title: Minimal residual disease detection after allogeneic stem cell transplantation is correlated to relapse in patients with acute lymphoblastic leukaemia.
abstract: Minimal residual disease (MRD) assessments were performed retrospectively after allogeneic stem cell transplantation (SCT) in 32 patients (23 children and nine adults) with acute lymphoblastic leukaemia (ALL). Using immunoglobulin and T-cell receptor rearrangements as clonal markers, MRD was detected after SCT in nine patients, eight of whom have relapsed. The median time between first MRD detection and relapse was 5.5 (range 0.5-30) months. In 23 patients without MRD, six have relapsed to date: lower sensitivity, central nervous system relapse and clonal exchange of the leukaemic clone were factors that may explain the failure to detect MRD before relapse in these patients. In univariate analysis, factors associated with decreased risk of relapse were transplantation in first remission (P=0.02), the combination of acute and chronic graft-versus-host disease (P=0.03) and absence of MRD after SCT (P=0.005). In multivariate analysis, only MRD detection after SCT was significantly associated with increased risk of relapse (P=0.05). In conclusion, MRD detection after SCT is correlated with relapse and provides the opportunity for initiating immunotherapeutic intervention at an early stage when the tumour cell burden is still low.
authors.affiliation: Department of Clinical Immunology and Centre for Allogeneic Stem Cell Transplantation, Karolinska Institutet at Huddinge University Hospital, Stockholm, Sweden. mehmet.uzunel@labmed.ki.se
authors.forename: Mehmet
authors.initials: M
authors.lastname: Uzunel
authors.forename: Marie
authors.initials: M
authors.lastname: Jaksch
authors.forename: Jonas
authors.initials: J
authors.lastname: Mattsson
authors.forename: Olle
authors.initials: O
authors.lastname: Ringdén
mesh_terms: D000293:Adolescent; D000328:Adult; D002648:Child; D002675:Child, Preschool; D005260:Female; D005500:Follow-Up Studies; D015329:Gene Rearrangement, T-Lymphocyte; D006086:Graft vs Host Disease; D006801:Humans; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D018365:Neoplasm, Residual / Q000473:pathology*; D011184:Postoperative Period; D054198:Precursor Cell Lymphoblastic Leukemia-Lymphoma / Q000401:mortality / Q000473:pathology* / Q000601:surgery*; D012008:Recurrence; D012074:Remission Induction; D012189:Retrospective Studies; D012306:Risk; D033581:Stem Cell Transplantation; D015996:Survival Rate; D014184:Transplantation, Homologous