Pulmonary hemosiderin in deceased infants - Baseline data for further study of infant mortality

Infant lung samples were obtained prospectively at autopsy by medical exami ner pathologists in five areas of the United States. Tissues were submitted regardless of the cause of death. Lung sections were stained with Prussian blue to detect deposits of hemosiderin. Fifty-nine cases were evaluated fo r the study. The four sections examined for each case were taken from the a nterior and posterior aspects of the right and left upper lung. Three patho logists independently scanned the lung sections microscopically using a 10X objective lens (with 10X ocular lens) and indicated an "iron score" by ind icating for each section if it showed no staining for iron-hemosiderin (Sco re 0), occasional staining with most fields negative (Score 1), focally abu ndant staining with most fields having no staining (Score 2), focally abund ant staining with most fields showing positive staining (Score 3), or promi nent staining throughout the section (Score 4). There was good agreement be tween pathologists on the iron score for each case. A total iron score was calculated by adding the scores based on each pathologist's observations. T he mean total iron score was 6 (range, 1-44), with the range of possible to tal iron scores being 0 to 48. There was no significant difference between the four lung sections in a given case. Six cases had total iron scores tha t were at least twice the mean (i.e., total iron score > 12); in five of th ese cases death was caused by conditions other than sudden infant death syn drome, including one case in which asphyxia was the cause of death. These d ata are consistent with other reports that pulmonary hemosiderin in decease d infants is suggestive of a cause of death other than sudden infant death syndrome. The data may be useful as baseline data for further studies of in fant mortality involving possible pathologic changes in the lungs.