Sequential monitoring of chimerism and detection of minimal residual disease after allogeneic blood stem cell transplantation (BSCT) using multiplex PCR amplification of short tandem repeat-markers

Allogeneic SCT is important in myelodysplastic syndrome, the BCR-ABL-negative chronic myeloproliferative diseases (CMPDs) and in poor-risk AML. Techniques to monitor the minimal residual disease, for example, by PCR or immunophenotyping gain increasing importance in the post transplantation period as basis for improved and earlier therapeutic interventions in impending relapse. Recent markers such as the NPM1 mutations in AML or the JAK2V617F mutation in the CMPD can be exactly quantified by real-time PCR and were evaluated for their prognostic value in the post transplantation phase and for their utility to plan adoptive immunotherapy in case of molecular relapse. With respect to chimerism, new and very sensitive methods were introduced, for example, quantitative assessment of genetic polymorphisms by realtime PCR, but also methods here are still highly individualized. Only in CML, where SCT focuses now on poor-risk cases or cases of tyrosine kinase inhibitor failure, follow-up schedules are standardized. Standardization of the different diagnostic techniques and of the intervals in the post transplantation period is urgently needed also in other myeloid malignancies and should be focus of future studies.

Section: Discussionmentioning

confidence: 99%

Section: Chimerismmentioning

confidence: 99%

Minimal residual disease diagnostics in myeloid malignancies in the post transplant period

Bacher

Zander

Haferlach

et al. 2008

“…2,8 Serial, quantitative chimerism studies have been recommended for children with ALL after allogeneic HCT to identify those patients at high risk of relapse. 10 In general, analysis of PB cells is more useful than BM cells because lineage-specific chimerism can be determined.…”

Section: Discussionmentioning

confidence: 99%

“…Sensitivity by both methods achieved at least 5% sensitivity as documented by external proficiency challenges. 7,8 Depending on the relative size of the informative VNTR markers, sensitivity was as low as 0.1%, as assessed by internal mixing studies. Sensitivity of STR analysis routinely achieved 0.5% sensitivity as assessed by mixing studies.…”

Section: Methodsmentioning

confidence: 99%

Lack of utility of chimerism studies obtained 2–3 months after myeloablative hematopoietic cell transplantation for ALL

Doney

Loken²,

Bryant

et al. 2008

Lineage specific chimerism studies are commonly obtained at several time points after nonmyeloablative haematopoietic cell transplantation to assess the tempo and degree of engraftment, and to monitor graft rejection. For patients who receive myeloablative transplants, the value of frequent chimerism analyses using sensitive molecular techniques is less certain. In this study, a retrospective analysis was performed to assess the transplant outcome of 89 adult patients with acute lymphocytic leukaemia who had chimerism studies of unfractionated bone marrow cells or peripheral blood subsets performed approximately 80 days after transplantation. These patients received unmanipulated, myeloablative transplants using either HLA-identical or HLA-mismatched, related or unrelated donor stem cells. Incomplete donor engraftment was present only in the CD3 + peripheral blood T-cells in a small percentage of patients. There was no correlation of mixed chimerism with transplant outcome. Routine "Day 80" chimerism studies in this group of patients who receive intensive, myeloablative conditioning regimens are not recommended.

“…This was carried out using HLA allele analysis using the RSCA (reference strand mediated conformation analysis) method and/or by quantitative molecular genotype analysis using 15 markers of DNA STR (short tandem repeat) tagged with four fluorochromes and analyzed by ABI PRISM 3100 sequencer and the Gene Mapper 3.0 software. 5,6 This method was also used to analyze DNA from biopsy material taken from GVHD skin lesions to evaluate the presence of donor cells.…”

Section: Preparative Regimen Gvhd Prophylaxis and Supportive Carementioning

confidence: 99%

Cord blood transplants supported by co-infusion of mobilized hematopoietic stem cells from a third-party donor

Bautista

Cabrera

Regidor

et al. 2008

This open label clinical study provides updated evaluation of the strategy of single unit cord blood transplants (CBTs) with co-infusion of third-party donor (TPD) mobilized hematopoietic stem cells (MHSC). Fifty-five adults with high-risk hematological malignancies, median age 34 years (16-60 years) and weight 70 kg (43-95 kg), received CBTs (median 2.39 Â 10 7 total nucleated cell (TNC) per kg and 0.11 Â 10 6 CD34 þ per kg) and TPD-MHSC (median 2.4 Â 106 CD34 þ per kg and 3.2 Â 10 3 CD3 þ per kg). Median time to ANC and to CB-ANC 40.5 Â 10 9 /l as well as to full CB-chimerism was 10, 21 and 44 days, with maximum cumulative incidences (MCI) of 0.96, 0.95 and 0.91. Median time to unsupported platelets 420 Â 10 9 /l was 32 days (MCI 0.78). MCI for grades I-IV and III-IV acute GVHD (aGVHD) were 0.62 and 0.11; 12 of 41 patients (29%) who are at risk developed chronic GVHD, becoming severely extensive in three patients. Relapses occurred in seven patients (MCI ¼ 0.17). The main causes of morbi-mortality were post-engraftment infections. CMV reactivations were the most frequent, their incidence declining after the fourth month. Five-year overall survival and disease-free survival (Kaplan-Meier) were 56 % and 47% (63% and 54% for patients p40 years). In conclusion, CBT with single units of relatively low cell content and 0-3 HLA mismatches is feasible as a first choice option for adult patients who lack a readily available adequate adult donor.