Relapse of preB-ALL after rituximab treatment for chronic graft versus host disease: implications for its use?

In acute lymphatic leukaemia (ALL) treated with allogenic stem cell transplantation limited chronic graft versus host disease (cGVHD) is associated with a higher 5 year disease free survival. This indicates an important graft-versus-leukemia (GVL) effect, although this effect is less pronounced in ALL than in other malignancies. B-cell depletion using Rituximab is a treatment option in therapy refractory cGVHD that has been used successfully in a limited number of patients with an approximate response rate of 70%. Only two ALL patients with cGVHD treated with Rituximab are found in the literature. Here we describe a pre-B-ALL patient with therapy refractory cGVHD who relapsed only one month after receiving Rituximab therapy for cGVHD. The Rituximab therapy may have triggered the relapse by targeting the shared cGVHD and GVL mechanisms, diminishing the GVL effect. Although no definite conclusions can be drawn from one case this might have implications for the use of Rituximab in cGVHD in ALL patients.