Immune haemolytic anaemia following T cell-depleted allogeneic bone marrowtransplantation for chronic myeloid leukaemia: association with leukaemic relapse and treatment with donor lymphocyte infusions

Immune haemolytic anaemia (IHA) is a recognised complication after allogene ic stem cell transplantation (SCT) and occurs more frequently if marrow cel ls have been subjected to T cell depletion (TCD). Among 58 consecutive pati ents who underwent TCD-allogeneic SCT from volunteer unrelated donors for t he treatment of CML at the Hammersmith Hospital during a 3-year period (1 M arch 1996 to 28 February 1999) we identified nine cases of IHA. All patient s had a strongly positive direct and indirect antiglobulin test and in eigh t patients the serological findings were typical of warm-type haemolysis of ten with antibody specificities within the Rh system. All nine cases had cl inically significant haemolysis and were treated initially with prednisolon e and immunoglobulin. The onset of IRA coincided with the occurrence of leu kaemic relapse in six cases, and the presence of host haemopoiesis confirme d by lineage-specific chimerism in all four cases studied. Five patients re ceived donor lymphocyte infusions (DLI); in three molecular remission and t he restoration of full donor chimerism coincided with resolution of haemoly sis. We conclude that in the context of leukaemic relapse, DLI is an effect ive therapy for IHA following allografts involving TCD.