Immunohistochemical examination of the lungs in infant death cases using antibodies against milk components

To examine the use of immunohistochemical staining with antibodies against milk components for detection of aspirated milk on lung sections, eighteen infant death cases were investigated. Immunostaining was performed with anti-human α lactalbumin, anti-human IgA, anti-human milk fat globulin 1, and anti-cow whey antibody. Reactivity with each antibody was examined, and semi-quantitative examinations were performed to compare the amount of aspirated milk using anti-human α lactalbumin antibody. Materials in the alveoli or bronchioli on lung sections suspected to be aspirated milk showed the most sensitive and clearest reaction with anti-human α lactalbumin antibody. Of the eighteen cases, ten cases showed positive reaction with this antibody. The amount of aspirated milk varied widely in each case. In conclusion, immunohistochemical staining with antibodies against human milk components, especially anti-human α lactalbumin antibody, can detect small amounts of milk. Using this method, we were able to compare the relative amount of aspirated milk among cases.