The KMT2A recombinome of acute leukemias in 2023.

Chromosomal rearrangements of the human KMT2A/MLL gene are associated with de novo as well as therapy-induced infant, pediatric, and adult acute leukemias. Here, we present the data obtained from 3401 acute leukemia patients that have been analyzed between 2003 and 2022. Genomic breakpoints within the KMT2A gene and the involved translocation partner genes (TPGs) and KMT2A-partial tandem duplications (PTDs) were determined. Including the published data from the literature, a total of 107 in-frame KMT2A gene fusions have been identified so far. Further 16 rearrangements were out-of-frame fusions, 18 patients had no partner gene fused to 5'-KMT2A, two patients had a 5'-KMT2A deletion, and one ETV6::RUNX1 patient had an KMT2A insertion at the breakpoint. The seven most frequent TPGs and PTDs account for more than 90% of all recombinations of the KMT2A, 37 occur recurrently and 63 were identified so far only once. This study provides a comprehensive analysis of the KMT2A recombinome in acute leukemia patients. Besides the scientific gain of information, genomic breakpoint sequences of these patients were used to monitor minimal residual disease (MRD). Thus, this work may be directly translated from the bench to the bedside of patients and meet the clinical needs to improve patient survival.

Clonal variegation and dynamic competition of leukemia-initiating cells in infant acute lymphoblastic leukemia with MLL rearrangement.

Distinct from other forms of acute lymphoblastic leukemia (ALL), infant ALL with mixed lineage leukemia (MLL) gene rearrangement, the most common leukemia occurring within the first year of life, might arise without the need for cooperating genetic lesions. Through Ig/TCR rearrangement analysis of MLL-AF4+ infant ALL at diagnosis and xenograft leukemias from mice transplanted with the same diagnostic samples, we established that MLL-AF4+ infant ALL is composed of a branching subclonal architecture already at diagnosis, frequently driven by an Ig/TCR-rearranged founder clone. Some MLL-AF4+ clones appear to be largely quiescent at diagnosis but can reactivate and dominate when serially transplanted into immunodeficient mice, whereas other dominant clones at diagnosis can become more quiescent, suggesting a dynamic competition between actively proliferating and quiescent subclones. Investigation of paired diagnostic and relapse samples suggested that relapses often occur from subclones already present but more quiescent at diagnosis. Copy-number alterations identified at relapse might contribute to the activation and expansion of previously quiescent subclones. Finally, each of the identified subclones is able to contribute to the diverse phenotypic pool of MLL-AF4+ leukemia-propagating cells. Unraveling of the subclonal architecture and dynamics in MLL+ infant ALL may provide possible explanations for the therapy resistance and frequent relapses observed in this group of poor prognosis ALL.

Pulse pressure variation as a predictor of fluid responsiveness in mechanically ventilated patients with spontaneous breathing activity: a pragmatic observational study.

INTRODUCTION: Pulse pressure variation predicts fluid responsiveness in mechanically ventilated patients passively adapted to the ventilator. Its usefulness in actively breathing ventilated patients was examined only by few studies with potential methodological shortcomings. This study sought to describe the performance of pulse pressure variation as a predictor of fluid responsiveness in hypotensive critically ill patients who trigger the ventilator. METHODS: We studied forty two hypotensive, mechanically ventilated patients with documented spontaneous breathing activity in whom a fluid challenge was deemed necessary by the attending physician. All patients were ventilated with a Maquet Servo-i Ventilator in different ventilatory modes with a flow-regulated inspiratory trigger set on position 4. Pulse pressure variation, mean and systolic arterial pressure were observed before and after the fluid challenge, which consisted in the intravenous administration of a 250 ml bolus of 6% hetastarch. Fluid responsiveness was defined as a more than 15% increase in arterial pressure after volume expansion. RESULTS: The area under the receiver operator characteristic curve for pulse pressure variation was 0.87 (95% CI 0.74 -0.99; p<0.0001) and the grey zone limits were 10% and 15%. Pulse pressure variation was correlated with increase in systolic arterial pressure (r2=0.32; p<0.001) and mean arterial pressure (r2=0.10; p=0.037). CONCLUSIONS: Pulse pressure variation predicts fluid responsiveness in patients who actively interact with a Servo-i ventilator with a flow-regulated inspiratory trigger set on position 4.

High prevalence of undiagnosed anxiety symptoms among HIV-positive individuals on cART: a cross-sectional study.

INTRODUCTION: Anxiety disorders are frequent in HIV-infected individuals, can pre-exist or occur during HIV infection. We evaluated with a self-reported questionnaire whether anxiety is related to HIV clinical status and therapeutic success in a cohort of HIV-positive subjects in Sicily. PATIENTS AND METHODS: We enrolled 251 patients on combination antiretroviral therapy (cART) for at least six months; Self Rating Anxiety State SAS 054 was used to diagnose anxiety and a Z score ≥ 45 points was considered diagnostic. RESULTS: 47% of patients were diagnosed with anxiety. Patients showing symptoms related to anxiety had experienced a high number of therapeutic switches (fourth line or more). CONCLUSIONS: These data confirm a high prevalence of anxiety symptoms among subjects with HIV infection in Eastern Sicily. Physicians should be aware of the extent of the problem and should be able to adequately manage anxiety in the setting of HIV infection.

Long-term results of the Italian Association of Pediatric Hematology and Oncology (AIEOP) Studies 82, 87, 88, 91 and 95 for childhood acute lymphoblastic leukemia.

We analyzed the long-term outcome of 4865 patients treated in Studies 82, 87, 88, 91 and 95 for childhood acute lymphoblastic leukemia (ALL) of the Italian Association of Pediatric Hematology and Oncology (AIEOP). Treatment was characterized by progressive intensification of systemic therapy and reduction of cranial radiotherapy. A progressive improvement of results with reduction of isolated central nervous system relapse rate was obtained. Ten-year event-free survival increased from 53% in Study 82 to 72% in Study 95, whereas survival improved from 64 to 82%. Since 1991, all patients were treated according to Berlin-Frankfurt-Muenster (BFM) ALL treatment strategy. In Study 91, reduced treatment intensity (25%) yielded inferior results, but intensification of maintenance with high-dose (HD)-L-asparaginase (randomized) allowed to compensate for this disadvantage; in high-risk patients (HR, 15%), substitution of intensive polychemotherapy blocks for conventional BFM backbone failed to improve results. A marked improvement of results was obtained in HR patients when conventional BFM therapy was intensified with three polychemotherapy blocks and double delayed intensification (Study 95). The introduction of minimal residual disease monitoring and evaluation of common randomized questions by AIEOP and BFM groups in the protocol AIEOP-BFM-ALL 2000 are expected to further ameliorate treatment of children with ALL.

New insights to the MLL recombinome of acute leukemias.

Chromosomal rearrangements of the human MLL gene are associated with high-risk pediatric, adult and therapy-associated acute leukemias. These patients need to be identified, treated appropriately and minimal residual disease was monitored by quantitative PCR techniques. Genomic DNA was isolated from individual acute leukemia patients to identify and characterize chromosomal rearrangements involving the human MLL gene. A total of 760 MLL-rearranged biopsy samples obtained from 384 pediatric and 376 adult leukemia patients were characterized at the molecular level. The distribution of MLL breakpoints for clinical subtypes (acute lymphoblastic leukemia, acute myeloid leukemia, pediatric and adult) and fused translocation partner genes (TPGs) will be presented, including novel MLL fusion genes. Combined data of our study and recently published data revealed 104 different MLL rearrangements of which 64 TPGs are now characterized on the molecular level. Nine TPGs seem to be predominantly involved in genetic recombinations of MLL: AFF1/AF4, MLLT3/AF9, MLLT1/ENL, MLLT10/AF10, MLLT4/AF6, ELL, EPS15/AF1P, MLLT6/AF17 and SEPT6, respectively. Moreover, we describe for the first time the genetic network of reciprocal MLL gene fusions deriving from complex rearrangements.

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.

Clearance of HCV RNA following acute hepatitis A superinfection.

A transient reduction of hepatitis C virus replication during the course of acute hepatitis A virus infection has already been reported in the literature. The present study reports the case study of a subject with chronic hepatitis due to hepatitis C virus who went on to develop an acute hepatitis A. From the early onset of acute disease, hepatitis C virus ribonucleic acid became undetectable. Following recovery from acute hepatitis, alanine amino-transferase levels became persistently normal and liver biopsy revealed a reduction in the Knodell histological activity index score. Hepatitis C virus ribonucleic acid clearance was maintained up to 4 years after the onset of acute hepatitis A. During the course of the acute disease, a sharp increase in interferon gamma levels was detected in serum and in the supernatant of both unstimulated and phytoemagglutinin/lipopolysaccharide-stimulated peripheral blood mononuclear cells. Interferon gamma levels were still high 3 months later. We hypothesize that acute hepatitis A virus superinfection during the course of chronic hepatitis C may lead to hepatitis C virus ribonucleic acid clearance through an immunological mechanism related to interferon gamma production.

[Saccharomyces cerevisiae fungemia associated with multifocal pneumonia in a patient with alcohol-related hepatic cirrhosis]. / Fungemia da Saccharomyces cerevisiae con polmonite a focolai multipli in paziente con cirrosi epatica alcool correlata.

Saccharomyces cerevisiae is usually considered non-pathogenic and has rarely been reported as a cause of fungemia in immunocompromised patients, especially those admitted to an intensive care unit or those affected by acquired immune deficiency syndrome or under immunosuppressive treatment. In all described cases the use of probiotic yeast has been given as the main risk factor. We report a case of S. cerevisiae sepsis complicated by pneumonia in a patient affected by alcohol-related cirrhosis with no evidence of probiotic drug intake. In this case recovery was obtained after a treatment course with liposomal amphotericin B. S. cerevisiae should be taken into consideration when sepsis lacks to isolate any aetiological agent.

Complex MLL rearrangements in t(4;11) leukemia patients with absent AF4.MLL fusion allele.

The human mixed lineage leukemia (MLL) gene is frequently involved in genetic rearrangements with more than 55 different translocation partner genes, all associated with acute leukemia. Reciprocal chromosomal translocations generate two MLL fusion alleles, where 5'- and 3'-portions of MLL are fused to gene segments of given fusion partners. In case of t(4;11) patients, about 80% of all patients exhibit both reciprocal fusion alleles, MLL.AF4 and AF4.MLL, respectively. By contrast, 20% of all t(4;11) patients seem to encode only the MLL.AF4 fusion allele. Here, we analyzed these 'MLL.AF4(+)/AF4.MLL(-)' patients at the genomic DNA level to unravel their genetic situation. Cryptic translocations and three-way translocations were found in this group of t(4;11) patients. Reciprocal MLL fusions with novel translocation partner genes, for example NF-KB1 and RABGAP1L, were identified and actively transcribed in leukemic cells. In other patients, the reciprocal 3'-MLL gene segment was fused out-of-frame to PBX1, ELF2, DSCAML1 and FXYD6. The latter rearrangements caused haploinsufficiency of genes that are normally expressed in hematopoietic cells. Finally, patients were identified that encode only solitary 3'-MLL gene segments on the reciprocal allele. Based on these data, we propose that all t(4;11) patients exhibit reciprocal MLL alleles, but due to the individual recombination events, provide different pathological disease mechanisms.

CCR5 and CCR3 expression on T CD3+ lymphocytes from HIV/Leishmania co-infected subjects.

CC chemokine receptor 5 (CCR5) and CC chemokine receptor 3 (CCR3) are membrane-bound proteins involved in HIV-1 entry into susceptible cells. All T lymphocyte subsets display CCR5 and CCR3 on their membrane surface. T helper 1 cells are known to express CCR5 but not CCR3, and most of T cells expressing CCR3 are T helper 2. This study aimed to assess the expression of CCR5 and CCR3 on peripheral blood CD3+ T lymphocytes of HIV-Leishmania co-infected individuals. A total of 36 subjects were enrolled; nine had HIV-Leishmania co-infection; nine were HIV-infected without Leishmania, nine had visceral leishmaniasis without HIV co-infection and nine were healthy blood donors. HIV-Leishmania co-infected subjects showed a significantly higher rate of CCR5+CD3+ T lymphocytes in comparison with the other studied groups. The higher rate of CD3+ T-cells expressing CCR5 found in HIV-Leishmania co-infected subjects may be related to the role of Leishmania as an enhancer of the progression to AIDS.

The MLL recombinome of acute leukemias.

Chromosomal rearrangements of the human MLL gene are a hallmark for aggressive (high-risk) pediatric, adult and therapy-associated acute leukemias. These patients need to be identified in order to subject these patients to appropriate therapy regimen. A recently developed long-distance inverse PCR method was applied to genomic DNA isolated from individual acute leukemia patients in order to identify chromosomal rearrangements of the human MLL gene. We present data of the molecular characterization of 414 samples obtained from 272 pediatric and 142 adult leukemia patients. The precise localization of genomic breakpoints within the MLL gene and the involved translocation partner genes (TPGs) was determined and several new TPGs were identified. The combined data of our study and published data revealed a total of 87 different MLL rearrangements of which 51 TPGs are now characterized at the molecular level. Interestingly, the four most frequently found TPGs (AF4, AF9, ENL and AF10) encode nuclear proteins that are part of a protein network involved in histone H3K79 methylation. Thus, translocations of the MLL gene, by itself coding for a histone H3K4 methyltransferase, are presumably not randomly chosen, rather functionally selected.

Ribavirin up-regulates IL-12 p40 gene expression and restores IL-12 levels in Leishmania-treated PBMCs.

Ribavirin, a nucleoside analogue that interferes with viral mRNA synthesis and inhibits the replication of RNA and DNA viruses, has been recently proposed as an effective immune response modulator. In the present report, we studied the effect of ribavirin on IL-12 p40 gene expression in peripheral blood mononuclear cells (PBMCs) of healthy subjects. We also studied ribavirin effects on PBMCs activated with lipopolysaccharide (LPS) and phytohaemagglutinin (PHA) and treated with Leishmania donovani antigens. We provide evidence that ribavirin was able to up-regulate IL-12 p40 gene expression and to restore levels of IL-12 p40 gene expression and IL-12 secretion in fully activated PBMCs that were strongly inhibited by L. donovani antigens. Because effective management of leishmanial disease is usually associated with a prevalent T-helper 1 immune response with elevated production of IL-12,our preliminary results may be of particular interest, provided that they will be confirmed by further in vitro and in vivo studies, when considering a possible use of ribavirin as adjuvant in severe leishmanial disease.

Genetic polymorphism of NAD(P)H:quinone oxidoreductase is associated with an increased risk of infant acute lymphoblastic leukemia without MLL gene rearrangements.

NAD(P)H:quinone oxidoreductase 1 (NQO1) is a detoxification enzyme that protects cells against oxidative stress and toxic quinones. A polymorphism (C609T) in the gene produces in the heterozygous individuals (C/T) a reduction and in those homozygous for the variant allele (T/T) the abolishment of NQO1 protein activity. To assess whether NQO1 inactivating polymorphism (CT/TT) was a possible risk factor for infant acute lymphoblastic leukemia (iALL), we investigated the distribution of NQO1 genotype in 50 iALL patients, 32 with MLL gene rearrangements (MLL+) and 18 without (MLL-). As controls, 106 cases of pediatric ALL (pALL), and 147 healthy subjects were also studied. Compared to normal controls, the frequency of the low/null activity NQO1 genotypes was significantly higher in the iALL MLL- (72 vs 38%, P=0.006; odds ratio (OR) 4.22, 95% confidence interval (CI) 1.43-12.49), while no differences were observed in iALL MLL+ (44 vs 38%, P=0.553; OR 1.26, 95% CI 0.58-2.74). Similar results were observed when pALL were used as control. Our results indicate that only the iALL patients without MLL rearrangements had a significantly higher frequency of NQO1 genotypes associated with low/null activity enzyme, suggesting a possible role for NQO1 gene as an MLL-independent risk factor, in the leukemogenic process of this subtype of iALL.