Using natural killer cell-derived exosomes as a cell-free therapy for leukemia

Natural killer (NK) cells are components of the innate immune system which play a pivotal role in cancer cell surveillance. Despite promising results in clinical trials, the use of NK-based therapies is limited due to unsatisfactory efficiencies and safety issues. In recent years, exosomes have emerged as a powerful, natural therapeutic tool. Since exosomes are known to carry cargos that reflect the cellular makeup of their cell of origin, we were prompted to test whether NK-derived exosomes (NKexo) maintain the anti-leukemia capacity of NK-cells. We found NK92MI-cells to secrete large amounts of 100-200 nm cap-shaped particles expressing exosomal and NK biomarkers (CD63, CD81, CD56). We demonstrated that NKexo exert a potent, selective, anti-leukemia effect on all leukemia cell-lines tested. Furthermore, NKexo eliminated leukemia cells isolated from patients with acute and chronic leukemia and inhibited hematopoietic colony growth. While leukemia cells were targeted and severely affected by NKexo, healthy B-cells remained unaffected, indicating a selective effect. This selectivity was further confirmed by demonstrating that NKexo were specifically taken up by leukemic cells but not by healthy B-cells. Our in vivo data support our in vitro and ex vivo findings and demonstrate improved human-CD45+ leukemia blast counts and overall survival in NKexo treated humanized acute myeloid leukemia (HL-60) xenograft mice thus supporting the assumption that NKexo possess an anti-leukemia effect. Pending further analyses, our findings provide the pre-clinical evidence needed to test the NKexo approach in future pre-clinical and clinical studies to ultimately develop an acellular "off-the-shelf" product to treat leukemia.

The role of additional chemotherapy prior to autologous HCT in patients with relapse/refractory DLBCL in partial remission-A retrospective multicenter study

OBJECTIVES

To evaluate the role of additional chemotherapy before autologous hematopoietic cell transplantation (HCT) in patients with relapse/refractory diffuse large B-cell lymphoma (DLBCL) who achieve partial remission following first salvage therapy.

METHODS

We conducted a multicenter retrospective study of all adult patients with DLBCL who underwent HCT between 2008 and 2020 and achieved partial response (PR) after the first salvage and were either referred directly to HCT (n = 47) or received additional salvage therapy before HCT (n = 22).

RESULTS

Post-HCT CR rate and progression-free survival were comparable between the two groups (66% vs. 68%, p = .86 and median not reached vs. 10.2 months [95% confidence interval, CI 7.1-12.3], p = .27, respectively). Median overall survival (OS) and estimated 3-year OS favored patients who were directly referred to HCT (105.8 [95% CI 63-148] months vs. 14.5 [95% CI 0-44] months, p = .035, and 65% [95% CI 51%-75%] vs. 40% [95% CI 21%-53%], p = .035, respectively). In Cox regression model, while International Prognostic Index and primary refractory versus relapse disease did not impact OS, allocation to a second salvage regimen and older age were both associated with inferior survival (hazard ratio [HR] = 2.57 95% CI 1.1-5.8, p = .023 and HR = 1.04 95% CI 0.99-1.2, p = .064, respectively).

CONCLUSIONS

Referring patients with chemotherapy-sensitive disease in PR directly to HCT is associated with better OS compared to those receiving additional lines of treatment.

Infection prevention practices among EBMT hematopoietic cell transplant centers: the EBMT Infectious Disease Working Party survey

We aimed to describe the current status of infection prevention practices among EBMT centers. Questionnaires were distributed to all 553 EBMT transplant centers to capture clinical practices regarding antimicrobial prophylaxis, protective measures, isolation procedures and growth-factor support of patients undergoing hematopoietic cell transplantation. Responses from 127 centers in 32 countries were obtained. Most centers housed patients in single rooms (autologous-82%; allogeneic-98%), with high-efficiency particulate air (HEPA)-filters (autologous-73%; allogeneic-100%) and positive pressure (autologous-61%; allogeneic-88%). Pre-engraftment G-CSF was utilized by 77 and 31% of centers after autologous and allogeneic transplantation, respectively (P < 0.00001). Antibacterial prophylaxis was provided by 57 and 69% (P = 0.086) of centers and antifungal prophylaxis by 65 and 84% (P = 0.0008) of centers, to patients undergoing autologous and allogeneic transplantation, respectively. Yet, 16 and 3% of centers provided neither antibacterial nor antifungal prophylaxis to patients undergoing autologous and allogeneic transplantation, respectively. Considerable variation existed between centers and across countries in antimicrobial prophylaxis practices, medications employed and duration of preventive therapy. There were considerable discordances between guidelines and daily practices. JACIE accredited and non-accredited centers did not differ significantly in their antimicrobial prophylaxis practices. Whether these differences between transplant centers translated into differences in infectious morbidity, mortality and financial costs, warrants further research.

Infectious complications and long-term outcomes in patients with diffuse large B-Cell lymphoma and diabetes mellitus

Febrile neutropenia (FN) is a major complication in patients with diffuse large B-Cell lymphoma (DLBCL). Diabetes mellitus (DM) has deleterious effects on the immune system resulting in an increased risk of infections. We evaluated patients with DLBCL who started frontline treatment with R-CHOP, and compared outcomes according to presence of DM comorbidity. Between 2013 and 2018, 218 patients with DLBCL were included. 46 patients (21%) had DM. Rate of admissions for FN was higher for patients with DM (0.7 vs. 0.46 admissions/patient, p = .016), also after age and gender-matched subgroup analysis (p = .004). Improved glycemic control during FN hospitalizations was associated with shorter hospitalizations. Metformin was associated with improved median overall survival in diabetic patients (89 vs. 64 months, p = .018). In conclusion, Patients with DLBCL and DM had higher rates of FN hospitalizations. Improved glycemic control during FN hospitalization was associated with shorter length of stay.

Abstract 3849: Exosomes in polycythemia vera: "mini platelets" with oncogenic and thrombogenic potential

Polycythemia vera (PV) is a classical "myeloproliferative neoplasm" characterized by clonal proliferation of myeloid progenitor cells caused by their acquisition of a mutation in the JAK2 gene. Its common complications are thrombosis and second primary malignancies. Secreted from virtually all cell types, exosomes are extracellular vesicles that carry bioactive cargo derived from their cells of origin. When engulfed, their cargo may alter the phenotype of the recipient cells. For example, neoplastic exosomes modulate the cellular makeup of bystander cells. Therefore, since mutated JAK2 is present in virtually all PV-patients, we hypothesize that PV-derived exosomes (hereafter PV-exo) carry the mutated JAK2 oncogene and are taken up by non-clonal cells, thus contributing to the thrombotic manifestations and oncogenic potential of patients with PV. We isolated and characterized exosomes from PV-patients and from the Human erythroleukemia (HEL) cell line (hereafter HEL-exo). We exposed normal cells implicated in thrombosis and skin cells to these exosomes and examined the cells' phenotypic changes and activation after exposure. Using Sanger sequencing we discovered that both PV-exo and HEL-exo, like their parental cells, carry the mutated JAK2 transcripts, allowing clonal cells to export oncogenes to distant, non-clonal sites. Our preliminary findings suggest that these exosomes promote pro-coagulant and malignant phenotypes in multiple ways. Thrombin generation assay pointed to a significantly higher generation of thrombin in the presence of PV-exo than those derived from healthy donors. Similarly, flow cytometry analysis revealed that PV-exo increased the expression of platelet activation markers. Moreover, Trans Endothelial Electrical Resistance (TEER) assay results suggest that HEL-exo induces endothelial dysfunction. Furthermore, using the Sulforhodamine B assay, we found that exposure to HEL-exo increased the proliferation of normal keratinocytes. In summary, we developed the concept of exosomes as “mini metastasis” that might promote disease manifestations either directly or indirectly. Since unlike solid tumors, hematological malignancies do not metastasize, exosomes derived from neoplastic hematological cells may fulfill this function. Such exosomes may spread oncogenes (e.g., mutated JAK2), damage non-clonal tissues (e.g., endothelial dysfunction) or act as a miniature reflection of their cells of origin (e.g., exosomes as mini platelets) in a parallel way to "real" metastasis; this concept may affect treatment related decisions. For example, by reducing clonal burden, early treatment even in “low risk” patients may prevent exosomal spread and exosomal-dependent damage to distant tissues. The results of our study highlight PV-exo as promoters of PV-complications, thrombosis and malignant transformation.

Citation Format: Orit Uziel, Adi Shacham-Abulafia, Galia Spectre, Ester Ziv, Karyn Revital Geiger, Zinab Sarsor, Neria Ron, Einat Beery, Pia Raanani, Shoshana Revel-Vilk, Mira Naamad, Uri Rozovski. Exosomes in polycythemia vera: "mini platelets" with oncogenic and thrombogenic potential [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 3849.

STAT3 Activates the Pentraxin 3 Gene in Chronic Lymphocytic Leukemia Cells

Pentraxin-related protein 3 (PTX3), commonly produced by myeloid and endothelial cells, is a humoral pattern recognition protein of the innate immune system. Because PTX3 plasma levels of patients with chronic lymphocytic leukemia (CLL) are high and most circulating cells in patients with CLL are CLL cells, we reasoned that CLL cells produce PTX3. Western immunoblotting revealed that low-density cells from seven of seven patients with CLL produce high levels of PTX3, flow cytometry analysis revealed that the PTX3-producing cells are B lymphocytes coexpressing CD19 and CD5, and confocal microscopy showed that PTX3 is present in the cytoplasm of CLL cells. Because STAT3 is constitutively activated in CLL cells, and because we identified putative STAT3 binding sites within the PTX3 gene promoter, we postulated that phosphorylated STAT3 triggers transcriptional activation of PTX3. Immunoprecipitation analysis of CLL cells' chromatin fragments showed that STAT3 Abs precipitated PTX3 DNA. STAT3 knockdown induced a marked reduction in PTX3 expression, indicating a STAT3-induced transcriptional activation of the PTX3 gene in CLL cells. Using an EMSA, we established and used a dual-reporter luciferase assay to confirm that STAT3 binds the PTX3 gene promoter. Downregulation of PTX3 enhanced apoptosis of CLL cells, suggesting that inhibition of PTX3 might benefit patients with CLL.

Maintenance therapy after second autologous hematopoietic cell transplantation for multiple myeloma. A CIBMTR analysis

The role of maintenance therapy after high-dose chemotherapy and first autologous transplantation in multiple myeloma (MM) is well established. We explored the effect of maintenance therapy on outcomes after salvage second autologous hematopoietic cell transplant (AHCT2) using the Center for International Blood and Marrow Transplant Research registry. Outcomes of interest included non-relapse mortality (NRM), relapse/progression (REL), progression-free and overall survival (PFS, OS). Of 522 patients who underwent AHCT2 between 2010 and 2018, 342 received maintenance therapy and 180 did not. Maintenance regimens included lenalidomide (42%), pomalidomide (13%), and bortezomib (13%). Median follow up was 58 months in the maintenance group and 61.5 months in the no-maintenance group. Univariate analysis showed superior outcomes at 5 years in maintenance compared to the no-maintenance group: NRM 2 (0.7-3.9)% vs 9.9 (5.9-14.9)%, (p < 0.01), REL 70.2 (64.4-75.8)% vs 80.3 (73.6-86.3)% (p < 0.01), PFS 27.8 (22.4-33.5)% vs. 9.8 (5.5-15.2)% (p < 0.01), and OS 54 (47.5-60.5)% vs 30.9 (23.2-39.2)% (p < 0.01), respectively. Use of maintenance therapy retained its association with improved outcomes in multivariate analysis. There was no difference in second cancers in the two groups (p = 0.39). We conclude that maintenance after AHCT2 is associated with improved 5-year outcomes.

Humoral serological response to the BNT162b2 vaccine after allogeneic haematopoietic cell transplantation

Objectives

To assess the humoral immune response to the BNT162b2 vaccine after allogeneic haematopoietic cell transplantation (HCT).

Methods

This is a prospective cohort study. The SARS-CoV-2 IgGII Quant (Abbott©) assay was performed 4–6 weeks after the second BNT162b2 vaccine for quantitative measurement of anti-spike antibodies.

Results

The cohort included 106 adult patients. Median time from HCT to vaccination was 42 (range 4–439) months. Overall, 15/106 (14%, 95% confidence interval (CI) 7–21%) were seronegative despite vaccination, 14/52 patients on immunosuppression (27%, 95%CI 19–35%) compared to only 1/54 patients off immunosuppression (1.8%, 95%CI 1–4%) (p 0.0002). The proportion of seronegative patients declined with time; it was 46% (6/13) during the first year, 12.5% (3/24) during the second year and 9% (6/69) beyond 2 years from transplant. Patients with acute graft-versus-host disease (GVHD) (odds ratio (OR) 3.3, 95%CI 0.97–11.1, p 0.06) and moderate to severe chronic GVHD (OR 5.9, 95%CI 1.2–29, p 0.03) were more likely to remain seronegative. Vaccination was well tolerated by most patients. However, 7% (7/106) reported that GVHD-related symptoms worsened within days following vaccination.

Conclusion

A significant proportion of allogeneic HCT recipients receiving immunosuppression demonstrated an inadequate humoral response to the BNT162b2 vaccine. These patients should be recognized and instructed to take appropriate precautions. Recipients who were off immunosuppression had a humoral response that was comparable to that of the general population.

Humoral serologic response to the BNT162b2 vaccine is abrogated in lymphoma patients within the first 12 months following treatment with anti-CD2O antibodies

Patients with lymphoma, especially those treated with anti-CD20 monoclonal antibodies (MoAb), suffer high COVID-19-associated morbidity and mortality. The goal of this study was to assess the ability of lymphoma patients to generate a sufficient humoral response after two injections of BNT162b2 Pfizer vaccine and to identify factors impacting the response. Antibody titers were measured with the SARS-CoV-2 IgG II Quant (Abbott©) assay in blood samples drawn from lymphoma patients 4±2 weeks after the 2nd vaccine dose. The cutoff for a positive response was set at 50AU/ml. Positive serological responses were observed in 51% of the 162 patients enrolled in this cross-sectional study. In a multivariate analysis, an interval of.

Eltrombopag for enhancement of platelet engraftment in patients undergoing allogeneic cord blood transplantation

Platelet recovery after allogeneic umbilical cord blood (UCB) transplantation is delayed compared to other graft sources. We conducted a multicenter phase 2a study to explore whether eltrombopag, a thrombopoietin-receptor agonist, would enhance platelet recovery after UCB transplantation. Between 02/2013 and 07/2016, 12 (10 adults, 2 children) individuals (median age 50; range 6-74 years) with hematological malignancies in complete remission were enrolled. Eltrombopag was given for a median of 76 (range 15-175) days and was safe even at doses of 300 mg/day. Median time to neutrophil engraftment was 23 (range 16-40) days. Median time to platelets >20,000/µl and >50,000/µl was 55 (range 25-199) and 66 (range 31-230) days, respectively. A historical cohort comparison did not reveal an advantage for eltrombopag. In conclusion, in the present study eltrombopag seems safe. Based on our limited data, it seems unlikely that eltrombopag could enhance platelet engraftment after UCB transplantation.

Improved outcomes with maintenance therapy after salvage autologous hematopoietic cell transplantation (AHCT) in multiple myeloma: A CIBMTR study

8022

Background: Maintenance therapy in multiple myeloma (MM) after first autologous hematopoietic cell transplantation (AHCT1) is considered standard of care. Data regarding maintenance therapy after a salvage AHCT (AHCT2) in the setting of relapsed MM are scarce. Therefore, we used data from the Center for International Blood and Marrow Transplant Research (CIBMTR) registry to examine the use of maintenance therapy after AHCT2 in MM patients and its effect on post-transplant patient outcomes. Methods: We included US adult MM patients who underwent AHCT2 after melphalan conditioning regimen from 2010-2018, and excluded patients who underwent tandem transplants. Outcomes of interest included non-relapse mortality (NRM), relapse/progression (REL), progression-free and overall survival (PFS, OS). Cox proportional hazards models were developed to study the main effect (maintenance use) with other covariates of interest including age, sex, race, performance status, HCT-comorbidity index, MM subtype, stage, creatinine, cytogenetic, conditioning melphalan dose, disease status at transplant, and time from AHCT1 to AHCT2. Results: Of 522 patients, 342 received maintenance therapy and 180 did not after AHCT2. Baseline characteristics were similar between the two groups. Median follow up was 58 months in the maintenance group and 61.5 months in the no-maintenance group. Common maintenance regimens included immunomodulatory drugs (IMID)-lenalidomide (N = 145, 42%) or pomalidomide (N = 46, 13%) and proteasome inhibitor, bortezomib (N = 45, 13%). Univariate analysis showed superior outcomes at 5 years in maintenance compared to the no-maintenance group: NRM 2 (0.7-3.9)% vs 9.9 (5.9-14.9)%, p < 0.001, REL 70.2 (64.4-75.8)% vs 80.3 (73.6-86.3)%, p 0.003, PFS 27.8% (22.4-33.5) vs. 9.8% (5.5-15.2), p < 0.001, and OS 54% (47.5-60.5) vs 30.9% (23.2-39.2) p < 0.001, respectively. IMID-containing maintenance regimens were associated with an improved 5-year PFS and OS compared to other maintenance regimens. Use of maintenance therapy retained its association with improved outcomes in multivariate analysis, including NRM: hazard ratio (HR) 0.19 (0.08-0.44), p 0.0001, REL: HR 0.58 (0.47-0.72), p < 0.0001, PFS HR 0.52 (0.43-0.64), p < 0.0001, and OS HR 0.46 (0.36-0.60), p < 0.0001. We conducted additional analyses to investigate a possible selection bias in the maintenance group including landmark analysis at 100-days and 6-months post-AHCT2 as well as a subgroup analysis of patients who received melphalan 200mg/m2 as conditioning for AHCT2 (as a surrogate for fitness)- all these analyses also showed improved outcomes in the maintenance group. Second cancers were reported in 17 (5%) patients in the maintenance group and 6 (3%) patients and no-maintenance group (p 0.39). Conclusions: Maintenance therapy after AHCT2 is associated with superior outcomes in MM patients.

Post-transplantation maintenance with sorafenib or midostaurin for FLT3 positive AML patients - a multicenter retrospective observational study

The role of post allogeneic stem-cell transplantation (AlloSCT) FLT3 inhibition for acute myeloid leukemia in the real-world setting is unclear, especially in the era of widespread pre-transplant use of tyrosine kinase inhibitors (TKIs). In a multicenter nationwide study, we assessed 41 patients who were treated with post-transplant TKIs (sorafenib, n = 23, midostaurin, n = 18). The majority also received TKIs pre-transplant (n = 32, 79%). After a median follow up of 10 months post-transplant (range 3-53.6), 29 patients (71%) were alive and in complete remission. Similar results were seen in a subgroup analysis of pre-transplant TKI recipients (78%). In Univariate analysis, HCT-CI score < 4 and Type of TKI (sorafenib versus midostaurin) predicted longer overall survival. Seventeen patients (41%) suffered from side effects and seven patients (17%) stopped TKI therapy due to adverse events. Overall, our data suggest that post-transplant use of TKIs is safe and effective in an era of their widespread use prior to AlloSCT.

Diarrheal Morbidity During Hematopoietic Cell Transplantation: The Diagnostic Yield of Stool Cultures

INTRODUCTION

Diarrhea affects a significant proportion of patients undergoing hematopoietic cell transplantation (HCT). We explored the diagnostic yield of stool cultures for enteric pathogens among patients undergoing HCT.

METHODS

This is a single-center, retrospective study. Between 5/2007 and 4/2020, consecutive patients who underwent HCT were included if inpatient bacterial stool cultures were collected. Patient characteristics, results, and timing of stool cultures obtained during hospitalization were collected.

RESULTS

A total of 1072 individuals underwent autologous (n = 603) and allogeneic (n = 469) HCT. Overall, 947 stool culture samples were obtained from 561 (52%) patients with diarrheal illness during hospitalization for HCT. Most (99%) samples were obtained beyond 3 days of admission, mainly (77%) during neutropenia. Overall, only four (0.42%) (autologous, n = 3; allogeneic, n = 1) patients had a positive stool culture and in all cases Campylobacter spp. were the pathogens identified. The number of stool cultures needed-to-test to diagnose one case of bacterial infection was 237. The cost of diagnosing one case of bacterial diarrhea was US $8770. Patients with a positive stool culture did not have discerning characteristics.

CONCLUSIONS

In our experience, the yield of stool cultures for enteropathogens in patients undergoing HCT is extremely low and thus should be avoided in most cases.

STAT3 induces the expression of GLI1 in chronic lymphocytic leukemia cells

The glioma associated oncogene-1 (GLI1), a downstream effector of the embryonic Hedgehog pathway, was detected in chronic lymphocytic leukemia (CLL), but not normal adult cells. GLI1 activating mutations were identified in 10% of patients with CLL. However, what induces GLI1 expression in GLI1-unmutated CLL cells is unknown. Because signal transducer and activator of transcription 3 (STAT3) is constitutively activated in CLL cells and sequence analysis detected putative STAT3-binding sites in the GLI1 gene promoter, we hypothesized that STAT3 induces the expression of GLI1. Western immunoblotting detected GLI1 in CLL cells from 7 of 7 patients, flow cytometry analysis confirmed that CD19+/CD5+ CLL cells co-express GLI1 and confocal microscopy showed co-localization of GLI1 and phosphorylated STAT3. Chromatin immunoprecipitation showed that STAT3 protein co-immunoprecipitated GLI1 as well as other STAT3-regulated genes. Transfection of CLL cells with STAT3-shRNA induced a mark decrease in GLI1 levels, suggesting that STAT3 binds to and induces the expression of GLI1 in CLL cells. An electromobility shift assay confirmed that STAT3 binds, and a luciferase assay showed that STAT3 activates the GLI1 gene. Transfection with GLI1-siRNA significantly increased the spontaneous apoptosis rate of CLL cells, suggesting that GLI1 inhibitors might provide therapeutic benefit to patients with CLL.

Anticoagulation in patients with atrial fibrillation, thrombocytopenia and hematological malignancy

Managing anticoagulation in hematological malignancy patients with atrial fibrillation and thrombocytopenia is a clinical challenge with limited data. We aimed to identify anticoagulation management strategies and evaluate bleeding and thrombosis rates associated with each approach. A retrospective cohort study in Israel and the Netherlands was conducted. Patients with hematological malignancy and atrial fibrillation were indexed when platelets were < 50 × 10⁹/L and followed for 30 days. The cohort included 61 patients of whom 42 (69%) had anticoagulation held at index. On multivariate analysis, holding anticoagulation was associated with age < 65 years and atrial fibrillation diagnosed within 30 days prior index. Clinically relevant bleeding was diagnosed in 7 (16.7%) and 1 (5.3%) of patients who had anticoagulation held and continued respectively, while arterial thromboembolism occurred in 1 patient in each group (2.4% and 5.3%, respectively). All-cause mortality rate was high at 45%. Accordingly, the 30-day bleeding risk may outweigh the risk of arterial thromboembolism in hematological malignancy, platelets < 50 × 10⁹/L and atrial fibrillation.

Thrombin Generation in Patients with Atrial Fibrillation Undergoing Percutaneous Coronary Intervention

BACKGROUND

The optimal antithrombotic treatment for patients with atrial fibrillation (AF) that undergo percutaneous coronary intervention (PCI) is controversial. Dual therapy (clopidogrel and a direct oral anticoagulant [DOAC]) is safer than triple therapy (warfarin, aspirin, and clopidogrel), while efficacy is unclear. We aimed to evaluate thrombin generation (TG) under dual and triple therapy.

METHODS

A noninterventional prospective trial in patients with AF undergoing PCI. Patients received 4 weeks of triple therapy with aspirin, clopidogrel, and a DOAC followed by aspirin withdrawal. TG was measured in platelet-rich plasma (PRP) and platelet-poor plasma (PPP) at 3 five to 21 points, day 1 after PCI (TIME 0), 4 weeks after PCI (TIME 1), and 2 weeks after aspirin withdrawal (TIME 2).

RESULTS

Twenty-three patients (18 men, median age 78 years, 83% with acute coronary syndrome) were included. Endogenous thrombin potential (ETP) in PPP was high at TIME 0 compared with TIME 1 (ETP 3,178 ± 248 nM vs. 2,378 ± 222 nM, p = 0.005). These results remained consistent when measured in PRP. No significant difference in ETP was found before (TIME 1) and after aspirin withdrawal (TIME 2) although few patients had high ETP levels after stopping aspirin.

CONCLUSIONS

TG potential is high immediately after PCI and decreases 4 weeks after PCI in patients receiving triple therapy. TG remains constant after aspirin withdrawal in most patients, suggesting that after 1 month the antithrombotic effect of dual therapy may be similar to triple therapy.

Health-Related Quality of Life in Patients with Chronic Myeloid Leukemia Treated with First- Versus Second-Generation Tyrosine Kinase Inhibitors

The life expectancy of patients with chronic myeloid leukemia (CML) approaches that of the age-matched population and quality of life (QOL) issues are becoming increasingly important. To describe patients’ characteristics and assess QOL, we delivered a 30-item core questionnaire, a 24-item CML-specific questionnaire, both from the European Organization for Research and Treatment of Cancer (EORTC), and additional health-related items to 350 patients. Among 193 patients who completed the questionnaires, 139 received either imatinib (n = 70, 33%), dasatinib (n = 45, 23%) or nilotinib (n = 24, 12%). Patients’ median age was 58 (range: 23 to 89) years and 86 (63%) were males. Stratifying patients by treatment, we recognized two distinct populations. In comparison to patients on dasatinib and nilotinib, patients on imatinib were two decades older, had a longer duration of disease and current treatment, experienced fewer limitations on daily activities (p = 0.02), less fatigue (p = 0.001), lower degree of impaired body image (p = 0.022) and less painful episodes (p = 0.014). Similarly, they had better emotional functioning, were less worried, stressed, depressed or nervous (p = 0.01) and were more satisfied with their treatment (p = 0.018). Not only does age associate with current treatments, but it also predicts how patients perceive QOL. Young patients express impaired QOL compared with elderly patients.

Sequential treatment with FLAG-IDA/treosulfan conditioning regimen for patients with active acute myeloid leukemia

Sequential protocols combining salvage chemotherapy with reduced intensity conditioning (RIC) and allogeneic hematopoietic cell transplantation (alloHCT) for high-risk acute myeloid leukemia (AML) have been studied more than a decade. Purpose of this retrospective analysis was to evaluate the anti-leukemic efficacy and toxicity of FLAG-IDA protocol (fludarabine, cytarabine, and idarubicin) followed by treosulfan-based conditioning for patients with active AML. From January 2014 to November 2019, a total of 29 active AML patients [median age, 64 years (range, 23-73)] were treated. All patients completed protocol regimen and were transplanted. Five patients (17%) had grade 3-4 toxicities; therefore, treosulfan was substituted with total body irradiation (TBI) non-myeloablative conditioning. Six (20%) patients died within 30 post-transplant days, all from infectious complications. Out of 23 evaluable patients on day 30, 22 (96%) achieved complete hematologic remission with full donor chimerism. Non-relapse mortality (NRM) rates at 1 and 3 years were 22% and 49%, respectively. Median overall survival (OS) was 12 (95% CI, 4-20) months. OS and disease-free survival were 50% and 46% at 1 year and 28% and 17% at 2 years, respectively. Age, gender, disease burden, number of previous lines, and comorbidity score did not predict survival. Sequential strategy combining FLAG-IDA and treosulfan may offer a salvage option for few selected patients with active AML; however, high NRM presents a major obstacle to treatment success. Future efforts should focus on reducing NRM by moderating regimen intensity and by better selection of patients.

Epidural/spinal anesthesia during delivery in women with factor XI deficiency, a single center experience

INTRODUCTION

The safety of neuro-axial anaesthesia (epidural/spinal) at labour of women with partial factor XI (FXI) deficiency is uncertain. Although FXI deficiency is frequent in Ashkenazi Jews, it is not routinely measured before labour. Our institute serves a large Ashkenazi population. We assumed that 10% of them have undiagnosed FXI deficiency.

AIM

Assess the incidence, bleeding tendency and coagulation status among Jewish Ashkenazi women with FXI deficiency that underwent neuro-axial anaesthesia at delivery.

METHODS

Jewish Ashkenazi women who underwent neuro-axial anaesthesia at labour completed the SSC ISTH bleeding assessment tool (BAT) and had blood drawn for coagulation tests, FXI and thrombin generation after labour. Estimation for 10 years was calculated from the 1-year sample.

RESULTS

We recruited 261 women during 12 months. Among them, 39 (15%) had FXI deficiency (<70%) with median FXI levels of 63% (range: 33%-70%). Around 50% of them underwent amniocentesis in the current pregnancy and prior neuro-axial anaesthesia with no bleeding complications. BAT score and thrombin generation did not differ between women regardless of FXI status. aPTT was longer in women with partial FXI deficiency (median - 28.6 sec vs 26.3 sec, P < .001, Table 2), although within the normal range in all women. No bleeding complications after neuro-axial anaesthesia at delivery were reported in our centre in the last decade though, and according to our estimation, at least 2150 women had partial FXI deficiency.

CONCLUSIONS

A significant number of Jewish Ashkenazi women with undiagnosed partial FXI deficiency undergo neuro-axial anaesthesia at labour without bleeding complications.

Early detection of infectious complications during induction therapy for acute leukemia with serial C-reactive protein biomarker assessment

Febrile neutropenia (FN) and blood stream infections (BSI) are major complications of induction treatment for acute leukemia. We assessed the predictive utility of C-reactive protein (CRP), an acute phase reactant, for FN and BSI during induction. CRP levels and dynamics were analyzed in 138 consecutive patients. FN and BSI occurred in 110 (80.3%) and 10 (7.5%) patients, respectively. Median peak CRP level in the 24-hours preceding FN was 7.5 mg/dl (0.2-38.1) vs. median peak CRP level of 5.11 mg/dl (0.2-23.1, p = .009) in patients without FN. CRP levels preceding BSI were 13.1 mg/dl (6.9-27.9) vs. 6.3 mg/dl (0.16-38.14, p = .011). CRP increase prior to event (ΔCRP) was higher among patients with BSI vs. patients without BSI (p = .013). CRP was predictive for FN (p = .009) and BSI (p = .01) on ROC curve analysis and was also independently associated with FN on multivariate analysis. In conclusion, CRP is a sensitive biomarker that precedes FN and BSI.

Risk factors for high-dose methotrexate associated acute kidney injury in patients with hematological malignancies

High dose methotrexate (HDMTX)-induced acute kidney injury (AKI) is a well-known adverse event in hemato-oncology patients. Our purpose was to define factors and setup cut-offs that may help better identify patients at-risk for developing AKI following HDMTX. All consecutive patients who received MTX dose ≥1 g were retrospectively reviewed. We compared patients with or without renal toxicity. We used a logistic regression model to define baseline variables associated with AKI. Overall survival (OS) was estimated by the Kaplan-Meier method employing log-rank test. Between 2012 and 2017, 160 patients were included with a total of 265 courses. Indications included: primary central nervous system (CNS) lymphoma, CNS prophylaxis in other lymphoma types, acute lymphatic leukemia and others. Median age at diagnosis was 58 years (range, 18-84), 54% were males, median MTX dose was 1941 mg/m² (range, 743-5442) and AKI developed in 9% of drug administrations (n = 24). In univariate analysis: age > 40, LDH > 380 units/L, eGFR < 112 mL/min, albumin <3.6 mg/dL at baseline and Charlson comorbidity index (CCI) were associated with AKI. In multivariable analysis, only LDH > 380 units/L (OR = 4.1, 95% confidence interval [CI] 1.04-20.9, P = .04) and albumin levels <3.6 g/dL (OR = 4.17, 95% CI 1.04-6.5, P = .04) remained significant. In patients with AKI, median drug elimination was longer (8 days vs 5 days). In 80% of cases, the creatinine levels returned to normal within 1 month. Yet, the median survival of patients who developed AKI was 37 months, compared to 145 months in patients without AKI (Log rank = 0.015). In conclusion, LDH > 380 units/L and albumin <3.6 g/dL were the strongest factors associated with AKI in patients receiving HDMTX. Although the rise in creatinine levels was almost uniformly reversible, AKI was associated with increased mortality rates.

Profiling and bioinformatics analyses reveal chronic lymphocytic leukemia cells share a unique circular RNA expression pattern

Approximately 10% of the human transcriptome is composed of circular RNAs (circRNAs). These are non-coding RNA molecules in which a covalent bond between the 3' and 5' forms a stable circular loop. Herein, we profiled the expression of 13,368 cricRNAS in 21 patients with chronic lymphocytic leukemia (CLL). Regardless of clinical, genetic, or prognostic characteristics, CLL cells share a unique expression profile distinguishable from that of normal B cells. Specifically, 859 circRNAs from 592 genes were differentially expressed (fold change ≥2 and false discovery rate ≤0.05). Whether dysregulation of circRNAs contributes to the pathogenesis of CLL remains to be determined.

Correction: Premature ageing following allogeneic hematopoietic stem cell transplantation

An amendment to this paper has been published and can be accessed via a link at the top of the paper.

Premature ageing following allogeneic hematopoietic stem cell transplantation

Survivors of hematopoietic cell transplantation (HCT) have been shown to exhibit both clinical and biological features of accelerated ageing. Most studies used frailty measures, comorbidities for clinical assessment and several biological assessment of premature ageing. However, these tests are less suitable for age determination of individual patients. Recently, DNA methylation has emerged as a novel test to measure cellular age. In the present study, we assessed ageing in a cohort of 26 survivors of allogeneic HCT by frailty tests comprising the handgrip and 6 min walk tests and by biological tests including DNA methylation, telomere length and expression of p16INK^4A and serum levels of IL-6. DNA methylation was evaluated both in blood and buccal epithelial cells. Physiological reserve was markedly reduced in transplant survivors, reflected by 6 min walk test. Increased IL-6 serum levels and p16^ink4A correlated with accelerated ageing. Overall, the measured age of donor blood cells was significantly higher than these blood cells residing in their respective donors, as reflected by DNA methylation and by buccal epithelium methylation status. These clinical and biological observations suggest that allogeneic HCT is associated with accelerated ageing.

Genomic analysis of metastatic rhabdomyosarcoma masquerading as acute leukemia

Blast appearing cells in the peripheral blood and bone marrow may occasionally arise from non-hematopoietic tissues. We present a 58 year old female who presented at our emergency room with symptomatic pancytopenia. Several months earlier she was diagnosed and treated for rhabdomyosracoma of the nasopharynx and entered remission. When we examined the bone-marrow aspirate we estimated the number of blasts at 25 %. Based on this evaluation, a provisional diagnosis of acute leukemia was made. However, immunohistochemistry and flow cytometry analysis revealed that the cells presumed to be blasts were in fact rhabdomyosarcoma cells masquerading as leukemia. The mutational landscapes of the primary tumor and the bone marrow metastasis had similar yet distinct profiles. Annotation analysis suggested that the primary and metastatic tumors use alternate mutations to activate the RAS/AKT signaling pathways. In this case, looking beyond the mutational profiling revealed an additional layer of similarity between both the original and metastatic samples, exposing a common and possibly targetable pathway. Application of annotation tools in clinical practice could enable extraction of valuable information from somatic mutational gene panels.

Romidepsin treatment for relapsed or refractory peripheral and cutaneous T-cell lymphoma: Real-life data from a national multicenter observational study

Romidepsin is a class I selective histone deacetylase (HDAC) inhibitor approved by the Food and Drug Administration (FDA) for relapsed/refractory (R/R) cutaneous T-cell lymphoma (CTCL) and peripheral T-cell lymphoma (PTCL), treated with at least one prior systemic therapy. Currently, there is paucity of real-life data on the efficacy and safety of romidepsin in R/R T-cell lymphoma. This national, multicenter study presents real-life data on the efficacy and safety of romidepsin in R/R T-cell lymphoma. Patients diagnosed and treated with romidepsin for R/R CTCL or PTCL between 2013 and 2018 were retrospectively reviewed. Outcomes included overall survival (OS), event-free survival (EFS), overall response rate (ORR), complete response (CR), and adverse events. Fifty-three patients with R/R PTCL (n = 42) or CTCL (n = 11) were included. Among CTCL patients, median OS was not reached, ORR was 25%, and none achieved CR. Among PTCL patients, median OS was 7.1 months, EFS was 1.9 months, ORR rate was 33%, and 12.5% achieved CR. In a univariate analysis, predictors for longer EFS include any response to therapy, number of previous lines, and PTCL subclass (with better results for angioimmunobalstic T-cell lymphoma). In a univariate and multivariate analysis for OS, treatment response was the only factor predicting OS (OR 4.48; CI 95%, 1.57-12.79; P = .005). Most grade 3 and 4 adverse events were hematological (35%). Infections were reported in 34% of patients. This real-life experience with romidepsin confirms the results of the pivotal phase II trials. PTCL subtype and the number of previous lines of therapy have an impact on EFS. In addition, patients who had good response to romidepsin benefited most in terms of both EFS and OS. Efforts should be done to identify those patients.

STAT3-Induced Wnt5a Provides Chronic Lymphocytic Leukemia Cells with Survival Advantage

The wingless and integration site growth factor-5a (Wnt5a) is a ligand of the receptor tyrosine kinase-like orphan receptor-1 (ROR1). Because both Wnt5a and ROR1 are expressed in circulating chronic lymphocytic leukemia (CLL) cells, and because in other cell types, STAT3, which is constitutively activated in CLL, induces Wnt5a signaling, we wondered whether STAT3 induces the expression of Wnt5a in CLL cells. Sequence analysis detected four putative STAT3 binding sites in close proximity to the Wnt5a gene promoter's start codon. Chromatin immunoprecipitation and EMSA revealed that STAT3 binds to the Wnt5a gene promoter, and a luciferase assay showed that STAT3 activates the Wnt5a gene. Additionally, transfection of peripheral blood CLL cells with STAT3 short hairpin RNA downregulated Wnt5a mRNA and protein levels, suggesting that STAT3 binds to the Wnt5a gene promoter and induces the expression of Wnt5a in CLL cells. Flow cytometry and confocal microscopy determined that both Wnt5a and its receptor ROR1 are coexpressed on the surface of CLL cells, and Western immunoblotting showed an inverse correlation between Wnt5a and ROR1 protein levels, implying that, regardless of CLL cells' ROR1 levels, blocking the interaction between Wnt5a and ROR1 might be beneficial to patients with CLL. Indeed, transfection of CLL cells with Wnt5a small interfering RNA reduced Wnt5a mRNA and protein levels and significantly increased the spontaneous apoptotic rate of CLL cells. Taken together, our data unravel an autonomous STAT3-driven prosurvival circuit that provides circulating CLL cells with a microenvironment-independent survival advantage.

Indications for genetic testing leading to termination of pregnancy

PURPOSE

In this study, we aimed to assess the distribution of genetic abnormalities leading to termination of pregnancy and its fluctuation during the past 8 years in light of those technical advances.

METHODS

Our cohort consisted of all pregnant women who underwent termination of pregnancy because of genetic aberrations in their fetuses from January 2010 through April 2018 in our medical center. The information that was gathered included: maternal age, results of the nuchal scan, results of the first- and second-trimester biochemical screening, ultrasonographic findings, reasons for conducting a genetic evaluation, gestational age at which termination of pregnancy was carried out, and the type of genetic aberration.

RESULTS

816 women underwent termination of pregnancy at our institution due to genetic aberrations, most of them because of positive biochemical screening (n = 297, 36%) or because of maternal anxiety (n = 283, 35%). Findings in chromosomal microarray led to termination of pregnancy in 100 women (100/816, 12%). Chromosomal microarray had been performed due to maternal choice and not because of accepted medical indications among most of the women who underwent termination of pregnancy due to findings on chromosomal microarray (69/100, 69%).

CONCLUSION

Performing chromosomal microarray on a structurally normal fetus and identifying abnormal copy number variants may give the parents enough information for deciding on the further course of the pregnancy.

Prevalence and clinical significance of hypercalcemia at diagnosis in diffuse large B-cell lymphoma

The reported prevalence of hypercalcemia at diagnosis in non-Hodgkin-lymphoma ranges between 1.3% and 7.4%. These studies included all patients, regardless of lymphoma subtype. We performed a retrospective case-control study to determine the prevalence of hypercalcemia at time of diagnosis in patients with diffuse large B-cell lymphoma (DLBCL). Among 250 newly diagnosed patients, 46 (18%) had hypercalcemia. When compared with age-sex matched patients and normal calcium levels, those with hypercalcemia had higher levels of LDH, lower levels of albumin and more advanced stage. These differences were translated to shorter progression-free-survival and overall survival, but only in patients with hypercalcemia and low levels of parathyroid hormone (PTH). These findings suggest that in newly diagnosed patients with DLBCL, hypercalcemia is more frequent than previously appreciated. Furthermore, lymphoma-related but not primary hyperparathyroidism-related hypercalcemia is associated with adverse prognostic factors and adverse clinical outcomes in DLBCL. Hence, PTH should be obtained in patients with DLBCL and hypercalcemia at diagnosis.

The Effects of Proteasome Inhibitors on Telomerase Activity and Regulation in Multiple Myeloma Cells

The importance of telomerase, the enzyme that maintains telomere length, has been reported in many malignancies in general and in multiple myeloma (MM) in particular. Proteasome inhibitors are clinically used to combat effectively MM. Since the mechanism of action of proteasome inhibitors has not been fully described we sought to clarify its potential effect on telomerase activity (TA) in MM cells. Previously we showed that the first generation proteasome inhibitor bortezomib (Brt) inhibits TA in MM cells by both transcriptional and post-translational mechanisms and has a potential clinical significance. In the current study we focused around the anti- telomerase activity of the new generation of proteasome inhibitors, epoxomicin (EP) and MG-132 in order to clarify whether telomerase inhibition represents a class effect. We have exposed MM cell lines, ARP-1, CAG, RPMI 8226 and U266 to EP or MG and the following parameters were assessed: viability; TA, hTERT expression, the binding of hTERT (human telomerase reverse transcriptase) transcription factors and post-translational modifications. Epoxomicin and MG-132 differentially downregulated the proliferation and TA in all MM cell lines. The downregulation of TA and the expression of hTERT were faster in CAG than in ARP-1 cells. Epoxomicin was more potent than MG-132 and therefore further mechanistic studies were performed using this compound. The inhibition of TA was mainly transcriptionally regulated. The binding of three positive regulator transcription factors: SP1, c-Myc and NF-κB to the hTERT promoter was decreased by EP in CAG cells as well as their total cellular expression. In ARP-1 cells the SP1 and c-MYC binding and protein levels were similarly affected by EP while NF-κB was not affected. Interestingly, the transcription factor WT-1 (Wilms' tumor-1) exhibited an increased binding to the hTERT promoter while its total cellular amount remained unchanged. Our results combined with our previous study of bortezomib define telomerase as a general target for proteasome inhibitors. The inhibitory effect of TA is exerted by several regulatory levels, transcriptional and post translational. SP1, C-Myc and NF-κB were involved in mediating these effects. A novel finding of this study is the role of WT-1 in the regulation of telomerase which appears as a negative regulator of hTERT expression. The results of this study may contribute to future development of telomerase inhibition as a therapeutic modality in MM.

Anthracycline-Induced Cardiotoxicity in Acute Myeloid Leukemia Patients Who Undergo Allogeneic Hematopoietic Stem Cell Transplantation

INTRODUCTION

There is paucity of data regarding the cardiotoxic effects of anthracycline treatment in the context of acute myeloid leukemia (AML) patients who undergo allogeneic hematopoietic stem cell transplantation (HSCT). Even a transient decrease in cardiac function might affect transplantation outcome.

PATIENTS AND METHODS

We reviewed the clinical records and echocardiography examinations of 78 patients with AML who received induction therapy and underwent HSCT.

RESULTS

Twenty-two patients (28%) received daunorubicin at a dose of 90 mg/m² per day and 53 patients (68%) received 60 mg/m² per day or an equivalent dose of idarubicin. In 14 patients (18%) the postinduction ejection fraction declined by at least 10%. This change was temporary in 6 patients and longstanding in the remainder. Patients who developed systolic dysfunction had inferior overall survival (13 months compared with 27 months; P = .013). Patients whose diastolic function deteriorated had improved survival outcome (38 months compared with 17 months; P = .048).

CONCLUSION

Although even transient reduction in systolic function might compromise survival outcome, diastolic dysfunction predicts improved survival in patients with AML who undergo HSCT.

Characteristics and outcomes of young adults with Philadelphia-negative myeloproliferative neoplasms

OBJECTIVE

Approximately 10% of Philadelphia (Ph)-negative myeloproliferative neoplasms (NPM) are diagnosed at young adulthood. We aim to define the features of this group.

METHODS

A multicenter retrospective study, including patients 18-45 years of age, diagnosed with Ph-negative MPN between 1985 and 2017.

RESULTS

One hundred nine patients were included, 37 with polycythemia vera (34%), 54 with essential thrombocytosis (50%), 15 with primary myelofibrosis (PMF) (14%), and 3 with MPN unclassifiable (3%). Median age was 33 years and 62 (57%) were females. During a median follow-up of 8 years, 39 patients (37%) had at least one thrombotic event. 30/39 of events were venous (77%), 23/30 of which were splanchnic (77%). In 14/39 (36%), thrombosis preceded MPN diagnosis. In a multivariable analysis, only splenomegaly predicted for thrombosis (HR 5.6, CI: 1.4-22). The 10-year risk for secondary myelofibrosis was similar for ET and PV (0.13 vs 0.19, P = 0.51). The 10-year risk for leukemic transformation or mortality was significantly higher for PMF (0.3, P = 0.04).

CONCLUSIONS

The risks of mortality and of progression to MF/leukemia in young adults are similar to older population. Thrombotic events are frequently a presenting sign with a high incidence of venous, in particular splanchnic, events.

Human herpes virus 6 reactivation following autologous hematopoietic cell transplantation - a single-center experience

Data regarding presentation and management of human herpes virus 6 (HHV-6) reactivation among autologous hematopoietic cell transplantation (HCT) recipients are limited. We retrospectively reviewed medical charts of all autologous HCT patients tested for HHV-6 reactivation due to suspected clinical presentation between 1/2012 and 8/2017. Among 328 autologous HCT recipients, 44 patients were tested for HHV-6 reactivation. Thirty patients tested positive; 29 (97%) had sustained fever, six (20%) had rash and four (13%) had pneumonia. Median C-reactive protein was significantly lower in HHV-6 positive patients compared to negative patients (3.6 (range, 0.4-11) vs. 9.6 (range, 3.2-30) mg/dL, respectively, p = .004). Ganciclovir formulations were administrated in 29 (97%) patients with median time to fever resolution of one (range, 1-2) day. HHV-6 should be considered as an important cause of post engraftment fever in autologous HCT. Larger studies are warranted to evaluate incidence of HHV-6 reactivation and optimal treatment regimen.

Impaired lymphocyte reconstitution after autologous transplant is associated with apoptosis of CD8+ T cells and adverse clinical outcome

We noticed that the lymphocyte counts, after autologous hematopoietic stem cell transplantation, oscillated during the first 4 post-transplant months. Thereafter, the lymphocyte counts stabilized and segregated the patients into two groups, those who normalized their lymphocyte counts and those with prolonged lymphopenia. In both groups, the CD4 counts remained low for at least 6 months. However, in approximately half of the patient, the CD8 counts increased to normal or above normal values. Patients with prolonged lymphopenia had higher rates of lymphocytes' spontaneous apoptosis and the lymphocytes in patients who restored their counts expressed the intracellular CD14-derived MO2 epitope that protects the cells from apoptosis. These findings were translated to longer disease-free survival and overall survival in patients who restored the CD8 counts. Collectively, our data show that post-transplant lymphocytes that express intracellular CD14-MO2 epitope have survival advantage.

MYC protein expression is an important prognostic factor in acute myeloid leukemia

As new drugs targeting MYC show clinical activity in acute myeloid leukemia (AML), understanding MYC expression in AML is of critical importance. We assessed MYC protein expression by immunohistochemistry in bone marrow of patients with untreated AML (n = 265). Overall, 90% of patients demonstrated MYC overexpression and MYC immunopositivity ≤6% was associated with superior complete remission (CR) duration of 23 months versus 12 months for MYC immunopositivity >6% (p = .028). Among 241 patients at higher risk for relapse, including those ≥55 years of age and patients with intermediate- and high-risk AML, MYC immunopositivity ≤6% conferred significantly superior median overall survival (OS) (24 versus 13 months; p = .042), event-free survival (EFS) (14 versus 6 months; p = .048), and relapse-free survival (RFS) (25 versus 12 months; p = .024). The prognostic impact of MYC-immunopositivity was retained on multivariate analysis of OS, EFS, and RFS. We conclude that MYC immunopositivity is an important prognostic factor in patients with untreated AML, particularly those at higher risk for relapse.

Immune Mediated Cerebellar Ataxia: An Unknown Manifestation of Graft-versus-Host Disease

Neurologic complications of allogeneic hematopoietic cell transplantation (allo-HCT) include infections, cerebrovascular events, therapy-induced neurotoxicity, recurrent malignancies, and neurologic manifestations of graft-versus-host disease (GVHD). Anti-glutamic acid decarboxylase (GAD) antibody-associated cerebellar ataxia is a well-established disorder of autoimmune origin, but there are no reports in the literature of its occurrence following allo-HCT. We describe a middle-aged woman with chronic GVHD after allo-HCT who presented with a rapidly progressive cerebellar syndrome. Thorough investigation revealed only cerebellar atrophy on brain imaging and positive anti-GAD65 antibodies in serum and cerebrospinal fluid suggesting the diagnosis of anti-GAD antibody-associated cerebellar ataxia. Despite prompt treatment with high-dose corticosteroids, intravenous immunoglobulins, and rituximab, the patient's condition rapidly deteriorated, and she died 4 months later. This case suggests that anti-GAD antibody-associated cerebellar ataxia may be a rare manifestation of chronic GVHD.

STAT3 is constitutively acetylated on lysine 685 residues in chronic lymphocytic leukemia cells

Signal transducer and activator of transcription (STAT)-3 might be phosphorylated or acetylated. Unlike the phosphorylation of STAT3, little is known about the acetylation of STAT3 in chronic lymphocytic leukemia (CLL) cells. Because acetylation activates STAT3 transcription, we sought to study the acetylation status of STAT3 in CLL cells. Using Western immunoblotting, immunoprecipitation, and flow cytometry we found that, apart from its constitutive serine phosphorylation, STAT3 is constitutively acetylated on lysine 685 residues. Because the acetyltransferase p300 was found to acetylate STAT3 on lysine 685 residues, we wondered whether p300 acetylates STAT3 in CLL cells. Using Western immunoblotting we detected high levels of p300 protein in CLL but not normal B cells. Transfection of CLL cells with p300 small-interfering (si) RNA downregulated p300 transcripts as well as p300 and acetyl-STAT3 protein levels. In addition, p300 siRNA attenuated STAT3-DNA binding and downregulated mRNA levels of STAT3-regulated genes. Furthermore, transfection of CLL cells with p300-siRNA induced a 3-fold increase in the rate of spontaneous apoptosis. Taken together, our data suggest that in CLL cells STAT3 p300 induces constitutive acetylation and activation of STAT3. Whether inhibition of STAT3 acetylation might provide clinical benefit in patients with CLL remains to be determined.

Why Is the Immunoglobulin Heavy Chain Gene Mutation Status a Prognostic Indicator in Chronic Lymphocytic Leukemia?

The immunoglobulin heavy chain gene (IgHV) mutation status correlates with the clinical outcome of patients with chronic lymphocytic leukemia (CLL) treated with chemoimmunotherapy. Why the survival rate of patients with unmutated IgHV is worse than that of patients with mutated IgHV is unknown. CLL cells with unmutated IgHV were thought to originate from naïve B lymphocytes, whereas CLL cells with mutated IgHV were thought to arise from B cells that have undergone somatic hypermutation (SHM). Cell surface protein expression profile and gene expression studies showing that all CLL cells, regardless of their IgHV mutation status, are of postgerminal center origin, negated this hypothesis. We hereby propose that all CLL cells undergo SHM and their proliferation rate determines their IgHV mutation status. DNA breaks, accumulated during SHM, are restored by various DNA repair mechanisms. In rapidly dividing cells DNA breaks are repaired by the efficient high-fidelity homology-directed DNA repair apparatus, whereas in slowly dividing cells they are repaired by the inefficient low-fidelity nonhomology end-joining repair mechanism. Accordingly, a low IgHV mutation rate is found in rapidly dividing cells whereas a high mutation rate is typically found in slowly dividing cells. Thus, the proliferation rate of CLL cells determines the IgHV mutation status and patients' clinical outcome.

STAT3-activated CD36 facilitates fatty acid uptake in chronic lymphocytic leukemia cells

Although several studies established that unlike normal B cells chronic lymphocytic leukemia (CLL) cells metabolize fatty acids (FA), how CLL cells internalize FA is poorly understood. Because in various cell types CD36 facilitates FA uptake, we wondered whether a similar mechanism is operative CLL. We found that CD36 levels are higher in CLL cells than in normal B cells, and that small interfering RNA, CD36 neutralizing antibodies or sulfosuccinimidyl oleate (SSO) that inhibits CD36 significantly reduced the oxygen consumption of CLL cells incubated with FA. Because CD36 is oeverexpressed and STAT3 is constitutively activated in CLL cells, we wondered whether STAT3 induces CD36 expression. Sequence analysis identified putative STAT3 binding sites in the CD36 gene promoter. Chromatin immunoprecipitation and an electrophoretic mobility shift assay revealed that STAT3 binds to the CD36 gene promoter. A luciferase assay and STAT3-small hairpin RNA, that significantly decreased the levels of CD36 in CLL cells, established that STAT3 activates the transcription of the CD36 gene. Furthermore, SSO induced a dose-dependent apoptosis of CLL cells. Taken together, our data suggest that STAT3 activates CD36 and that CD36 facilitates FA uptake in CLL cells. Whether CD36 inhibition would provide clinical benefits in CLL remains to be determined.

Percentage of mesenchymal stem cells in high-grade glioma tumor samples correlates with patient survival

Background

Human mesenchymal stem cells (hMSCs) have been shown to reside as stromal cells in human gliomas as glioma-associated hMSCs (GA-hMSCs), but their biological role remains unclear. Because recent evidence indicates that GA-hMSCs drive tumor cell proliferation and stemness, we hypothesized that a higher percentage of GA-hMSCs in tumors predicts poor patient prognosis.

Method

We determined the percentage of cells coexpressing GA-hMSC markers CD105+/CD73+/CD90+ from patients with newly diagnosed high-grade glioma and analyzed the association between this percentage and overall survival (OS) in 3 independent cohorts: fresh surgical glioblastoma specimens (cohort 1, N = 9), cultured tumor specimens at passage 3 (cohort 2, N = 28), and The Cancer Genome Atlas (TCGA) database.

Results

In all cohorts, patient OS correlated with the percentages of GA-hMSCs in tumors. For cohort 1, the median OS of patients with tumors with a low percentage of triple-positive cells was 46 months, and for tumors with a high percentage of triple-positive cells, it was 12 months (hazard ratio [HR] = 0.24; 95% CI: 0.02-0.5, P = .02). For cohort 2, the median OS of patients with tumors with a low percentage of GA-hMSCs was 66 months, and for tumors with a high percentage, it was 11 months (HR = 0.38; 95% CI: 0.13-0.9, P = .04). In the database of TCGA, the median OS times in patients with high and low coexpression levels of CD105/CD73/CD90 were 8.4 months and 13.1 months (HR = 0.4; 95% CI: 0.1-0.88; P = .04), respectively.

Conclusions

The percentage of GA-MSCs inversely correlates with OS, suggesting a role for GA-MSCs in promoting aggressive behavior of gliomas.

Ibrutinib inhibits free fatty acid metabolism in chronic lymphocytic leukemia

Unlike normal B-cells, and similar to fat cells, chronic lymphocytic leukemia (CLL) cells aberrantly express lipoprotein lipase (LPL), which contributes to free fatty acids (FFAs) metabolism. Here we show that, in CLL cells, the B-cell receptor (BCR) inhibitor ibrutinib reduced LPL mRNA and protein levels and inhibited FFA metabolism in vitro. Likewise, in CLL cells from ibrutinib-treated patients, FFA metabolism was reduced and eventually stopped. Because ibrutinib disrupts CLL cells' ability to use FFAs for energy production, and because various BCR-dependent cellular functions rely on a continuous supply of chemical energy, ibrutinib interrupts several pathways imperative for cellular function in CLL cells.

Antibacterial prophylaxis with ciprofloxacin for patients with multiple myeloma and lymphoma undergoing autologous haematopoietic cell transplantation: a quasi-experimental single-centre before-after study

OBJECTIVES

We aimed to study whether ciprofloxacin prophylaxis reduces infectious complications in patients undergoing autologous haematopoietic cell transplantation (AHCT).

METHODS

This is a quasi-experimental, retrospective, before-after study. We compared the incidence of bacterial-related complications among 356 patients with multiple myeloma (MM) (n = 202) and lymphoma (n = 154) who underwent AHCT with (n = 177) or without (n = 179) ciprofloxacin prophylaxis between 03/2007 and 10/2012 and between 10/2012 and 07/2016, respectively, at a single centre.

RESULTS

Febrile neutropaenia, bacteraemia, and pneumonia were significantly more common among patients who underwent AHCT during the second study period and did not receive antibacterial prophylaxis compared with patients who underwent AHCT during the first study period and received antibacterial prophylaxis (89.9% (161/179) vs. 83.1% (147/177), difference 6.9%, 95% CI 0-14.1%, P = 0.002; 15.1% (27/179) vs. 4.5% (8/177), difference 10.6%, 95% CI 4.4-16.9%, p < 0.0001; 12.3% (22/179) vs. 6.2% (11/177), difference 6.1%, 95% CI 0-12.3%, p = 0.04, respectively). The number-needed-to-treat to prevent one episode of bacteraemia, pneumonia, and febrile neutropaenia was 8.6, 8.5, and 13.7, respectively. Patients with ciprofloxacin prophylaxis had higher rates of ciprofloxacin-resistant bacteraemia (62.5% (5/8) vs. 18.5% (5/27), difference 44%, 95% CI 7-70%, p = 0.01). In multivariate analysis, ciprofloxacin prophylaxis significantly decreased the odds of bacteraemia (OR 0.19, 95% CI 0.07-0.52; p < 0.0001) and pneumonia (OR 0.37, 95% CI 0.16-0.85, p = 0.02).

CONCLUSION

According to our single-centre experience, patients with MM and lymphoma undergoing AHCT may benefit from antibacterial prophylaxis with ciprofloxacin.

The absolute percent deviation of IGHV mutation rather than a 98% cut-off predicts survival of chronic lymphocytic leukaemia patients treated with fludarabine, cyclophosphamide and rituximab

The degree of somatic hypermutation, determined as percent deviation of immunoglobulin heavy chain gene variable region sequence from the germline (IGHV%), is an important prognostic factor in chronic lymphocytic leukaemia (CLL). Currently, a cut-off of 2% deviation or 98% sequence identity to germline in IGHV sequence is routinely used to dichotomize CLL patients into mutated and unmutated groups. Because dissimilar IGHV% cut-offs of 1-5% were identified in different studies, we wondered whether no cut-off should be applied and IGHV% treated as a continuous variable. We analysed the significance of IGHV% in 203 CLL patients enrolled on the original frontline fludarabine, cyclophosphamide and rituximab (FCR) trial with a median of 10 years follow-up. Using the Cox Proportional Hazard model, IGHV% was identified as a continuous variable that is significantly associated with progression-free (PFS) and overall survival (OS) (P < 0·001). Furthermore, we validated this finding in 323 patients treated with FCR off-protocol and in the total cohort (n = 535). Multivariate analysis revealed a continuous trend. Higher IGHV% levels were incrementally associated with favorable PFS and OS in both FCR-treated cohorts (P < 0·001, both cohorts). Taken together, our data suggest that IGHV% is a continuous variable in CLL patients treated with FCR.

Replacing carmustine by thiotepa and cyclophosphamide for autologous stem cell transplantation in Hodgkin's and non-Hodgkin's B-cell lymphoma

This study aimed to compare the real-life results of TECAM, a thiotepa-based conditioning regimen consisting of thiotepa (40 mg/m² days -5 to -2), etoposide (200 mg/m² days -6 to -3), cytarabine (200 mg/m² days -4 to -1), cyclophosphamide (60 mg/kg day -3), and melphalan (60 mg/m² days -2 to -1) with that of the conventional carmustine-based regimen BEAM. We reviewed 125 consecutive patients who underwent a first autologous transplantation (ASCT) for B-cell lymphomas at a large tertiary transplantation center between 1999 and 2014. TECAM (n=65) and BEAM (n=60) had comparable results (3yPFS 49 vs 62%, P=0.16; 3yOS 64 vs 71%, P=0.44; TRM 1.6 vs 5%, P=0.35) without a difference in toxicity or time to engraftment. Notably, comparable outcomes were observed even though patients treated with TECAM were older (55 vs 44) and had a trend towards more prior lines of therapy (>2 prior lines: 43 vs 27%, P=0.08). In this regard, 23% of TECAM patients were over the age of 65 yet could withstand therapy with similar results to younger patients. We conclude that, replacing carmustine by thiotepa and cyclophosphamide for ASCT conditioning, has comparable efficacy and safety profiles with a possible advantage in older patients.

Activation of the B-cell receptor successively activates NF-κB and STAT3 in chronic lymphocytic leukemia cells

In chronic lymphocytic leukemia (CLL) cells, both interleukin-6 (IL-6) and the B-cell receptor (BCR) activate Janus kinase 2 (JAK2) and induce the phosphorylation of signal transduction and activator of transcription 3 (STAT3) on tyrosine 705 residues. However, whereas IL-6 phosphorylates STAT3 within 15 min, stimulation of the BCR with anti-immunoglobulin M (IgM) antibodies phosphorylates STAT3 in 2-4 hr. Here, we show that this process takes longer because it requires transcriptional activity of NF-κB. Using an electromobility shift assay, we found that incubation with IgM antibodies for 4 or 18 hr, but not 15 min, increased NF-κB DNA-binding of CLL cells and increased binding was translated to increased transcriptional activity. Hence, 42% of the 83 NF-κB target genes were constitutively expressed in all CLL cells prior to any inducible stimuli. However, activation of the BCR increased the number of NF-κB target genes with detectable expression by 23%. Remarkably, prolonged incubation with anti-IgM antibodies induced a time-dependent transcription, production and secretion of IL-6 protein. The IgM-induced production of IL-6 prompted the phosphorylation of STAT3 on tyrosine residues. This effect was inhibited by the JAK1/2 inhibitor of the JAK/STAT3 pathway ruxolitinib. Taken together, these results suggest that in CLL cells, constitutive tonic activation of NF-κB can be further enhanced by the BCR and that the BCR-induced activation of the JAK/STAT3 pathway depends on the NF-κB induced production of IL-6.

The Effect of Combined Aspirin and Clopidogrel Treatment on Cancer Incidence

BACKGROUND

Multiple studies have shown an association between aspirin treatment and a reduction in newly diagnosed cancer. Conversely, there are conflicting clinical and laboratory data on the effect of combined clopidogrel and aspirin therapy on cancer incidence, including analyses suggesting an increased cancer risk. No large-scale cohort study has been performed to address this issue in a heterogeneous real-world scenario. We investigated the effect of clopidogrel and aspirin on cancer incidence compared with aspirin alone and no antiplatelet therapy.

METHODS

A population-based historical cohort study of subjects aged ≥50 years covered by Clalit Health Services, an Israeli health maintenance organization, was performed. Patients treated with the newer antiplatelet drugs, prasugrel or ticagrelor, which, like clopidogrel, inhibit adenosine diphosphate receptors, and those with prior cancer were excluded. Prescription records of antiplatelet medication were retrieved.

RESULTS

The cohort included 183,912 subjects diagnosed with 21,974 cancer cases based upon the International Classification of Diseases, Ninth Revision. Dual aspirin and clopidogrel was prescribed in 9.6%, while 49% received aspirin alone and 41% used neither. Compared with nonusers, there was a lower risk of cancer in subjects exposed to aspirin with (hazard ratio [HR] 0.46; 95% confidence interval [CI], 0.44-0.49) or without clopidogrel (HR 0.54; 95% CI, 0.52-0.56), on long-term follow-up. Combined treatment was associated with a lower cancer risk than the aspirin-only group (HR 0.92; 95% CI, 0.86-0.97).

CONCLUSIONS

Dual clopidogrel and aspirin treatment is safe regarding the cancer risk. This study generates the hypothesis that clopidogrel may reduce cancer incidence.

Ranolazine for Congenital Long-QT Syndrome Type III: Experimental and Long-Term Clinical Data

BACKGROUND

The basic defect in long-QT syndrome type III (LQT3) is an excessive inflow of sodium current during phase 3 of the action potential caused by mutations in the SCN5A gene. Most sodium channel blockers reduce the early (peak) and late components of the sodium current (I_Na and I_NaL), but ranolazine preferentially reduces I_NaL. We, therefore, evaluated the effects of ranolazine in LQT3 caused by the D1790G mutation in SCN5A.

METHODS AND RESULTS

We performed an experimental study of ranolazine in TSA201 cells expressing the D1790G mutation. We then performed a long-term clinical evaluation of ranolazine in LQT3 patients carrying the D1790G mutation. In the experimental study, I_NaL was significantly higher in D1790G than in wild-type channels expressed in the TSA201 cells. Ranolazine exerted a concentration-dependent block of I_NaL of the SCN5A-D1790G channel without reducing peak I_Na significantly. In the clinical study, among 8 patients with LQT3 and confirmed D1790G mutation, ranolazine had no effects on the sinus rate or QRS width but shortened the QTc from 509±41 to 451±26 ms, a mean decrease of 56±52 ms (10.6%; P=0.012). The QT-shortening effect of ranolazine remained effective throughout the entire study period of 22.8±12.8 months. Ranolazine reduced the QTc at all heart rates but less so during extreme nocturnal bradycardia. A type I Brugada ECG was never noticed.

CONCLUSIONS

Ranolazine blocks I_NaL in experimental models of LQT3 harboring the SCN5A-D1790G mutation and shortened the QT interval of LQT3 patients.

CLINICAL TRIAL REGISTRATION

URL: https://clinicaltrials.gov; Unique identifier: NCT01728025.