Análisis del quimerismo en niños con leucemia después del trasplante de médula ósea

Introduction. Chimerism evaluation is indispensable in the follow-up of patients in whom an allogenic bone marrow transplantation (Alo-BMT) is performed. The chimeric state may determine the BMT outcome, disease recurrence and survival. Material and methods. Peripheral blood samples were taken from 4 patients before and after BMT every week for 16 weeks, thereafter even 2 weeks, and every month after 6 month until 1 year of follow-up. DNA was extracted and HUMARA, D1S80, and TH01 loci were amplified through PCR assays. Results were compared with basal samples as well as with donor samples. Results. Complete chimerism was observed in 3 cases in whom no clinical complications were observed. Lack of engraftment in 2 occasions were observed in the remain patient in whom a mixed chimerism was detected; this patient recover after a third BMT and developed complete chimerism. Conclusions. Mixed chimerism after Alo-BMT may predict graft rejection; chimerism evaluation is a useful tool in the follow-up of patients with BMT.