Vaginal Dryness in Sjögren’s Traced Partly to Blood Vessel Defects
Vaginal dryness in women with primary Sjögren’s syndrome may be caused by defective blood vessels and an infiltration of immune cells in their vagina and cervix, a new study suggests.
The findings were published in the journal Rheumatology in the study, “Vaginal dryness in primary Sjögren’s syndrome: a histopathological case–control study.”
Sjögren’s is an autoimmune condition where the immune system attacks and damages secreting glands, leading to symptoms of dryness, most commonly in the eyes and mouth. But glands producing natural vaginal lubricants can also be affected.
Women with Sjögren’s syndrome are reported to be two-to-three times more likely to experience vaginal dryness than women of the same age without this condition. They also tend to have more severe manifestations.
Local inflammation in the vagina has been suggested as a possible cause of vaginal dryness. But most studies failed to include healthy people as a control group, or to have examined changes in blood vessels — which help produce a kind of vaginal lubricant called transudate — as another possible cause.
Since knowing the mechanisms causing vaginal dryness in Sjögren’s patients is key to developing effective treatments, a team at the University Medical Center Groningen, in the Netherlands, examined microscopic and immunological changes happening in the vagina and cervix of women with primary Sjögren’s syndrome.
Their study included 17 women who had not yet gone through menopause, and who were undergoing a laparoscopic procedure (a surgical diagnostic procedure to examine organs inside the abdomen). Among them, nine were Sjögren’s patients (ages 33 to 46) reporting vaginal dryness, and eight were healthy women (ages 36 to 44) who served as controls.
Participants were asked not to have sexual intercourse or to use tampons, lubricants, or any other vaginal products within 72 hours before the study visit. They were also asked to fill out a questionnaire, providing information that included their vaginal symptoms and sexual function.
A gynecologist examined their vaginal health, conducted a cervicovaginal lavage — in which a solution is flushed over the cervix and vagina to collect cells in those regions — and took samples from the cervix using a swab. Biopsies from both the vagina and cervix were also done.
Sjögren’s patients were found to have lower sexual function, use lubricants more often, and more often report pain during sexual intercourse than did controls. Their vaginal health was also significantly poorer, with the mucosa being the most affected subdomain — indicating a fragile mucosa with a higher tendency to bleed.
None of the women showed signs of vaginal atrophy, which is a cause of vaginal dryness in post-menopausal women.
At the cellular level, researchers found that patients had significantly more infiltrating immune cells in their vaginal and cervical tissues than did controls. The type of immune cell in elevated numbers, however, differed by tissue group: T-cells in the vagina, and B-cells in the cervix.
In both cases, these immune infiltrates were mostly found in a region of connective tissue that is highly enriched in blood and lymphatic vessels, and that produces the transudate.
Looking at these vessels, investigators found that patients had fewer vascular smooth muscle cells — which cover and provide support to vessels with high blood flow — in their vaginal region than did healthy women.
Those with Sjögren’s syndrome also had higher levels of the CXCL10 inflammatory molecule in swab and lavage samples compared to controls.
“Why lymphocytes [immune cells] migrate to these sites is not yet known, but it is likely that CXCL10 is involved,” the researchers wrote after finding that levels of this molecule in cervicovaginal lavage samples significantly correlated with levels of the infiltrated immune cells.
They also suggested that it is likely that these immune cells are causing vaginal dryness by either damaging blood vessels, or by interfering with transudate’s production.
This is supported by a decrease in smooth muscle cells, which “might disturb the production of transudate, considering the important role of smooth muscle cells in the regulation of the blood flow in the vaginal vascular network during sexual arousal,” researchers wrote.
“Taken together, we hypothesize that vaginal dryness is impaired in primary SS [Sjögren’s syndrome] patients as a result of vascular dysfunction,” the team concluded.