THE IMMUNOLOGIC AND ENDOCRINOLOGIC BASIS OF SUCCESSFUL TRANSPLANTATION OF HUMAN TROPHOBLAST

Influence of oral contraceptives in the development of post-molar trophoblastic neoplasia—A systematic review

OBJECTIVE

Controversy exists regarding the use of oral contraceptives following hydatidiform mole and possible increased risk of persistent trophoblastic neoplasia. The purpose of this study is to perform a systematic review of the literature to assess the evidence for and against a possible link between oral contraceptive use and the need for chemotherapy after molar evacuation.

METHODS

We searched the computerized databases MEDLINE, EMBASE, Popline, Web of Sciences, LILACS and the Cochrane Controlled Trials Register, ISI Proceedings, performed a hand search of references and wrote to experts to identify randomized controlled trials and observational studies comparing oral contraceptives with other methods of contraception. Quality assessment included: concealment of allocation; intention to treat analysis; plus attrition bias for trials; confounding factors and selection bias for observational studies. We collected or calculated risk ratios for the incidence of gestational trophoblastic neoplasia and hCG regression time associated with oral contraceptive use.

RESULTS

Two randomized controlled trials were included for analysis. The risk ratios for OC use were similar in both studies: 0.69 (0.12-3.98) and 0.71 (0.46-1.10) respectively. No attempt to summarize these results was made because the studies observed different disease stages. In five of the seven observational studies, the risk ratio ranged from 0.57 (CI = 0.14-2.37) to 1.46 (CI = 0.56-3.79).

CONCLUSION

No clear evidence for an association between oral contraceptive use during post-molar follow-up period and the incidence of gestational trophoblastic neoplasia was found. Practitioners should no longer avoid their use because of a supposed effect which we have shown here to be unsupported by evidence in the literature.

Translocatable estrogen receptors in rat splenocytes

Estradiol has previously been shown to suppress the response of the cellular immune system of the rat while enhancing the production of IgM antibodies. Analysis of the cytosol from rat splenocytes showed saturation of specific binding sites at concentrations of between 80 and 160 nM [3H]-estradiol with an approximate Kd of 12 nM. Competitive binding studies showed a dose-dependent decrease in the binding of [3H]-estradiol to the receptor in the presence of increasing concentrations of unlabeled estradiol. Dexamethasone, progesterone and R1881 (synthetic androgen) had no effect on the binding of [3H]-estradiol. The in vivo administration of estradiol resulted in increased nuclear binding of [3H]-estradiol as compared to vehicle treated controls. These results indicate that rat splenocytes possess specific, translocatable estrogen receptors which may be responsible for the observed modulation of the immune system.

Estradiol-induced alteration in the immune system. II. Suppression of cellular immunity in the rat is not the result of direct estrogenic action

Estradiol has been reported to suppress numerous cellular immune response. What is not known is how estradiol exerts this effect. In vivo administration of estradiol to male rats caused time-related immunomodulatory effects leading to enhancement of lymphocyte transformation while suppressing a mixed lymphocyte reaction (MLR) response. The suppression of the MLR response was not due to alterations in the ratio of helper and suppressor T cells, nor was it due to alterations in either cell viability or the number of cells in culture. Lymphocytes cultured in vitro with estradiol, however, fail to show any alteration in the responsiveness in either MLR or lymphocyte transformation assays. The suppressive effects of estradiol cannot be transferred from a primary MLR culture to a second MLR culture using the supernatants from the primary MLR culture. Lymphocytes from animals given estradiol in vivo show no alteration in the production of interleukin 2: added in vitro to primary MLR cultures, Interleukin 2 failed to restore full responsiveness to lymphocytes from animals treated in vivo with estradiol. These results suggest that estradiol acts indirectly to cause an alteration in the responsiveness of the regulatory cells of the cellular immune system.

Natural history of hydatidiform mole after primary evacuation

From 1962 to 1978, 738 patients with hydatidiform mole were referred to the John I. Brewer Trophoblastic Disease Center of Northwestern University for follow-up and human chorionic gonadotropin (hCG) testing after evacuation. There was spontaneous regression of trophoblastic disease in 596 (80.8%) of the 738 patients. Of these 596 patients, regression occurred in 11 (1.8%) by day 10 after evacuation, in 124 (20.8%) between days 11 and 30, in 255 (42.8%) between days 31 and 60, and in 206 (34.6%) between days 61 and 170. Treatment with chemotherapeutic agents was required in 142 (19.2%) of the 738 patients; 125 (16.9%) of these had invasive mole (107 nonmetastatic and 18 metastatic) and 17 (2.3%) had choriocarcinoma (13 nonmetastatic and four metastatic). All 596 patients whose hCG titers declined spontaneously to normal levels have remained well and free of disease. All 142 treated patients experienced permanent remission. Thus, all 738 patients are well and free of disease 4 to 18 years after evacuation of the hydatidiform mole. The follow-up regimen described in this report furnishes information on natural history of molar pregnancies after evacuation and provides an excellent means by which all patients can be safely managed following termination of a hydatidiform mole.

Trophoblastic tumour, oral contraceptive therapy and pregnancy associated alpha2-glycoprotein (PAAG), case report

Pregnancy associated alpha2-glycoprotein (PAAG) and human chorionic gonadotrophin (HCG) levels were studied in a patient with an invasive mole who was being treated with cytotoxic drugs and oral contraceptives. Both the PAAG and HCG levels fell during cytotoxic drug treatment while oral contraceptives caused a rise in PAAG concentrations. A relation between oestrogen-induced PAAG and prolonged survival of trophoblastic tumour is proposed.

Follow-up of hydatidiform mole by radioimmunoassay of human chorionic gonadotrophin

An improved method for the follow-up of patients delivered of a hydatidiform mole using radioimmunoassay of human chorionic gonadotrophin is employed to ensure adequate sensitivity. Four illustrative case histories are described. Their HCG findings are presented to show that this is the principal basis on which decisions should be made.There are three aspects to the work of the laboratory. The technical work of the assay, the clerical effort of patient follow-up, and the clinical interpretation of results. The laboratory keeps a close check on follow-up (one of its most important functions) and receives specimens direct from patients. Overall control of all three aspects is by a clinician. It has been found useful to organize a special clinic for these patients to be seen. In this region it has been possible for this to be run by the same clinician.