Association between follicular fluid levels of HMGB1 protein and outcomes in patients undergoing in vitro fertilization/intracytoplasmic sperm injection cycles

Abstract

The aim of the present study was to evaluate the association between follicular fluid (FF) levels of high-mobility group box 1 (HMGB1) protein and the reproductive outcome in patients undergoing in vitro fertilization (IVF) with intracytoplasmic sperm injection (ICSI). FF samples were collected from the ovarian follicles (≥14 mm) of 143 infertile patients that had undergone IVF/ICSI, and the HMGB1 expression levels were determined using ELISA. Spearman#s correlation and receiver operating characteristic (ROC) curve analysis were applied to analyze the results. Significantly increased levels of HMGB1 protein (7.38±2.02 vs. 6.14±2.52 ng/ml; P<0.01), endometrial thickness on the day of human chorionic gonadotropin (hCG) administration (10.3±1.3 vs. 9.7±1.7 mm; P<0.01) and retrieved oocyte counts (11.68±6.51 vs. 11.00±6.34; P<0.01) were observed in the pregnant group when compared with the non-pregnant group. Conversely, the level of luteinizing hormone on the day of hCG administration was significantly reduced in the pregnant group compared with the non-pregnant group (0.92±1.78 vs. 1.78±2.03 pmol/l, P<0.01). The ROC curve indicated a significant association between the FF level of HMGB1 protein and the pregnancy rate, with an area under the ROC curve of 0.673 (0.581-0.765; P<0.01). In addition, the HMGB1 protein level was shown to have a significant positive correlation with the endometrial thickness (r=0.170; P<0.05). Therefore, the present study indicated that the FF levels of HMGB1 protein are increased in pregnant patients and are positively correlated with endometrial thickness. Thus, FF levels of HMGB1 may be a useful factor for predicting the outcome of IVF/ICSI treatments.