Assessment of estrogen receptor distribution in human endometrium by direct immunofluorescence

To use a direct immunofluorescence technique employing a fluorescein labeled anti-idiotypic antibody that recognizes the estrogen receptor (ER) order to assess the distribution of ER in the uteri of normal women throughout the normal menstrual cycle and of a woman exposed prenatally to diethylstilbestrol (DES).

Included in the study were 25 women aged between 35 and 50 years and an amenorrheic patient diagnosed as "DES Syndrome".

Localization of ER expression in frozen sections of uterine tissue was achieved by direct immunofluorescence using a fluorescein labeled anti-idiotypic antibody that interacts with ER.

Analysis of the immunofluorescence staining indicated that in the normal human endometrium the intensity of ER staining varied according to the phase of the cycle as well as according to the cell type. On the other hand, endometrial ER evaluation of the patient with DES syndrome showed minimal expression of ER and after treatment with conjugated estrogens, endometrial biopsy revealed a significant increase in ER expression.

These findings indicate that the fluorescein labeled anti-idiotypic antibody can be used to detect ER in normal and pathological human endometrium and to monitor changes in ER expression in the endometrium during hormonal therapy.