purpose: Peanut allergy and its current management, involving peanut avoidance and use of rescue medication during instances of accidental exposure, are burdensome to patients and their caregivers and can be a source of stress, uncertainty, and restriction. Physicians may also be frustrated with a lack of effective and safe treatments other than avoidance in the current management of peanut allergy. Efficacy, determined using double-blind, placebo-controlled food challenges (DBPCFCs), of oral immunotherapy with peanut (Arachis hypogaea) allergen powder-dnfp (PTAH; Palforzia^®) was demonstrated versus placebo in children and adolescents aged 4 to 17 years in multiple phase 3 trials; continued benefit of PTAH was shown in a follow-on trial. The DBPCFC is a reproducible, rigorous, and clinically meaningful assessment accepted by regulatory authorities to evaluate the level of tolerance as an endpoint for accidental exposures to peanut in real life. It also provides useful clinical and patient-relevant information, including the amount of peanut protein an individual with peanut allergy can consume without experiencing dose-limiting symptoms, severity of symptoms, and organs affected upon ingestion of peanut protein. We explored symptoms of peanut exposure during DBPCFCs from phase 3 and follow-on trials of PTAH to further characterize treatment efficacy from a perspective relevant to patients, caregivers, and clinicians.

Methods: Symptom data recorded during screening and/or exit DBPCFCs from participants aged 4 to 17 years receiving PTAH or placebo were examined post hoc across three PTAH trials (PALISADE [ARC003], ARC004 [PALISADE follow-on], and ARTEMIS [ARC010]). The maximum peanut protein administered as a single dose during DBPCFCs was 1000 mg (PALISADE and ARTEMIS) and 2000 mg (ARC004). Symptoms were classified by system organ class (SOC) and maximum severity. Endpoints were changes in symptom severity and freedom from symptoms (ie, asymptomatic) during DBPCFC. Relative risk (RR) was calculated for symptom severity by SOC and freedom from symptoms between groups; descriptive statistics were used to summarize all other data.

Results: The risk of any respiratory (RR 0.42 [0.30-0.60], P < 0.0001), gastrointestinal (RR 0.34 [0.26-0.44], P < 0.0001), cardiovascular/neurological (RR 0.17 [0.08-0.39], P < 0.001), or dermatological (RR 0.33 [0.22-0.50], P < 0.0001) symptoms was significantly lower in participants treated with PTAH versus placebo upon exposure to peanut at the end of the PALISADE trial (ie, exit DBPCFC). Compared with placebo-treated participants (23.4%), the majority (76.3%) of PTAH-treated participants had no symptoms at the exit DBPCFC when tested at the peanut protein dose not tolerated (ie, reactive dose) during the screening DBPCFC. Significantly higher proportions of PTAH-treated participants were asymptomatic at doses ≤ 100 mg in the exit DBPCFC compar

Background: Subcutaneous immunotherapy (SCIT) is a well-validated and effective disease modification treatment for house dust mites (HDM)-induced allergic rhinitis (AR). Long-term post-treatment comparisons in children and adults treated with SCIT have rarely been published. This study aimed to evaluate the long-term efficacy of HDM-SCIT administered under a cluster schedule in children compared to adults.

Methods: This was an open-design, observational, long-term clinical follow-up study on children and adults with perennial AR treated with HDM-SCIT. The follow-up consisted of a three-year treatment duration plus a post-treatment follow-up of over three years.

Results: Patients in the pediatric (n = 58) and adult (n = 103) groups completed a post-SCIT follow-up of over three years. The total nasal symptom score (TNSS), combined symptom medication score (CSMS), and rhinoconjunctivitis quality-of-life questionnaire (RQLQ) score decreased significantly at T1 (three-year SCIT completed) and T2 (follow-up completed) in the pediatric and adult groups. In both groups, the improvement rate of TNSS (T0-T1) was moderately correlated with the baseline TNSS (r = 0.681, p < 0.001 and r = 0.477, p < 0.001 for children and adults, respectively). Only in the pediatric group, TNSS was significantly lower at T2 compared with that right after SCIT cessation (T1) (p = 0.030).

Conclusions: Children and adults with HDM-induced perennial AR could achieve a sustainable post-treatment efficacy for over three years (up to 13 years) following a three-year SCIT. Patients with relatively severe nasal symptoms at baseline may benefit more from SCIT. Children who have completed an adequate course of SCIT may gain further improvement in nasal symptoms after SCIT cessation.

Background: Previous studies have shown that CD134 (OX40) co-stimulation is involved in the pathogenesis of experimental autoimmune encephalomyelitis (EAE) models and the antigen is expressed within multiple sclerosis lesions in humans. OX40 (CD134) is thought to be a secondary co-stimulatory immune checkpoint molecule that is expressed by T cells. This study aimed to evaluate the mRNA expression of OX40 and its serum levels in the peripheral blood of patients with Multiple Sclerosis (MS) or Neuromyelitis Optica (NMO).

Methods: Patients with MS (n = 60), NMO (n = 20), and 20 healthy subjects were recruited from Sina Hospital, Tehran, Iran. The diagnoses were confirmed by a specialist in clinical neurology. Peripheral venous blood was obtained from all subjects, and mRNA quantification of OX40 was conducted using real-time PCR. Serum samples were also obtained and the concentration of OX40 was determined using an enzyme-linked immunosorbent assay (ELISA).

Results: There was a significant correlation between the mRNA expression and serum levels of OX40 and disability as assessed using the expanded disability status scale (EDSS) in the patients with MS, but not in the patients with NMO. Expression of OX40 mRNA was significantly higher in the peripheral blood of MS patients compared to healthy individuals and NMO patients (*P < 0.05). In addition, serum OX40 concentrations were also significantly higher in patients with MS patients compared with healthy subjects (9.08 ± 2.48 vs. 1.49 ± 0.54 ng/ml; P = 0.041).

Conclusions: It appears that an increased expression of OX40 may be associated with the hyperactivation of T cells in patients with MS, and this may play a role in the pathogenesis of the disease.

Background: Results of studies evaluating the relationship between asthma occurrence and early life antibiotic use have been conflicting. The aim of this study was to investigate the relationship between occurrence of asthma in children and systemic antibiotic use in the first year of life based on an incidence density study with careful consideration of the temporal aspects of the determinant-outcome relationship.

Methods: We conducted an incidence density study nested in a data collection project with information on 1128 mother-child pairs. Systemic antibiotic use in the first year of life was defined as excessive (≥ 4 courses) vs. non-excessive (< 4 courses) use based on information from weekly diaries. Events (cases) were defined as the first parent-reported occurrence of asthma in a child between 1 and 10 years of age. Population time 'at risk' was probed by sampling population moments (controls). Missing data were imputed. Multiple logistic regression was used to assess the association between current first asthma occurrence (incidence density) and systemic antibiotic use in the first year of life, to evaluate effect modification and adjust for confounding.

Results: Forty-seven first asthma events and 147 population moments were included. Excessive systemic antibiotic use in the first year of life showed more than twice the incidence density of asthma compared to non-excessive use (adjusted IDR [95% CI]: 2.18 [0.98, 4.87], p = 0.06). The association was more pronounced in children who have had lower respiratory tract infections (LRTIs) in the first year of life compared to children who had no LRTIs in the first year of life (adjusted IDR [95% CI]: 5.17 [1.19, 22.52] versus 1.49 [0.54, 4.14]).

Conclusions: Excessive use of systemic antibiotics in the first year of life may play a role in the genesis of asthma in children. This effect is modified by the occurrence of LRTIs in the first year of life, with a stronger association observed in children experiencing LRTIs in the first year of life.

Background: The most frequent non-immediate reactions described with iodinated contrast media (ICM) are mild to moderate, however, some cases of patients with severe non-immediate reactions, such as drug eruption with eosinophilia and systemic symptoms (DRESS) have been described.

Case presentation: An 84-year-old patient developed DRESS syndrome after administration of ICM ioversol. The patient fullfilled the RegiSCAR diagnostic criteria for DRESS (definite score = 6). He underwent intradermal skin testing (IDT) with the widest panel of ICM available at our center. IDT was positive with ioversol and iomeprol. A punch biopsy was performed on the positive IDT with the culprit drug (ioversol) and histopathology was compatible with a T-cell mediated mechanism.

Conclusion: In this case, the IDT-positive biopsy was consistent with DRESS syndrome caused by T-lymphocyte activation, supporting the clinical diagnosis.

Background: Penicillin allergy is a commonly listed medication allergy despite rare overall incidence. Many patients erroneously have this label, which has personal, health, and societal costs. Penicillin allergy delabelling requires an oral challenge, which can be a rate limiting step in the de-labeling process; this is even more relevant with the reduction of in-person visits during the COVID-19 pandemic.

Objective: To identify the utility and broader applicability of using a virtually supported platform, initially adopted given COVID-19 restrictions, to expedite penicillin oral provocation challenge and penicillin de-labeling in patients at low to moderate risk of immediate hypersensitivity reaction and based on shared decision making.

Methods: Patients in Vancouver catchment area were referred for penicillin allergy and virtually assessed by the consulting allergist between July 2020 and April 2021. Those deemed appropriate for oral challenge based on the allergist consultant were offered the option of a virtual oral provocation challenge to oral amoxicillin in a subsequent virtual visit. Patients who agreed and were consented underwent a virtually supervised oral amoxicillin challenge during the second virtual visit. Findings are summarized in this case series.

Results: Twenty-three patients, both adult and pediatric, ranging from no to significant co-morbidities were consented and underwent the virtual challenge. One hundred percent of patients were successful with no reaction after an hour post virtual oral provocation challenge with amoxicillin.

Conclusion: Virtual medicine is likely to remain in the allergist's practice. Virtually supported penicillin allergy delabelling, based on shared decision making and risk stratification, presents another pathway for penicillin allergy delabelling.