Vaginal Microbiome and the Development of Vulvovaginal Graft Versus Host Disease

Allogeneic stem cell transplantation involves transferring stem cells from a healthy person (the donor) to the patient, after high-intensity chemotherapy or radiation, given to destroy any remaining cancer cells in the body.

Of transplant-related complications, graft-versus-host disease (GVHD) is one of the most important complications. GVHD arises from donor immune cells, that identify the recipient's (the patient's) cells as foreign and attack them.

Approximately half of women undergoing transplantation will experience GVHD involving the genitalia (i.e., the vulva and vagina), termed vulvovaginal GVHD (VV-GVHD). VV-GVHD may cause irreversible anatomical changes, including complete vaginal obliteration, and not surprisingly, it has a severe impact on patients' quality of life and sexual function. This complication is unpredictable and non-preventable by the usual immunosuppressive treatment given to patients. Frequent gynecological examinations and prolonged follow-up of transplanted women are needed, to allow early diagnosis and prevention of harmful results of VV-GVHD. This follow-up adds inconvenience and anxiety to the patients.

The study is planned as a longitudinal, prospective, cohort-based study of women who undergo HSCT at Hadassah University Medical Center, Jerusalem. It will include frequent appointments for clinical evaluation and sample collection: before transplant, immediately after transplant and every three months for two years following transplant, representing the period of main VV-GVHD risk.

Detailed study plan:

Female patients planned for HSCT will receive an explanation regarding the study from their hematologist. After assessment of inclusion and exclusion criteria and patient's consent to participate, an external gynecological examination will be done and vaginal samples for microbiome analysis and cytomegalovirus (CMV) will be taken. Stool will be collected for simultaneous stool microbiome analysis. Obtaining vaginal swabs does not require a gynecological internal exam and can be completed by inserting a narrow applicator to the vagina.

Vaginal swabs will be taken pre-conditioning, at the day of transplant, at seven days post-transplant, at leukocyte engraftment, defined as the first of three consecutive days with an absolute neutrophil count (ANC) of >0.5 x 109/L (18), at day 30, and day 100, followed by 3-moths intervals (6 , 9, 12,15,18,21and 24 months) post-transplant.

Upon hospital discharge following HSCT, an appointment with the specializing gynecologist will be scheduled 1 month after HSCT, followed by 3-months interval follow-up appointments, for 2 years. Patients will be evaluated every three months during the first two years after HSCT, assessing VV-GVHD presence and for samples' collection. Fecal samples will be obtained in the same time points, to assess for possible associations between VV-GVHD and fecal microbiome.

At the first appointment following HSCT, an intake history will be completed, and the patient will receive a thorough explanation regarding VV-GVHD symptoms as well as its possible consequences, as part of the standard care.

Patients' medical charts will be surveyed for the following parameters: demographics, primary hematologic disease characteristics, transplant parameters (conditioning protocol, GVHD prophylaxis, source of cells for transplant, donor type, donor age, and CMV status of patient and donor), transplant associated complications, engraftment details, systemic acute and chronic GVHD manifestations and treatments, antibiotic administration. Gynecological and obstetric parameters will be documented (gravidity, parity, hormonal status prior to HSCT and chemotherapy, previous gynecological disorders, previous vaccination for HPV, previous findings of cervicovaginal HPV or dysplasia etc.).

In each appointment the patient will undergo gynecological examination, to evaluate findings of VV-GVHD as well as collection of vaginal samples for microbiome analysis and CMV presence. Hormonal status (amenorrhea, menstruation), menopausal symptoms, hormonal replacement therapy, vaginal preparations used (lubricants, topical hormonal therapy, topical steroids, antifungals, antibiotics) and intercourse frequency will be documented. A documentation of non-genital acute and chronic GVHD will be completed in every visit, as well as currently used medications.

A gynecological examination will be performed in follow-up visits, aimed to assess for VV-GVHD, and will include inspection of the vulva, vaginal digital palpation (to assess for adhesions, constriction, or stenosis), a speculum examination in those who are/were sexually active, and a wet mount in cases of vaginal inflammation or vaginitis symptoms.

Diagnosis of VV-GVHD is based on clinical findings. The National Institutes of Health (NIH) Consensus Development Program criteria is used for scoring severity of genital involvement. Diagnostic signs included vulvar lichen-planus-like features: erosions, fissures, reticulation, erythematous patches, peri-clitoral adhesions, clitoral hood scarring or buried clitoris, superficial vaginal inflammation, purulent discharge, vaginal erosions, cobweb-like soft-adhesions, firm-adhesions, concentric stenotic rings or side-to-side firm adhesions with vaginal narrowing or obstruction.

If VV-GVHD will be identified at any point during follow-up examinations, treatment will be initiated. Patients will be instructed to present to the clinic with the onset of any vulvovaginal symptoms or as soon as extragenital-GVHD appears or worsens.