Regression of endometrial explants in a rat model of endometriosis treatedwith the immune modulators loxoribine and levamisole

Objective: To investigate the effects of the immune modulators levamisole a nd loxoribine in a rat model of endometriosis. Design: Prospective, placebo-controlled study. Setting: Hospital-based research facility. Animal(s): Nineteen rats with experimentally induced endometriosis. Intervention(s): Rats were treated with three weekly intraperitoneal inject ions of levamisole (2 mg per rat; n = 6), loxoribine (1 mg per rat; n = 6), or saline (control; n = 7) and killed 8 weeks after treatment. Main Outcome Measure(s): Histologic and immunohistochemical analysis of end ometriotic explants. Result(s): The loxoribine-treated group showed marked regression of both ep ithelial and stromal components. Epithelial regression was noted in the con trol group, but the epithelium was strikingly preserved in the levamisole g roup. There were significantly greater numbers of dendritic cells in the ex plants of animals treated with loxoribine and levamisole. The number of nat ural killer cells was significantly reduced in loxoribine-treated explants. Conclusion(s): Loxoribine, a potent immunomadulatory drug, appeared to caus e regression in both stromal and epithelium components in a rat model of en dometriosis. Further, specific cell-mediated immune responses in this model of endometriosis were elucidated. (Fertil Steril(R) 1999;72:135-41. (C) 19 99 by American Society for Reproductive Medicine.)