Neonatal levels of inflammatory markers and later risk of schizophrenia.

Background: There is a long-standing interest in investigating the impact of early-life immune abnormalities on later onset of psychosis. The aim of this study was to assess inflammatory marker levels in neonatal dried blood spots and their association with later risk of schizophrenia.

Methods: This nested case-control study included 995 cases and 980 control subjects. Cases were identified using the Danish Psychiatric Central Register. Control subjects of same age and sex were identified using the Danish Civil Registration System. Samples for the identified individuals were retrieved from the Danish Neonatal Screening Biobank. Concentrations of 17 inflammatory markers were measured in eluates from dried blood spots using a bead-based multiplex assay. Incidence rate ratios were calculated using conditional logistic regression. Principal component analysis was used to capture the overall variation in the inflammatory markers' concentrations.

Results: No significant differences were found for any of the analyzed interleukins. We did not find any association with schizophrenia for any of the other examined inflammatory markers.

Conclusions: Our results suggest that persons who develop schizophrenia do not have higher or lower levels of the examined inflammatory markers at the time of birth. Our findings differ from the studies of maternal inflammatory changes during the antenatal period for which associations with schizophrenia have previously been demonstrated.