[Immunohistochemical localization of secretory component and IgA in the normal and cancerous endometrium]

Using normal and cancerous endometrial tissues obtained from climacteric and postmenopausal women as the subjects, localizations of secretory component (SC) and IgA were immunohistochemically investigated. The results were as follows: Similar to cyclic women, in normal endometrial tissues from climacteric and postmenopausal women, SC and IgA localized mainly in glandular epithelia. However, in women over 60 years of age, immunoreactivity of SC and IgA decreased. In cancerous tissues, staining intensity of SC and IgA decreased clearly as compared to normal tissues. Also, the loss of polarity was recognized in the localization pattern of SC and IgA. In relation to the tissue differentiation, a further decline was recognized in the SC and IgA staining intensity in the poorly differentiated carcinoma as compared to the well differentiated type. The above findings suggested that the decline of the local immune system in the endometrium, namely, weakening of the local defense mechanism against infections, took place in women of advanced age. Also it was recognized that weakening of the ability to produce SC was caused by the malignant transformation of endometrium, and it was suggested that SC was a substance which had a close relationship to tissue differentiation.