Lower LPS responsiveness in Estonian than Swedish infants associates with less allergy development and high endotoxin exposure

• Background: Allergic diseases have increased in the last decades, particularly in countries with an affluent lifestyle, possibly due to a reduced or altered microbial exposure during infancy. Objective: The aim of this study was to follow lipopolysaccharide (LPS) induced immune responses prospectively in infants from Estonia and Sweden, i.e. two countries with different frequencies of allergic disease and a different domestic endotoxin exposure. ' Methods: The study included 14 Estonian and 36 Swedish infants who were followed prospectively from birth up to two years of age regarding development of allergy using questionnaires, clinical examinations and skin prick tests. Isolated cord blood mononuclear cells (birth) and peripheral blood mononuclear cells (obtained at 3, 6, 12 and 24 months) were cultured for 24h with LPS in combination with IFN-γ. The secretion of IL-6, CXCL8 (IL-8), IL-10, IL12p70, IL-17, IL-1β, CCL2 (MCP-1), CCL4 (MIP-1β) and TNF was analysed with a Luminex assay. Results: The Swedish, as compared to Estonian children, had higher levels of LPS/IFN-γ induced CCL4 and IL-6 at birth and of IL-1β, IL-12p70, IL-17 and TNF at 3 months as well as IL-6 at 6 months. Also, the levels of CCL2 at 3 and 6 months of age and CCL4 and TNF at 6 months of age were higher in Swedish than Estonian infants in unstimulated cultures. Sensitised Swedish infants had higher levels of LPS/IFN-γ induced IL-10 at 3 and 12 months of age compared to non-sensitised Swedish infants. Conclusion: The enhanced LPS/IFN-γ induced cytokine and chemokine secretion in Swedish, compared to Estonian infants may support a less rapid induction of immune regulation in an affluent society. This could possibly be due to a reduced microbial pressure on Swedish children during early childhood.

Keyword

Lipopolysaccharide

cytokines

chemokines

childhood

allergy

endotoxin

MEDICINE

MEDICIN

Publication and Content Type

vet (subject category)

ovr (subject category)