QUANTITATIVE ENZYME-IMMUNOASSAY AND SEMIQUANTITATIVE IMMUNOHISTOCHEMISTRY OF ESTROGEN AND PROGESTERONE RECEPTORS IN ENDOMETRIOTIC TISSUE AND ENDOMETRIUM

Background-The capacity of different tissues to respond to steroids ha s been evaluated mainly according to the concentrations of oestrogen ( ER) and progesterone (PR) receptors, which may be assayed either in ti ssue homogenates or histochemically. These two principles have been us ed in different studies of endometriotic tissue, giving somewhat diffe rent results, probably because the tissue is heterogeneously mixed wit h fibrotic tissue and blood cells to various degrees. Aims-To compare a quantitative and a qualitative, semiquantitative immunocytochemical assay for ER and PR in a heterogenous tissue (endometriotic) and a sim ilar but more homogenous tissue (endometrium). Methods-ER and PR conce ntrations were measured using enzyme immunoassay (EIA) and immunocytoc hemistry (ICA) in the same tissue samples (endometriotic tissue from 3 1 women and endometrium from 19 of the same women). Results-There was a significant correlation between PR concentration (using EIA) and sem iquantitation of PR using PRICA in endometrial epithelium (p = 0.028). The correlation between the two techniques for ER concentration was n ot significant. In endometriotic tissue no correlation was found betwe en the two techniques for ER or PR. Conclusions-These data show that i n heterogeneous tissues like endometriotic tissue different techniques for measuring steroid receptors may produce substantially different r esults. The two techniques (ELA and ICA) are complementary and a combi nation of the two techniques might aid in determining optimal treatmen t.