Clinical Impact of Pretransplant Multidrug-Resistant Gram-Negative Colonization in Autologous and Allogeneic Hematopoietic Stem Cell Transplantation.

Multidrug-resistant Gram-negative bacteria (MDR-GNB) are an emerging cause of morbidity and mortality after hematopoietic stem cell transplantation (HSCT). Three-hundred forty-eight consecutive patients transplanted at our hospital from July 2012 to January 2016 were screened for a pretransplant MDR-GNB colonization and evaluated for clinical outcomes. A pretransplant MDR-GNB colonization was found in 16.9% of allo-HSCT and in 9.6% of auto-HSCT recipients. Both in auto- and in allo-HSCT, carriers of a MDR-GNB showed no significant differences in overall survival (OS), transplant-related mortality (TRM), or infection-related mortality (IRM) compared with noncarriers. OS at 2 years for carriers compared with noncarriers was 85% versus 81% (P = .262) in auto-HSCT and 50% versus 43% (P = .091) in allo-HSCT. TRM at 2 years was 14% versus 5% (P = .405) in auto-HSCT and 31% versus 25% (P = .301) in allo-HSCT. IRM at 2 years was 14% versus 2% (P = .142) in auto-HSCT and 23% versus 14% (P = .304) in allo-HSCT. In multivariate analysis, only grade III to IV acute graft-versus-host disease was an independent factor for reduced OS (P < .001) and increased TRM (P < .001) and IRM (P < .001). During the first year after transplant, we collected 73 GNB bloodstream infectious (BSI) episodes in 54 patients, 42.4% of which sustained by a MDR-GNB. Rectal swabs positivity associated with the pathogen causing subsequent MDR-GNB BSI episodes in 13 of 31 (41.9%). Overall, OS at 4 months from MDR-GNB BSI episode onset was of 67.9%, with a 14-day attributed mortality of 12.9%, not being significantly different between carriers and noncarriers (P = .207). We conclude that in this extended single-center experience, a pretransplant MDR-GNB colonization did not significantly influence OS, TRM, and IRM both in auto- and allo-HSCT settings and that MDR-GNB attributed mortality can be controlled in carriers when an early pre-emptive antimicrobial therapy is started in case of neutropenic fever.

A New Clinicobiological Scoring System for the Prediction of Infection-Related Mortality and Survival after Allogeneic Hematopoietic Stem Cell Transplantation.

Infection-related mortality (IRM) is a substantial component of nonrelapse mortality (NRM) after allogeneic hematopoietic stem cell transplantation (allo-HSCT). No scores have been developed to predict IRM before transplantation. Pretransplantation clinical and biochemical data were collected from a study cohort of 607 adult patients undergoing allo-HSCT between January 2009 and February 2017. In a training set of 273 patients, multivariate analysis revealed that age >60 years (P = .003), cytomegalovirus host/donor serostatus different from negative/negative (P < .001), pretransplantation IgA level <1.11 g/L (P = .004), and pretransplantation IgM level <.305 g/L (P = .028) were independent predictors of increased IRM. Based on these results, we developed and subsequently validated a 3-tiered weighted prognostic index for IRM in a retrospective set of patients (n = 219) and a prospective set of patients (n = 115). Patients were assigned to 3 different IRM risk classes based on this index score. The score significantly predicted IRM in the training set, retrospective validation set, and prospective validation set (P < .001, .044, and .011, respectively). In the training set, 100-day IRM was 5% for the low-risk group, 11% for the intermediate-riak group, and 16% for the high-risk groups. In the retrospective validation set, the respective 100-day IRM values were 7%, 17%, and 28%, and in the prospective set, they were 0%, 5%, and 7%. This score predicted also overall survival (P < .001 in the training set, P < 041 in the retrospective validation set, and P < .023 in the prospective validation set). Because pretransplantation levels of IgA/IgM can be modulated by the supplementation of enriched immunoglobulins, these results suggest the possibility of prophylactic interventional studies to improve transplantation outcomes.

Human Herpesvirus 6 Infection Following Haploidentical Transplantation: Immune Recovery and Outcome.

Human herpesvirus 6 (HHV-6) is increasingly recognized as a potentially life-threatening pathogen in allogeneic hematopoietic stem cell transplantation (alloSCT). We retrospectively evaluated 54 adult patients who developed positivity to HHV-6 after alloSCT. The median time from alloSCT to HHV-6 reactivation was 34 days. HHV-6 was present in plasma samples from 31 patients, in bone marrow (BM) of 9 patients, in bronchoalveolar lavage fluid and liver or gut biopsy specimens from 33 patients, and in cerebrospinal fluid of 7 patients. Twenty-nine patients developed acute graft-versus-host disease (GVHD), mainly grade III-IV, and 15 had concomitant cytomegalovirus reactivation. The median absolute CD3+ lymphocyte count was 207 cells/µL. We reported the following clinical manifestations: fever in 43 patients, skin rash in 22, hepatitis in 19, diarrhea in 24, encephalitis in 10, BM suppression in 18, and delayed engraftment in 11. Antiviral pharmacologic treatment was administered to 37 patients; nonetheless, the mortality rate was relatively high in this population (overall survival [OS] at 1 year, 38% ± 7%). A better OS was significantly associated with a CD3+ cell count ≥200/µL at the time of HHV-6 reactivation (P = .0002). OS was also positively affected by the absence of acute GVHD grade III-IV (P = .03) and by complete disease remission (P = .03), but was not significantly influenced by steroid administration, time after alloSCT, type of antiviral prophylaxis, plasma viral load, or organ involvement. Although HHV-6 detection typically occurred early after alloSCT, better T cell immune reconstitution seems to have the potential to improve clinical outcomes. Our findings provide new insight into the interplay between HHV-6 and the transplanted immune system.

Phase I Study of Acalabrutinib Plus Danvatirsen (AZD9150) in Relapsed/Refractory Diffuse Large B-Cell Lymphoma Including Circulating Tumor DNA Biomarker Assessment.

PURPOSE: Novel targeted and immunotherapies have improved outcomes in relapsed/refractory (R/R) diffuse large B-cell lymphoma (DLBCL), but toxicities limit widespread use. The selective Bruton tyrosine kinase (BTK) inhibitor acalabrutinib has activity in patients with R/R DLBCL but durable responses are uncommon. STAT3 inhibition has demonstrated clinical activity in DLBCL. PATIENTS AND METHODS: Final results of the phase I study of acalabrutinib plus STAT3 inhibitor (danvatirsen; AZD9150) in patients with R/R DLBCL are reported. Danvatirsen 200 mg intravenous infusion [Days 1, 3, 5 (Cycle 1); weekly infusions starting Day 8, Cycle 1] was administered in combination with oral acalabrutinib 100 mg twice daily until progressive disease (PD) or unacceptable toxicity. Primary endpoints were safety and tolerability. Secondary endpoints included efficacy, pharmacokinetics, and immunogenicity. RESULTS: Seventeen patients received combination treatment. One dose-limiting toxicity (Grade 3 liver transaminase) occurred in 1 patient. The most common reason for treatment discontinuation was PD (65%). In evaluable patients (n = 17), objective response rate was 24%; median duration of response was 1.9 months. All responders with available DLBCL cell-of-origin data were either activated B-cell or nongerminal center B-cell like subtype. Genetic subtype did not correlate with response. Baseline and longitudinal plasma cell-free DNA (cfDNA) concentrations were mostly higher in nonresponding patients. cfDNA changes were generally concordant with imaging. Pretreatment circulating B-cell levels were higher in responders versus nonresponders. CONCLUSIONS: Targeting both STAT3 and BTK in combination is safe and tolerable but efficacy is limited in R/R DLBCL. Results support evaluation of circulating tumor DNA as a biomarker for clinical response.

Nanosphere's Verigene® Blood Culture Assay to Detect Multidrug-Resistant Gram-Negative Bacterial Outbreak: A Prospective Study on 79 Hematological Patients in a Country with High Prevalence of Antimicrobial Resistance.

Infections are a major cause of morbidity and mortality in hematological patients. We prospectively tested a new molecular assay (Verigene®) in 79 consecutive hematological patients, with sepsis by gram-negative bacteria. A total of 82 gram-negative microorganisms were isolated by blood cultures, of which 76 cases were mono-microbial. Considering the bacteria detectable by the system, the concordance with standard blood cultures was 100%. Resistance genes were detected in 20 of the isolates and 100% were concordant with the phenotypic antibiotic resistance. Overall, this new assay correctly identified 66/82 of all the gram-negative pathogens, yielding a general sensitivity of 80.5%, and providing information on genetic antibiotic resistance in a few hours. This new molecular assay could ameliorate patient management, resulting in a more rational use of antibiotics.

Adjuvant role of SeptiFast to improve the diagnosis of sepsis in a large cohort of hematological patients.

Febrile neutropenia and sepsis are common and life-threatening complications in hematological diseases. This study was performed retrospectively in 514 patients treated for febrile neutropenia at our institute, to investigate the clinical usefulness of a molecular tool, LightCycler® SeptiFast test (SF), to promptly recognize pathogens causing sepsis in hematological patients. We collected 1837 blood samples of 514 consecutive hematological patients. The time of processing is short. Overall, 757 microorganisms in 663 episodes were detected by molecular test and standard blood cultures (BC): 73.6% Gram-positive bacteria, 23.9% Gram-negative bacteria, and 2.5% fungal species. This large analysis demonstrated a significant episode-to episode agreement (71.9%) between the two methods, higher in negative samples (89.14%), and a specificity of 75.89%. Clinical variables that gave a statistically significant contribution to their concordance were absolute neutrophil count, ongoing antimicrobial therapy, timing of test execution, and organ localization of infection. The large analysis highlights the potential of molecular-based assays directly performed on blood samples, especially if implementing the detection of antibiotic resistance genes, which was lacking in the used study.

Enteric Microbiome Markers as Early Predictors of Clinical Outcome in Allogeneic Hematopoietic Stem Cell Transplant: Results of a Prospective Study in Adult Patients.

BACKGROUND: Infections and graft-vs-host disease (GvHD) still represent major, not easily predictable complications in allogeneic hematopoietic stem cell transplant (allo-HSCT). Both conditions have been correlated to altered enteric microbiome profiles during the peritransplant period. The main objective of this study was to identify possible early microbiome-based markers useful in pretransplant risk stratification. METHODS: Stool samples were collected from 96 consecutive patients at the beginning of the pretransplant conditioning regimen (T0) and at 10 (T1) and 30 (T2) days following transplant. When significant in univariate analysis, the identified microbiome markers were used in multivariate regression analyses, together with other significant clinical variables for allo-HSCT-related risk stratification. Four main outcomes were addressed: (1) septic complications, (2) GvHD, (3) relapse of the underlying disease, and (4) mortality. RESULTS: The presence of >5% proinflammatory Enterobacteriaceae at T0 was the only significant marker for the risk of microbiologically confirmed sepsis. Moreover, ≤10% Lachnospiraceae at T0 was the only significant factor for increased risk of overall mortality, including death from both infectious and noninfectious causes.Finally, a low bacterial alpha-diversity (Shannon index ≤ 1.3) at T1 was the only variable significantly correlating with an increased risk of GvHD within 30 days. CONCLUSIONS: Microbiome markers can be useful in the very early identification of patients at risk for major transplant-related complications, offering new tools for individualized preemptive or therapeutic strategies to improve allo-HSCT outcomes.

Integrating a prospective pilot trial and patient-derived xenografts to trace metabolic changes associated with acute myeloid leukemia.

Despite the considerable progress in understanding the molecular bases of acute myeloid leukemia (AML), new tools to link disease biology to the unpredictable patient clinical course are still needed. Herein, high-throughput metabolomics, combined with the other "-omics" disciplines, holds promise in identifying disease-specific and clinically relevant features.In this study, we took advantage of nuclear magnetic resonance (NMR) to trace AML-associated metabolic trajectory employing two complementary strategies. On the one hand, we performed a prospective observational clinical trial to identify metabolic changes associated with blast clearance during the first two cycles of intensive chemotherapy in nine adult patients. On the other hand, to reduce the intrinsic variability associated with human samples and AML genetic heterogeneity, we analyzed the metabolic changes in the plasma of immunocompromised mice upon engraftment of primary human AML blasts.Combining the two longitudinal approaches, we narrowed our screen to seven common metabolites, for which we observed a mirror-like trajectory in mice and humans, tracing AML progression and remission, respectively. We interpreted this set of metabolites as a dynamic fingerprint of AML evolution.Overall, these NMR-based metabolomic data, to be consolidated in larger cohorts and integrated in more comprehensive system biology approaches, hold promise for providing valuable and non-redundant information on the systemic effects of leukemia.

A novel self-lipid antigen targets human T cells against CD1c(+) leukemias.

T cells that recognize self-lipids presented by CD1c are frequent in the peripheral blood of healthy individuals and kill transformed hematopoietic cells, but little is known about their antigen specificity and potential antileukemia effects. We report that CD1c self-reactive T cells recognize a novel class of self-lipids, identified as methyl-lysophosphatidic acids (mLPAs), which are accumulated in leukemia cells. Primary acute myeloid and B cell acute leukemia blasts express CD1 molecules. mLPA-specific T cells efficiently kill CD1c(+) acute leukemia cells, poorly recognize nontransformed CD1c-expressing cells, and protect immunodeficient mice against CD1c(+) human leukemia cells. The identification of immunogenic self-lipid antigens accumulated in leukemia cells and the observed leukemia control by lipid-specific T cells in vivo provide a new conceptual framework for leukemia immune surveillance and possible immunotherapy.