oGVHD After Bone Marrow Transplantation: a Territory-wide Cohort

Allogeneic Haematopoietic stem cell transplantation (HSCT) is an effective treatment for all array of blood or blood-producing organ disorders. Graft-versus-host-disease (GVHD) occurs as a result of an overactive immunological system against normal host tissues. It can happen in the liver, skin, mucosal surface of the eye, gastrointestinal tract, and genitalia.

Ocular GVHD occurs in 30-70% of patients after HSCT. It mainly affects the ocular surface, including the conjunctiva and cornea. In severe cases, multiple clinical manifestations can lead to painful non-healing corneal ulcers, secondary infections, and visual loss.

oGVHD can be debilitating and severely impact patients' quality of life. However, there are no widely accepted guidelines available for prevention and management.

In collaboration with the Department of Haematology of Queen Mary Hospital, the investigators set out to establish a territory-wide cohort of patients receiving HSCT. Primarily, the investigators aim to establish the population-based epidemiology of oGVHD and understand the natural history and the long-term ophthalmic outcomes of oGVHD via this study.

Allogeneic haematopoietic stem cell transplantation (HSCT) is an effective treatment for all array of haematological disorders. Graft-versus-host-disease (GVHD) occurs as a result of an overactive systemic immunological response against normal host tissues, in particular the liver, skin, mucosal surface of the eye, gastrointestinal tract, and genitalia.

Ocular graft-versus-host-disease (oGVHD) occurs in 30-70% patients after allogeneic HSCT. It mainly affects the ocular surface, and pathologically it is characterized by decreased conjunctival goblet cell density, increased conjunctival squamous metaplasia, and infiltration of tissues with inflammatory cells. Common clinical manifestations include keratoconjunctivitis sicca, marginal keratitis, conjunctivitis, and conjunctival scarring, and anterior uveitis. In severe cases, these can lead to painful non-healing corneal ulcers, secondary infections, and visual loss. Risk factors for oGVHD reported in the literature included non- Caucasian race, male recipient from female donor, more extensive and severe systemic involvement, pre-existing diabetes mellitus, and use of anti-thymocyte globulin.

oGVHD can be debilitating and severely impact patients' quality of life. Although common and significant, currently there are no widely accepted guidelines available for prophylaxis and management.

The Haemopoietic Stem Cell Transplantation Centre at Queen Mary Hospital is the only quaternary referral centre for adults in Hong Kong since 1990 and now it serves over 100 patients per year. In collaboration with the Department of Haematology of QMH, the investigators set out to establish a territory-wide cohort of patients receiving allogeneic HSCT to fill the current knowledge gaps.

Eligibility Criteria:
Inclusion Criteria:

* Patient aged 18 or above
* Underwent allogeneic HSCT in QMH in the two-year recruitment period

Exclusion Criteria:

* Underwent autologous HSCT
* Patient unable to attend follow-up visits

Family Control Subjects The research team will invite an accompanying family member to be the family control. Microbiome and tear samples will be collected for comparison. The sample collection schedule is the same as the corresponding post-HSCT case.