[Effects of long-term installation of intrauterine devices on intrauterine microenvironment]

To study the effect of long-term installation of intrauterine devices (IUD) on the intrauterine microenvironment.

Eighty-nine healthy 26 - 50-year-old women undergoing physical examination or having their IUD removed were recruited. Among them 62 had used IUDs, including 32 inert IUD (I-IUD) and 30 copper releasing IUD (T-IUD), for 5 - 20 years, and 27 women without installation of IUD were used as controls. In the 3rd to 13th day of menstrual cycle, 3 ml of irrigation of intrauterine cavity were collected to examine the concentrations of tumor necrosis factor-alpha (TNF-alpha), interleukin 2 (IL-2) and secretary IgA (SIgA) by radioimmunoassay (RIA). Hysteroscopy was used to obtain 3 pieces of endometrium at the place where the IUD was attached for each subject. Three pieces of endometrium were curretted from each control during the proliferative stage. Thirty specimens of endometrium, including 10 cases with I-IUD, 10 cases with T-IUD, and 10 control cases were used to examine the distribution of T cell subset by immunohistochemistry. Fifteen specimens of endometrium, including 6 cases with I-IUD, 6 cases with T-IUD, and 3 control cases, were used to examine the endometrial ultrastructure by scanning electron microscopy (SEM) and transmission electron microscopy (TEM). Twenty-five specimens of endometrium, including 10 cases with I-IUD, 10 cases with T-IUD, and 5 control cases, were used to detect the expression and mutation of P16, P53 and K-ras by PCR-SSCP technique.

There was no significant difference in TNF-alpha level in the irrigation among the three groups (P > 0.05). IL-2 and SIgA levels (0.39 +/- 0.18) microg/L and (2000 +/- 1224) microg/L respectively) in the T-IUD group were significantly lower than those in the control group (0.96 +/- 0.15) microg/L and (3377 +/- 1906) microg/L respectively, both (P < 0.05). There was a significant difference in the population of T lymphocytes (CD(8)(+) and CD(4)(+) lymphocytes) between the T-IUD group and control group (P < 0.05). SEM and TEM showed no necrosis and atypia in the endometrial cells of I-IUD group and T-IUD group. There was no positive expression of gene p16, p53 and K-ras in the endometrium of the three groups.

It is safe and effective using I-IUD or T-IUD for a long time, however, T-IUD has some effects on intrauterine local immune function.