Hosne Ara Ferdousi

Specific immunotherapy has long-term preventive effect of seasonal and perennial asthma: 10-year follow-up on the PAT study.

Background:  3‐year subcutaneous specific immunotherapy (SIT) in children with seasonal allergic rhinoconjunctivitis reduced the risk of developing asthma during treatment and 2 years after discontinuation of SIT (5‐year follow‐up) indicating long‐term preventive effect of SIT.

Five-year follow-up on the PAT study : specific immunotherapy and long-term prevention of asthma in children

Background:  A 3‐year course of specific immunotherapy (SIT) in children with hay fever to grass and/or birch pollen significantly reduced the risk of developing asthma. To investigate the long‐term preventive effect, we performed a follow up – 2 years after termination of immunotherapy.

Asthma, bronchial hyperreactivity and mediator release in children with birch pollinosis. ECP and EPX levels are not related to bronchial hyperreactivity

Background Symptoms of allergic asthma are triggered by allergen exposure inducing allergic inflammation and hyperreactivity of the bronchi.

Bronchial hyper-responsiveness predicts the development of mild clinical asthma within 2 yr in school children with hay-fever

In children with mild asthma, symptoms are not always apparent. Therefore, results of tests play an important role for the diagnosis. First, to investigate whether children with bronchial hyper‐responsiveness (BHR) but no symptoms of asthma in 1992 had developed clinical asthma at follow up in 1994. The second aim was to find out the diagnostic properties of tests for asthma/allergic inflammation, using either doctor diagnosed asthma (DDA), self‐assessed symptoms of asthma or iso‐capnic hyperventilation of cold air (IHCA), as the standard, to diagnose asthma in a group of children with hay fever. Twenty‐eight children with pollinosis, 12 of them with a history of asthma for the first time during the season 1992, were studied during the birch pollen season and in the autumn of 1994. During both periods, the bronchial hyper‐reactivity was estimated by methacholine bronchial provocation tests (MBPT), bronchial variability by peak expiratory flow rate variability, subjective symptoms of asthma by visual analogue scale (VAS) and bronchial inflammation by serum and urine levels of inflammatory mediators. In 1994 IHCA was added during both seasons. Eight of 16 children with BHR but without clinical asthma in 1992 had developed asthma in 1994, 14 of 16 reacted to IHCA and 13 to MBPT. All 12 children with DDA in 1992 had still asthma in 1994 and 14 children with BHR in 1992 had persistent BHR in 1994. Of 23 children with BHR in 1992, 17 had DDA in 1994 and all maintained their BHR. Furthermore, 20 of them reacted to IHCA in 1994. In 1994, 24 of 28 hay‐fever children had a positive IHCA tests and 24 had positive MBPT. In relation to VAS, the sensitivity of IHCA and MBPT to predict present asthma was high, but the specificity low, whereas the specificity of most other tests was high, but based on few individuals. In relation to DDA both the IHCA test (65–80%) and the MBPT test (79–85%) had a high sensitivity and it was three to six times more likely to find a positive test among asthmatics than in non‐asthmatics. Children with hay fever without clinical asthma have a high risk of developing asthma within 2 yr. In relation to DDA, inhalation of cold air and the MBPT showed a high sensitivity.

Seasonal differences of peak expiratory flow rate variability and mediators of allergic inflammation in non-atopic adolescents

Variations in peak expiratory flow (PEF) and serum eosinophil mediators were studied in healthy adolescents. Twenty‐five boys and 31 girls, 11–16 years of age (mean age 14.3 years), were selected and investigated during the birch pollen season of 1995; 45 were also investigated during the autumn of the same year. The PEF was measured twice daily and eosino‐phil mediators in serum and in urine were measured by radioimmunoassay (RIA) once during the birch pollen season and once in autumn. The type values of the daily PEF variation, expressed in amplitude percentage mean, were 6.4 and 3.9%, mean values were 7.35 and 6.74%, and the 95th percentiles were 18 and 14%, during the birch pollen season and autumn, respectively. The 95th percentiles were 41 and 38 µg/l for serum eosinophil cationic protein (s‐ECP), 74 and 62 µg/l for serum eosinophil protein X (s‐EPX), 987 and 569 µg/l for serum myeloperoxidase (s‐MPO), and 165 and 104 µg/mmol for urinary eosinophil protein X/urinary creatinine (u‐EPX/u‐creatinine), during the birch pollen season and autumn, respectively. The levels of the eosinophil mediators decreased significantly from May (n = 56) to November (n = 45), for s‐ECP from a median value of 14 µg/l to 7 µg/l (p= 0.001), for s‐EPX from a median value of 28 µg/l to 20 µg/l (p= 0.001), and for the neutrophil mediator, s‐MPO, from a median value of 440 g/l to 292 g/l (p< 0.001). The PEF variability decreased significantly (p= 0.037), from spring (n = 55; median 8%, 95% confidence interval [CI] 7.8–10.19) to autumn (n = 44; median 6%, 95% CI 6.1–8.9). A significant correlation was found between the levels of s‐ECP and s‐EPX (rs = 0.7, p< 0.001), between s‐ECP and s‐MPO (rs = 0.6, p< 0.001), between s‐EPX and s‐MPO (rs = 0.4, p< 0.005), and between s‐EPX and u‐EPX/u‐creatinine (rs = 0.6, p< 0.0001), in the birch pollen season (n = 56) and in the autumn (n = 45). There was a positive correlation found in PEF variability between the two seasons (n = 43; rs = 0.5, p= 0.0006). No other correlation was found between PEF variability and any other parameters. The difference in the levels of eosinophil mediators between seasons in non‐atopic, healthy children is unexplained. Normal limits for mediators were higher and PEF variability was almost the same as has been reported in adults. When using normal values, seasonal influences should be considered.