Sequential molecular monitoring of chimerism in chronic myeloid leukemia patients receiving donor lymphocyte transfusion for relapse after bone marrow transplantation

Abstract

Summary:chronic myeloid leukemia (CML) relapsed after allogeneic bone marrow transplantation (BMT). [1][2][3][4][5] Chimerism studies in patients who relapsed following an Recent observations of chimerism in patients relapsed following an allotransplant suggest the persistence of allotransplant suggest the persistence of immunotolerance thus offering a biologic rationale for the use of DLT. 6 Sevimmunotolerance, thus offering a biologic rationale for the use of donor lymphocyte transfusion (DLT). In this eral methods with different sensitivities are useful to evaluate the chimerism status in transplanted patients. These study, we have analyzed by PCR amplification of several VNTR regions, sequential bone marrow and peripheral include cytogenetics, Y body detection, protein polymorphism, and red cell phenotyping. 7-9 More recently, DNAblood DNA samples in four patients who received DLT for CML relapse after bone marrow transplantation.based methodology has provided more sensitive techniques. In particular, polymerase chain reaction (PCR) amplifiPrior to DLT, all patients showed mixed chimerism in peripheral blood cells while two had mixed chimerism cation of individual specific genetic loci, such as the variable tandem repeats (VNTR) and the short tandem repeats and two no chimerism in the BM. None of these four patients showed evidence of chimerism at the cyto-(STR), have increased the sensitivity of the analysis up to 1-0.1% and 0.1-0.01%, respectively. 10,11 Using these genetic level (all had 100% +ve metaphases). After DLT, a complete hematologic and molecular remission (ie disassays, a condition of mixed chimerism (MC) has been shown in 80% of CML patients receiving T cell-depleted appearance of the BCR/ABL fusion transcript) was obtained in the two patients who had bone marrow allografts. 11 With regard to CML patients treated with DLT for mixed chimerism prior to DLT. The two patients without evidence of marrow chimerism prior to DLT conrelapse after BMT, Mackinnon et al 12 have analyzed the chimerism status of T lymphocytes by PCR and shown that verted to a pattern of mixed chimerism after DLT, but both developed a severe bone marrow aplasia occurring a MC was present in almost every patient prior to DLT. While this observation encourages the use of adoptive at day 56 and 36, respectively. With regard to the sequential analysis of bone marrow chimerism after immunotherapy in these patients, it provides no prognostic information on the post-DLT clinical outcome. DLT we observed that: (1) the disappearance of BCR/ABL +ve cells paralleled the conversion to a patIn this study, we have analyzed by PCR amplification of several VNTR regions sequential bone marrow and periphtern of full donor chimerism; and (2) the time interval to achieve CR was inversely correlated with the percenteral blood DNA samples in four patients who received DLT for CML relapse after BMT. We show that bone marrow age of donor DNA in bone marrow. In conclusion, we have shown here that the assessment of bone marrow chimerism pre-DLT is pr...

Assessing quantitative chimerism longitudinally: technical considerations, clinical applications and routine feasibility

“…The relevance of this parameter to predicting engraftment, rejection and relapse has already been clearly recognized. 9,10,[12][13][14] However, the other two analytic options should be briefly discussed because they may foreshadow new clinical applications of the longitudinal monitoring approach. Our preliminary efforts in developing these applications are illustrated in several actual cases (Figures 6 and 7).…”

“…A drop or rise in a particular patient's chimerism levels can be interpreted as a basis for clinical intervention. In the absence of specific tumor markers, sequential analysis of %Chm may offer the only evidence on which sub-clinical relapse of disease can be assessed ( Figure 5); [10][11][12][13][14][15] the use of reduced intensity conditioning has made engraftment analysis based on recovery of neutrophil numbers anachronistic.…”

“…3,6,[9][10][11][12][14][15][16][17][18]20,[25][26][27][29][30][31][32][33][34][35] Each marker occurs at a characteristic chromosomal location, and represents a short core DNA nucleotide sequence that is repeated in tandem multiple times -hence short tandem repeat. As a core sequence may be repeated at a given allelic locus from 4 to 50 times, STR markers are considered highly polymorphic and thereby useful for human identity applications.…”

“…Such longitudinal assessments uniquely reveal the progressive kinetics of each patient's mixed chimeric state. [10][11][12][13][14][15] Quantitative chimerism testing, today, commonly relies on an assay for short tandem DNA repeats (STRs). Although, these data can be readily integrated into a longitudinal testing framework, 15,16 such an approach to chimerism monitoring has not received critical attention in other recent surveys.…”

Intensive graft-versus-host disease prophylaxis is required after unrelated-donor nonmyeloablative stem cell transplantation

“…Acute GVHD was graded according to Glucksberg criteria. 21 Chimerism, as determined by peripheral blood samples using informative short tandem repeat polymorphisms, 22,23 was evaluated beginning at least on day 30 and monthly thereafter. Secondary end points were maximum response, progression-free survival, transplant-related mortality, and overall survival.…”