Risk factors for asthma after infant bronchiolitis.

BACKGROUND: Five studies carried out after bronchiolitis at less than 24 months of age, with a follow-up of more than 10 years, reported that atopic dermatitis, family asthma, early-life exposure to tobacco smoke and rhinovirus aetiology were early-life risk factors for later asthma. This study evaluated the long-term outcome at 11-13 years of age of children who were hospitalized for bronchiolitis in early infancy. METHODS: We previously prospectively followed 166 children hospitalized for bronchiolitis at less than 6 months of age until 5-7 years of age. The current study included a structured questionnaire, parental interviews, clinical examinations and bronchodilation test of 138 of those children at 11-13 years of age. RESULTS: Respiratory syncytial virus caused 66% of the bronchiolitis cases, and nearly half of the patients were exposed to tobacco smoke in early life. Doctor-diagnosed asthma was present in 13% of the former bronchiolitis patients at 11-13 years of age. Maternal asthma was the only independently significant risk factor in early life (adjusted OR 3.45, 95% CI 1.07-11.74), as was allergic rhinitis at 5-7 years of age (adjusted OR 4.06, 95% CI 1.35-12.25). CONCLUSIONS: After bronchiolitis at less than 6 months of age, the risk of doctor-diagnosed asthma at 11-13 years was about twice that of the general Finnish population. Maternal asthma was the only independently significant early-life risk factor for current asthma at 11-13 years of age.

Asthma and lung function in adulthood after a viral wheezing episode in early childhood.

BACKGROUND: Viral aetiology of infection has a significant role in the long-term outcome of early-childhood wheezing. OBJECTIVE: This study examines asthma and lung function in adulthood after early-childhood wheezing induced by respiratory syncytial virus (RSV) and rhinovirus (RV). METHODS: A total of 100 children were hospitalized for a wheezing episode at less than 24 months of age from 1992 to 1993 in Kuopio University Hospital (Finland). Adenovirus, influenza A and B virus, parainfluenza (1-3) virus, and RSV were tested on admission using antigen detection and antibody assays, and RSV and RV were tested by polymerase chain reaction (PCR). In 2010, 49 cases and 60 population controls attended a follow-up study, which included spirometry with bronchodilation test and fractionally exhaled nitric oxide (FENO ) measurements. RESULTS: Current asthma was present in 64% of the cases with RV-induced wheezing (OR 17.0 [95%CI 3.9-75.3] vs controls), in 43% of the cases with RSV-induced wheezing episode (6.1 [1.5-24.9] vs controls), and in 12% of the controls. The RV group showed significantly higher mean FENO values than the RSV group and controls. RV-positive cases had lower MEF50 before bronchodilation and higher MEF50, FEV1, and FEV1/FVC bronchodilation responses than controls. RSV-positive cases had lower FVC than controls before bronchodilation. CONCLUSION: Cases with RV- and RSV-induced early-childhood wheezing had increased risk for asthma in adulthood, and RV-positive cases had significantly higher FENO values than RSV-positive cases and controls. Compared to controls, RV-positive cases showed more bronchial reactivity, and RSV-positive cases showed lower FVC before bronchodilation in lung function testing. CLINICAL RELEVANCE: Children with RV- or RSV-induced wheezing in early childhood have an increased risk for asthma and lung function abnormalities in adulthood.

Interleukin-10 gene promoter region polymorphisms are not associated with BCG osteitis in vaccinated infants.

SETTING: Complications arising from bacille Calmette-Guérin (BCG) vaccination were recorded in a national register in Finland until 1988. In the period 1960-1988, 222 patients suffered from BCG osteitis. OBJECTIVE: To evaluate whether single nucleotide polymorphisms (SNPs) in the promoter region of the gene encoding interleukin 10 (IL-10) are associated with BCG osteitis after vaccination in neonates. DESIGN: Blood samples of 132 former BCG osteitis patients now aged 21-49 years were analysed in a controlled study for IL10 rs1800896 (-1082G/A), rs1800871 (-819C/T), rs1800872 (-592C/A) and rs1800890 (-3575T/A) polymorphisms. RESULTS: The frequencies of genotypes of IL10 rs1800896, rs1800871, rs1800872 and rs1800890, the frequencies of variant genotypes and the frequencies of major or minor alleles did not differ between patients and controls. Furthermore, the frequencies of the eight possible combinations of the three IL10 alleles located close to each other (IL10 rs1800896, IL10 rs1800871 and IL10 rs1800872) were surprisingly similar. CONCLUSION: Our results suggest that polymorphisms of the IL-10 encoding gene do not play a central role in the development of complications due to BCG vaccination, although the IL10 gene, especially IL10 rs1800896 (-1082G/A) polymorphism, is known to be associated with tuberculosis risk in Europeans and North Americans.