The evidential value of intra-alveolar haemosiderin-macrophages in cases of sudden infant death syndrome (SIDS)

Intra-alveolar deposits of haemosiderin have repeatedly been brought into connection with some diagnostic value, such as markers for previous imposed suffocation, smothering due to Munchausen syndrome by proxy or sudden infant death syndrome (SIDS). This study is based on 104 SIDS cases and 14 controls (causes of death, e.g. inflammatory changes, internal haemorrhages, asphyxia, blunt force trauma or acute toxicity). The SIDS group comprised 44 females (aged 7 days to 12 months) and 60 males (aged 12 days to 16 months 8 days) with the ages of the controls ranging from 2 months 3 days to 47 months. Routine histology samples from the lungs were stained with Prussian blue and haemosiderin foci were counted in 20 hpf for each lung lobe by a pathologist blinded to the cause of death. Results were assigned to one of five categories for haemosiderin positivity. Data were analysed by the Levene-test revealing identical variances in both groups and with a two-sample t-test showing the mean values for haemosiderin counts not being significantly different between SIDS and control groups. Although the sizes of both samples differed considerably it is our opinion that the haemosiderin counts did not show sufficient diagnostic value. This outcome supports the latest results of other comparable investigations. Furthermore, it highlights the necessity to assess carefully positive haemosiderin findings to avoid false suspicion.