Immunocytochemical Study for Lactalbumin in Alveolar Macrophage of Human Milk Aspirated Mouse

인유(人乳) 흡인 백서의 폐포 대식세포에서 Lactalbumin에 대한 면역세포화학적 연구

Purpose : Aspiration of foreign material into the lungs can cause acute or chronic pulmonary diseases. It is difficult to detect small amounts of aspiration due to the lack of safe, sensitive and specific diagnostic tests. Recently, in animal or human studies, it has been reported that immunochemistry for lactalbumin can be used to detect the minimal aspiration. So, the authors' investigation was designed to determine whether human milk phagocytized alveolar macrophages can be detected in human milk aspirated mice. Methods : Sixty four male mice, 6-8 weeks old and 30-40 gm weighing, were used for this study. About 0.05 mL of human milk or normal saline were given intranasally once per day for 1 day or 3 days. Under anesthesia with ketamine and xylazine, the trachea of each mouse was cannulated with an 18G Jelco needle and then, each mouse's lungs were lavaged three times with 0.5 mL of phosphate buffer solution at 2, 8, 24, and 48 hours after the last milk or normal saline instillation. Cells in bronchoalveolar lavage fluid were stained with Oil Red O and immunocytochemistry for alpha-lactalbumin. Results : Immunocytochemical reactivity for alpha-lactalbumin or lipid-laden alveolar macrophages were not observed in the normal saline aspirated groups. Immunocytochemical reactivity for alpha-lactalbumin were observed in the human milk aspirated groups. They showed a peak at 8 hours and decreased markedly at 24 hours but persisted even at 48 hours after aspiration. Immunocytochemical stain positive alveolar macrophages were noted similarly in number between single and multiple aspiration groups. Conclusion : These observations suggested that alveolar macrophages for lactalbumin could be more easily detected on immunocytochemistry than Oil Red O stain, and immunocytochemistry could be used as a sensitive and specific diagnostic test for the detection of human milk aspiration.

목 적 : 인유를 탐식한 폐포 대식세포는 면역세포화학 반응에 관여하며, 기존의 염색법에서보다 면역세포화학기법에 의해 잘 관찰될 수 있음을 규명하여, 인유 흡인을 확인할 수 있는 진단에 활용하고자 본 연구를 시행하였다. 방 법 : 총 64마리의 백서를 대상으로 소량(0.05 mL)의 모유를 코를 통하여 기도에 흡인시킨 후 지정 시간별로 기관을 도관한 다음, 기관지폐포 세척을 실시하여 얻은 세포에 대하여 면역세포화학적 염색과 Oil Red O 염색을 실시하고 폐포 대식세포들의 탐식 정도를 관찰하였다. 결 과 : 인유 흡인 2시간 후에 Lactalbumin에 대한 양성 대식세포가 관찰되었으며 8시간에 최고이었고 24시간에 감소하였으며 48시간에도 양성 대식세포가 관찰되었다. 그러나 Oil Red O 염색에서 폐포 대식세포들의 검출률은 미미하였다. 결 론 : 본 실험의 결과는 소량의 인유 흡인을 면역세포화학적 기법에 의하여 기관지폐포 세척 액에서 검출할 수 있다는 것을 시사하는 것이었다.