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- Ferdousi, Hosne Ara, 1957-
(författare)
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Pollinosis in children with special reference to the development of asthma
- 2004
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Children with rhinoconjunctivitis and increased bronchial hyperreactivity (BHR) are prone to develop asthma later in life. Eosinophil granule proteins in serum are indirect measures of eosinophil activity and regarded as markers of inflammation. Measurement of eosinophil cationic protein (ECP) has also been evaluated for prediction, diagnosis and monitoring of treatment in children with asthma. In 1992, a multicenter preventive allergy treatment study (PAT-study) was started in order to prevent the development of asthma in children with pollinosis using specific immunotherapy treatment (SIT). Sensitization to cat allergen is common in asthma and up to 50% of children with asthma are sensitized. Exposure to cat allergen can not be avoided because exposure occurs in schools and even in homes without a cat and is a major cause of persisting airway inflammation and asthma in cat sensitized schoolchildren. Data are needed to know the level of allergen maintaining BHR or asthma.The aims of the thesis were: 1) To assess the relationship between seasonal symptoms of allergy, BHR, PEP-variability and release of markers of inflammation. 2) To investigate the level of markers of inflammation, and PEF variability, in healthy school children. 3) To investigate the diagnostic value of the tests e.g. BHR and mediators of allergic inflammation for diagnosis of asthma in pollinosis. 4) To investigate the efficacy of SIT regarding prevention of asthma, BHR, and polysensitization. 5) To assess, the levels of cat allergens inhaled daily by asthmatic schoolchildren sensitized to cat and relate the levels of allergen to symptoms of asthma and BHR.The PAT study population comprised 205 birch and/or grass pollen allergic children with pollinosis, from 7 centres in 5 countries in Northern and Central Europe, 28 were enrolled in the Linköping. We recruited 56 healthy school children to study the normal level of inflammatory markers and PEFR variability and 10 asthmatic schoolchildren sensitized to cat to assess the allergen levels in their daily environment.In the pollinosis children, sensitization status was determined by skin and conjunctival provocation test and RAST. Mediators of allergic inflammation like ECP, EPX, and neutrophil mediators like MPO were measured by RIA methods, non-specific BHR by Methacholine and/or cold air challenge tests and bronchial lability by PEF variability using Mini Wrights Peak-Flow meters. The level of cat allergens in dust samples were measured by ELISA, and in air by amplified ELISA methods. SIT was given by birch and/or grass pollen allergen extracts (Alutard), during a period of 3 years.In pollinosis children in Linköping, there was no correlation between mediators of allergic inflammation in serum and symptoms and signs of clinical asthma. BHR and PEFR-variability persisted in the autumn, though s-ECP and s-EPX did not, indicating that mediators of inflammation do not reflect asthma. Positive MBPT and IHCA tests were more often found in the children with clinical asthma. The other investigated tests were not useful for screening of asthma in this group of children with pollinosis. In healthy schoolchildren, the mean daily PEF variations were 7.35 and 6.74%, and the 9Sth percentiles were 18 and 14% during the spring and autumn respectively. The 95th percentils for s-ECP were 41 and 38 µg/L, for s-EPX 74 and 62µg/L, for s-MPO 987 and 569 µg/L and for u-EPX tucreatinine 165 and 104 µg/mmol, during spring and autumn, respectively. Our findings for mediator levels in schoolchildren were higher than reported in adults. There was a significant decrease in the levels of the eosinophil and neutrophil mediators from May to November (p ≤ 0.001) and so did the PEF variability (p=0.037) in our healthy children. As normal reference values post seasonal data would be more appropriate. In the environment of cat sensitive children, exposure levels of cat allergen varied from 0.5 µg/g to 751 µg/g dust in homes (median, 36 µg/g) and from 17 µg/g to 378 µg/g in schools (median, 137 µg/g). Airborne allergen levels varied from 13 to 2184 pg/m3 (median, 43 pg/m3 ) in the homes and 68 to 7718 pg/m3 (median 352 pg/m3) in the schools. The inhaled dose was 8 pg to 2336 pg/min. A relation between BHR and exposure level was found. In the PAT-study, children actively treated with SIT had significantly fewer asthma symptoms after 3 years (odds ratio 2.52; p<0.05) and MBPT was improved (p<0.05) compare to the control group. Thus, SIT reduced the development of asthma in our children with pollinosis.We followed the pollinosis children in Linköping in our centre for 11 years. Our findings were: I) there was a trend of diminishing in sensitivity to MBPT and in PEF variation with age. 2) Pollen counts in different years influenced MBPT results in that particular year. 3) MBPT in 1992 could predict the development of asthma in 1994.
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| 2. |
- Lundbäck, Bo, et al.
(författare)
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An interview study to estimate prevalence of asthma and chronic bronchitis : The obstructive lung disease in northern Sweden study
- 1993
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Ingår i: European Journal of Epidemiology. - 0393-2990 .- 1573-7284. ; 9:2, s. 123-133
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Tidskriftsartikel (refereegranskat)abstract
- A questionnaire of respiratory symptoms and diseases completed by 6610 adults in 3 age cohorts (35-36 y; 50-51 y and 65-66 y) in northern Sweden was followed-up by interview and lung function testing of 1243 subjects with asthmatic or bronchitic symptoms and 263 subjects assessed from the postal questionnaire as being healthy. We report the results of this follow-up study. According to the criteria used, 292 subjects (5.1% of the original study sample) were diagnosed as having asthma. Out of the 1243 subjects 334 (5.9% of the original study population) were diagnosed as having chronic bronchitis. However, examination of the 263 subjects who were healthy according to the postal questionnaire showed that elderly smokers, in particular, under-reported bronchitic symptoms; taking this into account, the prevalence of chronic bronchitis is estimated to be of the order of 9%. Diagnostic difficulties were noted in 70 subjects (corresponding to 1.2% of the original study sample) in whom asthma or chronic bronchitis were strongly suspected. Further investigation of these subjects was considered necessary. In this cross-sectional study, FEV1 < 80% of predicted values was found in 36% of subjects diagnosed as having asthma and in 31% of those with chronic bronchitis. Among subjects with attacks of breathlessness and wheezing, diagnostic criteria often used for asthma in questionnaire studies, 70% were diagnosed as having asthma. Of those with chronic productive cough, 62% were diagnosed as having chronic bronchitis. We consider that trained nurses provide reliable data that may be used in epidemiological surveys of obstructive lung diseases
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| 3. |
- Lundbäck, Bo, et al.
(författare)
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Epidemiology of respiratory symptoms, lung function and important determinants : Report from the Obstructive Lung Disease in Northern Sweden project
- 1994
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Ingår i: Tubercle and Lung Disease. - 0962-8479 .- 1532-219X. ; 75:2, s. 116-126
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Tidskriftsartikel (refereegranskat)abstract
- SETTING: Cross-sectional epidemiological study based on a representative sample of the general population in northern Sweden. OBJECTIVES: To assess the prevalence of respiratory symptoms, the role of respiratory symptoms as indicators of impairment of lung function, and to define risk factors for respiratory symptoms and lung function impairment. DESIGN: The 1340 subjects of 6610 who reported respiratory symptoms suggestive of asthma or chronic bronchitis in a postal questionnaire study were invited to a structured interview and lung function tests. A control group of 315 subjects was also invited. Risk factors were assessed from the postal questionnaire. RESULTS: 400 subjects in the symptomatic group had attacks of breathlessness and wheezing, while none in the control group had them, corresponding to 7% of the original study population. Chronic productive cough was present in 537 subjects, of whom 13 were from the control group, suggesting that 12% of the original study population had this symptom. Persistent wheeze was the symptom that predicted the greatest proportion of cases of impaired lung function. Attacks of breathlessness, wheezing, long-standing cough and sputum production were all related to age, smoking and a family history of asthma. Both chronic productive cough and impaired lung function correlated strongly with smoking and age, and their prevalences differed in different socio-economic groups. CONCLUSION: Impaired lung function can be predicted from respiratory symptoms. Data collected in postal questionnaires suffice for the identification of risk factors. Combinations of symptoms gave greater odds ratios than individual symptoms.
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| 4. |
- Lundbäck, Bo, et al.
(författare)
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Methacholine reactivity and asthma : Report from the Northern Sweden Obstructive Lung Disease Project
- 1993
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Ingår i: Allergy. European Journal of Allergy and Clinical Immunology. - : Wiley. - 0105-4538 .- 1398-9995. ; 48:2, s. 117-124
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Tidskriftsartikel (refereegranskat)abstract
- Methacholine tests were used in an epidemiologic study of the prevalence of asthma and chronic bronchitis in northern Sweden. Of 6610 subjects in three age groups from eight representative geographic areas in the northernmost province of Sweden, 5698 (86%) completed a postal questionnaire on respiratory symptoms, and 1506 underwent a structured interview and a lung function test. A total of 292 (5%) were diagnosed as having asthma. A subsample of 284 subjects (of 320 invited) classified at the interview as having asthma (n = 98) or as having respiratory symptoms that might be due to asthma but not fulfilling the interview criteria for the diagnosis of asthma (n = 186) underwent a methacholine test. Subjects who, before the interview study, already had a well-defined asthma diagnosis were not invited to the methacholine testing. Of those 98 subjects classified as having asthma, 61% reacted to methacholine doses < or = 4 mg/ml and 79% to doses < or = 8 mg/ml, while the corresponding figures in the symptomatic but nonasthma group were 20% and 34%, respectively. The results show that a carefully performed structured interview accurately diagnoses asthma in epidemiologic studies. The methacholine tests provide important diagnostic information primarily in subjects in whom the medical history is equivocal
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| 5. |
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| 6. |
- Sandstrom, T, et al.
(författare)
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Inflammatory cell response in bronchoalveolar lavage fluid after nitrogen dioxide exposure of healthy subjects: a dose-response study
- 1991
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Ingår i: European Respiratory Journal. - 1399-3003. ; 4:3, s. 332-339
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Tidskriftsartikel (refereegranskat)abstract
- The combination of environmental chamber exposure and bronchoalveolar lavage (BAL) was used to study the effects of the common air pollutant nitrogen dioxide (NO2). Eighteen healthy nonsmokers were exposed to NO2 during 20 min in an exposure chamber during light bicycle ergometer work. All subjects were examined with BAL at least 3 wks before exposure, as a reference. The subjects were re-examined with BAL, in groups of eight, 24 h after exposure to 4, 7 and 10 mg NO2.m.3 (2.25, 4.0 and 5.5 ppm), respectively. An inflammatory cell response was found after exposure to all concentrations. An increase in the number of lymphocytes in BAL fluid was observed after 7 and 10 mg.m.3 (p less than 0.05 and 0.02, respectively). An increase in the number of mast cells, that appears to be dose-dependent, was found after exposure to all concentrations. The proportion of lysozyme positive alveolar macrophages was elevated after exposure to 7 mg.m.3. The inflammatory mediators fibronectin, hyaluronan, angiotensin converting enzyme (ACE) and beta 2-microglobulin were unchanged by exposure. Due to the findings of inflammatory cell changes far below the peak exposure limits for work places in industrialized countries, 9-18 mg.m.3, the safety of these limits is questioned. Studies are in progress in our laboratory using BAL to evaluate the effects of repeated NO2 exposure.
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