Postdischarge thromboembolic outcomes and mortality of hospitalized patients with COVID-19: the CORE-19 registry.

Thromboembolic events, including venous thromboembolism (VTE) and arterial thromboembolism (ATE), and mortality from subclinical thrombotic events occur frequently in coronavirus disease 2019 (COVID-19) inpatients. Whether the risk extends postdischarge has been controversial. Our prospective registry included consecutive patients with COVID-19 hospitalized within our multihospital system from 1 March to 31 May 2020. We captured demographics, comorbidities, laboratory parameters, medications, postdischarge thromboprophylaxis, and 90-day outcomes. Data from electronic health records, health informatics exchange, radiology database, and telephonic follow-up were merged. Primary outcome was a composite of adjudicated VTE, ATE, and all-cause mortality (ACM). Principal safety outcome was major bleeding (MB). Among 4906 patients (53.7% male), mean age was 61.7 years. Comorbidities included hypertension (38.6%), diabetes (25.1%), obesity (18.9%), and cancer history (13.1%). Postdischarge thromboprophylaxis was prescribed in 13.2%. VTE rate was 1.55%; ATE, 1.71%; ΑCM, 4.83%; and MB, 1.73%. Composite primary outcome rate was 7.13% and significantly associated with advanced age (odds ratio [OR], 3.66; 95% CI, 2.84-4.71), prior VTE (OR, 2.99; 95% CI, 2.00-4.47), intensive care unit (ICU) stay (OR, 2.22; 95% CI, 1.78-2.93), chronic kidney disease (CKD; OR, 2.10; 95% CI, 1.47-3.0), peripheral arterial disease (OR, 2.04; 95% CI, 1.10-3.80), carotid occlusive disease (OR, 2.02; 95% CI, 1.30-3.14), IMPROVE-DD VTE score ≥4 (OR, 1.51; 95% CI, 1.06-2.14), and coronary artery disease (OR, 1.50; 95% CI, 1.04-2.17). Postdischarge anticoagulation was significantly associated with reduction in primary outcome (OR, 0.54; 95% CI, 0.47-0.81). Postdischarge VTE, ATE, and ACM occurred frequently after COVID-19 hospitalization. Advanced age, cardiovascular risk factors, CKD, IMPROVE-DD VTE score ≥4, and ICU stay increased risk. Postdischarge anticoagulation reduced risk by 46%.

Multiplex accurate sensitive quantitation (MASQ) with application to minimal residual disease in acute myeloid leukemia.

Measuring minimal residual disease in cancer has applications for prognosis, monitoring treatment and detection of recurrence. Simple sequence-based methods to detect nucleotide substitution variants have error rates (about 10-3) that limit sensitive detection. We developed and characterized the performance of MASQ (multiplex accurate sensitive quantitation), a method with an error rate below 10-6. MASQ counts variant templates accurately in the presence of millions of host genomes by using tags to identify each template and demanding consensus over multiple reads. Since the MASQ protocol multiplexes 50 target loci, we can both integrate signal from multiple variants and capture subclonal response to treatment. Compared to existing methods for variant detection, MASQ achieves an excellent combination of sensitivity, specificity and yield. We tested MASQ in a pilot study in acute myeloid leukemia (AML) patients who entered complete remission. We detect leukemic variants in the blood and bone marrow samples of all five patients, after induction therapy, at levels ranging from 10-2 to nearly 10-6. We observe evidence of sub-clonal structure and find higher target variant frequencies in patients who go on to relapse, demonstrating the potential for MASQ to quantify residual disease in AML.

Mechanism for IL-15-Driven B Cell Chronic Lymphocytic Leukemia Cycling: Roles for AKT and STAT5 in Modulating Cyclin D2 and DNA Damage Response Proteins.

Clonal expansion of B cell chronic lymphocytic leukemia (B-CLL) occurs within lymphoid tissue pseudofollicles. IL-15, a stromal cell-associated cytokine found within spleens and lymph nodes of B-CLL patients, significantly boosts in vitro cycling of blood-derived B-CLL cells following CpG DNA priming. Both IL-15 and CpG DNA are elevated in microbe-draining lymphatic tissues, and unraveling the basis for IL-15-driven B-CLL growth could illuminate new therapeutic targets. Using CpG DNA-primed human B-CLL clones and approaches involving both immunofluorescent staining and pharmacologic inhibitors, we show that both PI3K/AKT and JAK/STAT5 pathways are activated and functionally important for IL-15→CD122/ɣc signaling in ODN-primed cells expressing activated pSTAT3. Furthermore, STAT5 activity must be sustained for continued cycling of CFSE-labeled B-CLL cells. Quantitative RT-PCR experiments with inhibitors of PI3K and STAT5 show that both contribute to IL-15-driven upregulation of mRNA for cyclin D2 and suppression of mRNA for DNA damage response mediators ATM, 53BP1, and MDC1. Furthermore, protein levels of these DNA damage response molecules are reduced by IL-15, as indicated by Western blotting and immunofluorescent staining. Bioinformatics analysis of ENCODE chromatin immunoprecipitation sequencing data from cell lines provides insight into possible mechanisms for STAT5-mediated repression. Finally, pharmacologic inhibitors of JAKs and STAT5 significantly curtailed B-CLL cycling when added either early or late in a growth response. We discuss how the IL-15-induced changes in gene expression lead to rapid cycling and possibly enhanced mutagenesis. STAT5 inhibitors might be an effective modality for blocking B-CLL growth in patients.

Mechanistic Insights into CpG DNA and IL-15 Synergy in Promoting B Cell Chronic Lymphocytic Leukemia Clonal Expansion.

Malignant cell growth within patients with B cell chronic lymphocytic leukemia (B-CLL) is largely restricted to lymphoid tissues, particularly lymph nodes. The recent in vitro finding that TLR-9 ligand (oligodeoxynucleotide [ODN]) and IL-15 exhibit strong synergy in promoting B-CLL growth may be particularly relevant to growth in these sites. This study shows IL-15-producing cells are prevalent within B-CLL-infiltrated lymph nodes and, using purified B-CLL cells from blood, investigates the mechanism for ODN and IL-15 synergy in driving B-CLL growth. ODN boosts baseline levels of phospho-RelA(S529) in B-CLL and promotes NF-κB-driven increases in IL15RA and IL2RB mRNA, followed by elevated IL-15Rα and IL-2/IL-15Rß (CD122) protein. IL-15→CD122 signaling during a critical interval, 20 to 36-48 h following initial ODN exposure, is required for optimal induction of the cycling process. Furthermore, experiments with neutralizing anti-IL-15 and anti-CD122 mAbs indicate that clonal expansion requires continued IL-15/CD122 signaling during cycling. The latter is consistent with evidence of heightened IL2RB mRNA in the fraction of recently proliferated B-CLL cells within patient peripheral blood. Compromised ODN+IL-15 growth with limited cell density is consistent with a role for upregulated IL-15Rα in facilitating homotypic trans IL-15 signaling, although there may be other explanations. Together, the findings show that ODN and IL-15 elicit temporally distinct signals that function in a coordinated manner to drive B-CLL clonal expansion.

Pomalidomide reverses γ-globin silencing through the transcriptional reprogramming of adult hematopoietic progenitors.

Current therapeutic strategies for sickle cell anemia are aimed at reactivating fetal hemoglobin. Pomalidomide, a third-generation immunomodulatory drug, was proposed to induce fetal hemoglobin production by an unknown mechanism. Here, we report that pomalidomide induced a fetal-like erythroid differentiation program, leading to a reversion of γ-globin silencing in adult human erythroblasts. Pomalidomide acted early by transiently delaying erythropoiesis at the burst-forming unit-erythroid/colony-forming unit-erythroid transition, but without affecting terminal differentiation. Further, the transcription networks involved in γ-globin repression were selectively and differentially affected by pomalidomide including BCL11A, SOX6, IKZF1, KLF1, and LSD1. IKAROS (IKZF1), a known target of pomalidomide, was degraded by the proteasome, but was not the key effector of this program, because genetic ablation of IKZF1 did not phenocopy pomalidomide treatment. Notably, the pomalidomide-induced reprogramming was conserved in hematopoietic progenitors from individuals with sickle cell anemia. Moreover, multiple myeloma patients treated with pomalidomide demonstrated increased in vivo γ-globin levels in their erythrocytes. Together, these data reveal the molecular mechanisms by which pomalidomide reactivates fetal hemoglobin, reinforcing its potential as a treatment for patients with ß-hemoglobinopathies.

Binding of CLL subset 4 B-cell receptor immunoglobulins to viable human memory B lymphocytes requires a distinctive IGKV somatic mutation.

Amino acid replacement mutations in certain CLL stereotyped B-cell receptor (BCR) immunoglobulins (IGs) at defined positions within antigen-binding sites strongly imply antigen selection. Prime examples of this are CLL subset 4 BCR IGs using IGHV4-34/IGHD5-18/IGHJ6 and IGKV2-30/IGKJ2 rearrangements. Conspicuously and unlike most CLL IGs, subset 4 IGs do not bind apoptotic cells. By testing the (auto)antigenic reactivities of subset 4 IGs toward viable lymphoid-lineage cells and specific autoantigens typically bound by IGHV4-34+ IGs, we found IGs from both subset 4 and non-subset 4 IGHV4-34-expressing CLL cases bind naïve B cells. However, only subset 4 IGs react with memory B cells. Furthermore, subset 4 IGs do not bind DNA nor i or I carbohydrate antigens, common targets of IGHV4-34-utilizing antibodies in systemic lupus erythematosus and cold agglutinin disease, respectively. Notably, we found that subset 4 IG binding to memory B lymphocytes depends on an aspartic acid at position 66 of FR3 in the rearranged IGKV2-30 gene; this amino acid residue is acquired by somatic mutation. Our findings illustrate the importance of positive and negative selection criteria for structural elements in CLL IGs and suggest that autoantigens driving normal B cells to become subset 4 CLL cells differ from those driving IGHV4-34+ B cells in other diseases.

Acute myeloid leukemia ontogeny is defined by distinct somatic mutations.

Acute myeloid leukemia (AML) can develop after an antecedent myeloid malignancy (secondary AML [s-AML]), after leukemogenic therapy (therapy-related AML [t-AML]), or without an identifiable prodrome or known exposure (de novo AML). The genetic basis of these distinct pathways of AML development has not been determined. We performed targeted mutational analysis of 194 patients with rigorously defined s-AML or t-AML and 105 unselected AML patients. The presence of a mutation in SRSF2, SF3B1, U2AF1, ZRSR2, ASXL1, EZH2, BCOR, or STAG2 was >95% specific for the diagnosis of s-AML. Analysis of serial samples from individual patients revealed that these mutations occur early in leukemogenesis and often persist in clonal remissions. In t-AML and elderly de novo AML populations, these alterations define a distinct genetic subtype that shares clinicopathologic properties with clinically confirmed s-AML and highlights a subset of patients with worse clinical outcomes, including a lower complete remission rate, more frequent reinduction, and decreased event-free survival. This trial was registered at www.clinicaltrials.gov as #NCT00715637.

TLR-9 and IL-15 Synergy Promotes the In Vitro Clonal Expansion of Chronic Lymphocytic Leukemia B Cells.

Clinical progression of B cell chronic lymphocytic leukemia (B-CLL) reflects the clone's Ag receptor (BCR) and involves stroma-dependent B-CLL growth within lymphoid tissue. Uniformly elevated expression of TLR-9, occasional MYD88 mutations, and BCR specificity for DNA or Ags physically linked to DNA together suggest that TLR-9 signaling is important in driving B-CLL growth in patients. Nevertheless, reports of apoptosis after B-CLL exposure to CpG oligodeoxynucleotide (ODN) raised questions about a central role for TLR-9. Because normal memory B cells proliferate vigorously to ODN+IL-15, a cytokine found in stromal cells of bone marrow, lymph nodes, and spleen, we examined whether this was true for B-CLL cells. Through a CFSE-based assay for quantitatively monitoring in vitro clonal proliferation/survival, we show that IL-15 precludes TLR-9-induced apoptosis and permits significant B-CLL clonal expansion regardless of the clone's BCR mutation status. A robust response to ODN+IL-15 was positively linked to presence of chromosomal anomalies (trisomy-12 or ataxia telangiectasia mutated anomaly + del13q14) and negatively linked to a very high proportion of CD38(+) cells within the blood-derived B-CLL population. Furthermore, a clone's intrinsic potential for in vitro growth correlated directly with doubling time in blood, in the case of B-CLL with Ig H chain V region-unmutated BCR and <30% CD38(+) cells in blood. Finally, in vitro high-proliferator status was statistically linked to diminished patient survival. These findings, together with immunohistochemical evidence of apoptotic cells and IL-15-producing cells proximal to B-CLL pseudofollicles in patient spleens, suggest that collaborative ODN and IL-15 signaling may promote in vivo B-CLL growth.

Chronic lymphocytic leukemia immunoglobulins display bacterial reactivity that converges and diverges from auto-/poly-reactivity and IGHV mutation status.

Chronic lymphocytic leukemia (CLL) is an incurable leukemia of unknown etiology. Multiple studies suggest that the structure of the variable domains of the surface IGs on these cells, and signaling through them, play key roles in developing the disease. Hence, CLL appears to be driven by antigen-BCR interactions, and identifying the selecting antigens involved in this process is an important goal. We studied the antigen-binding characteristics of 23 CLL-derived, recombinantly-expressed IGs with 5 pathogenic bacteria, determining that CLL IGs differ in bacterial reactivity based on IGHV gene use, mutation status, and association with IGHD and IGHJ genes ("stereotypy"). Although most bacterial-reactive IGs followed the paradigm that IGHV-unmutated IGs were more auto-/poly-reactive, several did not. In addition, some CLL IGs were bacterial mono-reactive, and these displayed IGKV use biases. These findings are consistent with CLL B cells being driven into the leukemogenic process by bacterial as well as auto- antigens.

Assessing outcomes of adult oncology patients treated with linezolid versus daptomycin for bacteremia due to vancomycin-resistant Enterococcus.

BACKGROUND: The incidence and severity of vancomycin-resistant Enterococcus blood stream infections continue to rise and is a significant burden in the healthcare setting. Literature thus far is minimal regarding treatment outcomes in patients with malignancy and vancomycin-resistant Enterococcus bacteremia. Appropriate antibiotic selection is vital to treatment success due to high rates of resistance, limited antimicrobials and mortality in this patient population. We conducted this study to determine whether treatment outcomes differed between cancer patients treated with linezolid and those treated with daptomycin for vancomycin-resistant Enterococcus bacteremia. METHODS: This single-center, retrospective study included adult patients hospitalized on the oncology service with documented vancomycin-resistant Enterococcus faecium or Enterococcus faecalis bacteremia who received at least 48 h of either linezolid or daptomycin as primary treatment. RESULTS: A total of 65 patients were included in the analysis. Thirty-two patients received daptomycin as primary treatment, and 33 patients received linezolid as primary treatment. Twenty-six (76.5%) patients in the linezolid cohort versus 22 (71%) patients in the daptomycin cohort achieved microbiological cure (p = 0.6141). Median length of stay in days (30 vs. 42, p = 0.0714) and mortality (7/32 (20.6%) vs. 8/33 (25.8%), p = 0.6180) were also similar between the linezolid and daptomycin treated patients, respectively. CONCLUSION: No differences in microbiological cure, length of stay or mortality were identified between the groups. This study suggests that linezolid and daptomycin are each reasonable options for treating vancomycin-resistant Enterococcus bacteremia in oncology patients. Further prospective, randomized controlled trials are needed to assess the optimal treatment for vancomycin-resistant Enterococcus bacteremia in this patient population.

Tamibarotene in patients with acute promyelocytic leukaemia relapsing after treatment with all-trans retinoic acid and arsenic trioxide.

Treatment of acute promyelocytic leukaemia (APL) with arsenic trioxide (ATO) and all-trans retinoic acid (ATRA) is highly effective first-line therapy, although approximately 5-10% of patients relapse. Tamibarotene is a synthetic retinoid with activity in APL patients who relapse after chemotherapy and ATRA, but has not been studied in relapse after treatment with ATO and ATRA. We report on a phase II study of tamibarotene in adult patients with relapsed or refractory APL after treatment with ATRA and ATO (n = 14). Participants were treated with tamibarotene (6 mg/m(2) /d) during induction and for up to six cycles of consolidation. The overall response rate was 64% (n = 9), the rate of complete cytogenetic response was 43% (n = 6) and the rate of complete molecular response was 21% (n = 3). Relapse was frequent with 7 of 9 responders relapsing after a median of 4·6 months (range 1·6-26·8 months). The median event-free survival (EFS) was 3·5 months [95% confidence interval (CI) 0-8·6 months] and the median overall survival (OS) was 9·5 months (95% CI 5·9-13·1 months). These results demonstrate that tamibarotene has activity in relapsed APL after treatment with ATO and ATRA and further studies using tamibarotene as initial therapy and in combination with ATO are warranted.

Romidepsin in peripheral and cutaneous T-cell lymphoma: mechanistic implications from clinical and correlative data.

Romidepsin is an epigenetic agent approved for the treatment of patients with cutaneous or peripheral T-cell lymphoma (CTCL and PTCL). Here we report data in all patients treated on the National Cancer Institute 1312 trial, demonstrating long-term disease control and the ability to retreat patients relapsing off-therapy. In all, 84 patients with CTCL and 47 with PTCL were enrolled. Responses occurred early, were clinically meaningful and of very long duration in some cases. Notably, patients with PTCL receiving romidepsin as third-line therapy or later had a comparable response rate (32%) of similar duration as the total population (38%). Eight patients had treatment breaks of 3.5 months to 10 years; in four of six patients, re-initiation of treatment led to clear benefit. Safety data show slightly greater haematological and constitutional toxicity in PTCL. cDNA microarray studies show unique individual gene expression profiles, minimal overlap between patients, and both induction and repression of gene expression that reversed within 24 h. These data argue against cell death occurring as a result of an epigenetics-mediated gene induction programme. Together this work supports the safety and activity of romidepsin in T-cell lymphoma, but suggests a complex mechanism of action.

Recombinant interleukin-2 in patients aged younger than 60 years with acute myeloid leukemia in first complete remission: results from Cancer and Leukemia Group B 19808.

BACKGROUND: Recombinant interleukin-2 (rIL-2) induces cellular cytotoxicity against leukemia blasts. Patients with acute myeloid leukemia (AML) in first complete remission (CR) may harbor minimal residual disease that is susceptible to rIL-2-activated effector cells. METHODS: In the Cancer and Leukemia Group B (CALGB) 19808 study, patients with AML in first CR were randomly assigned after all planned chemotherapy to receive a 90-day course of subcutaneously administered rIL-2 or no further therapy. The primary objective was to compare disease-free survival (DFS) between the 2 treatment arms. A total of 534 patients achieved a CR, 214 of whom were randomized. Six courses of low-dose daily rIL-2 were given for the expansion of cytotoxic effector cells, each followed by 3-day high-dose boluses given to trigger cytotoxicity against minimal residual disease. RESULTS: On the protocol-specified intention-to-treat analysis, the hazards ratio for DFS was 0.75 (95% confidence interval, 0.52-1.09; P = .13); the 5-year DFS rate was 42% in the observation arm and 53% in the rIL-2 treatment arm. The hazards ratio for overall survival (OS) was 0.88 (95% confidence interval, 0.54-1.23; P = .34); the 5-year OS rate was 58% for the observation arm and 63% for the rIL-2 treatment arm. Twenty-five of the 107 patients randomized to treatment with rIL-2 either refused or were unable to initiate therapy and 30 patients did not complete their assigned therapy. However, significant toxicities were not commonly observed. The trial design did not anticipate the difficulties patients would encounter with protocol compliance. CONCLUSIONS: The efficacy of immunotherapy with rIL-2 administered after intensive postremission treatment was not assessed as planned because of unexpected refusals by patients and/or their physicians to comply with protocol-directed therapy. Neither DFS nor OS was found to be significantly improved.

T-cell independent, B-cell receptor-mediated induction of telomerase activity differs among IGHV mutation-based subgroups of chronic lymphocytic leukemia patients.

Although B-cell chronic lymphocytic leukemia (B-CLL) clones with unmutated IGHV genes (U-CLL) exhibit greater telomerase activity than those with mutated IGHV genes (M-CLL), the extent to which B-cell receptor (BCR) triggering contributes to telomerase up-regulation is not known. Therefore, we studied the effect of BCR stimulation on modulating telomerase activity. The multivalent BCR ligand, dextran conjugated anti-µ mAb HB57 (HB57-dex), increased telomerase activity and promoted cell survival and proliferation preferentially in U-CLL cases, whereas the PI3K/Akt inhibitor LY294002 blocked HB57-dex induced telomerase activation. Although both U-CLL and M-CLL clones exhibited similar membrane proximal signaling responses to HB57-dex, telomerase activity and cell proliferation, when inducible in M-CLL, differed. B-CLL cells stimulated using bivalent F(ab')(2) -goat anti-µ antibody (goat anti-µ) exhibited higher membrane proximal response in U-CLL than M-CLL cells, whereas telomerase activity, cell survival, and proliferation were induced to lower levels than those induced by HB57-dex. In normal B lymphocytes, HB57-dex induced less protein phosphorylation but more cell proliferation and survival than goat anti-µ. Although both anti-BCR stimuli induced comparable telomerase activity, normal CD5(+) B cells preferentially exhibited higher hTERT positivity than their CD5(-) counterparts. These findings provide an understanding of how BCR-mediated signals impact telomerase modulation in IGHV mutation-based subgroups of B-CLL and normal B cells.

IGHV-unmutated and IGHV-mutated chronic lymphocytic leukemia cells produce activation-induced deaminase protein with a full range of biologic functions.

Clonal evolution occurs during the course of chronic lymphocytic leukemia (CLL) and activation-induced deaminase (AID) could influence this process. However, this possibility has been questioned in CLL because the number of circulating AID mRNA(+) cells is exceedingly low; synthesis of AID protein by blood CLL cells has not been demonstrated; the full range of AID functions is lacking in unmutated CLL (U-CLL), and no prospective analysis linking AID expression and disease severity has been reported. The results of the present study show that circulating CLL cells and those within secondary lymphoid tissues can make AID mRNA and protein. This production is related to cell division because more AID mRNA was detected in recently divided cells and AID protein was limited to the dividing fraction and was up-regulated on induction of cell division. AID protein was functional because AID(+) dividing cells exhibited more double-stranded DNA breaks, IGH class switching, and new IGHV-D-J mutations. Each of these actions was documented in U-CLL and mutated CLL (M-CLL). Furthermore, AID protein was associated with worse patient outcome and adverse cytogenetics. We conclude that the production of fully functional AID protein by U-CLL and M-CLL cells could be involved in clonal evolution of the disease.

Clofarabine-induced kidney toxicity.

Clofarabine is a purine nucleoside analog indicated for treatment of relapsed or refractory acute lymphoblastic leukaemia in children. The drug is also increasingly used, outside of its FDA approved indication, for treatment of relapsed or refractory acute myeloid leukemia in adults. It acts by inhibiting DNA synthesis, the enzyme ribonucleotide reductase and repair and activation of mitochondrial repair processes. We describe a case of a 48-year-old male with refractory acute myeloid leukemia with acute kidney injury associated with clofarabine treatment. We conducted a review of the literature and utilized the Food and Drug Administration Adverse Event Reporting System to identify spontaneous reporting of renal adverse events with this drug in 29 other cases. Since clofarabine inhibits ribonucleotide reductase, we postulate by extrapolation from the animal studies that collapsing glomerulopathy or severe tubular injury or a combination of both may be the mechanism of acute kidney injury observed with this agent. This would be consistent with the observed severe acute kidney injury and proteinuria in humans.

Less is more: An analysis of venetoclax and hypomethylating agent post-induction treatment modifications in AML.

Venetoclax (Ven) combined with a hypomethylating agent (HMA) enhances survival in elderly/unfit acute myeloid leukemia (AML) patients, yet often necessitates regimen modifications due to intolerance. However, it is unclear how these modifications affect patient outcome. This retrospective cohort study evaluates the impact of post-induction HMA/Ven regimen modifications on disease progression and survival. This study reviewed 142 AML patients treated with HMA/Ven within the Northwell Health System from January 2019 to December 2022. To assess the impact of post-induction regimen modifications, patients were grouped according to median days between cycles (≤34 or ≥35 days cycle intervals) and median Ven days per cycle (≤14 or ≥15 days/cycle) based on only cycle 3 and beyond. Kaplan-Meier and Cox proportional hazard regression analyses were employed for univariate and multivariate assessments, respectively. There was no significant difference in median progression-free survival (mPFS)(11.6 vs 11.8 months, p = 0.73) or median overall survival (mOS)(15.1 vs 21.8 months, p = 0.16) between cycle interval groups. However, there was a clinically and statistically significant advantage in mPFS (15.8 vs 8.7 months, p = 0.01) and mOS (24.7 vs 11.3 months, p = 0.006) for patients with a median of ≤14 Ven days/cycle compared to ≥15 Ven days/cycle. Multivariate analysis demonstrated that ≤14 days of Ven for cycle 3 and beyond was an independent predictor of decreased mortality (HR 0.18, CI 0.07-0.48, p = 0.0007). Extended cycle intervals did not adversely affect mortality while reduced Ven duration per cycle post-induction was associated with improved survival in elderly AML patients.

Identification of outcome-correlated cytokine clusters in chronic lymphocytic leukemia.

Individual cytokines and groups of cytokines that might represent networks in chronic lymphocytic leukemia (CLL) were analyzed and their prognostic values determined. Serum levels of 23 cytokines were measured in 84 patients and 49 age-matched controls; 17 levels were significantly elevated in patients. Unsupervised hierarchical bicluster analysis identified 3 clusters (CLs) of highly correlated but differentially expressed cytokines: CL1 (CXCL9, CXCL10, CXCL11, CCL3, CCL4, CCL19, IL-5, IL-12, and IFNγ), CL2 (TNFα, IL-6, IL-8, and GM-CSF), and CL3 (IL-1ß, IL-2, IL-4, IL-15, IL-17, and IFNα). Combination scores integrating expression of CL1/CL2 or CL1/CL3 strongly correlated (P < .005) with time-to-first-treatment and overall survival (OS), respectively. Patients with the worst course had high CL1 and low CL2 or CL3 levels. Multivariate analysis revealed that CL1/CL2 combination score and immunoglobulin heavy chain variable region mutation status were independent prognostic indicators for time-to-first-treatment, whereas CL1/CL3 combination score and immunoglobulin heavy chain variable region mutation status were independent markers for OS. Thus, we identified groups of cytokines differentially expressed in CLL that are independent prognostic indicators of aggressive disease and OS. These findings indicate the value of multicytokine analyses for prognosis and suggest therapeutic strategies in CLL aimed at reducing CL1 and increasing CL2/CL3 cytokines.

A novel adoptive transfer model of chronic lymphocytic leukemia suggests a key role for T lymphocytes in the disease.

Chronic lymphocytic leukemia (CLL) is an incurable adult disease of unknown etiology. Understanding the biology of CLL cells, particularly cell maturation and growth in vivo, has been impeded by lack of a reproducible adoptive transfer model. We report a simple, reproducible system in which primary CLL cells proliferate in nonobese diabetes/severe combined immunodeficiency/γc(null) mice under the influence of activated CLL-derived T lymphocytes. By co-transferring autologous T lymphocytes, activated in vivo by alloantigens, the survival and growth of primary CFSE-labeled CLL cells in vivo is achieved and quantified. Using this approach, we have identified key roles for CD4(+) T cells in CLL expansion, a direct link between CD38 expression by leukemic B cells and their activation, and support for CLL cells preferentially proliferating in secondary lymphoid tissues. The model should simplify analyzing kinetics of CLL cells in vivo, deciphering involvement of nonleukemic elements and nongenetic factors promoting CLL cell growth, identifying and characterizing potential leukemic stem cells, and permitting preclinical studies of novel therapeutics. Because autologous activated T lymphocytes are 2-edged swords, generating unwanted graph-versus-host and possibly autologous antitumor reactions, the model may also facilitate analyses of T-cell populations involved in immune surveillance relevant to hematopoietic transplantation and tumor cytoxicity.