A large European study has found that children carrying a genetic variant linked to atopic eczema (rs10214237) are less likely to develop the condition if exposed to dogs during early childhood. Researchers analyzed data from 16 European cohorts involving 25,339 participants and confirmed their findings in an additional 10 cohorts with 254,532 participants.
The study examined interactions between 24 genetic markers associated with eczema and 18 early-life environmental factors. Among several significant gene-environment interactions, the link between dog exposure and the rs10214237 variant was confirmed, showing a protective effect. Children with the T allele of rs10214237 had a higher risk of developing eczema only if they had no early exposure to dogs. Those who grew up with dogs did not show this increased risk.
Laboratory tests revealed that skin cells (keratinocytes) with the T\:T genotype expressed higher levels of IL-7R mRNA. When exposed to dog allergens, these cells showed reduced levels of IL-33 and TSLP, and increased levels of immune-regulating molecules such as CXCL8, CSF2, CCL2, and TNF. These changes suggest enhanced IL-10 signaling, which may help suppress the development of atopic eczema.
Dr. Sara J. Brown from the University of Edinburgh, one of the study’s authors, noted that while it is known genetics affect eczema risk and previous research hinted at a protective role of dog ownership, this study is the first to reveal a possible molecular mechanism behind this effect. She emphasized that further research is needed but expressed hope that these findings could help prevent allergic diseases in the future.
The study was led by Marie Standl at the Helmholtz Zentrum München in Germany and published online on June 4 in the journal Allergy. The research was funded by the Innovative Medicines Initiative 2 Joint Undertaking, supported by the European Union and the European Federation of Pharmaceutical Industries and Associations.
The study’s limitations include the lack of genome-wide interaction analysis, some replication samples being underpowered, incomplete environmental data, and a participant pool primarily consisting of White individuals, which may limit the applicability of the results to other populations. Several authors disclosed receiving funding and honoraria from various research organizations and pharmaceutical companies.
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