The aim of this study was to
stain lung and thymus gland sections that had been taken from infants who had died of
sudden infant death syndrome (
SIDS) for interstitial
hemosiderin and to compare the results with those obtained for controls. There were two groups of
SIDS infants, one with, and a second group without, histories of
apparent life-threatening events (ALTEs). No significant difference in numbers of cases with interstitial
hemosiderin deposition was found between
SIDS infants with histories of ALTEs (n = 4 of 12, 33.3%),
SIDS infants without histories of ALTEs (n = 4 of 22, 18.2%), and controls (n = 4 of 24, 16.7%). However, if four of the control cases with histories of previous chest
trauma were excluded, there was a significantly greater number of cases with pulmonary interstitial
hemosiderin in the
SIDS infants with histories of ALTEs compared with the subgroup of control infants with no previous chest
trauma (n = 1 of 20, 5%) (P < .05). No relationship could be established between the timing of the ALTEs, the type of
resuscitation or age of the infant at death, and the presence of
hemosiderin. None of the sections of thymus gland stained positively for
hemosiderin. Positive staining for pulmonary interstitial
hemosiderin, therefore, differentiated a group of
SIDS infants with histories of previous ALTEs from a subgroup of control infants with no histories of previous chest
trauma. However, pulmonary interstitial
hemosiderin staining could not be used with certainly to confirm or exclude previous ALTEs in individual
SIDS cases as not every
SIDS case with a history of an ALTE stained for pulmonary interstitial
hemosiderin. In addition, positive staining occurred for
SIDS infants without histories of ALTEs and also for control infants who died of other causes.