Allergy and atopy from infancy to adulthood: Messages from the German birth cohort MAS.

OBJECTIVE: We present an overview of important results obtained during the first 20 years of the Multicenter Allergy Study (MAS), one of the first and longest-running population-based birth cohorts focusing on asthma and allergy. DATA SOURCE/STUDY SELECTIONS: The MAS is an observational population-based allergy-risk enriched cohort of 1,314 newborns enrolled in Germany in 1990. Assessments of various lifestyle and environmental exposures took place at 19 points, including 9 clinical visits for physical examinations and biosampling up to age 20 years.
RESULTS: A positive allergic family history was a strong predictor of asthma from childhood up to adulthood, more so for allergic multimorbidity than single allergic entities. For asthma prevalence, the early male preponderance shifted toward females during adolescence, leading to a sex-balanced distribution by age 20 years. Eczema prevalence switched toward a clear and persisting female predominance, whereas allergic rhinitis continued to affect more males up to age 20 years. The immunoglobulin (Ig) E antibody response to grass evolved in many allergic children from a simple, often mono- and oligomolecular to a polymolecular sensitization stage ("molecular spreading"). Indoor allergen exposure increased the risk for specific sensitization, which was linked to asthma and impaired lung function at early school-age. Moreover, the MAS birth cohort has made important contributions to the investigation of genetic factors in the manifestation of clinical subphenotypes and in the long-term temporal trajectory of allergic diseases.
CONCLUSION: Follow-up assessments over 2 decades provided new insights into risk factors and predictors for eczema, rhinitis, and asthma up to adulthood to develop better prevention strategies.