Vulvovaginal Graft-versus-Host Disease: Diagnosis and Microbiome Evaluation

The goal of this observational study is to investigate the development of vulvovaginal graft-versus-host- disease (GVHD), an under-reported and under-recognized manifestation of chronic GVHD. This study aims to characterize the vaginal microbiome in participants undergoing allogeneic hematopoietic cell transplantation (HCT). The main questions it aims to answer are: * Is the vaginal microbiome altered during allogeneic HCT? * What changes may help researchers understand the development of vulvovaginal GVHD? Participants will be asked to undergo an assessment of vulvovaginal symptoms through a vulvovaginal symptom questionnaire once pre-transplant, 6 months post-transplant, and twelve12 months post- transplant. Participants will also be asked to undergo a vaginal microbiome (collection of bacteria, fungi, and viruses that live on our bodies) evaluation through a vaginal exam performed by a gynecologist with collection of vaginal samples once pre-transplant and again six months post-treatment and twelve months post-transplant. If a participant develops symptoms of vulvovaginal GVHD at any point in time during the post-transplant follow up, the participant may partake in additional vaginal exams to diagnose GVHD at the time of symptom onset.

Inclusion Criteria: * Female participants planning to undergo allogeneic HCT for any disease indication, OR, female participants who have already received HCT and have developed vulvovaginal GVHD during their post-transplant follow-up period * All conditioning regimens (myeloablative or reduced intensity) will be included. * All donor sources (HLA matched/mismatched related, unrelated, umbilical cord, haploidentical) will be included. * All graft sources (bone marrow or peripheral blood stem cells) will be included. * All GVHD prophylaxis regimens will be included. * Aged 18-70. * English speaking and able to sign written informed consent. * Participants agree to a vaginal gynecologic exam. * Co-enrollment on other clinical trials will be allowed. Exclusion Criteria: * Participants who decline or unable to undergo vaginal gynecologic exam due to any discomfort or pain. * Any concurrent medical, psychiatric or other illness in which the provider believes the participants may not be able to comply with study assessments. * Participants with a current diagnosis of a sexually transmitted infection (STI) (Herpes Simplex Virus, Gonorrhea, Chlamydia, Trichomonas,) or a history of previously untreated STI which may incite inflammation that will impact the microbiome. * Participants with a history of lichen sclerosis, lichen planus, pre-transplant. * Participants with a history or current diagnosis of vaginal or vulvar malignancy.