Basal serum tryptase is not a risk factor for immediate-type drug hypersensitivity during childhood.

BACKGROUND: High serum basal tryptase (sBT) levels have been identified as a risk factor for both venom- and food-induced severe allergic reactions. The aim of this study was to compare sBT levels in children with different severity of actual drug hypersensitivity reactions (DHRs) with those of age- and sex-matched controls without any history of DHRs. METHOD: Patients between 0 and 18 years of age with a history of immediate-type DHRs manifested in 0-6 h after the culprit drug intake were included. Following ENDA (European Network for Drug Allergy) inquiries, patients were evaluated with skin and/or provocation tests to define the actual drug-hypersensitive patients. Serum BT levels were determined for both patients and controls. RESULTS: Of 345 children, 106 patients (30.7%) [(58.5% male), median age (interquartile range) 8.0 years (4.2-12.2)] were diagnosed as drug hypersensitive. Ninety-eight controls were also included. The sBT levels of drug-hypersensitive patients with and without anaphylaxis and the control group were similar [2.6 (2.0-3.6) µg/l vs. 2.8 (1.6-4.3) µg/l vs. 2.6 (1.8-3.6) µg/l, respectively, (p > 0.05)]. The sBT levels of the patients with sole cutaneous symptoms 2.8 (1.6-4.3) µg/l, mild anaphylaxis 3.0 (1.9-4.9) µg/l, and moderate-to-severe anaphylaxis 2.6 (2.0-3.6) µg/l were also comparable (p > 0.05). The onset of DHRs [those occurring in 1 h (n = 87) or in 1-6 h (n = 19) after the drug intake], positive results with skin tests with the culprit drug, or the classification of the patients according to different age groups [(0-2 years), (2-6 years), (6-12 years), (12-18 years)] did not correlate with sBT levels. CONCLUSION: The sBT levels in children with actual drug hypersensitivity would not be a risk factor for severe systemic reactions on the contrary to children with allergic reactions to food or insect venom.

Doublesex and mab-3 related transcription factor 1 (DMRT1) is a sex-specific genetic determinant of childhood-onset asthma and is expressed in testis and macrophages.

BACKGROUND: Asthma is a disease affecting more boys than girls in childhood and more women than men in adulthood. The mechanisms behind these sex-specific differences are not yet understood. OBJECTIVE: We analyzed whether and how genetic factors contribute to sex-specific predisposition to childhood-onset asthma. METHODS: Interactions between sex and polymorphisms on childhood asthma risk were evaluated in the Multicentre Asthma Genetics in Childhood Study (MAGICS)/Phase II International Study of Asthma and Allergies in Childhood (ISAAC II) population on a genome-wide level, and findings were validated in independent populations. Genetic fine mapping of sex-specific asthma association signals was performed, and putatively causal polymorphisms were characterized in vitro by using electrophoretic mobility shift and luciferase activity assays. Gene and protein expression of the identified gene doublesex and mab-3 related transcription factor 1 (DMRT1) were measured in different human tissues by using quantitative real-time PCR and immunohistochemistry. RESULTS: Polymorphisms in the testis-associated gene DMRT1 displayed interactions with sex on asthma status in a population of primarily clinically defined asthmatic children and nonasthmatic control subjects (lowest P = 5.21 × 10(-6)). Replication of this interaction was successful in 2 childhood populations clinically assessed for asthma but showed heterogeneous results in other population-based samples. Polymorphism rs3812523 located in the putative DMRT1 promoter was associated with allele-specific changes in transcription factor binding and promoter activity in vitro. DMRT1 expression was observed not only in the testis but also in lung macrophages. CONCLUSION: DMRT1 might influence sex-specific patterns of childhood asthma, and its expression in testis tissue and lung macrophages suggests a potential involvement in hormone or immune cell regulation.

Anaphylactic reaction to polyethylene-glycol conjugated-asparaginase: premedication and desensitization may not be sufficient.

In hypersensitive reactions to native L-asparaginase, either premedication and desensitization or substitution with polyethylene glycol conjugated asparaginase (PEG-ASP) is preferred. Anaphylaxis with PEG-ASP is rare. An 8-year-old girl and a 2.5-year-old boy, both diagnosed as having acute lymphoblastic leukemia, presented with native L-asparaginase hypersensitivity and substitution with PEG-ASP was preferred. They received a premedication (methylprednisolone, hydroxyzine and ranitidine) followed by desensitization with PEG-ASP infusion. Both patients developed anaphylaxis with peg-asparaginase. These are the first reported cases of anaphylactic reaction to PEG-ASP, despite the application of both premedication and desensitization. Anaphylaxis with PEG-ASP is very rare and premedication and desensitization protocols may not prevent these hypersensitive reactions.