title: Release of erythroblasts to the peripheral blood suggests higher exposure to hypoxia in cases of SIDS with co-sleeping compared to SIDS non-co-sleeping.
abstract: Sudden unexpected death in infancy (SUDI) includes sudden infant death syndrome (SIDS). Co-sleeping is regarded as a major risk factor for SIDS. Under normal circumstances, nucleated red blood cells (nRBCs) are absent from the peripheral blood and their release can occur in cases with a probable hypoxic mode of death. The aim of our study was to assess the significance of the release of nRBCs in SIDS occurring during co-sleeping and the association with hemorrhages in the dura and the lungs. 35 cases were retrospectively assigned to one of the following categories: (I) 9 SUDI (of various causes) with no co-sleeping; (II) 16 SIDS while co-sleeping; (III) cause of death in hypoxic circumstances (3 hangings, 2 cardiac malformations, 1 meningitis 1 intoxication with diazepam); (IV) 3 SIDS in the cot. nRBCs were present in 5/9 cases of Category I (mean: 0.5%); 10/16 cases of Category II (mean: 1.87%); 7/7 cases of Category III (mean: 3.8%) and 0/3 cases of Category IV (mean: 0). ANOVA one-way test showed a significance of 0.003 amongst the 4 groups. The presence of diffuse intra-alveolar hemorrhage was associated with a higher release of nRBCs (mean: 3.1%) than focal hemorrhage (mean 0.6%). nRBCs were associated with focal hemorrhages in the falx and tentorium (mean: 2.3 vs. 0.9% when no hemorrhages were seen). The high mean of nRBCs seen in the co-sleeping SIDS cases suggests a higher exposure to hypoxia in the co-sleeping group which may have led to the release of nRBCs. More cases need to be analyzed to confirm this hypothesis.
authors.affiliation: Sheffield Children's Hospital NHS Foundation Trust, Histopathology Department, Western Bank, Sheffield, Yorkshire, UK. Marta.Cohen@sch.nhs.uk
authors.forename: Marta C
authors.initials: MC
authors.lastname: Cohen
authors.forename: Chen-Yee
authors.initials: CY
authors.lastname: Yong
authors.forename: Clair
authors.initials: C
authors.lastname: Evans
authors.forename: Rod
authors.initials: R
authors.lastname: Hinchliffe
authors.forename: Rita E
authors.initials: RE
authors.lastname: Zapata-Vazquez
mesh_terms: D001513:Beds; D002675:Child, Preschool; D004388:Dura Mater / Q000473:pathology; D004900:Erythroblasts / Q000378:metabolism*; D049429:Forensic Pathology; D006470:Hemorrhage / Q000473:pathology; D006801:Humans; D000860:Hypoxia / Q000097:blood*; D007223:Infant; D008168:Lung / Q000473:pathology; D012189:Retrospective Studies; D012890:Sleep; D013398:Sudden Infant Death / Q000097:blood*