Minimal residual disease and outcome characteristics in infant KMT2A-germline acute lymphoblastic leukaemia treated on the Interfant-06 protocol.

BACKGROUND: The outcome of infants with KMT2A-germline acute lymphoblastic leukaemia (ALL) is superior to that of infants with KMT2A-rearranged ALL but has been inferior to non-infant ALL patients. Here, we describe the outcome and prognostic factors for 167 infants with KMT2A-germline ALL enrolled in the Interfant-06 study. METHODS: Univariate analysis on prognostic factors (age, white blood cell count at diagnosis, prednisolone response and CD10 expression) was performed on KMT2A-germline infants in complete remission at the end of induction (EOI; n = 163). Bone marrow minimal residual disease (MRD) was measured in 73 patients by real-time quantitative polymerase chain reaction at various time points (EOI, n = 68; end of consolidation, n = 56; and before OCTADAD, n = 57). MRD results were classified as negative, intermediate (<5∗10-4), and high (≥5∗10-4). RESULTS: The 6-year event-free and overall survival was 73.9% (standard error [SE] = 3.6) and 87.2% (SE = 2.7). Relapses occurred early, within 36 months from diagnosis in 28 of 31 (90%) infants. Treatment-related mortality was 3.6%. Age <6 months was a favourable prognostic factor with a 6-year disease-free survival (DFS) of 91% (SE = 9.0) compared with 71.7% (SE = 4.2) in infants >6 months of age (P = 0.04). Patients with high EOI MRD ≥5 × 10-4 had a worse outcome (6-year DFS 61.4% [SE = 12.4], n = 16), compared with patients with undetectable EOI MRD (6-year DFS 87.9% [SE = 6.6], n = 28) or intermediate EOI MRD <5 × 10-4 (6-year DFS 76.4% [SE = 11.3], n = 24; P = 0.02). CONCLUSION: We conclude that young age at diagnosis and low EOI MRD seem favourable prognostic factors in infants with KMT2A-germline ALL and should be considered for risk stratification in future clinical trials.

Enzyme replacement therapy with agalsidase alfa in a cohort of Italian patients with Anderson-Fabry disease: testing the effects with the Mainz Severity Score Index.

Anderson-Fabry disease (AFD) is a rare X-linked disorder caused by lysosomal storage of several glycosphingolipids, affecting virtually all organs and systems. Enzyme replacement therapy (ERT) for AFD has been available since 2001. Due to the highly variable nature of clinical manifestations in patients with AFD, it is very difficult to assess disease progression and the effects of therapy. We used the Mainz Severity Score Index (MSSI) as a measure of disease severity to study the effects of ERT in a population of 30 patients treated with agalsidase alfa for a median of 2.9 years (range, 1.0-6.2 years). Our data show that the MSSI captures the correlation between disease severity and both gender and age (1 - males performing worse than females at baseline and 2 - severity of diseases progresses with age in both sex). Furthermore, after at least 1 year of ERT, total MSSI scores were significantly lower than those at baseline (p < 0.001), suggesting a marked clinical improvement under ERT. In conclusion, the MSSI is a sensitive and useful tool for monitoring disease progression and assessing the effects of ERT in a population of patients from different treatment centres.

NG2 antigen is involved in leukemia invasiveness and central nervous system infiltration in MLL-rearranged infant B-ALL.

Mixed-lineage leukemia (MLL)-rearranged (MLLr) infant B-cell acute lymphoblastic leukemia (iMLLr-B-ALL) has a dismal prognosis and is associated with a pro-B/mixed phenotype, therapy refractoriness and frequent central nervous system (CNS) disease/relapse. Neuron-glial antigen 2 (NG2) is specifically expressed in MLLr leukemias and is used in leukemia immunophenotyping because of its predictive value for MLLr acute leukemias. NG2 is involved in melanoma metastasis and brain development; however, its role in MLL-mediated leukemogenesis remains elusive. Here we evaluated whether NG2 distinguishes leukemia-initiating/propagating cells (L-ICs) and/or CNS-infiltrating cells (CNS-ICs) in iMLLr-B-ALL. Clinical data from the Interfant cohort of iMLLr-B-ALL demonstrated that high NG2 expression associates with lower event-free survival, higher number of circulating blasts and more frequent CNS disease/relapse. Serial xenotransplantation of primary MLL-AF4+ leukemias indicated that NG2 is a malleable marker that does not enrich for L-IC or CNS-IC in iMLLr-B-All. However, NG2 expression was highly upregulated in blasts infiltrating extramedullar hematopoietic sites and CNS, and specific blockage of NG2 resulted in almost complete loss of engraftment. Indeed, gene expression profiling of primary blasts and primografts revealed a migratory signature of NG2+ blasts. This study provides new insights on the biology of NG2 in iMLLr-B-ALL and suggests NG2 as a potential therapeutic target to reduce the risk of CNS disease/relapse and to provide safer CNS-directed therapies for iMLLr-B-ALL.

Correction: NG2 antigen is involved in leukemia invasiveness and central nervous system infiltration in MLL-rearranged infant B-ALL.

The original version of this Article contained an error in the spelling of the author Juan Carlos Rodriguez-Manzaneque, which was incorrectly given as J Carlos Rodríguez-Manzaneque. This has now been corrected in both the PDF and HTML versions of the Article.

Outcome of relapsed infant acute lymphoblastic leukemia treated on the interfant-99 protocol.

This corrects the article DOI: 10.1038/leu.2015.246.

Impact of thrombotic thrombocytopenic purpura on leukemic children undergoing bone marrow transplantation.

Thrombotic thrombocytopenic purpura (TTP) has emerged as one of the main transplant-related complications over the last 15 years. The current study defines the incidence and the risk factors for the occurrence of TTP in 131 consecutive leukemic children who were transplanted between January 1994 and December 1997 at four Italian pediatric centers. Patients with ALL (101), AML (21), MDS (9), underwent an HLA-identical sibling BMT (82) or an HLA-identical unrelated BMT (49), receiving a conditioning regimen consisting of high-dose chemotherapy in 24 patients and of F-TBI combined with high-dose chemotherapy in 107 patients. The diagnosis of TTP was retrospectively evaluated on the basis of parallel criteria. TTP treatment varied according to the protocol of each treatment center. Twenty-eight of 131 patients (21.4%) developed TTP at a median of 46 days (range 21-80) after BMT. Multivariate analysis demonstrated that the risk of TTP was higher in patients who underwent unrelated BMT (P value = 0.02). Acute GVHD, stage of disease at BMT, conditioning with TBI, gender, age, did not appear to be associated with the occurrence of TTP. As to the outcome, TTP resolved in 19 patients while in nine it was the principal cause of death (32.1%). In patients with TTP, LDH peak value was the only statistically significant factor (P = 0.001) related to severe TTP. In conclusion, our experience demonstrates that leukemic children undergoing BMT, especially from an unrelated donor, should be carefully assessed for TTP which appears to be a severe and relatively common transplant-related complication when strict diagnostic criteria are applied.

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

Acute lymphoblastic leukemia (ALL) in infants younger than 1 year is a rare but relatively homogeneous disease ( approximately 80% MLL gene rearranged, approximately 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 > or =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.

Predictors of failure of transoesophageal cardioversion of common atrial flutter.

BACKGROUND: Common atrial flutter is due to a re-entry circuit in the right atrium. It is possible to entrain and interrupt this arrhythmia with transoesophageal pacing (TEAP) in a substantial percentage of patients. The aim of this study is to evaluate factors associated with failure of transoesophageal cardioversion of common atrial flutter. METHODS: One hundred consecutive patients underwent an attempted transoesophageal cardioversion of their common atrial flutter. In order to detect factors associated with failure of this procedure, the following were considered: (a) age and gender; (b) underlying heart disease; (c) time of onset of the arrhythmia; (d) antiarrhythmic treatment at the time of cardioversion; (e) flutter cycle length, (f) A/V deflection ratio at the site of transoesophageal pacing; and (g) longitudinal and transverse diameters of right and left atrium on the echocardiogram. RESULTS: In 84 of 100 patients, TEAP modified the atrial flutter circuit: in 23 of these, sinus rhythm was restored; in 31 patients, flutter was converted into atrial fibrillation which spontaneously reverted to sinus rhythm; and in remaining 30 patients, persistent atrial fibrillation was obtained. In 16 cases, no modification in atrial flutter circuit was obtained by TEAP (Group 2). Using univariate analysis, this group of patients showed no significant difference in flutter cycle length, a smaller A/V ratio at the site of TEAP, a longer transverse diameter of left atrium and a shorter transverse diameter of right atrium. Analysis of the therapy at cardioversion shows that no Group 2 patients was on intravenous amiodarone, while a greater percentage of patients of the former group was on chronic amiodarone treatment. A logistic regression model applied to the data showed that flutter cycle length, transverse diameter of left atrium and A/V deflection ratio at the site of TEAP were independent variables with influence on the failure rate. CONCLUSION: Transoesophageal pacing is able to modify the circuit of common atrial flutter in a large percentage of patients, and can convert this arrhythmia to sinus rhythm in more than 50% of cases. Failure of this procedure is associated with electrophysiological parameters (flutter cycle length, A/V ratio at the site of TEAP), anatomical factors (left and right atrial diameters) and treatment in use at the time of TEAP.

Early and late deaths after elective end of therapies for childhood cancer in Italy.

The first cohort of subjects treated for cancer during childhood is now entering adulthood, and it is necessary to determine whether treatment has been sufficient to completely eradicate the neoplastic clone, and whether the cancer itself or treatment-related toxicity may have increased the risk of premature death. For these reasons, long-term survival and causes of death were evaluated in a cohort of subjects treated for childhood cancer who reached the elective end of therapy in continuous remission and were registered until 1992 in the Italian Registry of off-therapy subjects (OTR). The vital status of OTR subjects was ascertained in 1996 by a postal survey through census bureaux; for deceased subjects, the cause of death was defined and compared with the expected rates in the general population. At follow-up, out of 6402 eligible and evaluable subjects, 890 were found to have died; the estimated overall survival at 20 years was 80.7% (95% CI 79.3-82.1). Most of the patients (84.6%) died due to recurrence of the primary cancer, usually within the first 5 years after the OT. The cumulative incidence of death due to recurrence of the primary tumor was greater among subjects treated for solid tumor than among those treated for leukemia/lymphoma (p = 0.0001); in contrast, OT subjects after leukemia and lymphoma were more likely to die due to of medical complications of therapy (p < 0.02). Second cancers were the second most frequent cause of death, with a 12-fold risk compared with the general population; the figures were similar in the 2 cancer groups. Compared with the general population, OT subjects were 32 times more likely than same-age subjects to die. The SMR decreased to 6.1 when only non-cancer deaths were considered. Deaths due to external or avoidable causes occurred among survivors at a rate similar to that of the general population.

Clinical epidemiology of childhood cancer in Central America and Caribbean countries.

BACKGROUND: Countries with scarce resources have the right to appropriate essential health care but very few reports discuss how this can be achieved. We assessed the survival of a large cohort of pediatric oncological patients to provide hard data on which to base realistic evaluation and planning schemes. PATIENTS AND METHODS: This multicenter retrospective survey covered consecutively diagnosed and treated patients admitted to eight national level hospitals in seven countries in Central America and the Caribbean. The research protocol was discussed extensively, so the data to be collected and the criteria for their evaluation were clearly pre-defined. We analysed 2214 patients diagnosed between 1996 and 1999 with various cancers, classified as hemato-oncological disorders (70%) and solid tumors (30%). RESULTS: Three-year overall survival was 48.4% [standard error (SE) 1.3]. Detailed analysis of acute lymphoblastic leukemia highlighted the wide intercountry variability: 3-year survival was 62.2% (SE 5.3) in Cuba, 74.2% (SE 3.3) in Costa Rica, 61.7% (SE 4.9) in Nicaragua, and lower in the other four countries. CONCLUSIONS: The yield of diagnostic-therapeutic protocols depends largely on the context of care in which they are applied. This paper documents the importance of including epidemiological research in interventions for cooperation in complex health areas such as pediatric oncology.