Molecular and clinical follow-up after stem cell transplantation for multiple myeloma

Molecular follow-up has been carried out using immunoglobulin heavy-chain ( IgH) gene fingerprinting, a polymerase chain reaction (PCR)-based technique with a sensitivity of 0.1-0.01% (10(-3)-10(-4)), in 22 patients affected b y multiple myeloma and submitted to stem cell transplantation (SCT). Twelve patients were submitted to either single or double autologous unselected p eripheral blood progenitor cell transplantation, eight patients were submit ted to autologous CD34+ immunoselected transplantation and two patients wer e submitted to allogeneic bone marrow (one patient) or peripheral blood CD3 4+ stem cell (one patient) transplantation. At diagnosis, all patients show ed clonal CDIII rearrangement. The molecular analysis performed on leukaphe resis products and CD34+ purified fractions proved to be contaminated by my eloma cells. During follow-up after autografting, all but one patient retai ned clonal rearrangement despite clinical complete remission (CR) in ten of them. These ten patients either relapsed (Rel) or showed progressive disea se (PD) after transplantation: four of them died. Only one patient did not retain clonal rearrangement after autologous transplantation: she is curren tly alive in CR after a follow-up of 100 months. One patient submitted to a llogeneic transplantation is currently alive with no evidence of the diseas e, but still retains clonal rearrangement after a follow-up of 47 months. A nother patient died 4 months after transplantation after succumbing to fata l pneumonia showing myeloma progression.