[Assessment of minimal residual disease in adult patients with B-lineage acute lymphoblastic leukemia using rearranged immunoglobulin loci detection].
OBJECTIVE
To explore detection of immunoglobulin heavy chain gene (IgH) rearrangement by real-time quantitative polymerase chain reaction (RQ-PCR) for minimal residual disease (MRD) monitoring in adult B-lineage acute lymphoblastic leukemia (B-ALL) patients.


METHODS
DNA samples of fifteen newly diagnosed adult B-ALL patients were collected. The IgH gene rearrangements were detected by PCR followed by sequencing and subsequent blasting for monoclonal PCR products. Allele-specific oligonucleotides (ASO) were designed based on the sequence of junction regions, using PRIMER 5.0 software. MRD targets were detected in 115 bone marrow samples by RQ-PCR, in which ASO upstream primers in combination with the consensus JH probes and downstream primers were used. Transcripts copies of bcr-abl fusion gene were also measured in 7 Ph(+) ALL cases.


RESULTS
The detection sensitivity of ASO-PCR varied between 10(-3) and 10(-5) leukemia cells in 15 adult ALL patients. The background and nonspecific amplification was detectable at a low level. Quantification monitoring MRD showed that high-risk adult ALL patients in complete remission (CR) had a higher MRD level than those of standard-risk. Patients with MRD > 10(-3) had a higher relapse rate and a shorter survival time. Besids, the dynamic curves of the quantified level of respective IgH rearrangement were consistent with the expression levels of bcr-abl fusion genes in seven Ph(+) patients during follow-up.


CONCLUSIONS
The individual quantification of IgH rearrangement by RQ-PCR using ASO primers was a sensitive, specific and reliable method for accurate evaluation of malignant clones. These data indicates a close correlation between the level of rearranged IgH and the treatment response and prognosis in adult ALL patients. It may be a helpful method for monitoring MRD in clinical trials.
Jiangsu Institute of Hematology, The First Affiliated Hospital, Suzhou University, Key Laboratory of Thrombosis and Hemostasis, Ministry of Health, Suzhou 215006, China.
Li
L
Yao
Zi-Xing
ZX
Chen
Jian-Nong
JN
Cen
Hong
H
Liu
Jun
J
He
De-Pei
DP
Wu
D000328:Adult; D017931:DNA Primers; D006801:Humans; D007143:Immunoglobulin Heavy Chains / Q000235:genetics; D007136:Immunoglobulins / Q000627:therapeutic use; D018365:Neoplasm, Residual / Q000175:diagnosis; D016133:Polymerase Chain Reaction; D015452:Precursor B-Cell Lymphoblastic Leukemia-Lymphoma / Q000235:genetics; D054198:Precursor Cell Lymphoblastic Leukemia-Lymphoma / Q000235:genetics
D017931:DNA Primers; D007143:Immunoglobulin Heavy Chains; D007136:Immunoglobulins