Intrafollicular nerve growth factor concentration in patients with polycystic ovary syndrome: a case-control study.

BACKGROUND: To evaluate the concentration of nerve growth factor (NGF) in follicular fluid of women affected by polycystic ovary syndrome (PCOS) undergoing to In Vitro Fertilization cycle.

METHODS: In the context of an in-vivo study, a sample of 52 women was considered: 20 were without pathology (male infertility - control group) and 32 were affected by PCOS. All patients received a long stimulation protocol and the oocytes obtained by pick-up were fertilized with standard procedures of intracytoplasmic sperm injection (ICSI). Samples of follicular fluid (FF) were collected at oocyte pick-up. After centrifugation at 560 × g for 3 min, follicular fluid samples were frozen at -80 °C. After thawing the values of NGF in FF were determined by enzyme immunoassay ELISA using commercially available NGF enzyme-linked immunosorbent assay kits. The results of study were analyzed statistically with Student's t-test.

RESULTS: The content of NGF was higher in FF of PCOS patients (2023.30±587.09 pg/mL) in comparison with control group (1704.09±326.8 pg/mL; P<0.05). The levels of serum estrogen (E2) were higher in patients with PCOS (1724.24±635.79 pg/mL) than in control group (1305.3±298.12 pg/mL; P<0.05). The number of retrieved oocytes was more in PCOS patients (9.7±4.6) than in control group (8±4.4), but oocytes in metaphase II were similar in two groups (6.2±2.4 vs. 6.09±4).

CONCLUSIONS: The present results show that ovaries of PCOS patients produce more NGF than non-PCOS patients; it confirms that an excess of ovarian NGF might be an abnormality contributing to polycistic ovary morphology and PCOS.