ABSTRACT
BACKGROUND: Specific IgE measurement predicts the outcome of oral food challenges with considerable uncertainty when evaluating food allergy. OBJECTIVE: Our aim was to assess whether accounting for the ratio of component- or allergen-specific to total IgE can improve this prediction. METHODS: This multicenter study collected blood samples from children with suspected peanut or hazelnut allergy referred to allergy specialist clinics for food challenges. Specific IgE to peanuts, hazelnuts, and their components (Ara h 1, Ara h 2, Ara h 3, Ara h 8, Cor a 1, Cor a 8, Cor a 9, and Cor a 14) and total IgE levels were determined by using the ImmunoCAP-FEIA. Specific to total IgE ratios were compared with raw IgE levels in terms of discrimination and prediction. RESULTS: Eighty-eight (43%) of 207 children with suspected peanut allergy and 44 (31%) of 142 children with suspected hazelnut allergy had symptoms during food challenge. Discrimination was similar for raw and ratio measures: areas under the curve of 0.93 for Ara h 2-specific IgE versus 0.92 for the Ara h 2-specific/total IgE ratio and 0.89 for Cor a 14-specific IgE versus 0.87 for the Cor a 14-specific/total IgE ratio. The probability for a positive peanut challenge with 0.35 kU/L Ara h 2-specific IgE was 16% when the total IgE level was greater than 500 kU/L compared with 51%/48% for low/medium total IgE levels (<100/100-500 kU/L). A positive hazelnut challenge with 0.35 kU/L Cor a 14-specific IgE was estimated in 7% when total IgE levels were high compared with 34%/32% with low/medium total IgE levels. CONCLUSIONS: Raw Ara h 2- and Cor a 14-specific IgE levels were the best single predictors for pediatric peanut and hazelnut allergies, suggesting the omission of challenges at very high levels. Calculating ratio measures did not improve prediction in this population. However, estimation of individual probabilities for challenge outcomes could be supported by total IgE levels because high levels might indicate lower probabilities at a given component-specific IgE level.
Subject(s)
Arachis/adverse effects , Corylus/adverse effects , Immunoglobulin E/immunology , Nut Hypersensitivity/diagnosis , Nut Hypersensitivity/immunology , Allergens/administration & dosage , Allergens/immunology , Antibody Specificity/immunology , Antigens, Plant/immunology , Area Under Curve , Child , Child, Preschool , Comorbidity , Female , Humans , Immunization , Immunoglobulin E/blood , Infant , Male , Peanut Hypersensitivity/diagnosis , Peanut Hypersensitivity/immunology , ROC CurveABSTRACT
BACKGROUND: Long-term adherence to positive airway pressure (PAP) treatment is essential in patients with obstructive sleep apnea syndrome (OSAS). OBJECTIVES: The aim of the present study was to analyze treatment adherence under real-life conditions and factors associated with discontinuation of PAP therapy. METHODS: Patients newly diagnosed with OSAS and started on PAP therapy were contacted by telephone after a minimum of 1 year. Side effects, quality of life, subjective treatment adherence and Epworth Sleepiness Scale (ESS) scores were assessed. Objective treatment adherence was calculated by reading the built-in run time counter of the PAP device. Anthropometric parameters, level of education, apnea-hypopnea index (AHI), ESS score and the type of PAP therapy prescribed at the time of the first stay in the sleep lab were collected retrospectively. RESULTS: Median follow-up was 13 months (range 7-18 months). Of 303 patients (69 female, 234 male) available for this study, 191 patients (63%) still used the PAP device regularly ('users'), while 83 (27.4%) had definitively discontinued PAP treatment ('nonusers'). In the nonusers group, 29 patients (34.9%) discontinued PAP treatment within the first 3 months. In the users group, subjective PAP usage was 6.6 ± 1.5 h/night and objective adherence was 4.7 ± 2.3 h/night. Objective nightly use of PAP treatment correlated significantly with baseline AHI (r = 0.13, p = 0.041) but not with sex, age, body mass index, ESS score or education level. Patients with a low AHI and ESS score and patients without a coexisting medical condition or with more than two comorbidities tended to discontinue PAP therapy more frequently. CONCLUSIONS: PAP treatment adherence has to be optimized in OSAS patients. When initiating PAP therapy, clinicians have to focus on those patients at risk for discontinuing treatment. Education sessions and closer follow-up are possible strategies to improve treatment adherence and to avoid treatment discontinuation.
