BOF: General (Haemoglobinopathy)

Severe beta thalassaemia major may be cured with bone marrow transplantation in carefully selected patients. Which ONE of the following statements is true regarding allogeneic bone marrow transplantation as treatment for beta thalassaemia major?

a) Adult patients are at a higher risk of relapse of their disease following transplant than children.

b) Cardiac tamponade is more commonly encountered than in other transplant patients.

c) In patients with persistent mixed chimerism after two years of follow up there is a greater than 60% risk of relapse

d) Incidence of hepatic veno-occlusive disease is associated with level of hepatic iron prior to transplantation.

e) Recurrence following transplant should be treated with a second transplantation procedure.

The answer is:

Cardiac tamponade is more commonly encountered than in other transplant patients.

Explanation:

Transplantation for beta thalassaemia is an acceptable treatment as long as a thorough risk assessment has been made based on the quality of chelation therapy and degree of hepatomegaly and hepatic fibrosis. Adults are at greater risk of TRM, improved by attenuating the cyclophosphamide dose, children at greater risk of relapse, improved by using a more erythrosuppressive and immunosuppressive conditioning regime (with hypertransfusion, hydroxyurea, azathioprine, fludarabine and supportive growth factors as well as busulfan and cyclophosphamide).

Veno-occlusive disease is not more common, spontaneous cardiac tamponade occurs in around 2-3% and is of unclear origin.

Matched related donors (whether umbilical cord blood or mobilised donor stem cells) are the only acceptable source of stem cells except in experienced centres undergoing clinical trials where unrelated (but fully matched) donors may be trialled, and reduced intensity conditioning methods used.

Under these circumstances overall survival is around 97% and disease free survival 90%.

Unmatched donor transplants and second transplant procedures have dire outcomes with current conditioning regimes (20-30% survival).

Reference:

Angelucci E, Matthes-Martin S, Baronciani D, et al. Hematopoietic stem cell transplantation in thalassemia major and sickle cell disease: indications and management recommendations from an international expert panel. Haematologica 2014; 99:811.