Relation between stressful life events, neuropeptides and cytokines: results from the LISA birth cohort study.

Stressful life events evidently have an impact on development of allergic diseases, but the mechanism linking stress to pathological changes of immune system function is still not fully understood. The aim of our study was to investigate the relationship between stressful life events, neuropeptide and cytokine concentrations in children. Within the LISAplus (Life style-Immune system-Allergy) study, blood samples from children of 6 yr of age were analysed for concentration of the neuropeptides vasoactive intestinal peptide (VIP), somatostatin (SOM), substance P (SP) and the Th1/Th2 cytokines interferon-gamma (IFN-gamma) and interleukin (IL)-4. Life events such as severe disease or death of a family member, unemployment or divorce of the parents were assessed with a questionnaire filled in by the parents. For 234 children, blood analysis and questionnaire data regarding life events were available. Children with separated/divorced parents showed high VIP levels and high concentrations of the Th2 cytokine IL-4 in their blood. Severe diseases and death of a family member were neither associated with neuropeptide levels nor with cytokine concentrations. Unemployment of the parents was associated with decreased IFN-gamma concentrations in children's blood but not with neuropeptide levels, whereas children experiencing concomitant severe disease and death of a family member had reduced SP blood levels. The neuropeptide VIP might be a mediator between stressful life events and immune regulation contributing to the Th2 shifted immune response in children with separated/divorced parents. Unemployment of the parents was associated with immune regulation in children on the basis of a still unknown mechanism whereas reduced SP levels seem to have no effect on immune regulation.