Schrauder, A.

The controversy of varicella vaccination in children with acute lymphoblastic leukemia (Article)

2012-01-01T00:00:00Z

Late MRD response determines relapse risk overall and in subsets of childhood T-cell ALL: Results of the AIEOP-BFM-ALL 2000 study (Article)

2011-08-25T00:00:00Z

The prognostic value of MRD in large series of childhood T-ALL has not yet been established. Trial AIEOP-BFM-ALL 2000 introduced standardized quantitative assessment of MRD for stratification, based on immunoglobulin and TCR gene rearrangements as polymerase chain reaction targets: Patients were considered MRD standard risk (MRD-SR) if MRD was negative at day 33 (time point 1 [TP1]) and day 78 (TP2), analyzed by at least 2 sensitive markers;MRDintermediate risk (MRDIR) if positive either at day 33 or 78 and < 10+3at day 78; and MRD high risk (MRD-HR) if ≥ 10-3at day 78. A total of 464 patients with T-ALL were stratified by MRD: 16% of them were MRD-SR, 63% MRD-IR, and 21% MRD-HR. Their 7-year event-free-survival (SE)was 91.1% (3.5%), 80.6% (2.3%), and 49.8% (5.1%) (P < .001), respectively. Negativity of MRD at TP1 was the most favorable prognostic factor. An excellent outcome was also obtained in 32% of patients turning MRD negative only at TP2, indicating that early (TP1) MRD levels were irrelevant if MRD at TP2 was negative (48% of all patients).MRD≥ 10+3at TP2 constitutes the most important predictive factor for relapse in childhood T-ALL. The study is registered at http://www.clinicaltrials. gov; "Combination Chemotherapy Based on Risk of Relapse in Treating Young Patients With Acute Lymphoblastic Leukemia," protocol identification#NCT00430118 for BFM and #NCT00613457 for AIEOP.

Late recurrence of childhood T-cell acute lymphoblastic leukemia frequently represents a second leukemia rather than a relapse: First evidence for genetic predisposition (Article)

2011-04-20T00:00:00Z

Purpose Relapse of childhood T-cell acute lymphoblastic leukemia (T-ALL) often occurs during treatment, but in some cases, leukemia re-emerges off therapy. On the basis of previous analyses of T-cell receptor (TCR) gene rearrangement patterns, we hypothesized that some late recurrences of T-ALL might in fact represent second leukemias. Patients and Methods In 22 patients with T-ALL who had late relapses (at least 2.5 years from diagnosis), we studied TCR gene rearrangement status at first and second presentation, NOTCH1 gene mutations, and the presence of the SIL-TAL1 gene fusion. We performed genome-wide copy number and homozygosity analysis by using oligonucleotide- and single nucleotide polymorphism (SNP) -based arrays. Results We found evidence of a common clonal origin between diagnosis and relapse in 14 patients (64%). This was based on concordant TCR gene rearrangements (12 patients) or concordant genetic aberrations, as revealed by genome-wide copy number analysis (two patients). In the remaining eight patients (36%), TCR gene rearrangement sequences had completely changed between diagnosis and relapse, and gene copy number analysis showed markedly different patterns of genomic aberrations, suggesting a second T-ALL rather than a resurgence of the original clone. Moreover, NOTCH1 mutation patterns were different at diagnosis and relapse in five of these eight patients. In one patient with a second T-ALL, SNP analysis revealed a germline del(11)(p12; p13), a known recurrent aberration in T-ALL. Conclusion More than one third of late T-ALL recurrences are, in fact, second leukemias. Germline genetic abnormalities might contribute to the susceptibility of some patients to develop T-ALL. Copyright

Molecular response to treatment redefines all prognostic factors in children and adolescents with B-cell precursor acute lymphoblastic leukemia: Results in 3184 patients of the AIEOP-BFMALL 2000 study (Article)

2010-04-22T00:00:00Z

The Associazione Italiana di Ematologia Oncologia Pediatrica and the Berlin-Frankfurt-Münster Acute Lymphoblastic Leukemia (AIEOP-BFM ALL 2000) study has for the first time introduced standardized quantitative assessment of minimal residual disease (MRD) based on immunoglobulin and T-cell receptor gene rearrangements as polymerase chain reaction targets (PCR-MRD), at 2 time points (TPs), to stratify patients in a large prospective study. Patients with precursor B (pB) ALL (n = 3184) were considered MRD standard risk (MRD-SR) if MRD was already negative at day 33 (analyzed by 2 markers, with a sensitivity of at least 10-4); MRD high risk (MRD-HR) if 10-3or more at day 78 and MRD intermediate risk (MRD-IR): others. MRD-SR patients were 42% (1348): 5-year event-free survival (EFS, standard error) is 92.3% (0.9). Fifty-two percent (1647) were MRD-IR: EFS 77.6% (1.3). Six percent of patients (189) were MRD-HR: EFS 50.1% (4.1; P < .001). PCR-MRD discriminated prognosis even on top of white blood cell count, age, early response to prednisone, and genotype. MRD response detected by sensitive quantitative PCR at 2 predefined TPs is highly predictive for relapse in childhood pB-ALL. The study is registered at http://clinicaltrials.gov: NCT00430118 for BFM and NCT00613457 for AIEOP. (Blood. 2010;115(16):3206-3214)

Standardized MRD quantification in European all trials: Proceedings of the second international symposium on MRD assessment in Kiel, Germany, 18-20 September 2008 (Article)

2010-03-01T00:00:00Z

Assessment of minimal residual disease (MRD) has acquired a prominent position in European treatment protocols for patients with acute lymphoblastic leukemia (ALL), on the basis of its high prognostic value for predicting outcome and the possibilities for implementation of MRD diagnostics in treatment stratification. Therefore, there is an increasing need for standardization of methodologies and harmonization of terminology. For this purpose, a panel of representatives of all major European study groups on childhood and adult ALL and of international experts on PCR-and flow cytometry-based MRD assessment was built in the context of the Second International Symposium on MRD assessment in Kiel, Germany, 18-20 September 2008. The panel summarized the current state of MRD diagnostics in ALL and developed recommendations on the minimal technical requirements that should be fulfilled before implementation of MRD diagnostics into clinical trials. Finally, a common terminology for a standard description of MRD response and monitoring was established defining the terms complete MRD response, MRD persistence and MRD reappearance. The proposed MRD terminology may allow a refined and standardized assessment of response to treatment in adult and childhood ALL, and provides a sound basis for the comparison of MRD results between different treatment protocols.

Cluster analysis of genomic ETV6-RUNX1 (TEL-AML1) fusion sites in childhood acute lymphoblastic leukemia (Article)

2009-08-01T00:00:00Z

Fusion between ETV6 and RUNX1 defines the largest genetic subgroup in childhood ALL. The genomic fusion site, unique to individual patients and specific for the malignant clone, represents an ideal molecular marker for quantification of minimal residual disease. Sequencing of DNA breakpoints has been difficult due to the extended size of the respective breakpoint cluster regions. We therefore evaluated a specially designed multiplex long-range PCR assay in 65 diagnostic bone marrow samples for its suitability in routine use. Resulting fusion sites and breakpoints derived from previous studies were subject to cluster analysis to identify potential sequence motifs involved in translocation initiation.

Prognostic significance of minimal residual disease in infants with acute lymphoblastic leukemia treated within the Interfant-99 protocol (Article)

2009-02-13T00:00:00Z

Acute lymphoblastic leukemia (ALL) in infants younger than 1 year is a rare but relatively homogeneous disease (∼80% MLL gene rearranged, ∼70% CD10-negative) when compared with childhood and adult ALL. Several studies in children and adults with ALL have shown that minimal residual disease (MRD) status is a strong and independent prognostic factor. We therefore evaluated the prognostic significance of MRD in infant ALL. Ninety-nine infant patients treated according to the Interfant-99 protocol were included in this study. MRD was analyzed by real-time quantitative PCR analysis of rearranged immunoglobulin genes, T-cell receptor genes and MLL genes at various time points (TP) during therapy. Higher MRD levels at the end of induction (TP2) and consolidation (TP3) were significantly associated with lower disease-free survival. Combined MRD information at TP2 and TP3 allowed recognition of three patients groups that significantly differed in outcome. All MRD-high-risk patients (MRD levels ≥10-4 at TP3; 26% of patients) relapsed. MRD-low-risk patients (MRD level <10-4 at both TP2 and TP3) constituted 44% of patients and showed a relapse-rate of only 13%, whereas remaining patients (MRD-medium-risk patients; 30% of patients) had a relapse rate of 31%. Comparison between the current Interfant-06 stratification at diagnosis and the here presented MRD-based stratification showed that both stratifications recognized different subgroups of patients. These data indicate that MRD diagnostics has added value for recognition of risk groups in infant ALL and that MRD diagnostics can be used for treatment intervention in infant ALL as well.Leukemia advance online publication, 12 February 2009; doi:10.1038/leu.2009.17.

In Childhood Acute Lymphoblastic Leukemia, Blasts at Different Stages of Immunophenotypic Maturation Have Stem Cell Properties (Article)

2008-07-08T00:00:00Z

We examined the leukemic stem cell potential of blasts at different stages of maturation in childhood acute lymphoblastic leukemia (ALL). Human leukemic bone marrow was transplanted intrafemorally into NOD/scid mice. Cells sorted using the B precursor differentiation markers CD19, CD20, and CD34 were isolated from patient samples and engrafted mice before serial transplantation into primary or subsequent (up to quaternary) recipients. Surprisingly, blasts representative of all of the different maturational stages were able to reconstitute and reestablish the complete leukemic phenotype in vivo. Sorted blast populations mirrored normal B precursor cells with transcription of a number of stage-appropriate genes. These observations inform a model for leukemia-propagating stem cells in childhood ALL.

Minimal residual disease-directed risk stratification using real-time quantitative PCR analysis of immunoglobulin and T-cell receptor gene rearrangements in the international multicenter trial AIEOP-BFM ALL 2000 for childhood acute lymphoblastic leukemia (Article)

2008-04-01T00:00:00Z

Detection of minimal residual disease (MRD) is the most sensitive method to evaluate treatment response and one of the strongest predictors of outcome in childhood acute lymphoblastic leukemia (ALL). The 10-year update on the I-BFM-SG MRD study 91 demonstrates stable results (event-free survival), that is, standard risk group (MRD-SR) 93%, intermediate risk group (MRD-IR) 74%, and high risk group (MRD-HR) 16%. In multicenter trial AIEOP-BFM ALL 2000, patients were stratified by MRD detection using quantitative PCR after induction (TP1) and consolidation treatment (TP2). From 1 July 2000 to 31 October 2004, PCR target identification was performed in 3341 patients: 2365 (71%) patients had two or more sensitive targets (≥10-4), 671 (20%) patients revealed only one sensitive target, 217 (6%) patients had targets with lower sensitivity, and 88 (3%) patients had no targets. MRD-based risk group assignment was feasible in 2594 (78%) patients: 40% were classified as MRD-SR (two sensitive targets, MRD negativity at both time points), 8% as MRD-HR (MRD ≤10-3at TP2), and 52% as MRD-IR. The remaining 823 patients were stratified according to clinical risk features: HR (n=108) and IR (n=715). In conclusion, MRD-PCR-based stratification using stringent criteria is feasible in almost 80% of patients in an international multicenter trial.

Childhood secondary ALL after ALL treatment (Article)

2007-07-01T00:00:00Z

Data on secondary acute lymphoblastic leukaemia (sALL) following ALL treatment are very rare. However, the incidence might be underestimated as sALLs without a significant lineage shift might automatically be diagnosed as relapses. Examination of immunoglobulin and T-cell receptor gene rearrangements brought a new tool that can help in discrimination between relapse and sALL. We focused on the recurrences of childhood ALL to discover the real frequency of the sALL after ALL treatment. We compared clonal markers in matched presentation and recurrence samples of 366 patients treated according to the Berlin-Frankfurt-Munster (BFM)-based protocols. We found two cases of sALL and another three, where the recurrence is suspicious of being sALL rather than relapse. Our proposal for the 'secondary ALL after ALL' diagnostic criteria is as follows: (A) No clonal relationship between diagnosis and recurrence; (B) significant immunophenotypic shift - significant cytogenetic shift - gain/loss of a fusion gene. For the sALL (A) plus at least one (B) criterion should be fulfilled. With these criteria, the estimated frequency of the sALL after ALL is according to our data 0.5-1.5% of ALL recurrences on BFM-based protocols. Finally, we propose a treatment strategy for the patients with secondary disease.

Acute lymphoblastic leukemia with t(4;11) in children 1 year and older: The 'big sister' of the infant disease? (Article)

2007-04-01T00:00:00Z

The t(4;11)-positive acute lymphoblastic leukemia (ALL) is a rare disease in children above the age of 1 year. We studied the clinical and biological characteristics in 32 consecutively diagnosed childhood cases (median age 10.0 years, range 1.0-17.1 years). Immunophenotyping revealed a pro-B and a pre-B stage in 24 and eight cases, respectively. IGH genes were rearranged in 84% of leukemias with a predominance of incomplete DJHjoints. Whereas IGK-Kde and TCRD rearrangements were rare, TCRG rearrangements were present in 50% of cases and involved mainly Vγ11 or Vγ9 together with a Jγ1.3./2.3 gene segment, an unusual combination among t(4;11)-negative B-cell precursor ALL. Oligoclonality was found in about 30% as assessed by heterogeneous IGH and TCRG rearrangements. Our data are in line with transformation of a precursor cell at an early stage of B-cell development but retaining the potential to differentiate to the pre-B cell stage in vivo. Although a distinct difference between infant and older childhood cases with t(4;11) became evident, no age-related biological features were found within the childhood age group. In contrast to infants with t(4;11)-positive ALL, childhood cases had a relatively low cumulative incidence of relapse of 25% at 3.5 years with BFM-based high-risk protocols.

Immunobiological diversity in infant acute lymphoblastic leukemia is related to the occurrence and type of MLL gene rearrangement (Article)

2007-04-01T00:00:00Z

The aim of this study was to identify immunobiological subgroups in 133 infant acute lymphoblastic leukemia (ALL) cases as assessed by their immunophenotype, immunoglobulin (Ig) and T-cell receptor (TCR) gene rearrangement pattern, and the presence of mixed lineage leukemia (MLL) rearrangements. About 70% of cases showed the pro-B-ALL immunophenotype, whereas the remaining cases were common ALL and pre-B-ALL. MLL translocations were found in 79% of infants, involving MLL-AF4 (41%), MLL-ENL (18%), MLL-AF9 (11%) or another MLL partner gene (10%). Detailed analysis of Ig/TCR rearrangement patterns revealed IGH, IGK and IGL rearrangements in 91, 21 and 13% of infants, respectively. Cross-lineage TCRD, TCRG and TCRB rearrangements were found in 46, 17 and 10% of cases, respectively. As compared to childhood precursor-B-ALL, Ig/TCR rearrangements in infant ALL were less frequent and more oligoclonal. MLL-AF4 and MLL-ENL-positive infants demonstrated immature rearrangements, whereas in MLL-AF9-positive leukemias more mature rearrangements predominated. The immature Ig/TCR pattern in infant ALL correlated with young age at diagnosis, CD10 negativity and predominantly with the presence and the type of MLL translocation. The high frequency of immature and oligoclonal Ig/TCR rearrangements is probably caused by early (prenatal) oncogenic transformation in immature B-lineage progenitor cells with germline Ig/TCR genes combined with a short latency period.

Optimization of PCR-based minimal residual disease diagnostics for childhood acute lymphoblastic leukemia in a multi-center setting (Article)

2007-04-01T00:00:00Z

Minimal residual disease (MRD) diagnostics is used for treatment stratification in childhood acute lymphoblastic leukemia. We aimed to identify and solve potential problems in multicenter MRD studies to achieve and maintain consistent results between the AIEOP/BFM ALL-2000 MRD laboratories. As the dot-blot hybridization method was replaced by the real-time quantitative polymerase chain reaction (RQ-PCR) method during the treatment protocol, special attention was given to the comparison of MRD data obtained by both methods and to the reproducibility of RQ-PCR data. Evaluation of all key steps in molecular MRD diagnostics identified several pitfalls that resulted in discordant MRD results. In particular, guidelines for RQ-PCR data interpretation appeared to be crucial for obtaining concordant MRD results. The experimental variation of the RQ-PCR was generally less than three-fold, but logically became larger at low MRD levels below the reproducible sensitivity of the assay (<10-4). Finally, MRD data obtained by dot-blot hybridization were comparable to those obtained by RQ-PCR analysis (r2=0.74). In conclusion, MRD diagnostics using RQ-PCR analysis of immunoglobulin/T-cell receptor gene rearrangements is feasible in multicenter studies but requires standardization; particularly strict guidelines for interpretation of RQ-PCR data are required. We further recommend regular quality control for laboratories performing MRD diagnostics in international treatment protocols.

Analysis of minimal residual disease by Ig/TCR gene rearrangements: Guidelines for interpretation of real-time quantitative PCR data (Article)

2007-04-01T00:00:00Z

Most modern treatment protocols for acute lymphoblastic leukaemia (ALL) include the analysis of minimal residual disease (MRD). To ensure comparable MRD results between different MRD-polymerase chain reaction (PCR) laboratories, standardization and quality control are essential. The European Study Group on MRD detection in ALL (ESG-MRD-ALL), consisting of 30 MRD-PCR laboratories worldwide, has developed guidelines for the interpretation of real-time quantitative PCR-based MRD data. The application of these guidelines ensures identical interpretation of MRD data between different laboratories of the same MRD-based clinical protocol. Furthermore, the ESG-MRD-ALL guidelines will facilitate the comparison of MRD data obtained in different treatment protocols, including those with new drugs.