Elevation of plasma soluble CD26 levels during pregnancy

Aim: CD26 is a type II transmembrane protein with dipeptidyl peptidase IV (DPPIV) activity expressed on a variety of cell types. Recent studies have indicated that CD26 or enzymatic activity levels were previously associated with immune-mediated disorders. As immunoregulation is very important for a successful pregnancy, we hypothesize that CD26 may play an important role during pregnancy, and herein, we sought to determine the association between circulating levels of soluble CD26 (sCD26) and pregnancy outcome. Material and Methods: In this study, a stable hybridoma cell line 1F1 was produced by fusion of murine splenocytes and myeloma cells. An indirect competitive enzyme-linked immunosorbent assay (ic-ELISA) was developed for the detection of the maternal plasma sCD26. We measured the plasma levels of sCD26 in 80 normal pregnant women and 45 non-pregnant women. Results: Our results indicated that the plasma level of sCD26 was significantly higher in the pregnant group (P < 0.001) than that in the non-pregnant group. Conclusion: These findings hinted that CD26 may play a role in successful pregnancy and it is not an absolute surrogate marker for the Th1-type immunity as the dominant Th2-type immunity during pregnancy.