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Spontaneous remission (SR) of acute myeloid leukemia (AML) is a very rare phenomenon. AML characterized byFLT3internal tandem duplication (FLT3ITD) is typically associated with an aggressive clinical course with rapid progression, relapse, and short overall survival in the absence of transplantation. We report here the first case of SR ofFLT3ITD mutant AML in the literature. Our patient was an elderly woman with relapsedNPM1andFLT3ITD mutant AML whose disease underwent SR for a brief duration without precipitating cause. We review the potential immune mechanisms underlying SR in AML and discuss the implications for novel immunotherapeutic approaches forFLT3mutant AML.

NUT midline carcinomas (NMC) comprise a group of highly aggressive tumors that have been reported primarily in the head, neck, and mediastinum of younger individuals. These tumors overexpress the nuclear protein in testis (NUT), most commonly due to a chromosomal translocation that fuses the NUT gene on chromosome 15 with the BRD4 gene on chromosome 19. Although the earliest recognized cases were described in the thymus or mediastinum, an extensive survey for NMC among malignant thymic or other mediastinal neoplasms has not been reported. We examined NUT expression in 114 cases of poorly differentiated carcinomas or unclassified mediastinal malignancies using a clinically validated NUT-specific monoclonal antibody. Four of 114 (3.5%) cases showed nuclear NUT expression. A NUT translocation was confirmed by fluorescence in situ hybridization (FISH) in 3 of these cases. These tumors arose in two male and two female adults with a median age of 50 (range 28 to 68). Three of the tumors were originally diagnosed as undifferentiated epithelioid or round cell malignant neoplasms; one tumor contained focal squamous differentiation and was originally diagnosed as a poorly differentiated squamous carcinoma of probable thymic origin. We find that the incidence of NMC within the mediastinum, particularly amongst undifferentiated tumors, is similar to that reported at other anatomic sites. NMC should be considered in the differential diagnosis of any poorly-differentiated epithelioid mediastinal tumor, regardless of age.

The diagnosis of myelodysplastic syndrome (MDS) can be challenging, and may be facilitated by correlation with cytogenetic testing. Microarray analysis using comparative genomic hybridization and/or single-nucleotide polymorphism array can detect chromosomal abnormalities not seen by standard metaphase cytogenetics. We examined the ability of combined comparative genomic hybridization and single-nucleotide polymorphism analysis (hereafter referred to as 'combined array') to detect changes among 83 patients with unexplained cytopenias undergoing pathologic evaluation for MDS and compared results with 18 normal bone marrow controls. Thirty-seven patients (45%) were diagnosed with MDS, 12 patients (14%) were demonstrated to have 'indeterminate dyspoiesis' (insufficient for classification of MDS), 27 (33%) were essentially normal, and 7 patients (8%) had alternative pathologic diagnoses. Twenty-one MDS patients (57% of diagnoses) had effectively normal metaphase cytogenetics, but combined array showed that 5 of these (13% of MDS patients) harbored major cryptic chromosomal aberrations. Furthermore, nearly half of patients with 'indeterminate dyspoiesis' and 1 with normal morphology had clonal cytopenia(s) of undetermined significance by combined array analysis. Cryptic array findings among MDS patients and those with clonal cytopenias(s) included large-scale copy-neutral loss of heterozygosity (up to 118 Mb) and genomic deletion of loci implicated in MDS pathogenesis (eg, TET2 (4q22) and NUP98 (11p15)). By comparison, in MDS patients with abnormal metaphase cytogenetics, microarray mostly recapitulated findings seen by routine karyotype. Combined array analysis has considerable diagnostic yield in detecting cryptic chromosomal aberrations in MDS and in demonstrating aberrant clonal hematopoiesis in cytopenic patients with indeterminate morphologic dysplasia.

Down-regulation of miR-150 and up-regulation of its target FOXP1 is associated with transformation of follicular lymphoma.Down-regulation of miR-150 and up-regulation of its target FOXP1 is associated with transformation of follicular lymphoma.

Little is known about herpesvirus modulation of T cell activation in latently infected individuals or the implications of such for chronic immune disorders. Murine gammaherpesvirus 68 (MHV68) elicits persistent activation of CD8(+) T cells bearing a Vbeta4(+) T cell receptor (TCR) by a completely unknown mechanism. We show that a novel MHV68 protein encoded by the M1 gene is responsible for Vbeta4(+) CD8(+) T cell stimulation in a manner reminiscent of a viral superantigen. During infection, M1 expression induces a Vbeta4(+) effector T cell response that resists functional exhaustion and appears to suppress virus reactivation from peritoneal cells by means of long-term interferon-gamma (IFNgamma) production. Mice lacking an IFNgamma receptor (IFNgammaR(-/-)) fail to control MHV68 replication, and Vbeta4(+) and CD8(+) T cell activation by M1 instead contributes to severe inflammation and multiorgan fibrotic disease. Thus, M1 manipulates the host CD8(+) T cell response in a manner that facilitates latent infection in an immunocompetent setting, but promotes disease during a dysregulated immune response. Identification of a viral pathogenecity determinant with superantigen-like activity for CD8(+) T cells broadens the known repertoire of viral immunomodulatory molecules, and its function illustrates the delicate balance achieved between persistent viruses and the host immune response.

Summary A patient with relapsed and refractory chronic lymphocytic leukaemia with Richter transformation was treated with chimeric antigen receptor (CAR)-modified T cells targeted for CD19 but later relapsed with a clonally related plasmablastic lymphoma. The loss of most routine markers of pre-plasma cell or B lymphoid differentiation (including CD19) highlights the ability of such mature lymphomas to evade lineage-specific targeted immunotherapy by differentiating along pathways comparable to their normal cellular counterparts. Molecular genetic evaluation demonstrated multiple independent lines of CD19-negative disease that eventually evolved in this single patient. Such plasticity represents potential challenges for antigen-directed CAR-T cell therapy, while serving as a testament to the selective pressure exerted by these engineered T cells over time.

Sequence analysis of the murine gamma-herpesvirus 68 (γHV68) genome previously identified several open reading frames (ORFs) located at the left end of the viral genome that do not share homology with other known herpesvirus or cellular genes. Here, we show that one of these ORFs, M4, encodes a secreted glycoprotein that influences the establishment of splenic latency at early times post-infection. We generated a mutant virus containing a premature translation termination codon in the M4 ORF (M4.STOP), and demonstrated that this mutant virus replicates in vitro equivalent to wild type and marker rescue (M4.MR) viruses. M4.STOP was also capable of high-titer lytic replication in vivo, but at 16 days post-infection the establishment of latency in the spleen was significantly impaired. The defect in the establishment of splenic latency was apparent following either intranasal or intraperitoneal inoculation. In contrast, the M4.STOP mutant did not exhibit a defect in the establishment of latency in peritoneal cells. These results suggest that M4 mediates an extracellular host-pathogen interaction that impacts the establishment of latent infection in the spleen, but not the peritoneum.

Plasmodium knowlesi variant antigens are expressed at the surface of infected erythrocytes and are encoded by the Schizont Infected Cell Agglutination variant antigen ( SICAvar ) multigene family. The 3′ region of the SICAvar gene locus encoding the 205 kDa variant antigen expressed in the Pk1(B+)1+ parasites was found to be altered compared to the Pk1(A+) parental clone. Here we report that this alteration is the result of a DNA rearrangement and that the original and altered 205 SICAvar alleles appear to encode bona fide variant antigens. Importantly, 205A and 205B SICAvar RNA sequences are detectable in similar apparent quantities as determined by quantitative real-time reverse-transcription polymerase chain reaction (qRT-PCR) amplification experiments. However, expression of the 205 kDa SICA protein at the surface of the infected erythrocyte is not characteristic of the Pk1(A+) parasites and the 205 SICAvar transcript has not been detected in Pk1(A+) parasites by northern blot analysis. Furthermore, we report that many distinct SICAvar transcripts were detected in P. knowlesi Pk1(B+)1+ cDNA library hybridization screens. Of special interest, in light of these data, distinctive differences at the 3′ end of the 205A and 205B alleles are observed, which may be of functional importance. An analysis of the 3′ untranslated region (UTR) of SICAvar genes in more than 100 sequences revealed a surprising common sequence pattern characterized by blocks of imperfect, GT-rich, heptad repeated motifs (Block I), followed by A and T rich homopolymers (Block II) and in a large number of genes, GC-rich segments (Block III). We show that this region undergoes extensive recombination and that the preferential stability of the 205 SICAvar transcript in Pk1(B+)1+ parasites may be associated with the presence of its specific Block III sequences. We speculate that the conserved yet polymorphic SICAvar 3′UTR sequences, and comparable regions in P. falciparum var genes, function in the stage-specific and developmentally regulated post-transcriptional gene silencing (PTGS) of variant antigen transcripts.

MicroRNAs (miRNAs) are important post-transcriptional regulators of gene expression, and are frequently aberrantly expressed in cancer. We aimed to understand their role in the transformation of indolent follicular lymphoma (FL) into an aggressive diffuse large B cell lymphoma. This happens in ~3% of cases per year during the course of the disease, and is associated with median survival of only 2 years. The NGS revealed number of aberrations associated with transformed FL (tFL), including frequent high-level activity of MYC (amplifications, translocations, and mutations) or loss of DNA damage regulators (p53, CDKN2A/B). Firstly, we performed a miRNA profiling (TaqMan miRNA Arrays) in paired FL and tFL samples (N=8 pairs). This revealed a relatively small group of 5 miRNAs that are consistently differentially expressed in tFL (P1.5). Since the most frequently acquired aberration in tFL is the high-level activity of MYC we performed a correlation analysis of MYC levels and expression of these miRNAs in additional samples of FL, tFL, and CLL samples with/without MYC duplication (N=40 FL/tFL, N=39 CLL). This revealed that at least one of these miRNAs is significantly down-modulated (P Citation Format: Katerina Musilova, Gabriela Pavlasova, Vaclav Seda, Eva Vojackova, Katerina Cerna, Veronika Svobodova, Robert Pytlik, Vit Prochazka, Zuzana Prouzova, Sarka Pospisilova, Lenka Zlamalikova, Heidi Mocikova, Lenka Kruzova, Marie Jarosova, Andrew Evans, Clive Zent, Leos Kren, Marek Trneny, Jiri Mayer, Andrea Janikova, Marek Mraz. Differential expression of microRNAs in transformation of follicular lymphoma to diffuse large B cell lymphoma [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 1479. doi:10.1158/1538-7445.AM2017-1479

The diagnosis of intraductal carcinoma (IDC) of the prostate remains subjective because 3 sets of diagnostic criteria are in use. An internet survey was compiled from 38 photomicrographs showing duct proliferations: 14 signed out as high-grade prostatic intraepithelial neoplasia (HGPIN), 17 IDC, and 7 invasive cribriform/ductal carcinoma. Each image was assessed for the presence of 9 histologic criteria ascribed to IDC. Thirty-nine respondents were asked to rate images as (1) benign/reactive, (2) HGPIN, (3) borderline between HGPIN and IDC, (4) IDC, or (5) invasive cribriform/ductal carcinoma. Intraclass correlation coefficient was 0.68. There was 70% overall agreement with HGPIN, 43% with IDC, and 73% with invasive carcinoma (P

We and others have shown that deregulation of microRNAs (miRNAs) is associated with the biology of B cell malignancies, including regulation of B cell proliferation and survival (Musilova & Mraz, Leukemia, 2015). We focused on studying miRNAs that associate with the aggressiveness of FL and its transformation to diffuse large B cell lymphoma (DLBCL). First, we analyzed the expression of 380 miRNAs (TaqMan Arrays, ABI) in 8 paired primary samples of FL that subsequently transformed to DLBCL. We identified statistically significant changes (P1.8) in the expression of 5 miRNAs. The most significant change was the down-regulation of miR-150 (~5 fold, P=0.01). Similarly, we observed significantly reduced miR-150 levels in an independent cohort of non-paired samples of FL before vs. after transformation to DLBCL, and miR-150 was significantly less expressed in de novo DLBCL in comparison with FL. MicroRNA miR-150 is of particular interest as we have shown that its expression determines BCR signaling propensity in chronic lymphocytic leukemia (CLL) B cells, and low levels associated with worse survival (Mraz et al., Blood, 2014). Therefore, we analyzed miR-150 expression in a cohort of 89 FL samples. We noticed that miR-150 expression was lower in samples from patients with a FLIPI score ≥3 (P=0.03), and with high Ki67 positivity (>20%; P=0.003). Moreover, FL patients with low miR-150 levels ( To determine the potential reason for variable miR-150 levels in FL B cells, we tested the effect of microenvironmental interactions on its expression. In this experiment, a short term (48hrs) co-culture of B cell lymphoma cells with stromal cells (HS-5) led to down-regulation of miR-150 levels (P CONCLUSION: Low miR-150 levels associate with a shorter overall survival in FL. This could be used as a reasonable prognostic marker since high miRNA stability allows reliable analyses of miR-150 levels from formalin-fixed, paraffin-embedded (FFPE) samples. Interactions with stromal cells and/or soluble microenvironmental factors down-modulate miR-150 levels in B cells, which support their BCR signalling potential. We are further investigating to what extent the miR-150 down-regulation is causally connected with the aggressiveness and/or transformation of FL. This work was supported by: the Ministry of Education, Youth and Sports of the Czech Republic under the project CEITEC 2020 (LQ1601); the European Union's Horizon 2020 research and innovation programme under grant agreement No. 692298; the research grant GACR (16-13334Y); the Ministry of Health of the Czech Republic, grant nr. 16-29622A. All rights reserved. This work was financed from the SoMoPro II Programme (project No. 4SGA8684), co-financed by European Union and the South-Moravian Region. This publication reflects only the author's views and the Union is not liable for any use that may be made of the information contained therein; Masaryk university as part of the project "New approaches in research, diagnostics and therapy of hematological malignancies III", number MUNI/A/1028/2015 with the support of the Specific University Research Grant, as provided by the Ministry of Education, Youth and Sports of the Czech Republic in the year 2016; the Ministry of Health of the Czech Republic - conceptual development of research organization (FNBr, 65269705, Sup 3/16); the Ministry of Education, Youth and Sports of the Czech Republic, grant nr. LD15144 (COST CZ); the research grant TACR (TEO2000058/2014-2019); and EHA Research Fellowship award granted by the European Hematology Association. G.P. is a city of Ostrava scholarship holder. Disclosures No relevant conflicts of interest to declare.

Introduction: Most patients (pts) with diffuse large B cell lymphomas (DLBCL) are cured with first line chemoimmunotherapy including an anthracycline and rituximab. Pts who obtain complete remission (CR) but latter relapse often can be cured with salvage therapy and autologous hematopoietic cell transplantation (auto-HCT). This management paradigm often is applied to pts with primary treatment failure (PTF). However, this group is heterogeneous and detailed data on outcomes in current era is needed to identify the DLBCL pts for whom novel therapeutic strategies should be designed. Methods: Fifteen US academic medical centers contributed pts to the REgistry of diFfuse large B cell lymphoma with prImary treatmeNt failurE (REFINE) collaboration. REFINE retrospectively captured patient, disease and treatment characteristics and treatment response as assessed by treating physician. Eligible pts were ≥ 18 years diagnosed with DLBCL during 2008-2015, who received upfront cheomoimmunotherapy including anthracycline and CD20-directed antibody and developed one of 3 patterns of PTF: relapse < 6 months following CR (early relapse- ER); only partial remission (PR) or stable disease (SD) with upfront therapy (residual disease-RD); progressive disease (PD) while receiving upfront therapy (primary progression-PP). Pts with HIV infection, primary CNS lymphoma or lymphoma transforming from a more indolent histology were excluded. Results: Patient characteristics for the 331 cases are summarized in Table 1. Median follow up of survivors was 18.9 months. R-CHOP was the upfront treatment for 87.6% of pts. Nearly all pts (94.6%) received salvage therapy after PTF and prior to any HCT, with a median of 1 and range 0 to 5 regimens. Response to first salvage regimen was CR in 19.9%, PR in 21.8%, SD in 9.0% and PD in 40.8%. Only 15.1% of pts were enrolled in clinical trials. One hundred and thirty-two pts (39.9%) underwent auto-HCT and 33 (10.0%) allogeneic-HCT (8 after failure of auto-HCT). Two-year overall survival (OS) from time of PTF was 45.5% (95% C.I. 34.5-56.5%) for ER, 30.6% (95% C.I. 20.0-41.2%) for RD and 18.5% (95% C.I. 11.4-25.6%) for PP (P Conclusions: Pts with DLBCL experiencing PTF have poor prognosis but low clinical trial participation even when treated in academic centers. Pts with PP disease, intermediate-high/high NCCN-IPI at time of PTF or with c-myc(+) tumors constitute a UHR category with dismal outcomes on existing therapies. REFINE provides benchmarking for future experimental agents targeting this population. UHR pts represent an unmet medical need and should receive high priority for development of new drugs and cellular therapies. Table 1. Table 1. Figure 1. Figure 1. Disclosures Chavez: Janssen: Speakers Bureau. Reddy:INFINITY: Membership on an entity's Board of Directors or advisory committees; celgene: Membership on an entity's Board of Directors or advisory committees; KITE: Membership on an entity's Board of Directors or advisory committees; GILEAD: Membership on an entity's Board of Directors or advisory committees. Karmali:Celgene: Speakers Bureau. Calzada:Seattle Genetics: Research Funding. Barta:Janssen: Honoraria, Speakers Bureau; Celgene, Merck, Seattle Genetics: Research Funding. Lansigan:Spectrum: Consultancy, Research Funding; Pharmacyclics: Consultancy; Celgene: Consultancy; Teva: Research Funding. Flowers:Roche: Consultancy, Research Funding; Acerta: Research Funding; TG Therapeutics: Research Funding; NIH: Research Funding; Pharmacyclics, LLC, an AbbVie Company: Research Funding; Infinity: Research Funding; Gilead: Consultancy, Research Funding; Millenium/Takeda: Research Funding; ECOG: Research Funding; AbbVie: Research Funding; Mayo Clinic: Research Funding; Genentech: Consultancy, Research Funding. Fenske:Seatle Genetics: Honoraria; Millennium/Takeda: Research Funding; Celgene: Honoraria; Pharmacyclics: Honoraria. Cohen:Novartis: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; Celgene: Consultancy, Membership on an entity's Board of Directors or advisory committees; Infinity: Consultancy, Membership on an entity's Board of Directors or advisory committees; Pharmacyclics: Consultancy, Membership on an entity's Board of Directors or advisory committees; Millennium/Takeda: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; Bristol-Myers Squibb: Research Funding; Seattle Genetics: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding. Hamadani:Takeda: Research Funding. Costa:Sanofi: Honoraria, Research Funding.

Introduction: Modern chemoimmunotherapy cures the majority of patients (pts) with newly diagnosed diffuse large B cell lymphomas (DLBCL). The paradigm for pts who relapse has been salvage chemotherapy followed by autologous hematopoietic cell transplantation (auto-HCT) when chemosensitive disease. This approach is often also applied to pts with primary treatment failure (PTF), although this group is heterogeneous and outcomes of HCT in this population have not been well described. Methods: Fifteen US academic medical centers contributed pts to the REgistry of diFfuse large B cell lymphoma with prImary treatmeNt failurE (REFINE) collaboration. REFINE retrospectively captured patient, disease and treatment characteristics and response as assessed by treating center. Eligible pts were ≥ 18 years diagnosed with DLBCL during 2008-2015, who received upfront therapy including anthracycline and CD20-directed antibody and developed one of 3 patterns of PTF: relapse < 6 months following CR (early relapse- ER); only partial remission (PR) or stable disease (SD) with upfront therapy (residual disease-RD); progressive disease (PD) while receiving upfront therapy (primary progression-PP). Pts with HIV infection, primary CNS lymphoma or lymphoma transforming from a more indolent histology were excluded. Results: Among 331 cases included in REFINE, patterns of PTF were ER in 95 (28.7%), RD in 92 (27.8%) and PP in 144 (43.5%) pts. Salvage therapy was administered to 94.6% of pts. We analyzed the 157 (47.4%) PTF pts who subsequently underwent HCT, 132 auto-HCT and 33 allo-HCT (8 after failure of auto-HCT) (Table). Nearly half of pts were in CR at transplant, after 1-2 lines of salvage therapy. Among all pts receiving auto-HCT, 2-year progression-free survival (PFS) from time of transplant was 38.4% (95% C.I. 29.6-47.2%) and overall survival (OS) 54.9% (95% C.I. 44.9-64.9%). Two-year OS from auto-HCT was affected by pattern of PTF: 71.3% for ER, 55.0% for RD and 41.7% for PP (P=0.05). OS at 2-years was 23.7% for auto-HCT pts with germinal center B (GCB)type,c-myc(+) (by FISH) tumors vs. 66.7% for GCB, c-myc (-), vs. 67.8% for non-germinal center (NGC) (P=0.01). Auto-HCT pts with intermediate-high/high NCCN-IPI at time of PTF had 2-year OS of 28.6% vs. 66.0% for intermediate-low and 80.9% for low risk (P Conclusions: Pts with DLBCL experiencing PTF and 2 or more UHF features have dismal outcome after auto-HCT and should be targeted for experimental modalities of cellular therapy. Outcomes of allo-HCT in DLBCL with PTF are poor, due to rapid and fatal relapses. Table. Table. Figure. Figure. Disclosures Costa: Sanofi: Honoraria, Research Funding. Reddy:INFINITY: Membership on an entity's Board of Directors or advisory committees; KITE: Membership on an entity's Board of Directors or advisory committees; celgene: Membership on an entity's Board of Directors or advisory committees; GILEAD: Membership on an entity's Board of Directors or advisory committees. Karmali:Celgene: Speakers Bureau. Chavez:Janssen: Speakers Bureau. Calzada:Seattle Genetics: Research Funding. Barta:Janssen: Honoraria, Speakers Bureau; Celgene, Merck, Seattle Genetics: Research Funding. Flowers:Pharmacyclics, LLC, an AbbVie Company: Research Funding; Mayo Clinic: Research Funding; Acerta: Research Funding; Roche: Consultancy, Research Funding; TG Therapeutics: Research Funding; ECOG: Research Funding; Genentech: Consultancy, Research Funding; Gilead: Consultancy, Research Funding; NIH: Research Funding; Infinity: Research Funding; Millenium/Takeda: Research Funding; AbbVie: Research Funding. Fenske:Seatle Genetics: Honoraria; Pharmacyclics: Honoraria; Celgene: Honoraria; Millennium/Takeda: Research Funding. Cohen:Pharmacyclics: Consultancy, Membership on an entity's Board of Directors or advisory committees; Millennium/Takeda: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; Celgene: Consultancy, Membership on an entity's Board of Directors or advisory committees; Infinity: Consultancy, Membership on an entity's Board of Directors or advisory committees; Novartis: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; Seattle Genetics: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; Bristol-Myers Squibb: Research Funding. Hamadani:Takeda: Research Funding.

Purpose: NUT midline carcinoma (NMC) is a poorly differentiated squamous cancer characterized by rearrangement of the NUT gene. Research advances have provided opportunities for targeted therapy in NMC, yet the clinical features of this rare disease have not been systematically characterized. We report on a large population of such patients to identify the disease characteristics and treatments, correlate them with outcome, and to consider clinical recommendations. Experimental Design: A clinical database was established using retrospective demographic and outcomes data available on all known cases of NMC. Questionnaires were completed by treating physicians. Pathologic, demographic, and clinical variables were assessed for 63 patients, the largest cohort of patients with NMC studied to date. Outcome data from 54 patients were available for survival analyses. Results: The diagnosis of NMC has increased annually since 2007. Since 2009, there has been an observed increase in the age at diagnosis (P < 0.05). Geographic distribution of patients with NMC has been concentrated in the United States (n = 41, 65%). The median overall survival for patients with NMC was 6.7 months. The 2-year progression-free survival (PFS) was 9% with a 95% confidence interval (CI) of 1% to 17% [1-year PFS 15% (5–24%) and 2-year overall survival (OS) was 19% with a 95% CI of 7%–31% (1-year OS: 30% (27–34%)]. Multivariate analysis suggested that extent of surgical resection and initial radiotherapy were independent predictors of PFS and OS. Notably, no chemotherapeutic regimen was associated with improved outcome. Conclusions: NMC portends a poor prognosis among all squamous cell neoplasms and seems to be frequently unrecognized. The finding that conventional chemotherapy has been inadequate indicates a pressing need for the development of targeted therapeutics. Intensive local therapies such as gross total resection and radiotherapy might be associated with enhanced survival. Clin Cancer Res; 18(20); 5773–9. ©2012 AACR.

Background: Diffuse large B-cell lymphoma (DLBCL) typically express monotypic surface immunoglobulin (sIg) light chain as part of the B-cell receptor (BCR) complex. Occasional cases are, however, sIg-negative and the clinical significance of this remains unclear. Distinct subtypes of DLBCL, including germinal center B-cell-like (GCB) and activated B-cell (ABC) type, exhibit differential dependence upon BCR-mediated survival signals. The role of activating mutations downstream of the BCR signaling complex (i.e. CD79A/B or CARD11), or in parallel costimulatory pathways (i.e. MYD88 mutations), are now well recognized in promoting such survival mechanisms. Surprisingly, however, less is known about the importance of sIg expression, or lack thereof, on various subsets of DLBCL or other aggressive large B cell lymphomas. Design: We sought to further characterize the clinicopathologic and genetic features of primary human surface Ig-negative DLBCL-not otherwise specified (NOS). All cases of large B-cell lymphoma that had flow cytometry performed at the University of Rochester from 2010-2013 were screened for evidence of a surface Ig-negative B-cell population. Additional available immunophenotypic data and/or clinicopathologic features were recorded. PCR heteroduplex analysis and sequencing of fresh frozen tumor samples was performed to identify putative compensatory activating mutations in MYD88 and CD79A /B, respectively. In addition, using multiplexed PCR and sequencing analysis we attempted to identify the presence or absence of functional immunoglobulin heavy chain (IGH)gene rearrangements. Results: Among 209 diagnostic specimens analyzed, 13 cases (6.2%) were found to contain a discrete population of CD19/CD20-positive B-cells lacking sIg light chain expression. These included 8 DLBCL-NOS, nearly all of which were GCB-type, including 6 out of 7 cases, or 83%, which were CD10-positive. This proportion is significantly greater than the 42% of all DLBCL-NOS that express CD10 (based on data from a large publicly available on-line database; p < 0.025, based on binomial probability). Furthermore, of the other high grade sIg-negative B cell lymphomas identified, 4 out of 5 were also CD10-positive. These included 2 cases of B-cell lymphoma, unclassifiable (BCL-U), intermediate between DLBCL and Burkitt lymphoma, and 2 cases of transformed follicular lymphoma (FL) - therefore also histologically and immunophenotypically consistent with derivation from a germinal center B-cell. The only exception was a non-GCB primary CNS lymphoma. Among 5 cases of sIg- DLBCL available for analysis, all were negative for the MYD88 L265P activating mutation, while only a single case contained an activating mutation in CD79A/B (CD79B Y196 ITAM mutation). In the same set, only 2 (of 5) cases produced amplicons by IGH PCR, and sequencing revealed only one of these had an intact reading frame. Conclusion: DLBCL-NOS lacking definitive sIg light chain expression are infrequent (less than 10%), but these tumors are predominantly GCB subtype. This observation lends support to the model that these tumors rely less on BCR-mediated survival signals, which may have implications for choosing targeted therapy. The mechanism by which these lymphoma survive despite the apparent lack of functional BCR is unknown, but compensatory activating mutations known to be frequent among ABC-type DLBCL appear to be lacking. Disclosures No relevant conflicts of interest to declare.

Malaria has been invoked, perhaps more than any other infectious disease, as a force for the selection of human genetic polymorphisms. Evidence for genome-shaping interactions can be found in the geographic and ethnic distributions of the hemoglobins, blood group antigens, thalassemias, red cell membrane molecules, human lymphocyte antigen (HLA) classes, and cytokines. Human immune responses and genetic variations can correspondingly influence the structure and polymorphisms of Plasmodium populations, notably in genes that affect the success and virulence of infection. In Africa, where the burden from Plasmodium falciparum predominates, disease severity and manifestations vary in prevalence among human populations. The evolutionary history and spread of Plasmodium species inform our assessment of malaria as a selective force. Longstanding host-pathogen relationships, as well as recent changes in this dynamic, illustrate the selective pressures human and Plasmodium species place on one another. Investigations of malaria protection determinants and virulence factors that contribute to the complexity of the disease should advance our understanding of malaria pathogenesis.

Therapies that control largely T cell-dependent allograft rejection in humans also possess the undesirable effect of impairing T cell function, leaving transplant recipients susceptible to opportunistic viruses. Prime among these opportunists are the ubiquitous herpesviruses. To date, studies are lacking that address the effect of viruses that establish a true latent state on allograft tolerance or the effect of tolerance protocols on the immune control of latent viruses. By using a mixed chimerism-based tolerance-induction protocol, we found that mice undergoing latent infection with γHV68, a murine γ-herpesvirus closely related to human γ-herpesviruses such as EBV and Kaposi’s sarcoma-associated herpesvirus, significantly resist tolerance to allografts. Limiting the degree of virus reactivation or innate immune response did not reconstitute chimerism in latently infected mice. However, γHV68-infected mice showed increased frequency of CD8+ T cell alloreactivity and, interestingly, expansion of virus-induced, alloreactive, “effector/effector memory” TCR Vβ4+CD8+ T cells driven by the γHV68-M1 gene was associated with resistance to tolerance induction in studies using γHV68-M1 mutant virus. These results define the viral gene and immune cell types involved in latent infection-mediated resistance to allograft tolerance and underscore the influence of latent herpesviruses on allograft survival.

Chimeric antigen receptor (CAR)-modified T cells specific for CD19 have resulted in complete responses in B lymphoblastic leukemia (B-ALL) and in chronic lymphocytic leukemia/small lymphocytic lymphoma (CLL/SLL). In B-ALL cases, clinical relapse with CD19-negative cells has been reported (Grupp et al NEJM 368; 1509-18). Here we report relapse in a CLL case treated with CAR-T cells specific for CD19 (CTL019) which demonstrated clonal evolution into plasmablastic lymphoma (PBL) lacking residual markers of B lymphoid differentiation. The patient was a 62 year old man diagnosed with CLL 4.5 years prior to the CTL019 therapy. At diagnosis his absolute lymphocyte count was 253K/uL, with 98% of lymphocytes being positive for CD19, CD20, CD5(dim), CD23, and lambda-restricted, but negative for CD10, CD38, and Zap-70. CT scans revealed splenomegaly (16 cm) and extensive lymphadenopathy (up to 6.9 cm). Standard CLL FISH panel was negative. Brief therapeutic responses were achieved but progression occurred on each of the following regimens: fludarabine, cyclophosphamide and rituximab for 6 cycles, bendamustine/rituximab for 2 cycles, ofatumumab for 5 infusions, and CHOP for 3 cycles. He was then enrolled on a series of clinical trials including flavopiridol and PCI 32765 (ibrutinib). Six months prior to CTL019 infusion, further node progression was demonstrated with trisomy 12, del 12p14, del 11q, and del 17p by FISH. Node and marrow biopsies were consistent with large B cell/Richter’s transformation. He received OFAR X 1 and was referred for the CTL019 CLL trial at the University of Pennsylvania where he had successful apheresis and expansion of T cells. Nodes were debulked with the XP01 inhibitor (KPT-330). He received radiation to a 9 cm right axillary mass without response. He received one cycle of fludarabine and cyclophosphamide followed by CTL019 cell infusion. There was marked expansion of CTL019 cells and he experienced cytokine release syndrome. He had a significant tumor response with 50% or more reduction in most nodal areas on CT scan and 80% reduction in tumor involvement of the marrow 1 month after infusion. He was lymphopenic and received monthly IVIG replacement. Approximately 6 months after the CTL019 infusion, he developed right jaw pain. A gingival biopsy revealed plasmablastic lymphoma (PBL). The cells were lambda-restricted by in-situ hybridization, and positive for CD45, CD138, MUM-1, CD56 (subset), and EMA, but negative for CD19, CD20, Pax-5, CD5, CD23, BCL-2, cyclin D1, CD30, ALK-1, HHV-8, and EBV (by EBER in situ hybridization). The Ki67 expression was >90%. At the time WBC was 3.7K/uL, HCT 44%, and platelets 78K/uL with ANC 2.2K/uL. About one month after relapse, neutropenia occurred, and atypical cells emerged which typed by flow cytometry as positive for CD45(dim), CD5, CD23, CD81, lambda-restricted, and negative for CD19. The patient developed sepsis with pancytopenia and died 7 months after his CTL019 cell infusion. Molecular analysis revealed the same size monoclonal gene rearrangements of the immunoglobulin heavy chain (IGH) and kappa light chain (IGK) genes in both the PBL, subsequent peripheral blood, and a prior SLL (2010) lymph node biopsy. Sequencing revealed identical productive and nonproductive IGH gene rearrangements in all three specimens, with the exception of a 2bp insertion in the CDR1 region which destroyed the IGH reading frame in the PBL. P53 sequencing revealed multiple mutations [p.Gly245Ser(heterozygous) and p.Val197Glu(heterozygous)] from the prior SLL lymph node and recent peripheral blood, but only a single mutation [p.Gly245Ser(homozygous)] present in the PBL, consistent with previously documented loss of 17p prior to CTL019 therapy. CAR-T cell therapy is an effective treatment modality for CLL and ALL. In this case, a plasmablastic lymphoma lacking well-differentiated B cell features, including CD19, emerged 6 months after CTL019 therapy, along with residual circulating CD19-negative/CD5-positive lambda-restricted B cells. This finding suggests that anti-CD19 selective pressure may divert lymphoid differentiation into other pathways or may foster proliferation of an alternatively differentiated stage of the original clonal tumor. This case demonstrates the ability of CD19-negative tumors to emerge after CD19 directed therapy in CLL, which also attests to the efficiency and continued activity of these directed T cells over time. Disclosures Porter: Novartis: Patents & Royalties, Research Funding. Liesveld:Glycomimetics: Honoraria, Membership on an entity's Board of Directors or advisory committees; GSK: Honoraria, Membership on an entity's Board of Directors or advisory committees.

Introduction: For patients with relapsed or refractory diffuse large B cell lymphoma (DLBCL), salvage treatment followed by consolidation with high-dose chemotherapy and autologous stem cell transplantation (HD-ASCT) is the standard of care for those with chemosensitive disease, as established by the PARMA and CORAL trials. In the pre-rituximab era, patients with DLBCL experiencing disease progression following HD-ASCT had a dismal prognosis with a median overall survival of 3 months. These early studies demonstrate that early progression following HD-ASCT is the most important predictor of poor outcome. In the rituximab era, there is very little data examining incidence and outcomes of patients with late relapses following HD-ASCT for relapsed/refractory DLCBCL. Therefore, we sought to evaluate survival outcomes in a cohort population of patients relapsing late after HD-ASCT for DLBCL. Methods: We reviewed consecutive patients who underwent HD-ASCT for biopsy confirmed relapsed or refractory DLBCL between 2001 and 2010 at the University of Rochester James P. Wilmot Cancer Institute. Eligible patients were required to have received rituximab as part of their therapeutic regimen. Survival probability was estimated by the Kaplan-Meier method. Comparisons were made using the X2 test and Fisher's exact test, where appropriate. Results: A total of 88 patients were identified. Median age was 55 (range 20-74). Eighty percent of patients received a BEAM – like conditioning regimen (Carmustine, Etoposide, Cytarabine, and Melphalan). Thirty-five patients were in complete remission at the time of transplant. Median follow up for surviving patient was 5.8 years (range 139 days -12.5 years). The median overall survival for all patients was 5.2 years (range of 15 days-12.5 years). In total, 51 patients died (58%); 31 of these deaths were related to DLBCL (61%). Median progression free survival was not reached. Thirty-five patients relapsed following ASCT. Of these, 89% relapsed < 3 years from ASCT (early relapse), 2 of whom remain alive. Only 4 patients (11%) relapsed ≥ 3 years from ASCT (late relapse), 2 of whom died, and 2 of whom remain alive. Of the deaths, 1 was lymphoma-related, and 1 was death from graft versus host disease in a patient undergoing subsequent allogeneic transplant. Median time to progression in the entire cohort was 167 days. Consistent with early studies, the presence of disease status prior to ASCT was associated with shorter time to progression, p=0.0028 by Fisher's exact test. Conclusions: Ours is one of few series examining late relapses following ASCT performed for relapsed and refractory DLBCL in the rituximab era. In this cohort, late relapses following ASCT for relapsed and refractory DLBCL occurred infrequently. Our data indicate that for the few patients relapsing beyond 3 years, there is a suggestion of long-term disease control. Figure 1: Figure 1:. Progression Free Survival of Patients Relapsing After ASCT for Relapsed/Refractory DLBCL Based on Time to Progression Disclosures No relevant conflicts of interest to declare.