Angiogenesis is identified as new capillaries being
formed from pre-existing blood vessels. This
phenomenon involves the interaction of some of the
closely synchronized molecules including vascular
endothelial growth factor (VEGF) (
Endometriosis is known as one of the most common
disease in women of reproductive age. Despite
the current controversy regarding the pathophysiology
of this disease (
There is a controversy among the literatures about
the possible variation of VEGF in serum and in PF
of endometriosis patients (
Most of published data related to VEGF variation in endometriosis were obtained from small sample size patients, and accordingly, we attempted to consider this inconsistency in a large number of patients referred to a clinic during three years. Therefore, we measured the level of VEGF in serum and in PF of endometriosis patients and compared with normal subjects.
This descriptive study was approved by Ethical Committee of Isfahan University of Medical Sciences. During years 2009-2011, a total of 392 patients subjected to laparoscopy for the evaluation of infertility or pelvic pain at the Isfahan Fertility and Infertility Center were considered. The medical record of each patient was exactly reviewed by an expert gynecologist in order to exclude those patients with hypertension, coronary arterial diseases, diabetes, renal diseases, active pelvic inflammatory disease or polycystic ovarian syndrome. Finally, 179 patients were assigned for this study. This sample size was selected based on our pilot study. After laparoscopy, the patients were allocated into the following two groups: group I: different types of endometriosis patients (n=90) and group II: non-endometriosis patients (n=89). The official informed consent was obtained for all subjects.
The venous blood samples were obtained from all patients before induction of anesthesia for laparoscopy procedure. The blood samples were centrifuged, and the serums were stored at -20˚C until measurement. In addition, the PF samples were collected from pelvis before any manipulation. The bloody fluids were excluded. The PF samples were also centrifuged and the supernatant were stored at -20˚C until measurement.
The serum and peritoneal levels of VEGF were measured using enzyme immunoassay kit (Immuno- Biological Laboratory Co., Japan). Briefly, the kit is a solid phase sandwich enzyme linked immunosorbent assay (ELISA) using specific polyclonal and monoclonal antibodies, while the coloring agent was tetra methyl benzidine (TMB). The sample (100 μl) was put in pre coated plate (Anti-Human VEGF (16F1) Mouse IgG M0Ab Affinity Purify (Immuno-Biological Laboratories Co., Ltd, Japan), then washed after incubating for 60 minutes in 37˚C. Afterwards, the labeled antibody (HRP conjugated Anti-Human VEGF Rabbit IgG Fab’ Affinity Purify (Immuno-Biological Laboratories Co., Ltd, Japan), was added, incubated and washed again. Finally, coloring agent was added, followed by stop solution, whereas the absorbance was determined at 450 nm by plate reader. The VEGF concentration was determined using standard curve.
Data was expressed as mean ± SEM. Unpaired t test was applied to compare the parameters between the groups, while paired t test was applied to compare the parameters within the groups. The value of p<0.05 was considered statistically significant.
The average age of groups I and II are 28.9 (range: 19-44) and 30.2 (range: 24-42), respectively, while there was no statistically significant difference between two groups. In this study, 166 women were in proliferative phase, and 13 women were in secretory phase. The obtained data for VEGF level in serum and in PF from group I (the patients with endometriosis) and group 2 (control) are demonstrated in figure 1. The VEGF level in serum was significantly less than that in PF in both groups (p=0.00). However no significant difference in serum level of VEGF was detected between the two groups, but the result indicates that group I had significantly higher level of VEGF in peritoneal fluid in comparison to group II (p=0.043).
The VEGF level in serum and peritoneal fluid from the patients with endometriosis (group I) and control subjects (group II).
Endometriosis, as a gynecologic disease, has been
subjected to many research in order to find the exact
cause of infertility related to this disorder (
In some studies, the serum level of VEGF in endometriosis
was reported differently compared to our
obtained result. Their findings showed higher levels
of VEGF in the serum of patients with endometriosis
compared to specific control group (
Endometriosis is a chronic disease associated with
a general inflammatory response in peritoneal cavity.
Evidence shows that immunological factors (
Also, VEGF is one of those molecules attributed to
the growth and maintenance of angiogenesis (
According to our data, it seems that angiogenic activity may increase by the elevated level of VEGF in the PF of endometriosis patients. This elevated level of VEGF possibly promotes neovascularization within the peritoneal environment. It seems, this disease is only associated with pelvic inflammation, while is not related to the change of VEGF level in circulation.