Increased Platelet-Derived Growth Factor and Cytokine Levels in the Cerebrospinal Fluid of Patients of Sudden Unexpected Death with or without Viral Infection.

Objective To clarify the pathogenesis of sudden unexpected natural death (SUD) as well as biomarkers to differentiate the underlying diseases, by performing cytokine analysis in the acute phase of pediatric patients in whom viral infection led to SUD. Methods An acute phase cytokine analysis of pediatric patients in whom viral infection led to SUD was performed, and the data obtained were compared with those from SUD patients not associated with viral infections. Subjects included 4 boys aged 1-16 mo who died of cardiopulmonary arrest associated with viral infections. The causative viruses were identified as enterovirus, parainfluenza virus, respiratory syncytial virus, and rotavirus. The 4 other infants/children (aged 2-12 mo) died of non-infectious episodes, i.e., 1, 2, and 1 died of drowning, falling, and a traffic accident, respectively. Cerebrospinal fluid samples (CSF) of the subjects were collected during cardiopulmonary resuscitation or within 24 h of the events. Results The infection-induced sudden death group showed elevated CSF levels of inflammatory cytokines and chemokines. No increase was observed in interleukin-10 levels. Furthermore, in the infection-induced sudden death group, platelet-derived growth factor levels correlated with inflammatory cytokine levels. Conclusions Infection-associated SUD may be differentiated from noninfectious SUD by measuring the levels of acute phase-inflammatory cytokines and chemokines at the onset of SUD.