Interleukin-3 and human trophoblast: in vitro explanations for the effect of interleukin in patients with antiphospholipid antibody syndrome

Objective: To examine the effect of interleukin (IL)-3 on in vitro trophoblast differentiation, hormone production, and invasiveness affected by antiphospholipid antibodies. Design: Primary cytotrophoblast cell cultures. Setting: Obstetrics and Gynecology Department of the Catholic University, Rome, Italy. Patient(s): Five normal pregnant women underwent uncomplicated vaginal delivery at 36 weeks of gestation. Intervention(s): Immunoglobulin (Ig) G antibodies were isolated from the plasma of two patients with antiphospholipid syndrome and two normal control subjects with the use of protein-G Sepharose columns. Cytotrophoblast cells were dispersed in Ringer’s bicarbonate buffer containing trypsin and DNAseI, filtered, and layered over a Percoll gradient in Hank’s balanced salt solution. Main Outcome Measure(s): We investigated the effects of IL-3 and antiphospholipid antibodies on trophoblast cell invasiveness, differentiation, and hormone secretion. Result(s): IgG obtained from patients with antiphospholipid syndrome bound to trophoblast cells, with inhibitory effects on the cells’ invasiveness, differentiation, and hCG secretion. IL-3 was able to restore in vitro placental functions. Conclusion(s): These results imply that IL-3 favorably affects human trophoblast implantation and development.