The relationship of serum concentrations of neuropilin-1 (NRP-1) and endometriosis

Serum NRP-1 is shown to have a high prediction power to discriminate women with and without endometriosis.

Key Points

Highlights:

• To define the serum neuropilin-1 (NRP-1) levels as a diagnostic tool for endometriosis, further validation studies in larger cohorts are needed.

Importance:

• Serum NRP-1 measurement may preoperatively predict the diagnosis of endometriosis.

What’s done here?

• The researchers evaluated the diagnostic performance of the angiogenic growth factor, NRP-1 in endometriosis and its usability as a potential non-invasive serum marker of endometriosis.

Key Points:

• More than 90% of the endometriosis group had disease stage II and III, mainly localized in the ovaries.
• The median age of the patients was 31 (30–33) years with no significant difference compared to the age of a healthy control group, 36 (35–37).
• Serum NRP-1 levels in the endometriosis group (mean, 9.40 mg/L; median, 8 mg/L) were found to be significantly higher than those of the control group (mean 29.91 mg/L; median 27 mg/L).

Limitations:

• The results of the present study were derived from a small subset of patients with stage IV endometriosis and without patients with stage I endometriosis.
• Blood samples were collected without considering the menstrual phase.

Lay Summary

Although many serum biomarkers or biomarker panels for endometriosis are evaluated, none of them is exact enough to be used in daily laboratory practice. In a recent study, which has been published in Scandinavian Journal Of Clinical and Laboratory Investigation, Barberic et al., researchers from Croatia, aimed to investigate the serum concentration of neuropilin-1 (NRP-1) in women with endometriosis and to evaluate the level of NRP-1 to preoperatively predict the diagnosis of endometriosis.

NRP-1 is is a transmembrane glycoprotein that serves as a receptor for the VEGF165 isoform of the VEGF to enhance cell migration during angiogenesis via the VEGF receptor. It is considered to be one of the main angiogenic growth factors in the endometrium.

A total of 200 women between 18 and 39 years of age who were undergoing laparoscopic surgery because of suspected endometriosis (based on medical history, clinical examination, ultrasound vaginal probe, and infertility) and sterilization were included in the study. Women were divided into two groups after laparoscopic surgery. One hundred and twenty patients were histologically confirmed to have endometriosis based on laparoscopy with histopathological analysis. Eighty healthy women who were undergoing laparoscopy because of sterilization were taken as the control group. Finally, endometriosis group comprised 120 patients divided into three groups; the first group (stage II endometriosis group) comprised 50 patients; while the second group (stage III endometriosis group) comprised 62 patients and the third group comprised eight patients diagnosed with stage IV endometriosis, respectively, according to revised American Society for Reproductive Medicine classification.

Blood samples were taken from all women undergoing laparoscopy half an hour before the induction of anesthesia, for the collection of serum. The level of NRP-1 in serum was assayed by a standardized sandwich enzyme-linked immunosorbent assay.

More than 90% of the endometriosis group had disease stage II and III, mainly localized in ovaries. Their median age was 31 (30–33) years with no significant difference compared to the age of a healthy control group, 36 (35–37). Serum NRP-1 levels in the endometriosis group (mean, 9.40 mg/L; median, 8 mg/L) were found to be significantly higher than those of the control group (mean 29.91 mg/L; median 27 mg/L), which is in agreement with the results of overexpression of NRP-1 in the ectopic lesion. No significant difference in serum NRP-1 level was seen for women with stage II vs. stage III and IV diseases.

The current study has some limitations. First of all, the results were derived from a small subset of patients with stage IV endometriosis and without patients with stage I endometriosis. Secondly, blood samples were collected without considering the menstrual phase.

To define the serum NRP-1 levels as a diagnostic tool for endometriosis, further validation studies in larger cohorts are needed.

Research Source: https://pubmed.ncbi.nlm.nih.gov/32069143