Quantitative reduction of peripheral CD4+ CD25+ FOXP3+ regulatory T cells in reproductive failure after artificial insemination by donor sperm.

PROBLEM: The objective of this study was to determine whether peripheral Treg-cell percentages were altered in women with reproductive failure after artificial insemination by donor sperm (AID) and which parameters can best discriminate women with AID failure and normal controls.

METHOD OF STUDY: A retrospective case-control study of 20 fertile controls and 20 patients undergoing more than four treatment cycles with negative pregnancy test (Group I), 20 experiencing biochemical pregnancy loss (Group II), and 20 undergoing missed abortion or spontaneous miscarriage (Group III) was performed. The peripheral percentages of CD4(+) CD25(+) and CD4(+) CD25 (+) Foxp3(+) Treg cells within CD4(+) T-cell population were evaluated at both late follicular and luteal phases of menstrual cycle by flow cytometry.

RESULTS

A significantly decreased percentage of CD4(+) CD25(+) Foxp3(+) Treg cells was detected at the late follicular phase in all AID failure groups compared with the controls. The percentage of CD4(+) CD25(+) Foxp3(+) Treg cells at the late follicular phase in the controls was higher than that at the luteal phase. Using receiver operating characteristic curve, we found that CD4(+) CD25(+) Foxp3(+) Treg-cell percentage <2% can best discriminate the AID failure and normal controls.

CONCLUSION

Reduced percentage of peripheral CD4(+) CD25(+) Foxp3(+) Treg cells at the late follicular phase was associated with AID failure and can be a potential biomarker for predicting AID-induced failure.