Toh, H.C., Spitzer, T.R., Preffer, F., Alexander, S.I., McAfee, S., Dombkowski, D., Clark, J.S., Colby, C., Saidman, S., Sackstein, R., and Sykes, M.
A 51-year-old patient with refractory non-Hodgkin lymphoma (NHL) received non-myeloablative conditioning and a two of six (A, B, DR) human leucocyte antigen (HLA) mismatched donor BMT. Post-BMT lymphocytes showed fluctuating T- and natural killer (NK)-cell chimerism, which culminated in mainly donor lymphocytes by Day + 100. Changes in lymphocyte chimerism correlated with antidonor and anti-host responses in mixed lymphocyte reaction (MLR). On Day + 100, a strong anti-host response was observed in MLR in the absence of graftversus-host disease (GVHD), together with near complete regression of the patient's lymphoma. A mild chronic GVHD later developed and, eventually, by 680 days postBMT, the lymphoma had relapsed and MLR reflected a state of global immune unresponsiveness. These observations demonstrate evolving host-versus-graft and graftversus-host tolerance that correlates with fluctuating lymphoid chimerism and graft-versus-lymphoma (GVL) effects, in the absence of severe GVHD. Eventual lymphoma relapse temporally correlated with a generalised immunosuppressed state. [ABSTRACT FROM AUTHOR]