Choriocarcinoma cell line resistance to NK lysis mainly involves an HLA-G–independent mechanism

Abstract

To investigate whether antitrophoblast antibodies are associated with unexplained recurrent miscarriages, we used choriocarcinoma cells JEG-3, since these cells are negative for class I and II antigens, but they do express HLA-G, resembling an antigen expression of endovascular and interstitial trophoblasts.Case-control study.Academic research center.One hundred ninety-four patients with two or more consecutive, idiopathic recurrent miscarriages (RM; <20 weeks of gestation) were compared with 110 controls with normal pregnancies and without pregnancy complications.Anti-JEG-3 reactivities were measured by using flow cytometry and comparisons with two in-house standards antibody samples of low and high reactivity.Anti-JEG-3 reactivities above the 95% confidence interval of controls were defined as positive.Sera of RM patients reacted significantly stronger with JEG-3 cells than that of controls. In addition, RM patients significantly more often had positive anti-JEG-3 reactivities (17.5%) than controls 5%. This difference was markedly increased with a subgroup of 80 RM patients who had three or more miscarriages, as 27 of these women (34%) were anti-JEG-3 positive.Antitrophoblast antibodies show significantly more mean channel shift reactivities, and positive reactivities are significantly more prevalent in RM patients as compared with controls. Such antibodies may be involved in mechanisms affecting pregnancies.