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The aim of this paper was to define, for the first time in Italy, normal levels of total serum IgE in a general population sample of North Italy. Total serum IgE in 1905 subjects, living in Po Delta area (near Venice), were measured by PRIST method. Normal values were derived from 558 subjects without asthma and/or asthmatic/rhinitic symptoms, noncurrent smokers, skin prick-test negatives (‘normals’). Cut-off values to differentiate ‘normals’ from the remaining part of the sample (‘others’), from asthmatic, and from rhinitic subjects, were established with the IgE value midway between the upper limit of the 95% confidence intervals (CI) of the geometric mean for ‘normals’ and the lower limit for ‘others’, asthmatics, and rhinitics, respectively. Geometric mean of normal children–adolescents was 45 kU/L (SD: 2.6; 95% CI: 38–63). In normal adults geometric mean was 29 kU/L (SD: 3.3; 95% CI: 25–40) in males and 19 kU/L (SD: 3.8; 95% CI: 16–22) in females. The diagnostic sensitivity of IgE test was low, while the specificity was very high. A good positive predictive value in discriminating ‘normals’ from ‘others’ was found, on the contrary, we found a good negative predictive value in discriminating ‘normals’ from asthmatics or from rhinitics. In conclusion, our results confirm that it is necessary to provide separate total serum IgE reference values for what concerns age in children–adolescents and in adults, and gender, in adults. Low level of total serum IgE are helpful to exclude allergic asthma or rhinitis.

To assess the role of risk factors for chronic obstructive lung disease (COPD) by multiple logistic models, the data of the first cross-sectional epidemiological survey in the unpolluted rural area of the Po River Delta were analyzed (n=2382; 20–64 years). Each subject filled out a standardized questionnaire; 94% of the subjects were also able to perform forced expirograms. Dependent variables were chronic respiratory symptoms, asthma, abnormal parameters of flow-volume curve (ABNFVC), and a complex characterized by chronic phlegm and/or any wheeze and/or dyspnea grade 2+ and/or diagnosis of asthma and/or an FEV1/FVC ratio less than 60% (ANYABN). Independent variables were: age, ever cigarette smoking (SMK) and lifetime cigarette consumption expressed as pack-years, childhood respiratory infections (CRI), adolescence-adulthood respiratory infections (ARI), familial history for COPD (FCOPD) or for asthma/allergies (FASTHMA), work exposure to dusts/chemicals (EXPO), low socio-economic conditions (SES). A significant relationship with almost all dependent variables was shown by pack-years, ARI and age in both sexes. In males, FCOPD was related to chronic mucus hypersecretion and to ABNFVC, FASTHMA was associated with wheeze and ANYABN. EXPO was related to dyspnea and asthmatic symptoms in both sexes and also to bronchitic symptoms in males. CRI was a significant contributor for asthma symptoms in males, for ANYABN in females. SES had no significant association. In conclusion, our findings show that, beside lifetime cigarette smoking, other host — or environment — related conditions are important risk factors for COPD, suggesting the need for a more thorough strategy for prevention.