Are silver-coated megaprostheses superior to uncoated megaprostheses in managing chronic end-stage periprosthetic hip and knee infection?

INTRODUCTION

Outcomes for silver coated megaprostheses (SC-MP) used in cases of end-stage periprosthetic joint infection (PJI) have not been clearly defined. Although attractive, concerns over implant longevity and the risk of infection relapse exist among the scientific community. Therefore, we sought to investigate the effect of silver coating in lower-extremity MPs used in such difficult-to-treat scenarios. The study's primary hypothesis was that the periprosthetic infection control rate would be higher in patients with silver-coated implants.

MATERIALS AND METHODS

Non-interventional retrospective study with a historical comparison group. We identified all consecutive end-stage hip and knee PJI cases at our center managed with exchange arthroplasty using a silver-coated megaprosthesis from January 2016 to March 2021, these cases were compared with a historical cohort of end-stage PJI cases managed with uncoated megaprostheses. The main outcome studied was infection control rate. Secondarily, we analyzed the short-to-medium-term survivorship of this type of silver-coated implant.

RESULTS

Fifty-nine megaprostheses used in cases of end-stage PJI were included in this study. We identified 30 cases of chronic hip or knee PJI in which a silver-coated modular megaprosthesis was implanted. Our non-coated megaprosthesis (NC-MP) historical group included 29 patients. Both groups had similar demographic characteristics. We found no statistically significant differences in infection control rate (80% vs. 82.8%, p = 0.47) or implant survivorship (90% vs. 89.65%, p = 1) after a mean follow-up for SC-MP of 46.43 months, and 48 months for the non-coated MP group. In relapsed cases, there were no differences in infection eradication after DAIR (66% SC-MP vs. 60% NC-MP success rate, p = 1). During the follow-up we observed one case of skin argyria without further repercussion.

CONCLUSION

We were unable to confirm our initial hypothesis that use of silver-coated implants in end-stage PJI scenarios may be associated with better outcomes in terms of infection control or implant survivorship.

Validation of the Artificial Intelligence Prognostic Scoring System for Myelodysplastic Syndromes in chronic myelomonocytic leukaemia: A novel approach for improved risk stratification

Chronic myelomonocytic leukaemia (CMML) is a rare haematological disorder characterized by monocytosis and dysplastic changes in myeloid cell lineages. Accurate risk stratification is essential for guiding treatment decisions and assessing prognosis. This study aimed to validate the Artificial Intelligence Prognostic Scoring System for Myelodysplastic Syndromes (AIPSS-MDS) in CMML and to assess its performance compared with traditional scores using data from a Spanish registry (n = 1343) and a Taiwanese hospital (n = 75). In the Spanish cohort, the AIPSS-MDS accurately predicted overall survival (OS) and leukaemia-free survival (LFS), outperforming the Revised-IPSS score. Similarly, in the Taiwanese cohort, the AIPSS-MDS demonstrated accurate predictions for OS and LFS, showing superiority over the IPSS score and performing better than the CPSS and molecular CPSS scores in differentiating patient outcomes. The consistent performance of the AIPSS-MDS across both cohorts highlights its generalizability. Its adoption as a valuable tool for personalized treatment decision-making in CMML enables clinicians to identify high-risk patients who may benefit from different therapeutic interventions. Future studies should explore the integration of genetic information into the AIPSS-MDS to further refine risk stratification in CMML and improve patient outcomes.

Evolution in the frontline treatment of patients with chronic lymphocytic leukemia: experience from one European center

Treatment of chronic lymphocytic leukemia (CLL) has dramatically evolved over the last decades thanks to the introduction of targeted therapies. We aimed to describe retrospectively the evolution in the frontline prescription in the CLL patients from our institution. As a secondary objective, the impact of frontline therapy on the time-to-next-treatment (TTNT) and overall survival (OS). After a median of 6.4 years (0.1-36.4) of follow-up from diagnosis, 323 of 780 CLL patients (41.4%) required therapy. Alkylating agents in monotherapy (chlorambucil) were the most used until 2012, and from then, chemoimmunotherapy. Since 2018, targeted therapies were the most common therapeutic strategy (74.1%). Patients who received targeted therapies had significantly longer TTNT compared to other regimens. In the multivariable analyses, mutated IGHV genes targeted therapies and chemoimmunotherapy regimens were related to longer TTNT, and sex female, age younger than 65, and mutated IGHV genes were associated with better OS.

Clonal heterogeneity and rates of specific chromosome gains are risk predictors in childhood high-hyperdiploid B-cell acute lymphoblastic leukemia

B‐cell acute lymphoblastic leukemia (B‐ALL) is the commonest childhood cancer. High hyperdiploidy (HHD) identifies the most frequent cytogenetic subgroup in childhood B‐ALL. Although hyperdiploidy represents an important prognostic factor in childhood B‐ALL, the specific chromosome gains with prognostic value in HHD‐B‐ALL remain controversial, and the current knowledge about the hierarchy of chromosome gains, clonal heterogeneity and chromosomal instability in HHD‐B‐ALL remains very limited. We applied automated sequential‐iFISH coupled with single‐cell computational modeling to identify the specific chromosomal gains of the eight typically gained chromosomes in a large cohort of 72 primary diagnostic (DX, n = 62) and matched relapse (REL, n = 10) samples from HHD‐B‐ALL patients with either favorable or unfavorable clinical outcome in order to characterize the clonal heterogeneity, specific chromosome gains and clonal evolution. Our data show a high degree of clonal heterogeneity and a hierarchical order of chromosome gains in DX samples of HHD‐B‐ALL. The rates of specific chromosome gains and clonal heterogeneity found in DX samples differ between HHD‐B‐ALL patients with favorable or unfavorable clinical outcome. In fact, our comprehensive analyses at DX using a computationally defined risk predictor revealed low levels of trisomies +18+10 and low levels of clonal heterogeneity as robust relapse risk factors in minimal residual disease (MRD)‐negative childhood HHD‐B‐ALL patients: relapse‐free survival beyond 5 years: 22.1% versus 87.9%, P < 0.0001 and 33.3% versus 80%, P < 0.0001, respectively. Moreover, longitudinal analysis of matched DX‐REL HHD‐B‐ALL samples revealed distinct patterns of clonal evolution at relapse. Our study offers a reliable prognostic sub‐stratification of pediatric MRD‐negative HHD‐B‐ALL patients.

41BB-based and CD28-based CD123-redirected T-cells ablate human normal hematopoiesis in vivo

BACKGROUND

Acute myeloid leukemia (AML) is a hematopoietic malignancy which is biologically, phenotypically and genetically very heterogeneous. Outcome of patients with AML remains dismal, highlighting the need for improved, less toxic therapies. Chimeric antigen receptor T-cell (CART) immunotherapies for patients with refractory or relapse (R/R) AML are challenging because of the absence of a universal pan-AML target antigen and the shared expression of target antigens with normal hematopoietic stem/progenitor cells (HSPCs), which may lead to life-threating on-target/off-tumor cytotoxicity. CD33-redirected and CD123-redirected CARTs for AML are in advanced preclinical and clinical development, and they exhibit robust antileukemic activity. However, preclinical and clinical controversy exists on whether such CARTs are myeloablative.

METHODS

We set out to comparatively characterize in vitro and in vivo the efficacy and safety of 41BB-based and CD28-based CARCD123. We analyzed 97 diagnostic and relapse AML primary samples to investigate whether CD123 is a suitable immunotherapeutic target, and we used several xenograft models and in vitro assays to assess the myeloablative potential of our second-generation CD123 CARTs.

RESULTS

Here, we show that CD123 represents a bona fide target for AML and show that both 41BB-based and CD28-based CD123 CARTs are very efficient in eliminating both AML cell lines and primary cells in vitro and in vivo. However, both 41BB-based and CD28-based CD123 CARTs ablate normal human hematopoiesis and prevent the establishment of de novo hematopoietic reconstitution by targeting both immature and myeloid HSPCs.

CONCLUSIONS

This study calls for caution when clinically implementing CD123 CARTs, encouraging its preferential use as a bridge to allo-HSCT in patients with R/R AML.

Gene expression workflow to analyze residual leukemic cells in Chronic Lymphocytic Leukemia

BACKGROUND

In chronic lymphocytic leukemia, a better understanding of leukemic cell characteristics after treatment would help to design specific therapeutic approaches aimed at preventing clinical relapse. Gene arrays have become a powerful approach to perform gene expression profiling; nevertheless, to work with residual cells entails an intensive labor. The aim of this study was to set forth an effective gene expression approach to analyze residual leukemic cells.

METHODS

Leukocytes from CLL patient's samples were sorted by flow cytometry using a 6-color panel. The quality and quantity of RNA isolated from different inputs of cells were compared by two silica column protocols: RNeasy Micro and RNeasy Mini. RNA amplifications were carried out according to two manufacturer's protocols: Ovation Pico SL and Ovation Pico WTA. A total of 3.5 μg of cDNA was labeled and hybridized to Human Gene 2.0 ST arrays.

RESULTS

RNA extracted from low number of input cells by RNeasy Micro showed similar RNA integrity number to that obtained from RNeasy Mini; however, the RNA quantity was higher using the RNeasy Micro Kit. In addition, those RNA samples obtained with RNeasy Micro and amplified with Ovation Pico WTA showed good quality to proceed for a gene array study, independently of the number of input cells (range: 1 × 10⁴ -5 × 10⁵ cells).

CONCLUSIONS

We observed that this workflow is a feasible approach to obtain genomic material extracted from leukemic cells as little as 1 × 10⁴ cells and it can be useful to carry out gene expression profile experiments to characterize residual leukemic cells in chronic lymphocytic leukemia.

The poor prognosis of low hypodiploidy in adults with B-cell precursor acute lymphoblastic leukaemia is restricted to older adults and elderly patients

The prognostic significance of low-hypodiploidy has not been extensively evaluated in minimal residual disease (MRD)-oriented protocols for adult acute lymphoblastic leukaemia (ALL). We analysed the outcome of hypodiploid adult ALL patients treated within Programa Español de Tratamientos en Hematología (PETHEMA) protocols. The 5-year cumulative incidence of relapse (CIR) of low-hypodiploid B-cell precursor (BCP)-ALL was significantly higher than that of high-hypodiploids (52% vs. 12%, P = 0.013). Low-hypodiploid BCP-ALL patients aged ≤35 years showed superior survival (71% vs. 21%, P = 0.026) and lower 5-year CIR (17% vs. 66%, P = 0.090) than low-hypodiploids aged >35 years. Older adults and elderly low-hypodiploid BCP-ALL patients show dismal prognosis although achieving an end-induction good MRD response.

An analysis of the impact of CD56 expression in de novo acute promyelocytic leukemia patients treated with upfront all-trans retinoic acid and anthracycline-based regimens

Out of 956, there were 95 (10%) CD56+ APL patients treated with PETHEMA ATRA and chemotherapy. CD56+ expression was associated with high WBC, BCR3 isoform, and co-expression of CD2, CD34, CD7, HLA-DR, CD15, and CD117 antigens. CD56+ vs CD56- APL presented higher induction death rate (16% vs 8%, p = .02) and 5-years cumulative incidence of relapse (33% versus 10%, p = .006), irrespectively of the Sanz score (low-risk 47% versus 5%, p < .001; intermediate 23% versus 7%, p < .001; and high-risk 42% versus 21%, p = .007). In the multivariate analysis, CD56 + (p < .0001), higher relapse-risk score (p = .001), and male gender (p = .05) retained the independent predictive value. CD56+ APL also showed a greater risk of CNS relapse (6% versus 1%, p < .001) and lower 5-year OS (75% versus 83%, p = .003). The AIDA-based LPA2012 trial, with an intensified consolidation schedule for CD56+ APL, will elucidate whether an intensified consolidation schedule could mitigate the relapse rate in this setting.

A novel deep targeted sequencing method for minimal residual disease monitoring in acute myeloid leukemia

A high proportion of patients with acute myeloid leukemia who achieve minimal residual disease negative status ultimately relapse because a fraction of pathological clones remains undetected by standard methods. We designed and validated a high-throughput sequencing method for minimal residual disease assessment of cell clonotypes with mutations of NPM1, IDH1/2 and/or FLT3-single nucleotide variants. For clinical validation, 106 follow-up samples from 63 patients in complete remission were studied by sequencing, evaluating the level of mutations detected at diagnosis. The predictive value of minimal residual disease status by sequencing, multiparameter flow cytometry, or quantitative polymerase chain reaction analysis was determined by survival analysis. The sequencing method achieved a sensitivity of 10⁻⁴ for single nucleotide variants and 10⁻⁵ for insertions/deletions and could be used in acute myeloid leukemia patients who carry any mutation (86% in our diagnostic data set). Sequencing–determined minimal residual disease positive status was associated with lower disease-free survival (hazard ratio 3.4, P=0.005) and lower overall survival (hazard ratio 4.2, P<0.001). Multivariate analysis showed that minimal residual disease positive status determined by sequencing was an independent factor associated with risk of death (hazard ratio 4.54, P=0.005) and the only independent factor conferring risk of relapse (hazard ratio 3.76, P=0.012). This sequencing-based method simplifies and standardizes minimal residual disease evaluation, with high applicability in acute myeloid leukemia. It is also an improvement upon flow cytometry- and quantitative polymerase chain reaction-based prediction of outcomes of patients with acute myeloid leukemia and could be incorporated in clinical settings and clinical trials.

Frequency and clinical impact of CDKN2A/ARF/CDKN2B gene deletions as assessed by in-depth genetic analyses in adult T cell acute lymphoblastic leukemia

Recurrent deletions of the CDKN2A/ARF/CDKN2B genes encoded at chromosome 9p21 have been described in both pediatric and adult acute lymphoblastic leukemia (ALL), but their prognostic value remains controversial, with limited data on adult T-ALL. Here, we investigated the presence of homozygous and heterozygous deletions of the CDKN2A/ARF and CDKN2B genes in 64 adult T-ALL patients enrolled in two consecutive trials from the Spanish PETHEMA group. Alterations in CDKN2A/ARF/CDKN2B were detected in 35/64 patients (55%). Most of them consisted of 9p21 losses involving homozygous deletions of the CDKNA/ARF gene (26/64), as confirmed by single nucleotide polymorphism (SNP) arrays and interphase fluorescence in situ hybridization (iFISH). Deletions involving the CDKN2A/ARF/CDKN2B locus correlated with a higher frequency of cortical T cell phenotype and a better clearance of minimal residual disease (MRD) after induction therapy. Moreover, the combination of an altered copy-number-value (CNV) involving the CDKN2A/ARF/CDKN2B gene locus and undetectable MRD (≤ 0.01%) values allowed the identification of a subset of T-ALL with better overall survival in the absence of hematopoietic stem cell transplantation.

Chronic Lymphocytic Leukemia: Clinical Stages Maintain Their Prognostic Significance Over the Course of the Disease and Are Surrogates for Response to Therapy

BACKGROUND

To determine whether in patients with chronic lymphocytic leukemia (CLL), the clinical stage maintains prognostic significance over time and can be considered as a surrogate for the response to therapy.

PATIENTS AND METHODS

The data from 229 CLL patients were retrospectively evaluated. The main aims of the study were to describe the changes in clinical stage during the course of CLL as a result of the response to treatment and to determine the time to next therapy (TTNT) and overall survival (OS) according to those changes, in particular, among the heterogeneous International Workshop on CLL (IWCLL) partial response (PR) category.

RESULTS

Among the patients in the IWCLL PR category, differences were found in TTNT and OS according to the clinical stage at the response evaluation. With a median follow-up period of 91 months (range, 2-390 months), patients with a PR- Binet A at the response evaluation had significantly longer TTNT and OS compared with those with PR-Binet B/C (median TTNT, 26 vs. 11 months; P = .00; median OS, 63 vs. 43 months; P = .047).

CONCLUSION

The results of the present study have shown that for patients with CLL, the Binet clinical stages are good outcome predictors throughout the disease course and also suggest that changes in Binet clinical stage could be useful as response surrogates and to divide the IWCLL PR category into different prognostic subgroups.

A 4-gene expression prognostic signature might guide post-remission therapy in patients with intermediate-risk cytogenetic acute myeloid leukemia

In intermediate-risk cytogenetic acute myeloid leukemia (IRC-AML) patients, novel biomarkers to guide post-remission therapy are needed. We analyzed with high-density arrays 40 IRC-AML patients who received a non-allogeneic hematopoietic stem-cell transplantation-based post-remission therapy, and identified a signature that correlated with early relapse. Subsequently, we analyzed selected 187 genes in 49 additional IRC-AML patients by RT-PCR. BAALC, MN1, SPARC and HOPX overexpression correlated to refractoriness. BAALC or ALDH2 overexpression correlated to shorter overall survival (OS) (5-year OS: 33 ± 8.6% vs. 73.7 ± 10.1%, p = .006; 32 ± 9.3% vs. 66.4 ± 9.7%, p = .016), whereas GPR44 or TP53INP1 overexpression correlated to longer survival (5-year OS: 66.7 ± 10.3% vs. 35.4 ± 9.1%, p = .04; 58.3 ± 8.2% vs. 23.1 ± 11.7%, p = .029). A risk-score combining these four genes expression distinguished low-risk and high-risk patients (5-year OS: 79 ± 9% vs. 30 ± 8%, respectively; p = .001) in our cohort and in an independent set of patients from a public repository. Our 4-gene signature may add prognostic information and guide post-remission treatment in IRC-AML patients.

Reproducible diagnosis of chronic lymphocytic leukemia by flow cytometry: An European Research Initiative on CLL (ERIC) & European Society for Clinical Cell Analysis (ESCCA) Harmonisation project

The diagnostic criteria for CLL rely on morphology and immunophenotype. Current approaches have limitations affecting reproducibility and there is no consensus on the role of new markers. The aim of this project was to identify reproducible criteria and consensus on markers recommended for the diagnosis of CLL. ERIC/ESCCA members classified 14 of 35 potential markers as “required” or “recommended” for CLL diagnosis, consensus being defined as >75% and >50% agreement, respectively. An approach to validate “required” markers using normal peripheral blood was developed. Responses were received from 150 participants with a diagnostic workload >20 CLL cases per week in 23/150 (15%), 5–20 in 82/150 (55%), and <5 cases per week in 45/150 (30%). The consensus for “required” diagnostic markers included: CD19, CD5, CD20, CD23, Kappa, and Lambda. “Recommended” markers potentially useful for differential diagnosis were: CD43, CD79b, CD81, CD200, CD10, and ROR1. Reproducible criteria for component reagents were assessed retrospectively in 14,643 cases from 13 different centers and showed >97% concordance with current approaches. A pilot study to validate staining quality was completed in 11 centers. Markers considered as “required” for the diagnosis of CLL by the participants in this study (CD19, CD5, CD20, CD23, Kappa, and Lambda) are consistent with current diagnostic criteria and practice. Importantly, a reproducible approach to validate and apply these markers in individual laboratories has been identified. Finally, a consensus “recommended” panel of markers to refine diagnosis in borderline cases (CD43, CD79b, CD81, CD200, CD10, and ROR1) has been defined and will be prospectively evaluated. © 2017 International Clinical Cytometry Society

Detailed Characterization of Mesenchymal Stem/Stromal Cells from a Large Cohort of AML Patients Demonstrates a Definitive Link to Treatment Outcomes

Bone marrow mesenchymal stem/stromal cells (BM-MSCs) are key components of the hematopoietic niche thought to have a direct role in leukemia pathogenesis. BM-MSCs from patients with acute myeloid leukemia (AML) have been poorly characterized due to disease heterogeneity. We report a functional, genetic, and immunological characterization of BM-MSC cultures from 46 AML patients, stratified by molecular/cytogenetics into low-risk (LR), intermediate-risk (IR), and high-risk (HR) subgroups. Stable MSC cultures were successfully established and characterized from 40 of 46 AML patients irrespective of the risk subgroup. AML-derived BM-MSCs never harbored tumor-specific cytogenetic/molecular alterations present in blasts, but displayed higher clonogenic potential than healthy donor (HD)-derived BM-MSCs. Although HD- and AML-derived BM-MSCs equally provided chemoprotection to AML cells in vitro, AML-derived BM-MSCs were more immunosuppressive/anti-inflammatory, enhanced suppression of lymphocyte proliferation, and diminished secretion of pro-inflammatory cytokines. Multivariate analysis revealed that the level of interleukin-10 produced by AML-derived BM-MSCs as an independent prognostic factor negatively affected overall survival. Collectively our data show that AML-derived BM-MSCs are not tumor related, but display functional differences contributing to therapy resistance and disease evolution.

FcγRIIb expression in early stage chronic lymphocytic leukemia

In normal B-cells, B-cell antigen receptor (BCR) signaling can be negatively regulated by the low-affinity receptor FcγRIIb (CD32b). To better understand the role of FcγRIIb in chronic lymphocytic leukemia (CLL), we correlated its expression on 155 samples from newly-diagnosed Binet A patients with clinical characteristics and outcome. FcγRIIb expression was similar in normal B-cells and leukemic cells, this being heterogenous among patients and within CLL clones. FcγRIIb expression did not correlate with well known prognostic markers [disease stage, serum beta-2 microglobulin (B2M), IGHV mutational status, expression of ZAP-70 and CD38, and cytogenetics] except for a weak concordance with CD49d. Moreover, patients with low FcγRIIb expression (69/155, 44.5%) required therapy earlier than those with high FcγRIIb expression (86/155, 55.5%) (median 151.4 months vs. not reached; p=.071). These results encourage further investigation on the role of FcγRIIb in CLL biology and prognostic significance in larger series of patients.

Prognostic significance of copy number alterations in adolescent and adult patients with precursor B acute lymphoblastic leukemia enrolled in PETHEMA protocols

BACKGROUND

Some copy number alterations (CNAs) have independent prognostic significance for adults with acute lymphoblastic leukemia (ALL).

METHODS

This study analyzed via multiplex ligation-dependent probe amplification the frequency and prognostic impact of CNAs of 12 genetic regions in 142 adolescents and adults with de novo precursor B-cell ALL.

RESULTS

The cyclin-dependent kinase inhibitor 2A/B (CDKN2A/B) deletion (59 of 142 or 42%) was the most frequent CNA, and it was followed by Ikaros family zinc finger 1 (IKZF1) losses (49 of 142 or 35%). IKZF1 deletions were more prevalent in Philadelphia chromosome (Ph)-positive ALL and were associated with advanced age and high white blood cell (WBC) counts. The multivariate analysis showed that advanced age and early B-cell factor 1 (EBF1) deletions were associated with chemotherapy resistance in both the whole series (hazard ratios, 0.949 and 0.135, respectively) and the Ph-negative subgroup (hazard ratios, 0.946 and 0.118, respectively). High WBC counts and focal IKZF1 deletions correlated with disease recurrence (hazard ratios, 1.005 and 1.869, respectively), whereas advanced age and CDKN2A/B losses influenced overall survival in both the whole series (hazard ratios, 1.038 and 2.545, respectively) and the Ph-negative subgroup (hazard ratios, 1.044 and 2.105, respectively).

CONCLUSIONS

Deletions of EBF1, IKZF1, and CDKN2A/B have an independent adverse prognosis for adolescents and adults with B-precursor ALL, and this suggests that these CNAs should be included in the initial risk assessment of ALL.

Subcutaneous passage increases cell aggressiveness in a xenograft model of diffuse large B cell lymphoma

Xenograft models of human diffuse large B cell lymphoma (DLBCL) are widely used to test new drugs against this neoplasia. Most of them, however, are subcutaneous xenografts that do not show a disseminated disease as it is found in the human neoplasia. In this paper, we aimed to develop a disseminated xenograft model of DLBCL by performing a subcutaneous passage of DLBCL cells before their intravenous injection in mice. WSU-DLCL-2 (WSU) cells were injected into both flanks of NOD/SCID mice. The subcutaneous tumours were disaggregated and a cell suspension (WSU-SC) was obtained. Two groups of 10 NOD/SCID mice were intravenously injected with WSU-SC or WSU cells. All mice injected with WSU-SC cells developed lymphoma in 32-47 days and showed lymph node and bone marrow infiltration. WSU-SC cells showed a significantly higher engraftment rate and faster dissemination than WSU cells after intravenous injection in mice. When molecularly compared, WSU-SC cells showed higher expression levels of FAK, p130Cas and phosphorylated AKT than WSU cells. The subcutaneous passage enhanced the engraftment and the metastatic capacity of WSU cells, allowing the generation of a rapid and disseminated DLBCL xenograft model. The aggressive behaviour of WSU-SC cells was associated with increased p130Cas and FAK expression and AKT activation.

The Notch/Hes1 pathway sustains NF-κB activation through CYLD repression in T cell leukemia

It was previously shown that the NF-κB pathway is downstream of oncogenic Notch1 in T cell acute lymphoblastic leukemia (T-ALL). Here, we visualize Notch-induced NF-κB activation using both human T-ALL cell lines and animal models. We demonstrate that Hes1, a canonical Notch target and transcriptional repressor, is responsible for sustaining IKK activation in T-ALL. Hes1 exerts its effects by repressing the deubiquitinase CYLD, a negative IKK complex regulator. CYLD expression was found to be significantly suppressed in primary T-ALL. Finally, we demonstrate that IKK inhibition is a promising option for the targeted therapy of T-ALL as specific suppression of IKK expression and function affected both the survival of human T-ALL cells and the maintenance of the disease in vivo.

Immunophenotype of acute myeloid leukemia with NPM mutations: prognostic impact of the leukemic compartment size

NPM mutations are the most common genetic abnormalities found in non-promyelocytic AML. NPM-positive patients usually show a normal karyotype, a peculiar morphologic appearance with frequent monocytic traits and good prognosis in the absence of an associated FLT3 mutation. This report describes the immunophenotypic and genetic characteristics of a consecutive series of NPM-mutated de novo AML patients enroled in the CETLAM trial. Eighty-three patients were included in the study. Complete immunophenotype was obtained using multiparametric flow cytometry. Associated genetic lesions (FLT3, MLL, CEBPA and WT1 mutations) were studied by standardized methods. Real-time PCR was employed to assess the minimal residual status. The most common pattern was CD34-CD15+ and HLA-DR+. Small CD34 populations with immunophenotypic aberrations (CD15 and CD19 coexpression, abnormal SSC) were detected even in CD34 negative samples. Nearly all cases expressed CD33 (strong positivity), CD13 and CD117, and all were CD123+. The stem cell marker CD110 was also positive in most cases. Biologic parameters such as a high percentage of intermediate CD45+ (blast gate) (>75% nucleated cells), CD123+ and FLT3-ITD mutations were associated with a poor outcome. Quantitative PCR positivity had no prognostic impact either after induction or at the end of chemotherapy. Only PCR positivity (greater than 10 copies) detected in patients in haematological remission was associated with an increased relapse rate. Further studies are required to determine whether the degree of leukemic stem cell expansion (CD45+CD123+cells) increases the risk of acquisition of FLT3-ITD and/or provides selective advantages.

The use of tetradecanoylphorbol acetate-stimulated peripheral blood cells enhances the prognostic value of interphase fluorescence in situ hybridization in patients with chronic lymphocytic leukemia

Interphase fluorescence in situ hybridization (I-FISH) studies have a remarkable prognostic value in patients with chronic lymphocytic leukemia (CLL). I-FISH studies can be performed either on tetradecanoylphorbol acetate stimulated peripheral blood cells (I-FISH-TPA) or unstimulated peripheral blood mononuclear cells (I-FISH-PBMC). The aim of the study was to evaluate whether this finding was clinically relevant in a group of 235 patients with CLL. Fifty-six patients had both I-FISH-TPA and I-FISH-PBMC results. Compared with uncultured cells, the cytogenetic detection rate rose from 57 to 80% with the use of TPA-stimulated cells (P = 0.014). I-FISH-TPA provided a better prediction of treatment-free survival compared with I-FISH-PBMC (P = 0.031 vs. 0.166). Then, I-FISH-PBMC results from 93 historical patients were compared with 86 recent patients with I-FISH-TPA results. Genomic aberrations were detected in 46 and 67% of patients from the I-FISH-PBMC and I-FISH-TPA cohorts, respectively. The detection rate of 13q deletion as the only aberration increased from 10% with I-FISH-PBMC to 37% with I-FISH-TPA (P = 0.006). In conclusion, I-FISH-TPA increased the detection rate of 13q deletion and had an improved prognostic value compared with I-FISH-PBMC.

Real-time quantitative polymerase chain reaction detection of minimal residual disease by standardized WT1 assay to enhance risk stratification in acute myeloid leukemia: a European LeukemiaNet study

PURPOSE

Risk stratification in acute myeloid leukemia (AML) is currently based on pretreatment characteristics. It remains to be established whether relapse risk can be better predicted through assessment of minimal residual disease (MRD). One proposed marker is the Wilms tumor gene WT1, which is overexpressed in most patients with AML, thus providing a putative target for immunotherapy, although in the absence of a standardized assay, its utility for MRD monitoring remains controversial.

PATIENTS AND METHODS

Nine published and in-house real-time quantitative polymerase chain reaction WT1 assays were systematically evaluated within the European LeukemiaNet; the best-performing assay was applied to diagnostic AML samples (n = 620), follow-up samples from 129 patients treated with intensive combination chemotherapy, and 204 normal peripheral blood (PB) and bone marrow (BM) controls.

RESULTS

Considering relative levels of expression detected in normal PB and BM, WT1 was sufficiently overexpressed to discriminate > or = 2-log reduction in transcripts in 46% and 13% of AML patients, according to the respective follow-up sample source. In this informative group, greater WT1 transcript reduction after induction predicted reduced relapse risk (hazard ratio, 0.54 per log reduction; 95% CI, 0.36 to 0.83; P = .004) that remained significant when adjusted for age, WBC count, and cytogenetics. Failure to reduce WT1 transcripts below the threshold limits defined in normal controls by the end of consolidation also predicted increased relapse risk (P = .004).

CONCLUSION

Application of a standardized WT1 assay provides independent prognostic information in AML, lending support to incorporation of early assessment of MRD to develop more robust risk scores, to enhance risk stratification, and to identify patients who may benefit from allogeneic transplantation.

Beta2-microglobulin is a better predictor of treatment-free survival in patients with chronic lymphocytic leukaemia if adjusted according to glomerular filtration rate

Even in the era of newer and sophisticated prognostic markers, beta(2)-microglobulin (B2M) remains a simple but very powerful predictor of treatment-free survival (TFS) and overall survival (OS) in patients with chronic lymphocytic leukaemia (CLL). However, B2M levels are heavily influenced by the patient's glomerular filtration rate (GFR) and this study aimed to evaluate whether GFR-adjusted B2M (GFR-B2M) had improved prognostic value compared to unadjusted B2M in a cohort of over 450 consecutive CLL patients from two separate institutions. Multivariate analysis identified a significantly shorter TFS in patients who were ZAP-70 + (P < 0.001), with increased GFR-B2M (P < 0.001), and del(11q) or del(17p) as detected by fluorescence in situ hybridization (FISH; P < 0.001). When OS was evaluated by multivariate analysis, age 65 years or older (P < 0.001) and poor risk FISH abnormalities (P < 0.001) had a confirmed adverse prognostic impact, but the predictive value of GFR-B2M was lost in the validation analysis. In all survival models, B2M did not attain independent significance unless GFR-B2M was eliminated from the analysis. In conclusion, GFR-B2M is a better predictor of TFS than unadjusted B2M in CLL patients.

Role of MTHFR (677, 1298) haplotype in the risk of developing secondary leukemia after treatment of breast cancer and hematological malignancies

Therapy-related myelodysplasia and acute myeloid leukemia (t-MDS/AML) is a malignancy occurring after exposure to chemotherapy and/or radiotherapy. Polymorphisms involved in chemotherapy/radiotherapy response genes could be related to an increased risk of developing this neoplasia. We have studied 11 polymorphisms in genes of drug detoxification pathways (NQO1, glutathione S-transferase pi) and DNA repair xeroderma pigmentosum, complementation group (3) (XPC(3), X-ray repair cross complementing protein (1)), Nijmegen breakage syndrome (1), excision repair cross-complementing rodent repair deficiency, complementation group (5) and X-ray repair cross complementing protein (3) and in the methylene tetrahydrofolate reductase gene (MTHFR(2), 677C>T, 1298A>C), involved in DNA synthesis. The analyzed groups were a t-MDS/AML patients group (n=81) and a matched control group (n=64) treated similarly, and they did not develop t-MDS/AML. We found no significant differences when the groups were compared globally. However, when analysis was carried out according to the primary neoplasia involved, a significant association was observed between the MTHFR haplotype (single nucleotide polymorphisms 677 and 1298) and the risk of developing t-MDS/AML in the breast cancer patients group (P=0.016) and cyclophosphamide-treated hematological disease group (P=0.005). Risk haplotype was different for each case, corresponding to the 677T1298A haplotype after breast cancer treatment and the 677C1298C haplotype after hematological malignancy treatment. We postulate that such differences are related to variations in chemotherapy schemes between hematological and breast cancers and their differential interaction with the MTHFR route.

SNPs associated with the genetic predisposition to develop therapy-related acute myelogenous leukemia after chemotherapy for breast cancer

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Background: t-AML is a syndrome occurring after exposure to chemo or radiotherapy. Since for similar treatments only some patients ends developing a secondary leukemia, it has been proposed a genetic predisposition associated to this syndrome. Methods: To analyse single nucleotide polymorphisms (SNPs) on genes that could be involved on risk of developing t-AML by means of RFLP and SNP genome screening using high density microarrays .Two groups of individuals were genotyped: Group A, composed by patients that develop t-AML after chemotherapy for breast cancer (BC) and Group B (control), formed by chemotherapy treated BC patients that after a period of more than 10 years have not developed t-AML. We have studied 12 polymorphisms on genes from drug detoxification pathways (NOQ1, GSTP1), DNA repair (XPC[3 ], XRCC1[2 ], NBS1, ERCC5 and XRCC3) and DNA synthesis (MTHFR[2 ]), in which the nucleotide change implies a change in the protein sequence (nA=16, nB=18) . Alternatively, for each patient, more than 10.000 SNPs were genotyped by means of of high density microarrays (Affymetrix) (nA=12, nB=18). The alele frequencies for each SNP between two groups were compared. Results: In RFLP study, we observe two SNPs on MTHFR gene displaying remarkably different allele frequencies between BC patients (Table). In microarray study, we found 12 SNPs with differences of allele frequency higher that 45% between A and B groups, located 6 on chromosome 8. Conclusions: The results suggest that the MHFTR gene is a candidate for being studied by its possible relation with the genetic predisposition to develop t-AML after BC treatment although its functional implication with the disease must still be elucidated. Moreover, data from SNP arrays suggest that the genome regions marked by those 12 SNPs, specially those on chromosome 8, are candidate for being studied by its possible relation with the genetic predisposition to develop t-AML after BC treatment. Financed by FIS G03/008.

[Table: see text]

No significant financial relationships to disclose.

Incidence and clinicobiologic characteristics of leukemic B-cell chronic lymphoproliferative disorders with more than one B-cell clone

Leukemic B-chronic lymphoproliferative disorders (B-CLPDs) are generally believed to derive from a monoclonal B cell; biclonality has only occasionally been reported. In this study, we have explored the incidence of B-CLPD cases with 2 or more B-cell clones and established both the phenotypic differences between the coexisting clones and the clinicobiologic features of these patients. In total, 53 B-CLPD cases with 2 or more B-cell clones were studied. Presence of 2 or more B-cell clones was suspected by immunophenotype and confirmed by molecular/genetic techniques in leukemic samples (n = 42) and purified B-cell subpopulations (n = 10). Overall, 4.8% of 477 consecutive B-CLPDs had 2 or more B-cell clones, their incidence being especially higher among hairy cell leukemia (3 of 13), large cell lymphoma (2 of 10), and atypical chronic lymphocytic leukemia (CLL) (4 of 29). In most cases the 2 B-cell subsets displayed either different surface immunoglobulin (sIg) light chain (n = 37 of 53) or different levels of the same sIg (n = 9 of 53), usually associated with other phenotypic differences. Compared with monoclonal cases, B-CLL patients with 2 or more clones had lower white blood cell (WBC) and lymphocyte counts, more frequently displayed splenomegaly, and required early treatment. Among these, the cases in which a CLL clone coexisted with a non-CLL clone were older and more often displayed B symptoms, a monoclonal component, and diffuse infiltration of bone marrow and required early treatment more frequently than cases with monoclonal CLL or 2 CLL clones.

Frequent inactivation of the p73 gene by abnormal methylation or LOH in non-Hodgkin's lymphomas

p73 is a candidate tumor suppressor and imprinted gene that shares significant homology with the p53 gene. It is located on 1p36, a region frequently deleted in neuroblastoma and other tumors. To investigate the pattern of inactivation of this gene in human lymphomas, we studied 59 tumors to identify abnormal methylation in exon 1 and loss of heterozygosity (LOH) at this locus. p73 was methylated in 13/50 (26%) B cell lymphomas. There was no evidence of p73 methylation in the 9 T cell lymphomas analyzed. Burkitt's lymphomas showed the highest proportion of methylated cases (36%), although this alteration also affected other aggressive lymphomas such as diffuse large cell and some marginal zone lymphomas. LOH at the p73 locus was detected in 4/34 (11%) B and 1/9 (11%) T cell lymphomas. The p73 expression analysis showed absence or low level of p73 product in methylated lymphomas, whereas p73 was always detected in unmethylated tumors. We found monoallelic expression in normal peripheral blood samples, consistent with imprinting. None of the tumors showed LOH and methylation of the remaining allele simultaneously, suggesting that alteration of the expressed allele could lead to the total inactivation of the gene. Our results show that deletion or methylation of the p73 gene could be important mechanisms in suppressing p73 expression in B cell non-Hodgkin's lymphomas.

Quantitative detection of AML1-ETO rearrangement by real-time RT-PCR using fluorescently labeled probes

The persistence of the AML1-ETO rearrangement performed by reverse transcription polymerase chain reaction (RT-PCR) has been reported in acute myeloid leukemia (AML) patients in long-term complete remission (CR). This persistence, which is not associated with hematological relapse, limits the clinical use of qualitative RT-PCR. Here, we present a new quantitative real-time PCR method to detect AML1-ETO rearrangement using fluorescently labeled probes. Quantitative detection of AML1-ETO was performed in capillary tubes using two fluorescently labeled probes in the LightCycler equipment. The reliability of the method was checked in twenty-two bone marrow samples and one apheresis sample from eight patients with t(8;21) collected at diagnosis and during follow-up assessment. The regression coefficients obtained for standard curves of AML1-ETO and AML were all greater than 0.98. The sensitivity attained allowed the detection of rearrangements at a dilution of 10(-5) Kasumi-1 cDNA. The intra-assay coefficient of variation was 4% for AML1-ETO, and 7% for AML. The inter-assay coefficient of variation was 19% for AML1-ETO and 12% for AML. A log reduction from two to four in the AML1-ETO/AML ratio was evident after CR. The study of the method and first results obtained in patient samples support that quantitative real-time PCR with hybridization probes is a new reliable and sensitive method to monitor minimal residual disease in AML patients. Moreover, the fluorescent probes with the Light-Cycler technology offer the advantage of a rapid detection.

Rituximab can be useful as treatment for minimal residual disease in bcr-abl-positive acute lymphoblastic leukemia

We report the results of administering CD20 monoclonal antibody (MoAb) in a 32-year-old man with bcr-abl-positive acute lymphoblastic leukemia. Morphological complete remission was achieved after two lines of chemotherapy with persistence of blast cells (2%) in flow cytometric analysis of marrow cells. Since no HLA-matched donor for allogeneic bone marrow transplantation (BMT) was found, anti-CD20 MoAb therapy was administered for in vivo marrow purging, prior to autologous peripheral blood stem cell (PBSC) harvest and transplantation. After MoAb therapy <0.1% of blast cells were observed and the molecular abnormality (bcr-abl gene rearrangement) disappeared.

Distribution and pattern of BCL-6 mutations throughout the spectrum of B-cell neoplasia

BCL-6 mutations are accumulated during B-cell transit through the germinal center (GC) and provide a histogenetic marker for B-cell tumors. On the basis of a comprehensive analysis of 308 B-cell neoplasms, we (1) expand the spectrum of tumors associated with BCL-6 mutations; (2) corroborate the notion that mutations cluster with GC and post-GC B-cell neoplasms; and (3) identify heterogeneous mutation frequency among B-lineage diffuse large cell lymphoma (B-DLCL) subsets. Mutations are virtually absent in acute lymphoblastic leukemia (P <.001) and mantle cell lymphoma (P <.05), whereas they occur frequently in GC or post-GC neoplasms, including lymphoplasmacytoid lymphoma, follicular lymphoma, MALT lymphomas, B-DLCL and Burkitt lymphoma. Among B-DLCL, mutations occur frequently in systemic nodal B-DLCL, primary extranodal B-DLCL, CD5(+) B-DLCL, CD30(+) B-DLCL, and primary splenic B-DLCL, suggesting a similar histogenesis of these B-DLCL subsets. Conversely, mutations are rare in primary mediastinal B-DLCL with sclerosis (10.0%; P <.01), supporting a distinct histogenesis for this lymphoma. Longitudinal follow-up of B-DLCL transformed from follicular lymphoma shows that they BCL-6 mutations may accumulate during histologic progression. Mutations also occur in some B-cell chronic lymphocytic leukemias, small lymphocytic lymphomas, and hairy cell leukemias, consistent with the hypothesis that a fraction of these lymphoproliferations are related to GC-like cells. Finally, the molecular pattern of 193 mutational events reinforces the hypothesis that mutations of BCL-6 and immunoglobulin genes are caused by similar mechanisms. (Blood. 2000;95:651-659)

Genetic lesions associated with blastic transformation of polycythemia vera and essential thrombocythemia

Polycythemia vera (PV) and essential thrombocythemia (ET) are chronic myeloproliferative disorders that may progress to acute leukemia in a subset of patients. This study aimed at investigating the genetic lesions associated with the blastic transformation of PV and ET. A panel of PV and ET cases at different stages of disease was analyzed for the presence of genetic alterations of TP53, NRAS, KRAS, and MDM2 by a combination of mutational analysis and Southern blot hybridization. The occurrence of microsatellite instability (MSI) was also tasted in selected cases. Samples of PV and ET analyzed in chronic phase disease were consistently devoid of all genetic lesions tested, suggesting that alterations of TP53, NRAS, KRAS, and MDM2 do not contribute significantly to development of chronic phase PV and ET. Conversely, mutations of TP53 were detected in 7/15 (46.6%) blastic phase cases, including 3/5 PV and 4/10 ET. In blastic phase patients for whom the corresponding chronic phase DNA was also available, it could be documented that the genetic lesion had arisen at the time of blastic transformation. In addition to TP53 mutations, cases of blastic phase PV and ET occasionally harbored mutations of NRAS (one case of blastic phase ET) or displayed MSI (one case of blastic phase PV). These data indicate that inactivation of TP53 is a relatively frequent event associated with the blastic transformation of PV and ET and may be responsible for the tumor progression of these disorders.

Distribution of TP53 mutations among acute leukemias with MLL rearrangements

Acute leukemias carrying MLL rearrangements are characterized by a high degree of clinical and immunologic heterogeneity, as demonstrated by variability in their immunophenotype, consistent with lymphoid or myeloid/monoblastic derivation, as well as their occurrence in distinct age groups from infancy to adulthood. Recently, it was shown that inactivation of the TP53 tumor suppressor gene occurs frequently in cases of acute lymphoblastic leukemia carrying MLL rearrangements. In order to assess the extent of TP53 inactivation throughout the immunophenotypic and clinical spectrum of MLL+ acute leukemias, we tested for TP53 mutations 29 cases of MLL+ acute leukemias displaying lymphoid (13 cases) or myeloid/monoblastic (16 cases) features and belonging to different age groups. Mutations were detected in 6/16 myeloid/monoblastic cases and in 3/13 lymphoid cases. Among myeloid/monoblastic leukemias, the TP53 mutations occurred in 3/4 infants, but only in 3/16 cases in other age groups. Overall, our data suggest that (1) TP53 inactivation is a relatively common event in leukemias with MLL rearrangements irrespective of the leukemic phenotype and of the patients' age; (2) at least two genetic lesions (i.e., MLL rearrangement and TP53 mutation) have accumulated in the short time (few weeks after the birth or conception of the child) corresponding to the development of acute leukemias of infancy.

Distribution of Kaposi's sarcoma herpesvirus sequences among lymphoid malignancies in Italy and Spain

In this study we have tested the distribution of Kaposi's sarcoma herpesvirus (KSHV) DNA sequences throughout the spectrum of lymphoid neoplasia in Italy and Spain. 180 cases of lymphoid malignancies representative of the major histologic and immunophenotypic categories of B- and T-cell tumours were analysed by means of a polymerase chain reaction-based assay. KSHV sequences were consistently absent in all categories of lymphoid malignancies studied, with the exception of a subset of B-cell non-Hodgkin's lymphomas localizing in the pleural, pericardial or peritoneal cavities, and fulfilling the diagnostic criteria of body-cavity-based lymphoma. The selective and consistent association of KSHV sequences with cases of body-cavity-based lymphoma throughout the spectrum of lymphoid neoplasms suggests that KSHV may be involved in the pathogenesis of this peculiar type of lymphoid malignancy.

Genetic analysis of chromosome 13 deletions in BCR/ABL negative chronic myeloproliferative disorders

Chromosomal deletions of band 13q14 occur recurrently in BCR/ABL negative chronic myeloproliferative disorders (CMPD), including myelosclerosis with myeloid metaplasia (MMM), polycythemia vera (PV), essential thrombocythemia (ET), juvenile chronic myeloid leukemia (JCML), and the so-called BCR/ABL- chronic myeloid leukemia (CML). The RBI tumor suppressor locus, mapping to 13q14, has long since been hypothesized as the important gene. In this report, we have determined the frequency of 13q14 deletions at the molecular level in a large panel of BCR/ABL- CMPD at different disease stages and performed a detailed genetic analysis of gross rearrangements/deletions and point mutations of the RBI gene in these disorders. Our data show that molecular deletions of 13q14 are detected in a relatively large fraction of BCR/ABL- CMPD (38%), that they appear to be more frequent in MMM than in other BCR/ABL- CMPD, and that they may be present at diagnosis or occur during blastic evolution of the neoplasia. The RBI gene displayed a germline configuration in all BCR/ABL- CMPD tested, suggesting that 13q14 deletions in these disorders affect a tumor suppressor locus distinct from RBI.

p53 gene inactivation in acute lymphoblastic leukemia of B cell lineage associates with chromosomal breakpoints at 11q23 and 8q24

The clinical heterogeneity of acute lymphoblastic leukemia (ALL) of B cell lineage reflects the presence of distinct molecular pathways leading to well-defined ALL molecular subtypes. These molecular pathways include the formation of the fusion transcripts BCR/ABL and E2A/PBX1, due to t(9;22) and t(1;19), respectively, as well as rearrangements of the MLL gene at 11q23 and of c-MYC at 8q24. Hyperdiploid ALL in the absence of chromosomal structural abnormalities is an additional ALL molecular subtype. Mutations of the RAS family genes and of the p53 tumor suppressor gene represent additional genetic lesions detected in a fraction (10-20%) of ALL cases. RAS activation in ALL may be detected in all molecular subtypes of ALL and denotes poor prognosis. Conversely, little is known regarding the clinical and biological features of ALL cases carrying p53 mutations. In order to help clarify the role of p53 inactivation in ALL development, we have determined the frequency of p53 mutations throughout the molecular spectrum of B cell lineage ALL. We report that p53 inactivation in ALL of B cell lineage is restricted to cases carrying a rearrangement of MLL or c-MYC, whereas it is consistently negative in other molecular subgroups. These data underline the molecular heterogeneity of ALL of B cell lineage and indicate that at least some of the molecular pathways involved in ALL pathogenesis require more than one genetic lesion.

Aggressive natural killer cell leukaemia/lymphoma in two patients with lethal midline granuloma

We report two patients with leukaemic proliferations of large granular lymphocytes. The immunophenotype study showed that the leukaemic cells were positive for CD2, CD38, CD56 and anti-HLA-DR monoclonal antibodies and negative for other T-cell (CD3, CD4, CD8) and B-cell markers (CD19, CD20 and surface immunoglobulins). The clinical course was acute and a diagnosis of aggressive natural killer cell leukaemia/lymphoma was made. No clonal rearrangements of either C beta T-cell receptor or JH immunoglobulin genes were found. Functional studies done in one patient demonstrated non-restricted cytotoxic activity after activation with IL-2. Lethal midline granuloma had been previously diagnosed in both patients. A possible relationship between this entity and the natural killer cell leukaemia is discussed.