Intraperitoneal and subcutaneous treatment of experimental endometriosis with recombinant human interferon-alpha-2b in a murine model.
To determine the effect of human interferon (IFN)-alpha-2b on experimental endometriosis in rats. Experimental, controlled, double-blind randomized study. Experimental surgery laboratory in a university department. Ninety-six Wistar rats with endometriosis, induced by transplanting four endometrial fragments into the peritoneal cavity. One third of the animals served as controls (group A). The others were randomly divided into two groups and were given IFN-alpha-2b either as a single intraperitoneal dose (group B) or as three SC doses (on alternate days) (group C). Laparotomy was performed to measure the size of each implant at various times (days 0, 6, 12, 20, and 120 after treatment). There were no differences among the groups in the size of the average implants before IFN was administered (17.3+/-6.7, 19.7+/-7.8, and 18.1+/-9.2 mm for groups A, B, and C, respectively). These values were significantly smaller after treatment in group B (14.9+/-8.0 mm) and group C (14.0+/-9.5 mm) than in the control group (17.6+/-7.5 mm) (P<.05). Intraperitoneal IFN produced an initial maximum decrease in the size of the implants (40% reduction on day 6), which diminished until day 20 (20%) and then was maintained on a plateau until day 120 (25%). By contrast, group C showed an initial minimal reduction (13% at day 6), which increased up to day 20 (19%), after which a plateau was reached (23% at day 120). Thus, the effects in both treatment groups were similar in the long term. Two short regimens of human IFN-alpha-2b reduced the size of experimental endometriosis in rats.