Witzig, Thomas E.

Abstract Background: Isolation of malignant plasma cells from bone marrow of patients with monoclonal gammopathies is critical for studies into the disease biology. The isolation of plasma cells have generally been performed by positive selection using plasma cell markers such as CD138 or by negative selection by removing other marrow cells using a cocktail of antibodies. We have previously demonstrated differences in apoptotic rates in plasma cells with and without this enrichment step. Here we have examined the effect of CD138 magnetic bead selection on the surface phenotype of plasma cells by flow cytometry. Methods: Bone marrow aspirates from patients with myeloma (n=12) were first washed, and then lysed with ACK to eliminate red cells. The samples were split with a portion of the cells further processed for CD138 selection. ACK lysed only whole bone marrow (WBM) and sorted cells were stained with CD38, CD45, CD56, activation markers CD71 and CD69, adhesion markers CD49d, CD11b, and CD66, B cell markers CD19 and CD20, and clonality (kappa and lambda). Gates were drawn around the plasma cells and plasma cell subsets on the basis of CD38/45 expression for both sorted and unsorted samples. In addition, an aliquot of the sorted preparation was examined by immunohistochemistry to calculate the purity of the sorted sample. Results: Significant differences were observed in terms of the percentage of plasma cells expressing the different antigens when the cells were selected using CD138. This difference included a greater than 10% difference in expression between the two preparations as well as a change from positive to negative in several cases. There was a substantial loss in the expression of CD20, CD71 and CD11b on plasma cells following CD138 based sorting (Table). Among the other markers, CD49d remains unchanged and changes are variable for the other markers. In addition, in 8 of the 12 cases, there was a nearly complete loss of the CD45 positive subset with a loss of discrimination between CD45 negative and CD45 positive plasma cell subsets in the remaining CD138 sorted preparations (figure: unsorted left, sorted right). Conclusion: In conclusion, the process of CD138 sorting of plasma cells appears to change important markers on the plasma cells and may even eliminate a key subset from further analysis. This should be kept in mind when isolating plasma cells using CD138 positive selection for analysis such as gene expression profiling. Consideration should be given to negative selection using antibodies against other cell types to deplete them. Marker Unsorted % Sorted % CD56 74 67 CD69 11 2 CD71 23 8 CD49d 95 92 CD11b 33 4 CD66 5 1 CD20 16 6 Figure Figure

The median survival in primary systemic (AL) amyloidosis is less than 18 months. No published series of patients with AL amyloidosis have reported survival of more than 10 years. The records of all Mayo Clinic patients with a diagnosis of AL amyloidosis between January 1, 1966 and March 1, 1987 were reviewed. Patients with secondary amyloidosis, familial amyloidosis, senile systemic amyloidosis, and localized amyloidosis were excluded. During the 21 years of the study, 841 patients with AL amyloidosis were seen. Of these, 29 were excluded because the diagnosis was made at autopsy, and 2 others were excluded because no follow-up data were available. Actuarial survival for the 810 patients was 51% at 1 year, 16% at 5 years, and 4.7% at 10 years. Thirty patients survived for 10 years or more after the histologic diagnosis of AL amyloidosis; all received alkylating-agent therapy. In 14 patients, the monoclonal protein disappeared from the serum or urine. Of 10 patients with nephrotic syndrome, 4 had an objective response. Congestive heart failure, older age, creatinine value of 2 mg/dL or more, bone marrow plasma cell value of 20% or more, platelet count of 500 × 109/L or less, and the presence of peripheral neuropathy were underrepresented in the 10-year survivors and are unfavorable prognostic features. Five percent of patients with AL amyloidosis survived for 10 years or more.

Abstract Background: Patients with early stage myeloma are typically observed without therapy until symptomatic disease occurs. We have reported early results of therapy with single-agent thalidomide as initial therapy for early stage multiple myeloma in an attempt to delay progression to symptomatic disease (Leukemia2003;17:775–9). We now report the long-term results of this phase II trial. Methods: Thirty-one patients with smoldering or indolent multiple myeloma were enrolled between April 1999–March 2002. All pts had bone marrow (BM) plasma cells >=10% and measurable disease defined as serum monoclonal (M) protein >=2gm/dL and/or urine M protein >=400mg/24 hours. Two patients were deemed ineligible because they were found to have received prior therapy for myeloma and were excluded from analysis. Thalidomide was initiated at a dose of 200 mg/day and increased as tolerated by 200 mg/day every 2 weeks to a maximum dose of 800 mg/day. The dose of thalidomide was decreased as needed to minimize toxicity. Treatment was continued until disease progression or serious toxicity, except for patients achieving less than a minor response (<25% paraprotein reduction) to therapy in whom therapy was stopped at one year. Response was defined as a decrease in serum and urine monoclonal (M) protein by 50% or higher. If the serum M protein was unmeasurable, a 90% or higher decrease in urine M protein was required. Responses need to be confirmed at least 4 weeks apart. Results: Ten patients (34%) had indolent myeloma, including 4 patients with lytic bone lesions, 3 patients with anemia (Hb <11gm/dL), and 3 patients with both anemia and lytic bone lesions. Median follow up of living patients is 5.6 years (range, 4.0–7.1 years). Of the twenty-nine eligible patients, ten (34%) had a partial response to therapy with at least 50% or greater reduction in serum and urine monoclonal (M) protein. Three patients are still on study and receiving therapy. The remaining have gone off-study: seven patients (27%)had progressive disease while on therapy; other reasons for ending study treatment included completed therapy per protocol (2 pts), patient refusal (2pts), toxicity (8 pts), alternate treatment (3 pts), other medical problems (1 pt), died on study (1 pt), and other (2 pts). The median time to progression (TTP) was 3.2 years (95% CI 2.1–5.6 yrs). Median progression free survival (PFS) was 3.0 yrs (95% CI 2.0–5.1 yrs). Median overall survival has not been reached; 5 year survival rate by the Kaplan Meier method is 60%. Major grade 3–4 non-hematologic adverse events at any time during therapy were noted in 34% of patients; this includes 14% with grade 4 toxicity. Grade 3–4 toxicities occurring in more than one patient include neuropathy (2 pts) and sinus bradycardia (2 pts). Conclusions: Thalidomide has activity in asymptomatic myeloma. This approach must be further tested in randomized trials to determine if the survival estimates are superior to observation. Given the activity of thalidomide, trials are also needed with lenalidomide.

Abstract We have previously shown that CD4+CD25+Foxp3+ regulatory T cells from NHL tumors suppress the function of infiltrating CD4+ T cells and cytolytic CD8+ T cells. Expression of Foxp3 has been demonstrated to be crucial to the development and function of CD4+CD25+ regulatory T cells. However, the mechanistic details that drive development of Foxp3 expression in T cells, in both the normal and malignant scenario, remains to be fully elucidated. Previous studies suggest that Foxp3 expression in CD4+CD25− T cells can be upregulated by tolerizing stimuli such as activation through TCR, corticosteroids, estrogen, and TGF-beta. Because lymphoma B cells have been shown to induce T-cell tolerance, we postulated that lymphoma B cells may play a role in the generation of regulatory T cells by inducing Foxp3 expression in CD4+CD25− T cells. FoxP3 expression was initially thought to be restricted to CD4+CD25+ regulatory T cell population. However, recent literature suggests that Foxp3 may also be expressed in CD4+CD25− T cells. Using biopsy specimens from patients with B-cell NHL, we found that a subset, 15%, of infiltrating CD4+CD25− T cells express Foxp3 and are capable of suppressing the proliferation and granule production of infiltrating cytotoxic CD8+ T cells. These initial studies suggest that CD4+CD25−Foxp3+ T cells have regulatory function. To explore the underlying mechanism by which Foxp3 expression is regulated, we determined the effect of costimulatory signals on Foxp3 expression in CD4+CD25−Foxp3− T cells. Activation with OKT3/anti-CD28 Ab as well as DC-mediated activation induced Foxp3 expression in a subset of CD4+CD25− T cells. We also found that the presence of lymphoma B cells during activation augmented the induction of Foxp3 expression in CD4+CD25− T cells and that NHL B cell-mediated Foxp3 expression was cell contact-dependent. To better understand the contribution of NHL B cells in Foxp3 expression, we explored the possibility that CD27-CD70 interaction may be involved in Foxp3 expression. Lymphoma B cells express CD70, but not B7-1 and B7-2, which have been shown to be important in protecting tumor cells from lysis and contributing to cancer pathogenesis. Ligation of CD27 by receptor cross-linking enhanced Foxp3 expression in infiltrating CD4+CD25− T cells in B-cell NHL. Taken together these studies reveal a novel role for NHL B cells in development of regulatory T cells. Our data show that lymphoma B cells induce expression of Foxp3 in infiltrating CD4+CD25− T cells and may result in development of T cells with regulatory function within the tumor microenvironment. Our results also suggest a potential role for CD27-CD70 interactions in this process. The ability of malignant B cells to drive development of regulatory T cells may be one mechanism by which lymphoma B cells protect themselves from anti-tumor immunity. (Supported in part by the Iowa/Mayo Lymphoma SPORE CA97274).

Abstract Abstract 1540 Background: Diffuse Large B-cell Lymphoma (DLBCL) is the most common lymphoma in the western world. Outcomes have improved with the standard initial therapy of rituximab and anthracyline based chemotherapy (immunochemotherapy). However, 20–40% of patients will either fail to achieve remission or relapse following initial immunochemotherapy. Most relapses occur early, and long-term outcome of relapsed/refractory patients is generally poor despite salvage regimens and stem cell transplant. Traditionally, studies for DLBCL have been evaluated using progression-free and/or overall survival. However, the event rate in DLBCL slows significantly approximately 12–18 months after diagnosis, and late events are often due to competing (non-DLBCL related) risks, especially in older patients. Here we examine outcome of DLBCL patients based on their event status at 12 months. Methods: Newly diagnosed DLBCL patients were prospectively enrolled in the University of Iowa/Mayo Clinic Lymphoma SPORE Molecular Epidemiology Resource (MER). Clinical data were abstracted from medical records using a standard protocol. Patients were actively followed for events (progression, re-treatment, or death due to any cause) and overall survival (OS). Event-free status at 12 months after diagnosis (EFS12) was assessed as a dichotomous variable. Cause of death was determined by medical record and death certificate review using prospectively determined definitions. Expected survival was based on age and sex matched survival using the Minnesota population death rates. Confirmation cohorts were from a Lyon, France hospital based registry and NCCTG clinical trial N0489. Results: 680 patients with newly diagnosed DLBCL and treated with rituximab + anthracycline based chemotherapy were enrolled in the MER from 2002 to 2009. The median age was 62 years (range 18–92). 53% were male. At a median follow-up of 59 months (range 8–116), 266 patients (39%) had an event and 188 patients (28%) died. 162 patients (24%) had an event in the first 12 months after diagnosis, comprising 60% of all events. Patients with an event in the first 12 months had poor survival with death almost exclusively due to disease (Figures 1a, 2a). In contrast, patients who were event-free at 12 months had comparable survival to the age and sex matched general population (Figure 2b) and were more likely to die of other causes than DLBCL (Figure 1b). Overall survival rates by EFS12 status were validated in patients from a French hospital-based registry (N=265) and the NCCTG N0489 clinical trial (N=87) with additional replication studies underway. Conclusions: DLBCL patients who are event-free at 12 months after diagnosis have an excellent prognosis with an overall survival similar to that of an age- and sex- matched general population and are more likely to die of other causes than DLBCL. This finding has implications for clinical management, new clinical trials, and follow-up testing in this patient population. In contrast, patients with an event within the first 12 months after diagnosis have a poor prognosis with almost all deaths secondary to DLBCL. EFS status at 12 months identifies patients with poor outcomes due to disease. This can be utilized as an endpoint in biologic studies and clinical trials to address early treatment failures. EFS status at 12 months should be incorporated into prognostic models to identify high risk patients in newly diagnosed DLBCL. Disclosures: No relevant conflicts of interest to declare.

Abstract Plasma cell (PC) proliferative disorders vary in behavior ranging from MGUS, a usually indolent disorder, to multiple myeloma, an aggressive disease with poor long-term survival. Detecting PC immunoglobulin (Ig) light chain restriction is commonly used to demonstrate PC clonality and establish the diagnosis. Furthermore, greater degrees of peripheral blood (PB) and/or bone marrow (BM) involvement are associated with more aggressive disease types and, therefore, are adverse prognostic indicators. Flow cytometric immunophenotyping (FCIP) is often used for detecting PC Ig light chain restriction. Shortcomings of FCIP as traditionally performed include its relative insensitivity and its underestimation of PC number. For these reasons, the FCIP PC clonality assessment in our laboratory is currently supplemented with a slide-based immunofluorescence (IF) technique. Recent advances in flow cytometry have led to the development of powerful instruments and reagents, potentially enhancing the ability of FCIP to analyze PC clones. In this study a newly available single tube, 6-color FCIP approach for detecting and enumerating monotypic PCs was compared to the current combined FCIP/IF assay. 94 PB and 124 BM samples were analyzed by combined FCIP/IF and single tube 6-color FCIP assays. For PB, FCIP/IF used 2-color CD38-PE/ CD45-PerCP FCIP to enumerate PCs and slide based IF to detect Ig light chain restriction. For BM FCIP/IF used two 4-color FCIP tubes (Tube1: cytoplasmic (cy)-kappa Ig-FITC/CD20-PE/CD45-PerCP/CD38-APC; Tube 2: cy-lambda Ig-FITC/CD56-PE/CD45-PerCP/CD38 APC) and slide-based IF to confirm clonality. These FCIP assays were performed on a FACSCaliber. The single tube, 6-color FCIP assay used the following fluorochrome-antibody combination: cy-kappa Ig-FITC/cy-lambda Ig-PE/CD138-PerCP-Cy5.5/CD38-APC/CD19-PE-Cy7/CD45-APC-Cy7 with data acquired on a FACSCanto. The results are summarized in Tables 1 & 2, the concordance between the methods was high. All false-negative 6-color FCIP results were attributable to the use of isotonic lysis for cell isolation. When limiting the comparison to the ficolled cells alsoused for FCIP/IF, 6-color FCIP was consistently more sensitive. The 6-color assay also allowed for the discriminition between CD19-positive polytypic PCs and CD19-negative monotypic PCs and the detection of CD45-positive monotypic PC subsets which were often present and which were not identified in the combined FCIP/IF approach. Estimates of PB disease burden generated from the 6-color technique were similar to those determined from the FCIP/IF data which have previously been shown to be of prognositic significance. 6-color FCIP allows for the rapid, sensitive detection of monotypic PCs. The ability of 6-color FCIP to detect phenotypically distinct clonal PC subsets enhances the sensitivity and may provide prognositically significant data through both more complete cell enumeration and charactarization. Given these advantages, 6-color FCIP may eventually supplant traditional FCIP methods of PC analysis. Method Comparsion in BM Bone Marrow 6-color FCIP 6-color FCIP Positive negative total Positive = clone detected; negative = no clone detected. FCIP/IF Positive 81(65%) 3(2%) 84 FCIP/IF Negative 5(4%) 35(28%) 40 Total 86 38 124 Method Comparsion in PB Peripheral Blood 6-color FCIP 6-color FCIP Positive negative total Positive = clone detected; negative = no clone detected. FCIP/IF positive 24(26%) 7(7%) 31 FCIP/IF negative 9(10%) 54(57%) 63 total 33 61 94

Abstract Introduction: Diffuse large B-cell lymphoma (DLBCL) is an aggressive non-Hodgkin’s lymphoma (NHL) comprising 3 molecular subtypes: germinal center B-cell (GCB), activated B-cell (ABC) and class III. ABC patients (pts) have a poor prognosis. The immunomodulatory drug lenalidomide (Len) produces durable responses in pts with aggressive NHL (Witzig 2011), with preferential activity reported in non-GCB DLBCL (Hernandez-Ilizaliturri 2011). Methods: This randomized, multicenter, open-label, phase 2/3 study was conducted to determine the efficacy and safety of single-agent Len vs single-agent investigator’s choice (IC) in relapsed/refractory DLBCL pts who received ≥2 prior therapies, or were ineligible for stem cell transplantation or further combination chemotherapy. DLBCL subtype (GCB vs non-GCB) was determined by a central pathology lab using immunohistochemistry (IHC) per the Hans method (Hans 2004). Pts were stratified by subtype, then randomized 1:1 to receive Len (25 mg/day, 21 days of 28-day cycle) or IC (gemcitabine, rituximab, etoposide, or oxaliplatin) until progressive disease (PD), unacceptable toxicity, or voluntary withdrawal. In the event of radiologically confirmed PD, pts in the IC arm were allowed to cross over to Len. The primary endpoint for Stage 1 was overall response rate (ORR), as determined by an Independent Response Assessment Committee. Progression-free survival (PFS), overall survival (OS) and subtype analysis using gene expression profiling (GEP) were exploratory endpoints. Concordance of GEP and IHC was evaluated from 3 separate laboratories. Results: IHC subtyping agreement rate among the 3 laboratories ranged from 87.5%-97.9%, and sensitivity of IHC to detect ABC or GCB subtypes vs GEP ranged from 92.3%-100.0%. By IHC, 102 DLBCL pts (GCB, n=48; non-GCB, n=54) were treated with ≥1 dose of Len or IC (modified intent-to-treat population) in Stage 1. In this heavily pretreated population, >90.0% of pts received ≥2 prior systemic chemotherapies; 25 pts in Len and 32 pts in IC received ≥3 prior systemic chemotherapy regimens. Median age was 65 y in the IC arm vs 69 y in the Len arm. Twenty-nine pts crossed over from IC to Len after confirmed PD. All pts, regardless of subtype or therapy group, experienced ≥1 treatment-emergent adverse event, with neutropenia, anemia, and thrombocytopenia being the most common. Efficacy data are presented in the Table. Pts with GCB or non-GCB DLBCL (per IHC) treated with Len had similar ORR, but the data suggested greater improvements in PFS and OS with Len vs IC in the non-GCB pts. In an exploratory analysis of pts subtyped by GEP, ABC pts treated with Len vs IC-treated showed greater improvements in ORR, PFS, and OS compared with GCB pts. Prespecified criterion to advance to Stage 2 was a 2-sided 15% significance level in ORR in favor of Len based on IHC-defined subtype. The data did not fulfill this requirement, and Stage 2 was not opened. Conclusion: Len monotherapy showed clinical activity in heavily pretreated pts with DLBCL. The data suggest improved ORR, PFS, and OS with Len vs IC in the non-GCB population as defined by IHC, and the difference appears to be more pronounced in the ABC population as defined by GEP. Subtyping by GEP is warranted in further studies of Len in DLBCL. Abstract 628. Table 1.Table. Efficacy DataBy IHCBy GEPOverallGCBNon-GCBGCBABCLen(n=51)IC(n=51)Len(n=23)IC(n=25)Len(n=28)IC(n=26)Len(n=14)IC(n=16)Len(n=11)IC(n=16)ORR, % (95% CI)27.5 (15.9-41.7)11.8 (4.4-23.9) 26.1 (10.2-48.4)12.0 (2.5-31.2)28.6 (13.2-48.7)11.5 (2.4-30.2)21.4 (4.7-50.8)12.5 (1.6-38.3)45.5 (16.7-76.6)18.8 (4.0-45.6)P Value .079 .279 .179 .642 .206PFS, med wk (95% CI)13.6 (8.6-17.7)7.9 (6.3-9.0) 10.1 (8.3-22.3)29.0 (6.3-20.6)15.1 (8.3-24.1)7.1 (5.3-8.4)13.2 (8.3-24.9)7.1 (6.0-20.6)82.0 (7.3-NA)6.2 (4.3-10.1)P Value .041 .550 .021 .506 .105HR (95% CI) 0.64 (0.41-0.99) 0.82 (0.43-1.57) 0.50 (0.27-0.92) 0.77 (0.35-1.68) 0.44 (0.15-1.23)OS, med wk (95% CI)31.0 (16.6-41.3)24.6 (12.7-33.9) 30.0 (14.9-44.4)24.9 (13.7-58.3)32.3 (15.9-48.1)20.4 (10.3-33.9)30.0 (18.0-34.6)20.1 (13.7-36.9)108.4 (9.6-108.4)18.6 (6.6-48.0)P Value .673 .526 .253 .767 .144HR (95% CI) 0.91 (0.59-1.41) 1.23 (0.65-2.34) 0.70 (0.38-1.30) 1.12 (0.52-2.42) 0.47 (0.17-1.33) Abbreviations: CI, confidence interval; HR, hazard ratio; med, median; NA, not applicable/not available. Disclosures Czuczman: Celgene: Consultancy. Off Label Use: This abstract describes a clinical trial of lenalidomide, which is an orally-available immunomodulatory agent under investigation for treating patients with diffuse large B-cell lymphoma.. Davies:GlaxoSmithKlein: Research Funding; Hoffman La Roche: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Celgene: Research Funding. Wagner-Johnston:Celgene: Research Funding. Gascoyne:Celgene: Consultancy, Research Funding. Salles:Pfizer: Honoraria; Gilead: Honoraria; Jansen: Honoraria; Hoffman La Roche: Honoraria; Celgene: Honoraria; Mundipharma: Honoraria. Witzig:Celgene Corporation: Membership on an entity's Board of Directors or advisory committees, Research Funding. Zinzani:Mundipharma: Honoraria; Pfizer: Honoraria; Gilead: Honoraria, Membership on an entity's Board of Directors or advisory committees; Roche: Honoraria; Millennium Takeda: Honoraria; Celgene: Honoraria; Teva: Membership on an entity's Board of Directors or advisory committees. Wright:Celgene: Research Funding. Staudt:Celgene Corporation: Research Funding. Repici:Celgene: Employment. Song:Celgene: Employment. Manzke:Celgene: Employment.

Abstract Background: Multiple myeloma cells are heterogenous in terms of the expression of CD45 and previous studies have suggested important clinical and biological implications of the CD45 expression. It has been shown that expression of CD45 on myeloma cells has prognostic value and that the CD45 positive cells contain the proliferative fraction of the myeloma cells. We have also demonstrated that the CD45+ population has a higher apoptotic rate compared to CD45− cells. Given the hypothesis that CD45+ cells represent myeloma cells earlier in their development and are more proliferative and more dependent on the marrow microenvironment we studied differences between the two populations in patients with different stages of monoclonal gammopathies and in normal plasma cells. Methods: Fresh bone marrow aspirates were subjected to ACK lysis for removal of RBCs subjected to multicolor flow cytometry to study the expression of different surface antigens on the plasma cells. Plasma cells were identified based on their characteristic CD38/45 expression. The surface expression of CD19 (B cell marker), CD56 (NCAM), CD87, (involved in cellular adhesion, cell motility and angiogenesis), CD126 (IL-6 receptor alpha chain), sVEGF (surface VEGF; surrogate measure of VEGF receptor expression), and CD71 (proliferation marker) were studied and compared between the CD45 + and CD45− cells by gating separately on these populations. Results: Patients with active myeloma (76), smoldering myeloma (32), MGUS/amyloid (44), and normal patients (23) were studied. Not all markers were performed on all patients. Among the patient samples, the expression of CD19, CD87, CD71, CD126, and sVEGF were higher among the CD45+ cells compared to CD45− cells (Table: % of cells with expression). There was no significant difference between the two in terms of the expression of CD56. Among the normal plasma cells, the expression of CD19, CD87, CD126 and sVEGF was greater on the CD45+ cells compared to CD45− plasma cells and CD56 was not different. When the patient cells were compared to normal cells, the expression of CD19 was higher among the normal CD45+ plasma cells and CD56, CD87 and CD126 were less. The expression sVEGF was comparable Conclusion: In this study we demonstrate differences between CD45+ and CD45− plasma cells in patients with monoclonal gammopathies. These findings are important for understanding the disease biology and provide an insight into the functional differences seen between these two populations. The increased expression of CD19 in the CD45+ cells supports the notion that these cells are likely to be at an earlier developmental stage. The comparable CD56 expression is not in accordance with previous studies and needs to be examined in a larger group of patients. Increased expression of sVEGF and CD126 as well as the adhesion molecules is in accordance with increased responsiveness and dependence of the CD45+ cells to VEGF and IL-6 and the increased proliferative rates. These findings indirectly support the hypothesis that CD45 negative cells are less dependent on the marrow microenvironment and the cytokine milieu that it provides.

Abstract Background: Absolute lymphocyte count (ALC) recovery is an independent prognostic factor for survival for different hematological malignancies treated with autologous stem cell transplantation. Recently, we reported superior overall survival (OS) in patients with follicular lymphomas that presented with a higher ALC (ALC ≥ 1 x 109/L) at diagnosis. The role of ALC at diagnosis on survival in T cell lymphomas is not known. Methods: All patients evaluated at the Mayo Clinic for T cell lymphomas from October 1984 until April 2005 were analyzed in the study. The primary objective of the study was to assess the role of ALC at diagnosis and survival in T cell lymphomas. ALC at diagnosis was obtained from the standard complete blood cell count (CBC). Results: 223 patients with T cell lymphomas were included in the study. The histology included: peripheral T-cell lymphoma-unspecified (40%), anaplastic large cell (13%), angioimmunoblastic (10%), angiocentric (4%), intestinal T-cell (2%), and other (31%). The median follow-up was 18.6 months (range: 1 month – 229 months [19 years]). The sample population included 60% male and 40% females with a median age of 60 years (15–90 years). The median ALC at diagnosis was 1.2 x 109/L (range: 0.04–6.7 x 109/L). ALC as a continuous variable was identified as predictor for OS in the univariate analysis (HR= 0.690, 95%CI: 0.542–0.862, p < 0.0006). ALC ≥ 1 x 109/L was selected as the dichotomized value because it yielded the maximum difference in survival by c2 analysis looking at different cut-point from 0.6 to 1.7 x 109/L that were included between the 25% and 75% quartiles. Univariately, ALC ≥ 1 x 109/L was also identified as a predictor for OS (HR = 0.682, 95%CL= 0.578–0.804, p < 0.0001). Patients (N = 122) with an ALC ≥ 1 x 109/L experienced superior survival compared to patients (N = 101) with an ALC < 1 x 109/L [median OS: 76.3 vs 10.6 months, respectively; and 5 years OS estimates of 53% vs 23%, respectively, p < 0.0001]. When ALC ≥ 1 x 109/L was compared to the international prognostic index (IPI), ALC ≥ 1 x 109/L remained an independent predictor for survival in the multivariate analysis (HR = 0.779, 95%CL: 0.655–0.925, p < 0.004). Conclusion: This study demonstrates ALC as an independent predictor for OS in T cell lymphomas, suggesting that the host immune system affects survival in this group of patients.

Abstract Abstract 1604 Background EBV (+) DLBCL of the elderly is a lymphoproliferative disorder recently included as a provisional entity in the 2008 WHO classification of lymphoid tumors. Defined as EBV (+) DLBCL in patients over the age of 50 years without known immunosuppression, information is evolving in this entity. To date, the true incidence of EBV (+) DLBCL in adults remains imprecisely determined and may vary regionally. This study sought to determine the incidence, presenting clinical characteristics, and outcome of EBV (+) in an unselected cohort of DLBCL patients enrolled in a prospective observational study. Methods The University of Iowa/Mayo Clinic SPORE Molecular Epidemiology Resource (MER) is a prospective, longitudinal observational study designed to collect information on patterns of care and outcomes for patients with newly diagnosed lymphoma. Patients seen at the Mayo Clinic, Rochester MN and the University of Iowa within 9 months of their initial diagnosis of lymphoma are offered enrollment. HIV (+) patients are excluded. Baseline patient reported data, clinical data and initial management are collected using a standard protocol and a central pathology review is performed. After enrollment, patients are actively followed for events (disease progression, retreatment, and death) and disease related comorbidities. Tissue Micro Arrays (TMA) are constructed on available primary biopsy specimens. Epstein Barr Encoded RNA (EBER) EBV testing was performed by in-situ hybridization, and scored by an expert hematopathologist. EBER reactivity in more than 30% of malignant cells were required for EBV(+) designation. All DLBCL patients from the MER with available TMA excluding primary mediastinal DLBCL and post transplant lymphoproliferative disorders (PTLD) are included in the current analysis. Event free survival (EFS) was defined as time from diagnosis until recurrence, retreatment, or death due to any cause. Results 184 newly diagnosed DLBCL patients with available TMAs were enrolled in the MER from 2002–2009. The median age at enrollment was 62 (range 18–89) and 57% were male. 89.7% were treated with immunochemotherapy. At a median follow-up of 66 months (range 1–116), 80 patients (43%) had an event which included 59(32%) deaths. TMA testing was positive for EBV in 13 (7 %) samples with an even distribution among age groups. There was a trend toward higher percentage of stage III/IV disease (85 vs 57%, p = 0.052), and BM involvement (46 vs 16%). EBV (+) was not associated with other extranodal disease or further identifiable differences in presenting clinical characteristics. Controlling for IPI, the hazard ratio for EFS among EBV+ in DLBCL pts over 50 was 0.41 (95% CI = 0.13–1.32) p = 0.14. EFS and OS curves for pts over 50 are shown below. There were no events or deaths in the 4 EBV+ pts under age 50. Conclusions EBV+ DLBCL represents a small proportion of DLBCL patients presenting for care to our academic medical centers, consistent with reports from other regions. Substantial unique clinical characteristics at presentation for those pts with EBV+ disease were not identified, and outcomes were no worse than EBV (−) counterparts. Given the apparent regional differences in reports of EBV(+) DLBCL of the elderly, future clinical series will need to establish a more precise definition or determine more distinctive features to justify adoption of EBV(+) DLBCL of the elderly as a full entity in the WHO classification. Disclosures: No relevant conflicts of interest to declare.