title: Detection of bcr/abl transcripts by RT-PCR and their colorimetric evaluation in chronic myeloid leukemia patients receiving allogeneic bone marrow transplantation.
abstract: BACKGROUND
  Chronic myeloid leukemia (CML) is a disease characterized by the presence of a unique molecular marker, i.e. the fusion gene bcr-abl and its mRNA and protein products. This marker permits minimal residual disease follow-up after bone marrow transplantation (BMT) through cytogenetic or molecular analysis. Although the reverse transcriptase polymerase chain reaction (RT-PCR) method is largely employed, the clinical value and impact of a positive RT-PCR as a herald of hematological relapse has not yet been definitively ascertained.
  
  
  METHODS
  In order to verify the frequency of bcr-abl positivity in CML patients who underwent alloBMT, we performed serial two-step RT-PCR on 63 peripheral blood and bone marrow specimens obtained at different times after non T-cell-depleted BMT from 16 CML patients treated in our Institution. After amplification, RT-PCR products were always checked by liquid hybridization with a specific probe. Median molecular follow-up after BMT was 38 months (range 2-144 months).
  
  
  RESULTS
  None of the patients studied presented clinical hematological relapse after BMT. Six out of sixteen patients were found to be positive for bcr-abl. PCR positivity appeared in 4/6 patients more than one year post-BMT and in 2/6 patients within one year post BMT. In both instances PCR was an isolated finding in 5/6 patients and reverted to negativity in subsequent analysis; only one case was PCR-positive twice. It is noteworthy that RT-PCR positivity appeared in five patients presenting acute or chronic graft versus host disease (GVHD) and in one patient who had received MUD-BMT.
  
  
  CONCLUSIONS
  In our cohort of patients, transient bcr-abl positivity had no clinical relevance and was also found in MUD-BMT without heralding hematological relapse. Our observations further stress the importance of applying only quantitative PCR methods during the post BMT follow-up of CML patients.
authors.affiliation: Department of Hematology, University of Florence, Italy. santini@cesit1.unifi.it
authors.forename: V
authors.initials: V
authors.lastname: Santini
authors.forename: A
authors.initials: A
authors.lastname: Zoccolante
authors.forename: A
authors.initials: A
authors.lastname: Bosi
authors.forename: S
authors.initials: S
authors.lastname: Guidi
authors.forename: R
authors.initials: R
authors.lastname: Saccardi
authors.forename: A M
authors.initials: AM
authors.lastname: Vannucchi
authors.forename: G
authors.initials: G
authors.lastname: Martinazzo
authors.forename: P A
authors.initials: PA
authors.lastname: Bernabei
authors.forename: P R
authors.initials: PR
authors.lastname: Ferrini
mesh_terms: D000293:Adolescent; D000328:Adult; D016026:Bone Marrow Transplantation; D003124:Colorimetry; D005069:Evaluation Studies as Topic; D005260:Female; D016044:Fusion Proteins, bcr-abl / Q000235:genetics*; D006801:Humans; D015464:Leukemia, Myelogenous, Chronic, BCR-ABL Positive / Q000378:metabolism / Q000628:therapy*; D008297:Male; D008875:Middle Aged; D016133:Polymerase Chain Reaction / Q000379:methods*; D012333:RNA, Messenger / Q000032:analysis*; D012194:RNA-Directed DNA Polymerase; D014184:Transplantation, Homologous
chemical_list: D012333:RNA, Messenger; D016044:Fusion Proteins, bcr-abl; D012194:RNA-Directed DNA Polymerase