Rituximab, cyclophosphamide, doxorubicin, vincristine, and prednisolone combined with high-dose methotrexate plus intrathecal chemotherapy for newly diagnosed intravascular large B-cell lymphoma (PRIMEUR-IVL): a multicentre, single-arm, phase 2 trial.

BACKGROUND: Intravascular large B-cell lymphoma (IVLBCL) is a rare disease for which there is no available standard treatment. We aimed to ascertain the safety and activity of R-CHOP (rituximab, cyclophosphamide, doxorubicin, vincristine, and prednisolone) with high-dose methotrexate and intrathecal chemotherapy as CNS-oriented therapy for patients with previously untreated IVLBCL. METHODS: PRIMEUR-IVL is a multicentre, single-arm, phase 2 trial at 22 hospitals in Japan. Eligible patients had untreated histologically confirmed IVLBCL, were aged 20-79 years, had an Eastern Cooperative Group performance status of 0-3, and had no apparent CNS involvement at diagnosis. Patients received three cycles of R-CHOP (rituximab 375 mg/m2 intravenously on day 1 [except cycle one, which was on day 8]; cyclophosphamide 750 mg/m2, doxorubicin 50 mg/m2, and vincristine 1·4 mg/m2 [maximum 2·0 mg] intravenously on day 1 of cycle one and day 2 of cycles two and three; and prednisolone 100 mg/day orally on days 1-5 of cycle one and days 2-6 of cycles two and three) followed by two cycles of rituximab with high-dose methotrexate (3·5 g/m2 intravenously on day 2 of cycles four and five) every 2 weeks and three additional cycles of R-CHOP. Intrathecal chemotherapy (methotrexate 15 mg, cytarabine 40 mg, and prednisolone 10 mg) was administered four times during the R-CHOP phase. The primary endpoint was 2-year progression-free survival. Efficacy analyses were done in all enrolled patients; safety analyses were done in all enrolled and treated patients. The trial is registered in the UMIN Clinical Trials Registry (UMIN000005707) and the Japan Registry of Clinical Trials (jRCTs041180165); the trial is ongoing for long-term follow-up. FINDINGS: Between June 16, 2011, and July 21, 2016, 38 patients were enrolled, of whom 37 were eligible; one patient was excluded because of a history of testicular lymphoma. Median follow-up was 3·9 years (IQR 2·5-5·5). 2-year progression-free survival was 76% (95% CI 58-87). The most frequent adverse events of grade 3-4 were neutropenia and leucocytopenia, which were reported in all 38 (100%) patients. Serious adverse events were hypokalaemia, febrile neutropenia with hypotension, hypertension, and intracerebral haemorrhage (reported in one [3%] patient each). No treatment-related deaths occurred during protocol treatment. INTERPRETATION: R-CHOP combined with rituximab and high-dose methotrexate plus intrathecal chemotherapy is a safe and active treatment for patients with IVLBCL without apparent CNS involvement at diagnosis, and this regimen warrants future investigation. FUNDING: The Japan Agency for Medical Research and Development, the Center for Supporting Hematology-Oncology Trials, and the National Cancer Center.

Ultra-high sensitivity HBsAg assay can diagnose HBV reactivation following rituximab-based therapy in patients with lymphoma.

BACKGROUND & AIMS: HBV reactivation is a risk in patients receiving anti-CD20 antibodies for the treatment of lymphoma. The purpose of this post hoc analysis was to evaluate the efficacy of an ultra-high sensitivity HBsAg assay to guide preemptive antiviral treatment in patients with lymphoma and resolved HBV infections using prospectively stored samples from an HBV DNA monitoring study. METHODS: HBV reactivation (defined as HBV DNA levels of ≥11 IU/ml) was confirmed in 22 of 252 patients. A conventional HBsAg assay (ARCHITECT, cut-off value: 0.05 IU/ml) and an ultra-high sensitivity HBsAg assay employing a semi-automated immune complex transfer chemiluminescence enzyme technique (ICT-CLEIA, cut-off value: 0.0005 IU/ml) were performed at baseline, at confirmed HBV reactivation and monitored after HBV reactivation. RESULTS: Baseline HBsAg was detected using ICT-CLEIA in 4 patients; in all of whom precore mutants with high replication capacity were reactivated. Of the 6 patients with HBV DNA detected below the level of quantification at baseline, 5 showed HBV reactivation and 3 of the 5 had precore mutations. Sensitivity for detection by ARCHITECT and ICT-CLEIA HBsAg assays at HBV reactivation or the next sampling after HBV reactivation was 18.2% (4 of 22) and 77.3% (17 of 22), respectively. Of the 5 patients undetectable by ICT-CLEIA, HBV reactivation resolved spontaneously in 2 patients. All 6 patients reactivated with precore mutations including preS deletion could be diagnosed by ICT-CLEIA HBsAg assay at an early stage of HBV reactivation. Multivariate analysis showed that an anti-HBs titer of less than 10 mIU/ml, HBV DNA detected but below the level of quantification, and HBsAg detected by ICT-CLEIA at baseline were independent risk factors for HBV reactivation (adjusted hazard ratios, 15.4, 31.2 and 8.7, respectively; p <0.05). CONCLUSIONS: A novel ICT-CLEIA HBsAg assay is an alternative method to diagnose HBV reactivation. CLINICAL TRIAL NUMBER: UMIN000001299. LAY SUMMARY: Hepatitis B virus can be reactivated in lymphoma patients receiving anti-CD20 antibodies such as rituximab. Currently, reactivation requires the monitoring of HBV DNA, but monitoring of the surface antigen (HBsAg) could provide a relatively inexpensive, quick and easy alternative. We assessed the performance of an ultra-high sensitivity HBsAg assay and showed that it could be effective for the diagnosis and monitoring of HBV reactivation.

Truncated RUNX1 Generated by the Fusion of RUNX1 to Antisense GRIK2 via a Cryptic Chromosome Translocation Enhances Sensitivity to Granulocyte Colony-Stimulating Factor.

Fusions of the Runt-related transcription factor 1 (RUNX1) with different partner genes have been associated with various hematological disorders. Interestingly, the C-terminally truncated form of RUNX1 and RUNX1 fusion proteins are similarly considered important contributors to leukemogenesis. Here, we describe a 59-year-old male patient who was initially diagnosed with acute myeloid leukemia, inv(16)(p13;q22)/CBFB-MYH11 (FAB classification M4Eo). He achieved complete remission and negative CBFB-MYH11 status with daunorubicin/cytarabine combination chemotherapy but relapsed 3 years later. Cytogenetic analysis of relapsed leukemia cells revealed CBFB-MYH11 negativity and complex chromosomal abnormalities without inv(16)(p13;q22). RNA-seq identified the glutamate receptor, ionotropic, kinase 2 (GRIK2) gene on 6q16 as a novel fusion partner for RUNX1 in this case. Specifically, the fusion of RUNX1 to the GRIK2 antisense strand (RUNX1-GRIK2as) generated multiple missplicing transcripts. Because extremely low levels of wild-type GRIK2 were detected in leukemia cells, RUNX1-GRIK2as was thought to drive the pathogenesis associated with the RUNX1-GRIK2 fusion. The truncated RUNX1 generated from RUNX1-GRIK2as induced the expression of the granulocyte colony-stimulating factor (G-CSF) receptor on 32D myeloid leukemia cells and enhanced proliferation in response to G-CSF. In summary, the RUNX1-GRIK2as fusion emphasizes the importance of aberrantly truncated RUNX1 in leukemogenesis.

DA-EPOCH-R combined with high-dose methotrexate in patients with newly diagnosed stage II-IV CD5-positive diffuse large B-cell lymphoma: a single-arm, open-label, phase II study.

CD5-positive diffuse large B-cell lymphoma (CD5+ DLBCL) is characterized by poor prognosis and a high frequency of central nervous system relapse after standard immunochemotherapy. We conducted a phase II study to investigate the efficacy and safety of dose-adjusted (DA)- EPOCH-R (etoposide, prednisone, vincristine, cyclophosphamide, doxorubicin, and rituximab) combined with high-dose methotrexate (HD-MTX) in newly diagnosed patients with CD5+ DLBCL. Previously untreated patients with stage II to IV CD5+ DLBCL according to the 2008 World Health Organization classification were eligible. Four cycles of DA-EPOCH-R followed by two cycles of HD-MTX and four additional cycles of DAEPOCH- R (DA-EPOCH-R/HD-MTX) were planned as the protocol treatment. The primary end point was 2-year progression-free survival (PFS). Between September 25, 2012, and November 11, 2015, we enrolled 47 evaluable patients. Forty-five (96%) patients completed the protocol treatment. There were no deviations or violations in the DA-EPOCH-R dose levels. The complete response rate was 91%, and the overall response rate was 94%. At a median follow up of 3.1 years (range, 2.0-4.9 years), the 2- year PFS was 79% [95% confidence interval (CI): 64-88]. The 2-year overall survival was 89% (95%CI: 76-95). Toxicity included grade 4 neutropenia in 46 (98%) patients, grade 4 thrombocytopenia 12 (26%) patients, and febrile neutropenia in 31 (66%) patients. No treatment-related death was noted during the study. DA-EPOCH-R/HD-MTX might be a first-line therapy option for stage II-IV CD5+ DLBCL and warrants further investigation. (Trial registered at: UMIN-CTR: UMIN000008507.).

Epstein-Barr virus (EBV)-positive diffuse large B-cell lymphoma arising in patient with a history of EBV-positive mucocutaneous ulcer and EBV-positive nodal polymorphous B-lymphoproliferative disorder.

Elderly patients with Epstein-Barr virus (EBV) infection are at increased risk for developing B-cell lymphoproliferative disorder (B-LPD) due to immunosenescence. Here, we describe a case of a 75-year-old man who developed an EBV-positive (EBV+) mucocutaneous ulcer (EBVMCU) in the gingiva with spontaneous regression. Eighteen months after regression, he had a cervical lymph node enlargement that was diagnosed as EBV+ nodal polymorphous B-LPD, Ann Arbor stage IA. Clinicians decided to observe his clinical course without any treatment. Fourteen months later, the patient developed EBV-positive diffuse large B-cell lymphoma (DLBCL), Ann Arbor stage IIA, and received six courses of age-adjusted dose chemotherapy and achieved a complete remission. No evidence of a clonal relationship was found among these three lesions by standard polymerase chain reaction (PCR) analysis for immunoglobulin heavy chain. However, they all had expression of PD-L1 in the EBV+ large B-cells and Hodgkin Reed-Sternberg-like cells. This is the first case report of a PD-L1-positive (PD-L1+) EBVMCU and the development of multiple EBV-driven B-LPDs in the setting of immunosenescence within a 32-month period.

Reappraisal of Epstein-Barr virus (EBV) in diffuse large B-cell lymphoma (DLBCL): comparative analysis between EBV-positive and EBV-negative DLBCL with EBV-positive bystander cells.

AIMS: Epstein-Barr virus (EBV)-positive diffuse large B-cell lymphoma (DLBCL) not otherwise specified is defined as monoclonal EBV+ B-cell proliferation affecting patients without any known immunosuppression. Non-neoplastic EBV+ cells proliferating in or adjacent to EBV- DLBCL were reported recently, but their clinical significance is unclear. Thus, the aim of this study was to investigate the prognostic impact of EBV+ cells in DLBCL. METHODS AND RESULTS: We compared the clinicopathological characteristics of 30 EBV+ DLBCL patients and 29 and 604 EBV- DLBCL patients with and without EBV+ bystander cells (median age of onset 71, 67 and 62 years, respectively). Both EBV+ DLBCL patients and EBV- DLBCL patients with EBV+ bystander cells tended to have high and high-intermediate International Prognostic Index scores (60% and 59%, respectively), as compared with only 46% of EBV- DLBCL patients without EBV+ bystander cells. EBV- DLBCL patients with EBV+ bystander cells showed a significantly higher incidence of lung involvement than those without EBV+ bystander cells (10% versus 2%, P < 0.05). Furthermore, EBV+ DLBCL patients and EBV- DLBCL patients with EBV+ bystander cells had a poorer prognosis than patients without any detectable EBV+ cells [median overall survival (OS) of 100 months and 40 months versus not reached, P < 0.01]. Notably, EBV+ DLBCL patients and EBV- DLBCL patients with EBV+ bystander cells treated with rituximab showed overlapping survival curves (OS, P = 0.77; progression-free survival, P = 1.0). CONCLUSIONS: EBV- DLBCL with bystander EBV+ cells has similar clinical characteristics to EBV+ DLBCL. DLBCL with EBV+ bystander cells may be related to both age-related and microenvironment-related immunological deterioration.

The prognostic significance of EBV DNA load and EBER status in diagnostic specimens from diffuse large B-cell lymphoma patients.

Epstein-Barr virus (EBV)-encoded small RNA in situ hybridization (EBER-ISH) is a widely accepted method to evaluate EBV involvement in diffuse large B-cell lymphoma (DLBCL), although little is known regarding associations between EBV DNA load and the EBER status and whether EBV DNA load data provide additional clinical information. In this study, we quantified EBV DNA load in diagnostic specimens from DLBCL patients diagnosed at our hospital to evaluate clinical implications of EBV DNA load in diagnostic specimens as contrasted with EBER-ISH. Among 140 DLBCL patients without underlying immunodeficiency, 51 were evaluable for both EBER and EBV DNA load, 83 for EBER only and one for EBV DNA load only. The median EBV DNA load was 708 copies/µg. Although EBV DNA load was significantly higher for EBER-positive patients than for EBER-negative patients (p < 0.001), EBV DNA was detected in up to 72% of EBER-negative patients. Progression-free survival and overall survival were significantly worse for patients with EBV DNA load above 700 copies/µg than for those with EBV DNA load below 700 copies/µg (p = 0.009 and p = 0.003); they were also significantly worse for EBER-positive patients than for EBER-negative patients (p < 0.001 and p = 0.001). Even among EBER-negative patients, higher EBV DNA load conferred worse progression-free survival and overall survival (p = 0.041 and p = 0.013). These findings indicate that EBV DNA load in diagnostic specimens is not a simple surrogate for the EBER status and may be a potential biomarker associated with EBV involvement and prognosis in DLBCL. Copyright © 2015 John Wiley & Sons, Ltd.

ETV6-LPXN fusion transcript generated by t(11;12)(q12.1;p13) in a patient with relapsing acute myeloid leukemia with NUP98-HOXA9.

ETV6, which encodes an ETS family transcription factor, is frequently rearranged in human leukemias. We show here that a patient with acute myeloid leukemia with t(7;11)(p15;p15) gained, at the time of relapse, t(11;12)(q12.1;p13) with a split ETV6 FISH signal. Using 3'-RACE PCR analysis, we found that ETV6 was fused to LPXN at 11q12.1, which encodes leupaxin. ETV6-LPXN, an in-frame fusion between exon 4 of ETV6 and exon 2 of LPXN, did not transform the interleukin-3-dependent 32D myeloid cell line to cytokine independence; however, an enhanced proliferative response was observed when these cells were treated with G-CSF without inhibition of granulocytic differentiation. The 32D and human leukemia cell lines each transduced with ETV6-LPXN showed enhanced migration towards the chemokine CXCL12. We show here for the first time that LPXN is a fusion partner of ETV6 and present evidence indicating that ETV6-LPXN plays a crucial role in leukemia progression through enhancing the response to G-CSF and CXCL12.

Influence of R-CHOP Therapy on Immune System Restoration in Patients with B-Cell Lymphoma.

OBJECTIVE: To assess the immunosuppressive effect of R-CHOP in patients with B-cell lymphoma at 2 years. METHODS: Parameters of humoral and cell-mediated immunity were assessed in 89 patients with diffuse large B-cell lymphoma or follicular lymphoma before and after 6-8 cycles of R-CHOP-14 or R-CHOP-21 regimen. RESULTS: Data on pre- and posttreatment serum IgG (sIgG) levels were available for all 89 patients, while the corresponding data on serum CD20+, CD3+, CD4+, and CD8+ lymphocyte counts were available in only 43. Median sIgG levels significantly decreased from 1,221 mg/dl (baseline) to 733 mg/dl (after chemotherapy) (p < 0.001). Although CD20+ and CD4+ cell counts decreased (p < 0.001), no significant effect of chemotherapy on CD3+ and CD8+ cell counts was observed. CD20+ cell counts were restored to baseline levels at the 12-month follow-up. sIgG levels and CD4+ cell counts were not completely restored at 24 months, indicating a sustained immunosuppressive effect of R-CHOP in these patients. The incidence of infections over the 2-year period was 16.3-23.6%. CONCLUSION: The immunosuppressive effect of R-CHOP in newly diagnosed cases of B-cell lymphoma tends to persist for >2 years, although sIgG levels were restored more quickly than CD4+ cell counts.

Clinicopathologic analysis of TAFRO syndrome demonstrates a distinct subtype of HHV-8-negative multicentric Castleman disease.

Multicentric Castleman disease (MCD) describes a heterogeneous group of disorders involving systemic inflammation, characteristic lymph node histopathology, and multi-organ dysfunction because of pathologic hypercytokinemia. Whereas Human Herpes Virus-8 (HHV-8) drives the hypercytokinemia in a cohort of immunocompromised patients, the etiology of HHV-8-negative MCD is idiopathic (iMCD). Recently, a limited series of iMCD cases in Japan sharing a constellation of clinical features, including thrombocytopenia (T), anasarca (A), fever (F), reticulin fibrosis (R), and organomegaly (O) has been described as TAFRO syndrome. Herein, we report clinicopathological findings on 25 patients (14 males and 11 females; 23 Japanese-born and two US-born), the largest TAFRO syndrome case series, including the first report of cases from the USA. The median age of onset was 50 years old (range: 23-72). The frequency of each feature was as follows: thrombocytopenia (21/25), anasarca (24/25), fever (21/25), organomegaly (25/25), and reticulin fibrosis (13/16). These patients frequently demonstrated abdominal pain, elevated serum alkaline phosphatase levels, and acute kidney failure. Surprisingly, none of the cases demonstrated marked hypergammoglobulinemia, which is frequently reported in iMCD. Lymph node biopsies revealed atrophic germinal centers with enlarged nuclei of endothelial cells and proliferation of endothelial venules in interfollicular zone. 23 of 25 cases were treated initially with corticosteroids; 12 patients responded poorly and required further therapy. Three patients died during the observation period (median: 9 months) because of disease progression or infections. TAFRO syndrome is a unique subtype of iMCD that demonstrates characteristic clinicopathological findings. Further study to clarify prognosis, pathophysiology, and appropriate treatment is needed.

Efficacy and safety of febuxostat for prevention of tumor lysis syndrome in patients with malignant tumors receiving chemotherapy: a phase III, randomized, multi-center trial comparing febuxostat and allopurinol.

BACKGROUND: Control of serum uric acid (sUA) levels is very important during chemotherapy in patients with malignant tumors, as the risks of tumor lysis syndrome (TLS) and renal events are increased with increasing levels of sUA. We investigated the efficacy and safety of febuxostat, a potent non-purine xanthine oxidase inhibitor, compared with allopurinol for prevention of hyperuricemia in patients with malignant tumors, including solid tumors, receiving chemotherapy in Japan. METHODS: An allopurinol-controlled multicenter, open-label, randomized, parallel-group comparative study was carried out. Patients with malignant tumors receiving chemotherapy, who had an intermediate risk of TLS or a high risk of TLS and were not scheduled to be treated with rasburicase, were enrolled and then randomized to febuxostat (60 mg/day) or allopurinol (300 or 200 mg/day). All patients started to take the study drug 24 h before chemotherapy. The primary objective was to confirm the non-inferiority of febuxostat to allopurinol based on the area under the curve (AUC) of sUA for a 6-day treatment period. RESULTS: Forty-nine and 51 patients took febuxostat and allopurinol, respectively. sUA decreased over time after initiation of study treatment. The least squares mean difference of the AUC of sUA between the treatment groups was -33.61 mg h/dL, and the 95 % confidence interval was -70.67 to 3.45, demonstrating the non-inferiority of febuxostat to allopurinol. No differences were noted in safety outcomes between the treatment groups. CONCLUSION: Febuxostat demonstrated an efficacy and safety similar to allopurinol in patients with malignant tumors receiving chemotherapy. TRIAL REGISTRY: http://www.clinicaltrials.jp ; Identifier: JapicCTI-132398.

Monitoring of Hepatitis B Virus (HBV) DNA and Risk of HBV Reactivation in B-Cell Lymphoma: A Prospective Observational Study.

BACKGROUND: There is no standard management of reactivation of hepatitis B virus (HBV) infection in HBV-resolved patients without hepatitis B surface antigen (HBsAg), but with antibodies against hepatitis B core antigen and/or antibodies against HBsAg (anti-HBs). METHODS: We conducted a prospective observational study to evaluate the occurrence of HBV reactivation by serial monthly monitoring of HBV DNA and to establish preemptive therapy guided by this monitoring in B-cell non-Hodgkin lymphoma (B-NHL) treated with rituximab plus corticosteroid-containing chemotherapy (R-steroid-chemo). The primary endpoint was the incidence of HBV reactivation defined as quantifiable HBV DNA levels of ≥ 11 IU/mL. RESULTS: With a median HBV DNA follow-up of 562 days, HBV reactivation was observed in 21 of the 269 analyzed patients. The incidence of HBV reactivation at 1.5 years was 8.3% (95% confidence interval, 5.5-12.4). No hepatitis due to HBV reactivation was observed in patients who received antiviral treatment when HBV DNA levels were between 11 and 432 IU/mL. An anti-HBs titer of <10 mIU/mL and detectable HBV DNA remaining below the level of quantification at baseline were independent risk factors for HBV reactivation (hazard ratio, 20.6 and 56.2, respectively; P < .001). Even in 6 patients with a rapid increase of HBV due to mutations, the monthly HBV DNA monitoring was effective at preventing HBV-related hepatitis. CONCLUSIONS: Monthly monitoring of HBV DNA is useful for preventing HBV reactivation-related hepatitis among B-NHL patients with resolved HBV infection following R-steroid-chemo (UMIN000001299).

Prognostic significance of Epstein-Barr virus DNA detection in pretreatment serum in diffuse large B-cell lymphoma.

It is still a matter of debate whether detection of Epstein-Barr virus (EBV) DNA in pretreatment serum has clinical implications for diffuse large B-cell lymphoma. For this study, we measured EBV DNA load in pretreatment serum from 127 diffuse large B-cell lymphoma patients without any underlying immunodeficiency to evaluate its effects on clinical manifestations and prognosis. Anthracycline-based chemotherapy in combination with rituximab was given as initial therapy for 119 patients (94%). Epstein-Barr virus DNA was detected in 15 patients (12%), who were older (P = 0.005) and tended to be at a more advanced disease stage (P = 0.053). They showed significantly worse progression-free survival (PFS) and overall survival (OS) than other patients (P < 0.001 each). This effect remained significant (P = 0.004 and P = 0.027, respectively) after adjustment for age, lactate dehydrogenase, performance status, stage, and extranodal sites. The status of EBV-encoded small RNA in situ hybridization was known for 123 patients; 6 of 8 positive patients (75%) and 9 of 115 negative patients (8%) had detectable EBV DNA in pretreatment serum. While patients positive for EBV-encoded small RNA had significantly worse PFS and OS than negative patients (P = 0.001 and P = 0.029, respectively), EBV DNA detection in pretreatment serum was associated with poorer PFS and OS even for the 115 patients negative for EBV-encoded small RNA (P < 0.001 each). These findings suggest that EBV DNA detection in pretreatment serum may have an adverse prognostic impact for patients with diffuse large B-cell lymphoma.

Prognostic model for mantle cell lymphoma in the rituximab era: a nationwide study in Japan.

Mantle cell lymphoma (MCL) is essentially incurable with conventional chemotherapy. The MCL International Prognostic Index (MIPI) is a validated specific prognostic index, but was derived from patients with advanced-stage disease primarily in the pre-rituximab era. We analysed 501 MCL patients (median age, 67 years; range 22-90) treated with rituximab-containing chemotherapy, and evaluated the prognostic factors adjusted by the treatment. Five-year overall survival (OS) in the low, intermediate and high MIPI groups was 74%, 70% and 35%, respectively. Additional to MIPI risk factors, multivariate analysis revealed that low serum albumin and bone-marrow involvement were also significantly associated with a poor outcome. The revised-MIPI (R-MIPI) was constructed using six factors, namely age, performance status, white blood cell count, serum lactate dehydrogenase, bone-marrow involvement and serum albumin, which is divided into four prognostic groups. Five-year OS in low, low-intermediate (L-I), high-intermediate (H-I) and high R-MIPI groups was 92%, 75%, 61% and 19%, respectively. Hazard ratio for OS of L-I, H-I and high risk to low risk patients were 5·4, 8·3 and 33·0, respectively. R-MIPI, a new prognostic index with easy application to the general patient population, shows promise for identifying low- and high-risk MCL patients in the rituximab era.

NUP214-RAC1 and RAC1-COL12A1 Fusion in Complex Variant Translocations Involving Chromosomes 6, 7 and 9 in an Acute Myeloid Leukemia Case with DEK-NUP214.

DEK-NUP214 gene fusion in acute myeloid leukemia (AML) is associated with poor prognosis. It is most often a sole translocation and more rarely observed as complex chromosomal forms. We describe an AML case with complex karyotype abnormalities involving chromosome bands 6p23, 6q13, 7p22, and 9q34. RNA sequencing analysis revealed that exon 17 of NUP214 (9q34) was fused to exon 2 of RAC1 (7p22). We also detected that the 5'-end of intron 1 of RAC1 was fused with the antisense strand of intron 5 of COL12A1 (6q13). RT-PCR analysis confirmed the expression of DEK-NUP214, NUP214-RAC1, RAC1-COL12A1, NUP214, and RAC1. These results suggest that the 5'- and 3'-ends of NUP214 from the breakpoint in the same locus were fused to RAC1 and DEK, respectively, and the 5'-end of RAC1 was fused to COL12A1. The reading frame of NUP214 was not matched with RAC1; however, high expression of the RAC1 protein was detected by Western blotting. This study identifies the variant complex fusion genesNUP214-RAC1 and RAC1- COL12A1 in a case of AML.

Gene expression profiling of Epstein-Barr virus-positive diffuse large B-cell lymphoma of the elderly reveals alterations of characteristic oncogenetic pathways.

Epstein-Barr virus (EBV)-positive diffuse large B-cell lymphoma (DLBCL) of the elderly (EBV[+]DLBCL-E) is classified as a subtype of DLBCL. Until now, its molecular pathogenesis has remained unknown. To identify pathways characteristic of EBV(+)DLBCL-E, gene expression profiling of five EBV(+)DLBCL-E and seven EBV-negative DLBCL (EBV[-]DLBCL) cases was undertaken using human oligonucleotide microarray analysis. Gene set enrichment analysis and gene ontology analysis showed that gene sets of the Janus kinase-signal transducer and activator of transcription (JAK-STAT) and nuclear factor kappa B (NF-κB) pathways were enriched in EBV(+)DLBCL-E cases. To confirm the results of the expression profiles, in vitro analysis was performed. Expression profiling analysis showed that high activation of the JAK-STAT and NF-κB pathways was induced by EBV infection into DLBCL cell lines. Activation of the NF-κB pathway was confirmed in EBV-infected cell lines using an electrophoretic mobility shift assay. Western blot analysis revealed an increased protein expression level of phosphorylated signal transducer and activator of transcription 3 (STAT3) in an EBV-infected cell line. Protein expression of phosphorylated STAT3 was frequently observed in lymphoma cells of EBV(+)DLBCL-E clinical samples using immunohistochemistry (EBV[+]DLBCL-E: 80.0% [n = 20/25] versus EBV[-]DLBCL: 38.9% [n = 14/36]; P = 0.001). The results of the present study suggest that activation of the JAK-STAT and NF-κB pathways was characteristic of EBV(+)DLBCL-E, which may reflect the nature of EBV-positive tumor cells. Targeting these pathways as therapies might improve clinical outcomes of EBV(+)DLBCL-E.

A varicella outbreak in B-cell lymphoma patients receiving rituximab-containing chemotherapy.

Varicella, characterized by a vesicular rash, occurs primarily in young children. Although older individuals can also be affected or vaccinated, outbreaks among adults are rare. We investigated a small outbreak of varicella in B-cell lymphoma patients for elucidation of risk factor of the disease. We experienced four cases of varicella after an index herpes zoster case. All varicella cases were confirmed varicella zoster virus (VZV) infection by PCR. All varicella cases occurred in diffuse large B-cell lymphoma patients receiving rituximab-containing chemotherapy. On the other hand, only three of the 18 non-varicella patients in the same room were receiving rituximab-containing chemotherapy (P = 0.005). All varicella patients had detectable serum anti-varicella zoster virus IgG antibodies before chemotherapy. Even in the presence of neutralizing antibodies to the virus, lymphoma patients treated with rituximab-containing chemotherapy can possibly become re-infected with varicella. These findings suggest that zoster patients should be strictly isolated in hematology and oncology ward, and prophylactic acyclovir should be considered for such patients when exposed to zoster/varicella.