Lung function measurements in children - copsac
Lung function measurements in children - copsac
Lung function measurements in children - copsac
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Mean gestational age was 35.5 weeks. There was no significant difference between RSV<br />
hospitalized and non-hospitalized tw<strong>in</strong>s with respect to birth weight (mean 2369 g), neonatal<br />
treatment for lung complications (Cont<strong>in</strong>uous Positive Airway Pressure, surfactant or<br />
pneumothorax) and birth order (22/37 probands were first born).<br />
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Forty-n<strong>in</strong>e % of the tw<strong>in</strong> pairs had parental atopic predispositions. The average age when<br />
hospitalized for severe RSV bronchiolitis was 10.6 months (<strong>in</strong>terquartile range: 5.1-13.3);<br />
median age 8.4 months. Mean duration of hospitalization was 4.3 days.<br />
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Accord<strong>in</strong>g to the <strong>in</strong>terviews (GINA guidel<strong>in</strong>es) the prevalence of asthma was 18% <strong>in</strong> our tw<strong>in</strong><br />
sample. The tw<strong>in</strong>s did not differ with respect to current asthma; use of <strong>in</strong>haled corticosteroid<br />
or beta 2 -agonist ever; atopic dermatitis ever; F E NO; basel<strong>in</strong>e lung <strong>function</strong>; bronchial<br />
responsiveness or sensitization (Table 1, table 1 onl<strong>in</strong>e).<br />
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DISCUSSION<br />
We found no difference with<strong>in</strong> co-habit<strong>in</strong>g MZ tw<strong>in</strong> pairs discordant for hospitalization for<br />
RSV bronchiolitis <strong>in</strong> <strong>in</strong>fancy on the asthma prevalence, basel<strong>in</strong>e lung <strong>function</strong>, bronchial<br />
responsiveness; biomarker of airway <strong>in</strong>flammation (F E NO) and sensitization 7 years after<br />
such severe RSV bronchiolitis. Though a number of criticisms may be raised <strong>in</strong>clud<strong>in</strong>g the<br />
small study population, it is noteworthy that no trends suggested a differential effect from<br />
severe RSV <strong>in</strong>fection. Therefore a strong effect from this virus seems unlikely.<br />
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Limitations and Strengths of the study design<br />
Monozygotic tw<strong>in</strong>s are useful for <strong>in</strong>vestigat<strong>in</strong>g the role of genetic and environmental factors<br />
on asthma because of their identical genetic background and similar childhood environmental<br />
exposures (29). However, comparison of MZ tw<strong>in</strong> pairs discordant to hospitalization for RSV<br />
bronchiolitis is prone to a number of biases.<br />
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