Application of polymerase chain reaction (PCR) to the hypervariable segment of the immunoglobulin heavy chain (IgH) gene allows detection of minimal residual disease (MRD) at a level of one leukemic cell in 103 104 no...Application of polymerase chain reaction (PCR) to the hypervariable segment of the immunoglobulin heavy chain (IgH) gene allows detection of minimal residual disease (MRD) at a level of one leukemic cell in 103 104 normal marrow cells. We used seminested PCR to amplify the DNA fragment of the complementarity-determining region-Ⅲ of the IgH gene from leukemic cell specimens of patients with leukemia. There was IgH gene rearrangement in 25 of 34 ( 74% ) acute lymphohlastic leukemia (ALL) patients, 3 of 4 (75%) chronic lymphocytic leukemia (CLL) patients. Five of 33 (15%) acute myeloid leukemia (AML) patients and 0 of 9 (0%) chronic myeloid leukemia (CML) patients. ALL PCR positive cases were confirmed by Southern blot analysis. Our results indicated that (1) the seminested PCR technique was found to have a higher sensitivity and less false-negative results than onestage PCR; (2) IgH gene rearrangement may not be Iimited to lymphoid leukemia of B cell lineage. In some patients,the leukemic transforming event may involve stem cells capable of both B cell and myeloid differentiation, or AML cells may differentiate along different lineages with the predominant appearance of one or the other subclone in the course of the disease. The mechanism needs to be further investigated.展开更多
PCR amplification was used to detect immunoglobulin heavy chain (IgH), T-cell receptor (TCR)Vγ1-Jγ, Vδ2-Dδ 3 rearranged genes in 45 cases of acute lymphoblastic leukemia (ALL) and IgH gene rearrangement in 41 case...PCR amplification was used to detect immunoglobulin heavy chain (IgH), T-cell receptor (TCR)Vγ1-Jγ, Vδ2-Dδ 3 rearranged genes in 45 cases of acute lymphoblastic leukemia (ALL) and IgH gene rearrangement in 41 cases acute nonlymphoblastic leukemia (ANLL). The positive percentage of the IgH, TCR Vγ1-Jγ and Vδ 2-Dδ3 gene rearrangement was found to be 66. 7%, 62.2%, and 35. 6%, respectively in 45 ALL patients. Multiple rearranged IgH gene bands were found in 8 (26. 7% ) out of 30 ALL patients with IgH gene rearrangement. IgH gene rearrangemens were found in 7 (17. 1% ) out of 41 ANLL patients. ALL patients with positive IgH rearranged gene were with B cell and those with positive TCR Vγ1-Jγ gene rearrangements and with negative IgH rearranged gene were with T-ALL,those with positive both IgH and TCR Vδ2-Dδ3 rearranged genes mostly were with preB-ALL. The complete remission (CR) rate was low in ALL patients with multiple rearranged heavy chains and ANLL patients with IgH gene rearrangement, who were more likely to have a clinical relapse, which may be due to clonal evolution. In complete remission (CR) patients, the cytologic relapse fell behind postive PCR results for an average periods of 7. 2 weeks (range 2 to 23 weeks). Using PCR to detect rearranged genes could be helpful in determining the efficacy of chemotherapy, predicting clinical relapse, assisting gene typing and predicting prognosis.展开更多
We report two cases of acute leukemia relapse resulting from clonal evolution in the course of disease. The case 1 was a 22-year-old female of acute non-lymphoblastic leukemia (ANLL)-M1, whose immunophenotypic and gen...We report two cases of acute leukemia relapse resulting from clonal evolution in the course of disease. The case 1 was a 22-year-old female of acute non-lymphoblastic leukemia (ANLL)-M1, whose immunophenotypic and gene markers of leukemia cells had changed as compared with those at admission 10months ago, which indicates the evolution of leukemic clone. The case 2 was a 36-year -old female with acute lymphoblastic leukemia (ALL)-L2. Difference in the gene markers of leukemic clone were found between the three times of relapse. It was indicated the patient’S leukemia clone also had evolution in the course of disease. Clonal evolution may be caused by subclonal increase. The major clones were inhibited after induction therapy, but drug-resistant subclonal evaluation from some primary main clone could exist continuously and might proliferate further, which could result in leukemia relapse with change of immunophenotype and/or genotype. Clonal evolution might play an important role in the pathogenesis of some tumors in blood system.展开更多
文摘Application of polymerase chain reaction (PCR) to the hypervariable segment of the immunoglobulin heavy chain (IgH) gene allows detection of minimal residual disease (MRD) at a level of one leukemic cell in 103 104 normal marrow cells. We used seminested PCR to amplify the DNA fragment of the complementarity-determining region-Ⅲ of the IgH gene from leukemic cell specimens of patients with leukemia. There was IgH gene rearrangement in 25 of 34 ( 74% ) acute lymphohlastic leukemia (ALL) patients, 3 of 4 (75%) chronic lymphocytic leukemia (CLL) patients. Five of 33 (15%) acute myeloid leukemia (AML) patients and 0 of 9 (0%) chronic myeloid leukemia (CML) patients. ALL PCR positive cases were confirmed by Southern blot analysis. Our results indicated that (1) the seminested PCR technique was found to have a higher sensitivity and less false-negative results than onestage PCR; (2) IgH gene rearrangement may not be Iimited to lymphoid leukemia of B cell lineage. In some patients,the leukemic transforming event may involve stem cells capable of both B cell and myeloid differentiation, or AML cells may differentiate along different lineages with the predominant appearance of one or the other subclone in the course of the disease. The mechanism needs to be further investigated.
文摘PCR amplification was used to detect immunoglobulin heavy chain (IgH), T-cell receptor (TCR)Vγ1-Jγ, Vδ2-Dδ 3 rearranged genes in 45 cases of acute lymphoblastic leukemia (ALL) and IgH gene rearrangement in 41 cases acute nonlymphoblastic leukemia (ANLL). The positive percentage of the IgH, TCR Vγ1-Jγ and Vδ 2-Dδ3 gene rearrangement was found to be 66. 7%, 62.2%, and 35. 6%, respectively in 45 ALL patients. Multiple rearranged IgH gene bands were found in 8 (26. 7% ) out of 30 ALL patients with IgH gene rearrangement. IgH gene rearrangemens were found in 7 (17. 1% ) out of 41 ANLL patients. ALL patients with positive IgH rearranged gene were with B cell and those with positive TCR Vγ1-Jγ gene rearrangements and with negative IgH rearranged gene were with T-ALL,those with positive both IgH and TCR Vδ2-Dδ3 rearranged genes mostly were with preB-ALL. The complete remission (CR) rate was low in ALL patients with multiple rearranged heavy chains and ANLL patients with IgH gene rearrangement, who were more likely to have a clinical relapse, which may be due to clonal evolution. In complete remission (CR) patients, the cytologic relapse fell behind postive PCR results for an average periods of 7. 2 weeks (range 2 to 23 weeks). Using PCR to detect rearranged genes could be helpful in determining the efficacy of chemotherapy, predicting clinical relapse, assisting gene typing and predicting prognosis.
文摘We report two cases of acute leukemia relapse resulting from clonal evolution in the course of disease. The case 1 was a 22-year-old female of acute non-lymphoblastic leukemia (ANLL)-M1, whose immunophenotypic and gene markers of leukemia cells had changed as compared with those at admission 10months ago, which indicates the evolution of leukemic clone. The case 2 was a 36-year -old female with acute lymphoblastic leukemia (ALL)-L2. Difference in the gene markers of leukemic clone were found between the three times of relapse. It was indicated the patient’S leukemia clone also had evolution in the course of disease. Clonal evolution may be caused by subclonal increase. The major clones were inhibited after induction therapy, but drug-resistant subclonal evaluation from some primary main clone could exist continuously and might proliferate further, which could result in leukemia relapse with change of immunophenotype and/or genotype. Clonal evolution might play an important role in the pathogenesis of some tumors in blood system.
