Diagnostic usefulness and prognostic impact of CD200 expression in lymphoid malignancies and plasma cell myeloma

Prognostic impact of CD200 and CD56 expression in pediatric B-cell acute lymphoblastic leukemia patients

This study aimed to determine the prognostic impact of CD200 and CD56 expression in pediatric B cell acute lymphoblastic leukemia (B-ALL) patients, both of which have been implicated in immune tolerance and previously suggested as independent risk factors. CD200 has a central role in immune tolerance that protects stem cells and other critical tissues from immune damage. The expression of CD200/CD56 in leukemic blasts were assessed in leukemic blasts before chemotherapy in 43 bone marrow (BM) and/or peripheral blood (PB) samples by flow cytometry. Twenty eight of 43 B-ALL cases (65%) showed CD200 positive expression, 5 of 43 cases (11.6%) showed CD56 expression, and only 2 patients (4.7%) expressed both CD200 and CD56. Patients with CD200⁺ and CD56⁺ were significantly associated with lower platelet count; less tendency for induction of remission response as compared to negative ones (p = .01 for both). The overall survival (OS) and DFS were significantly shorter in CD200⁺ and CD56⁺ cases as compared to those with CD200^- and CD56^- expression. In conclusion, CD200 and/or CD56 positive expression in B-ALL at diagnosis suggest a poor prognosis and may be associated with biological aggressiveness.

Chimeric Antigen Receptor T-Cell Therapy for Chronic Lymphocytic Leukemia: A Narrative Review

The treatment landscape for chronic lymphocytic leukemia (CLL) is changing rapidly. Novel targeted agents such as ibrutinib, venetoclax, and idelalisib have had a significant effect on first-line, relapsed/refractory, and high-risk disease. Despite these advances, there are continuous needs for new treatment options, especially for patients in whom these novel therapies fail or those who cannot tolerate these novel therapies. In 2011, Porter et al reported the first successful use of autologous chimeric antigen receptor T cells (CARTs) directed against cluster of differentiation (CD)19 in 3 refractory CLL patients. Several groups have since shown success with similar approaches in various settings of CLL, including failure of ibrutinib treatment and in patients who relapse after allogeneic stem cell transplantation. Although CD19-directed CART therapy holds great promise in CLL and other diseases, many challenges and questions remain including: optimization of the lymphodepletion regimen before CART infusion, optimal dosing of CART, a determination of the most effective CART product (T-cell subset[s]) as well as the optimal combinations and therapeutic sequences, and managing treatment-associated adverse events. Clinical trials addressing these challenges are in process. In this timely review, we analyze current state of CART therapy in CLL and attempt answering remaining questions.

Standardisation of minimal residual disease in multiple myeloma

The assessment of the effectiveness of chemotherapy in oncology cannot disregard the concept of minimal residual disease (MRD). In fact, the efforts of numerous scientific groups all over the world are currently focusing on this issue, with the sole purpose of defining sensitive, effective assessment criteria that are, above all, able to give acceptable, easily repeatable results worldwide. Regarding this issue, especially with the advent of new drugs, multiple myeloma is one of the haematologic malignancies for which a consensus has not yet been reached. In this review, we analyse various techniques that have been used to improve the sensitivity of response, aimed at reducing the cut-off values previously allowed, as well as serological values like serum-free light chain, or immunophenotypic tools on bone marrow or peripheral blood, like multi-parameter flow cytometry, or molecular ones such as allele-specific oligonucleotide (ASO)-qPCR and next-generation/high-throughput sequencing technologies (NGS). Moreover, our discussion makes a brief reference to promising techniques, such as mass spectrometry for identifying Ig light chain (LC) in peripheral blood, and the assessment of gene expression profile not only in defining prognostic risk at the diagnosis but also as a tool for evaluation of response.

Flow Cytometric Patterns of CD200 and CD1d Expression Distinguish CD10-Negative, CD5-Negative Mature B-Cell Lymphoproliferative Disorders

OBJECTIVES

The importance of distinguishing mature B-cell lymphoproliferative disorders (B-LPDs) is highlighted by the distinct treatments used for and varying prognoses seen in association with these different diseases. Immunophenotyping allows for accurate and efficient differentiation of many B-LPDs. Recently, we showed that CD200 is highly expressed in hairy cell leukemia (HCL) but not in marginal zone lymphoma (MZL), lymphoplasmacytic lymphoma (LPL), or hairy cell leukemia-variant (HCL-v). Here, we assessed the usefulness of a flow cytometric panel combining CD200 and CD1d with CD25, CD103, and CD11c to distinguish CD10-, CD5- B-LPDs.

METHODS

We analyzed the expression of CD200 and CD1d by flow cytometric analysis in 79 cases of CD10-, CD5- mature B-LPDs.

RESULTS

Distinct patterns of CD200 and CD1d expression were seen in the examined B-LPDs. HCL showed bright positivity for CD200 along with positive staining for CD1d, whereas HCL-v showed low levels of expression for both markers. LPL demonstrated positive staining for CD200 in combination with dim to negative staining for CD1d. In contrast, MZL was commonly positive for CD1d and negative for CD200.

CONCLUSIONS

Flow cytometric analysis of CD200 and CD1d, along with CD25, CD103, and CD11c, can aid in the diagnosis of CD10-, CD5- mature B-LPDs.

Quantitative flow cytometric evaluation of CD200, CD123, CD43 and CD52 as a tool for the differential diagnosis of mature B-cell neoplasms

BACKGROUND

Distinction between mature B-cell neoplasms can be difficult due to overlapping of immunologic features and clinical manifestations. This study investigated whether quantifying mean fluorescence intensity of four monoclonal antibodies in a flow cytometry panel is useful for the differential diagnosis and characterization of these disorders.

METHODS

The expressions of CD52, CD200, CD123 and CD43 were analyzed in samples from 124 patients with mature B-cell neoplasms. The quantitative estimation of these antigens was assessed by mean fluorescence intensity.

RESULTS

The cases included were 78 chronic lymphocytic leukemias, three atypical chronic lymphocytic leukemias, six marginal zone lymphomas, 11 splenic marginal zone lymphomas, nine lymphoplasmacytic lymphomas, six mantle cell lymphomas, two hairy cell leukemias, two hairy cell leukemias variant, five follicular lymphomas, one Burkitt lymphoma and one diffuse large B-cell lymphoma. The mean fluorescence intensity of CD200 was higher in atypical chronic lymphocytic leukemia, chronic lymphocytic leukemia and hairy cell leukemia cases. CD123 showed higher mean fluorescence intensities in hairy cell leukemia cells. Chronic lymphocytic leukemia, atypical chronic lymphocytic leukemia and mantle cell lymphoma had higher expression of CD43 and all follicular lymphoma cases had very low mean fluorescence intensity values. CD52 expression was consistently positive among all cases.

CONCLUSION

Quantitative evaluation of these markers can be a useful additional tool to better identify some types of mature B-cell neoplasms.

High CD200 expression is associated with poor prognosis in cytogenetically normal acute myeloid leukemia, even in FlT3-ITD-/NPM1+ patients

Overexpression of CD200, a trans-membrane protein belonging to the immunoglobulin superfamily, has been associated with poor prognosis in patients with acute myeloid leukemia (AML). As few data are available in the subset of cytogenetically-normal (CN) AML, we retrospectively evaluated the correlations between CD200 expression and response to therapy in a series of 139 adults with CN-AML. CD200 was expressed in 67/139 (48%) cases; 18 of them (28%) expressed CD200 at high intensity. No differences in CD200 expression rate were observed according to age, WBC count, type of leukemia, FLT3 or NMP1 mutation, and CD56 expression. A higher incidence of CD200 expression was observed in CD34+ cases (P<0.0001) and in BCL2+ patients (P=0.04). Complete remission (CR) was evaluable achieved in 98 patients (70%): 56/71 (79%) in CD200- and 47/67 (63%) in CD200+ patients (P=0.03), with a lower CR rate in patients with high CD200 intensity (9/18, 50%). CD200 expression had a negative impact on long-term outcome. CD200 expression, per se, did not impact on disease-free survival (DFS), but cases with high CD200 expression had a lower 3-year DFS compared to CD200-negative and low-expressing ones (0% vs 65% vs 68%, P=0.019). Three-year overall survival (OS) was 51% in CD200- and 27% in CD200+ patients (P=0.01), with a significant difference among cases with low or high CD200 expression (35% vs 0%, P=0.001). CD200 high expression defined a group with very poor DFS and OS also among the 37 FLT3-/NPM1+: 3-year DFS and OS were 88% and 60% in CD200-, 50% and 32% in CD200 low and 0% and 0% in CD200 high patients, respectively (P=0.01 for DFS and P=0.05 for OS). Our data suggest a negative impact of CD200 expression in CN-AML, with a further worsening in high-expressing cases, also in the subset of FLT3-/NPM1+ patients.

Chronic lymphocytic leukaemia

Chronic lymphocytic leukaemia (CLL) is a malignancy of CD5+ B cells that is characterized by the accumulation of small, mature-appearing lymphocytes in the blood, marrow and lymphoid tissues. Signalling via surface immunoglobulin, which constitutes the major part of the B cell receptor, and several genetic alterations play a part in CLL pathogenesis, in addition to interactions between CLL cells and other cell types, such as stromal cells, T cells and nurse-like cells in the lymph nodes. The clinical progression of CLL is heterogeneous and ranges from patients who require treatment soon after diagnosis to others who do not require therapy for many years, if at all. Several factors, including the immunoglobulin heavy-chain variable region gene (IGHV) mutational status, genomic changes, patient age and the presence of comorbidities, should be considered when defining the optimal management strategies, which include chemotherapy, chemoimmunotherapy and/or drugs targeting B cell receptor signalling or inhibitors of apoptosis, such as BCL-2. Research on the biology of CLL has profoundly enhanced our ability to identify patients who are at higher risk for disease progression and our capacity to treat patients with drugs that selectively target distinctive phenotypic or physiological features of CLL. How these and other advances have shaped our current understanding and treatment of patients with CLL is the subject of this Primer.

Chronic lymphocytic leukemia and small lymphocytic lymphoma: two faces of the same disease

INTRODUCTION

Chronic lymphocytic leukemia (CLL) and small lymphocytic lymphoma (SLL) are considered indolent lymphocytic malignancies, more often requiring active surveillance rather than intervention. Despite the indolent nature of CLL/SLL, treatment is likely indicated in a patients' lifetime. Recent changes in the therapeutic landscape have created more options to the clinician. Areas covered: The authors provide a broad assessment of the current state of disease, including the work-up, prognostic features, and mutational aspects of the disease that should be acknowledged when developing a rational treatment plan. Key studies, guideline recommendations, and expert analysis are used to create this update on CLL/SLL. Expert commentary: The recent pace of treatment additions in CLL/SLL is a welcome addition. Moving forward, it is anticipated that treatment modalities will continue to evolve, leading to additional management options that truly would define CLL/SLL as a chronic disease.

Role of Flow Cytometry in the Diagnosis and Prognosis of Plasma Cell Myeloma

This article provides an overview of the role of flow cytometry in the diagnosis and follow-up of plasma cell myeloma. A brief introduction to the general immunophenotypic features of normal and myeloma plasma cells is provided, followed by a discussion of technical issues as they relate to the application of flow cytometry in this entity. The prognostic and therapeutic utility of flow cytometric immunophenotyping in myeloma is also analyzed, with an emphasis on the growing role of minimal residual analysis as potential biomarker for evaluating treatment efficacy and for tailoring risk-adapted treatment, in prospective clinical trials.

Intragenic Variations in BTLA Gene Influence mRNA Expression of BTLA Gene in Chronic Lymphocytic Leukemia Patients and Confer Susceptibility to Chronic Lymphocytic Leukemia

The aim of this study was to determine the association between polymorphisms in gene encoding B- and T-lymphocyte attenuator (BTLA) and susceptibility to chronic lymphocytic leukemia (CLL) and their influence on mRNA expression of BTLA gene in T and B cells from CLL patients (pts.). The following BTLA single-nucleotide polymorphisms (SNPs): rs2705511, rs1982809, rs9288952, rs76844316, rs16859633, rs9288953, rs2705535, rs1844089, rs2705565, rs2633580 were genotyped with use of TaqMan probes in 321 CLL pts. and in 470 controls. The mRNA levels of human BTLA were determined in subpopulations of T and B cells from 37 CLL patients with use of Applied Biosystems assays. Three SNPs: rs1982809, rs2705511 and rs9288953 were associated with susceptibility to CLL. The frequency of rs1982809[G] allele and rs2705511[C] allele carriers was higher in patients compared to the controls (0.51 vs. 0.41, OR 1.51, 95% CI 1.14-2.02, p = 0.004 and 0.56 vs. 0.44, OR 1.62, 95% CI 1.22-2.16, p = 0.0009, respectively). Furthermore, rs9288953[TT] genotype was overrepresented in CLL pts. compared to the controls (0.22 vs. 0.14, OR 1.74, 95% CI 1.20-2.53, p = 0.004). The evaluation of the influence of BTLA SNPs on BTLA mRNA expression in CLL pts. showed that the presence of rs1982809[G] allele was associated with lower median (±SD) BTLA mRNA expression in T cells (expressed as 2-delta Ct) in CLL pts. as compared to [AA] homozygotes (0.009 ± 0.013 vs. 0.026 ± 0.012, p = 0.03). Our results indicate that rs1982809 BTLA gene polymorphism is associated with mRNA expression level and that variations in the BTLA gene might be considered as potentially low-penetrating CLL risk factor.

CD200 Expression on Plasma Cell Myeloma Cells is Associated with the Efficacies of Bortezomib, Lenalidomide and Thalidomide

Plasma cell myeloma (PCM) is a devastating disease with a highly heterogeneous outcome, with survival ranging from a few months to longer than 10 years. Treatment of multiple myeloma has changed markedly in the past decade due to the development of new drugs such as bortezomib, lenalidomide and thalidomide, which have greatly improved the outcome of PCM. The clinical and prognostic value of immunophenotyping in PCM remains questionable. The aim of this study was to determine the diagnostic and prognostic significance of CD200 expression in newly diagnosed PCM. We retrospectively reviewed the records of 107 patients newly diagnosed with PCM at Showa University Hospital between January 2004 and September 2013. Expression of CD200 was studied by immunohistochemistry. Clinical and pathological parameters were compared between CD200-positive and CD200-negative cases. CD200-positive PCM cases had lower serum albumin (p = 0.0001) compared to those without CD200 expression. Our results showed no significant difference in median overall survival between patients with CD200-positive and CD200-negative PCM. However, there was a strong correlation between CD200 expression and serum albumin level. In the CD200-negative group, median overall survival was significantly longer in patients who received new drug treatment. These findings suggest that CD200 expression is a useful marker for evaluation of the severity of PCM and that lack of CD200 expression may improve the sensitivity of PCM to therapy with new drugs.

CD200R, a co-inhibitory receptor on immune cells, predicts the prognosis of human hepatocellular carcinoma

The inhibitory CD200:CD200 receptor axis is essential in preventing inflammatory responses during early microbial infection. It was reported in several tumor models that CD200 expression is closely associated to tumor progression and the blockade of this pathway may restore anti-tumor responses. Our study for the first time investigates the role of CD200:CD200R axis in relation to tumor progression and prognosis of human hepatocellular carcinoma. CD200 and CD200R protein expressions were evaluated by immunostaining on liver tissue specimens and we found higher expressions of CD200 and CD200R in HCC patients comparing to healthy controls. CD200 expresses in peritumoral, peritumoral stroma and intratumoral regions of HCC while CD200R predominantly expresses in peritumoral stroma. Furthermore, protein intensity of CD200R is positively associated to the diameter of tumor and alpha-fetoprotein level, in addition, patients with higher pathological grade and absence of tumor capsule exhibit higher CD200R expression. CD200R predominantly expresses on infiltrating macrophages and may associate with liver injury. Moreover, both overall and recurrence-free survival rates are significantly lower in patients with high CD200R expression comparing to those with low CD200R expression. Our findings suggest a promising role of CD200R as a prognostic marker in predicting elevated recurrence and reduced survival, and a potential therapeutic target in treating hepatocellular carcinoma.

Clinical impact of CD200 expression in patients with acute myeloid leukemia and correlation with other molecular prognostic factors

CD200, a protein belonging to the immunoglobulin superfamily, has been associated with a poor prognosis in lymphoproliferative disorders and in acute leukemia. We studied the expression of CD200 in a series of 244 patients with diagnosis of acute myeloid leukemia (AML), to evaluate its impact on outcome and its possible association with other known prognostic factors.

CD200 was found in 136/244 (56%) patients, in 41 of whom (30%) with high intensity of expression (MFI ≥ 11). CD200 was more frequent in secondary compared to de novo leukemia (p = 0.0006), in CD34 positive cases (p = 0.00001), in Bcl2 overexpressing cases (p = 0.01), in those wild-type Flt3 (p = 0.004) and with favorable or unfavorable compared to intermediate karyotype (p = 0.0003). CD200+ patients have a two-fold lower probability to attain complete remission, both in univariate (p = 0.006) and multivariate (p = 0.04) analysis. The negative impact of CD200 was found also in overall survival (p = 0.02) and was correlated with the intensity of expression of the molecule (p = 0.024). CD200 has an additive negative impact on survival in patients with unfavorable cytogenetic (p = 0.046) and in secondary leukemia (p = 0.05), and is associate with a worsening of outcome in patients with favorable biological markers, such as mutated NPM (p = 0.02), wild-type Flt3 (p = 0.034), negativity of CD34 (p = 0.03) and of CD56 (p = 0.03).

In conclusion, CD200 is emerging as both a prognostic factor and a potential target of novel therapeutic approaches for AML, aiming to reverse the “do not eat me” signal of CD200 or to manipulate the suppressive immune microenvironment induced by CD200 binding to its receptor.

Chronic lymphocytic leukaemia

Chronic lymphocytic leukaemia (CLL) is the most common leukaemia among the adults in the Western World. CLL (and the corresponding nodal entity small lymphocytic lymphoma, SLL) is classified as a lymphoproliferative disorder characterised by the relentless accumulation of mature B-lymphocytes showing a peculiar immunophenotype in the peripheral blood, bone marrow, lymph nodes and spleen. CLL clinical course is very heterogeneous: the majority of patients follow an indolent clinical course with no or delayed treatment need and with a prolonged survival, while others experience aggressive disease requiring early treatment followed by frequent relapses. In the last decade, the improved understanding of CLL pathogenesis shed light on premalignant conditions (i.e., monoclonal B-cell lymphocytosis, MBL), defined new prognostic and predictive markers, improving patient stratification, but also broadened the therapeutic armamentarium with novel agents, targeting fundamental signaling pathways.

Association of 3' nearby gene BTLA polymorphisms with the risk of renal cell carcinoma in the Polish population

OBJECTIVE

T cells play an important role in antitumor immunity, and molecules regulating T-cell activity could influence cancer susceptibility. The distinct role of coinhibitory receptors in immunosurveillance has been considered. B- and T-lymphocyte attenuator (BTLA) is one of these receptors, which negatively regulate immune responses. The aim of this study was to investigate the association between BTLA gene polymorphisms and susceptibility to renal cell carcinoma (RCC) in the Polish population.

METHODS

Altogether 282 patients with RCC and 480 healthy subjects were genotyped for the following polymorphisms: rs2705511, rs1982809, rs9288952, rs16859633, rs9288953, rs2705535, and rs1844089 using the TaqManSNP Genotyping Assays.

RESULTS

Here, we found that the presence of rs1982809G allele (genotype GG+AG) is associated with increased risk of RCC (odds ratio = 1.38; 95% CI: 1.03-1.86; P = 0.03). In patients with clear-cell RCC (ccRCC) with high-grade (3 and 4) tumors, the frequency of rs1982809[GG] genotype was significantly higher as compared to those with low-grade (1 and 2) tumors and to the controls (0.14 vs. 0.06, P = 0.05 and 0.14 vs. 0.06, P = 0.04, respectively). Moreover, we have noticed the trend for overrepresentation of carriers of rs2705511C allele in patients with RCC as compared with the controls (0.51 vs. 0.44, P = 0.08) Haplotype rs2705511C/rs1982809G/rs9288952A/rs9288953T/rs2705535C/rs1844089G (CGATCG) increased the risk of RCC of 46% (odds ratio = 1.46; 95% CI: 1.08-1.96; Pcorrected = 0.05).

CONCLUSION

Our results indicate that polymorphisms rs1982809 situated in 3' UTR nearby region of BTLA gene might be considered as low-penetrating risk factor for RCC, but results have to be confirmed in further studies.

Ibrutinib enhances chimeric antigen receptor T-cell engraftment and efficacy in leukemia

Anti-CD19 chimeric antigen receptor (CAR) T-cell therapy is highly promising but requires robust T-cell expansion and engraftment. A T-cell defect in chronic lymphocytic leukemia (CLL) due to disease and/or therapy impairs ex vivo expansion and response to CAR T cells. To evaluate the effect of ibrutinib treatment on the T-cell compartment in CLL as it relates to CAR T-cell generation, we examined the phenotype and function of T cells in a cohort of CLL patients during their course of treatment with ibrutinib. We found that ≥5 cycles of ibrutinib therapy improved the expansion of CD19-directed CAR T cells (CTL019), in association with decreased expression of the immunosuppressive molecule programmed cell death 1 on T cells and of CD200 on B-CLL cells. In support of these findings, we observed that 3 CLL patients who had been treated with ibrutinib for ≥1 year at the time of T-cell collection had improved ex vivo and in vivo CTL019 expansion, which correlated positively together and with clinical response. Lastly, we show that ibrutinib exposure does not impair CAR T-cell function in vitro but does improve CAR T-cell engraftment, tumor clearance, and survival in human xenograft models of resistant acute lymphocytic leukemia and CLL when administered concurrently. Our collective findings indicate that ibrutinib enhances CAR T-cell function and suggest that clinical trials with combination therapy are warranted. Our studies demonstrate that improved T-cell function may also contribute to the efficacy of ibrutinib in CLL. These trials were registered at www.clinicaltrials.gov as #NCT01747486, #NCT01105247, and #NCT01217749.

Flow cytometric analysis of CD200 expression by pulmonary small cell carcinoma

BACKGROUND

CD200 is a membrane bound glycoprotein that is expressed by a variety of normal tissues and hematopoietic malignancies. Flow cytometric analysis of CD200 expression has utility in the evaluation of mature B-cell neoplasms, myeloma, and acute leukemia; however, CD200 expression in nonhematopoietic malignancies has not been extensively studied.

METHODS

We studied 14 cases of biopsy proven pulmonary small cell carcinoma in which a discrete CD45 negative, CD56 positive abnormal cell population was identified by flow cytometry. We retrospectively evaluated these cases for flow cytometric and immunohistochemical evidence of CD200 expression.

RESULTS

Twelve of the 14 cases of pulmonary small cell carcinoma showed convincing expression of CD200 by both immunohistochemistry and flow cytometry.

CONCLUSIONS

Pulmonary small cell carcinoma frequently expresses CD200 at a level that can be detected by flow cytometry and immunohistochemistry. CD200 expression therefore may be used to help identify pulmonary small cell carcinoma in flow cytometry specimens and tissue sections. CD200 may also play a role in the biology of pulmonary small cell carcinoma and is a potential target of future therapies. © 2015 International Clinical Cytometry Society.

Immunophenotype of normal vs. myeloma plasma cells: Toward antibody panel specifications for MRD detection in multiple myeloma

In recent years, several studies on large series of multiple myeloma (MM) patients have demonstrated the clinical utility of flow cytometry monitoring of minimal residual disease (flow-MRD) in bone marrow (BM), for improved assessment of response to therapy and prognostication. However, disturbing levels of variability exist regarding the specific protocols and antibody panels used in individual laboratories. Overall, consensus exists about the utility of combined assessment of CD38 and CD138 for the identification of BM plasma cells (PC); in contrast, more heterogeneous lists of markers are used to further distinguish between normal/reactive PCs and myeloma PCs in the MRD settings. Among the later markers, CD19, CD45, CD27, and CD81, together with CD56, CD117, CD200, and CD307, have emerged as particularly informative; however, no single marker provides enough specificity for clear discrimination between clonal PCs and normal PCs. Accordingly, multivariate analyses of single PCs from large series of normal/reactive vs. myeloma BM samples have shown that combined assessment of CD138 and CD38, together with CD45, CD19, CD56, CD27, CD81, and CD117 would be ideally suited for MRD monitoring in virtually every MM patient. However, the specific antibody clones, fluorochrome conjugates and sources of the individual markers determines its optimal (vs. suboptimal or poor) performance in an eight-color staining. Assessment of clonality, via additional cytoplasmic immunoglobulin (CyIg) κ vs. CyIgλ evaluation, may contribute to further establish the normal/reactive vs. clonal nature of small suspicious PC populations at high sensitivity levels, provided that enough cells are evaluated.

CD200/BTLA deletions in pediatric precursor B-cell acute lymphoblastic leukemia treated according to the EORTC-CLG 58951 protocol

DNA copy number analysis has been instrumental for the identification of genetic alterations in B-cell precursor acute lymphoblastic leukemia. Notably, some of these genetic defects have been associated with poor treatment outcome and might be relevant for future risk stratification. In this study, we characterized recurrent deletions of CD200 and BTLA genes, mediated by recombination-activating genes, and used breakpoint-specific polymerase chain reaction assay to screen a cohort of 1154 cases of B-cell precursor acute lymphoblastic leukemia uniformly treated according to the EORTC-CLG 58951 protocol. CD200/BTLA deletions were identified in 56 of the patients (4.8%) and were associated with an inferior 8-year event free survival in this treatment protocol [70.2% ± 1.2% for patients with deletions versus 83.5% ± 6.4% for non-deleted cases (hazard ratio 2.02; 95% confidence interval 1.23-3.32; P=0.005)]. Genetically, CD200/BTLA deletions were strongly associated with ETV6-RUNX1-positive leukemias (P<0.0001), but were also identified in patients who did not have any genetic abnormality that is currently used for risk stratification. Within the latter population of patients, the presence of CD200/BTLA deletions was associated with inferior event-free survival and overall survival. Moreover, the multivariate Cox model indicated that these deletions had independent prognostic impact on event-free survival when adjusting for conventional risk criteria. All together, these findings further underscore the rationale for copy number profiling as an important tool for risk stratification in human B-cell precursor acute lymphoblastic leukemia. This trial was registered at www.ClinicalTrials.gov as #NCT00003728.

Upregulation of CD200 is associated with regulatory T cell expansion and disease progression in multiple myeloma

Immune dysfunction is an important feature of multiple myeloma (MM) leading to infections, enhancement of tumour growth and resistance to chemotherapy. The overexpression of CD200, expansion of T regulatory (Treg) cell and increased levels of immune modulatory cytokines like IL10, IL6 and transforming growth factor beta (TGFβ) were suggested to have a role in this context. The aim of this study was to assess CD200 expression, Treg percentage by flow cytometry and immune modulatory cytokines (IL10, IL6, TGFβ) by enzyme-linked immunosorbent assay in MM patients at diagnosis. This study included 50 MM patients at diagnosis and 20 healthy controls. The positive CD200 expression was detected in 72% of MM patients. Among the CD200 positive group, 4/13 patients (30.8%) were classified as stage I, 18/23 (78.3%) were in stage II and 14/14 (100%) were in stage III; according to International scoring system. Treg percentage was significantly higher in stage III, followed by stage II then stage I (p < 0.01). Serum IL6, IL10 and TGFβ were significantly higher in MM patients as compared with controls (p < 0.01, p < 0.01, p < 0.05, respectively). The increased expression of CD200 and Treg percentages was associated with increased severity biomarkers (serum LDH and β2 microglobulin). The degree of CD200 expression was significantly positively correlated to Treg percentage (r = 0.565, p < 0.01). Analysis of the CD200 negative patients had a better progression free survival (p = 0.032) and overall survival (p = 0.04) as compared with those positive for CD200 expression. These findings illustrate a clear correlation between myeloma cell CD200 expression level and the frequency of immunosuppressive Treg cells. In conclusion, increased expression of CD200, expansion of suppressive Treg cells and elevation of cytokines might have a role in MM progression in this cohort of patients. Copyright © 2015 John Wiley & Sons, Ltd.

A unique population of IgG-expressing plasma cells lacking CD19 is enriched in human bone marrow

Healthy human BM is enriched for PC lacking CD19 that express a prosurvival and distinctly mature phenotype. CD19− PC resist mobilization into blood during immune responses after vaccination as well as B-cell depletion with rituximab.

Flow cytometric analysis of lymphoid enhancer-binding factor 1 in diagnosis of chronic lymphocytic leukemia/small lymphocytic lymphoma

OBJECTIVES

Nuclear overexpression of lymphoid enhancer-binding factor 1 (LEF1) assessed by immunohistochemistry has been shown to be highly associated with chronic lymphocytic leukemia/small lymphocytic lymphoma (CLL/SLL) among small B-cell lymphomas. The purpose of this study was to evaluate the utility of flow cytometric analysis of LEF1 in the diagnosis of CLL/SLL.

METHODS

Normal peripheral blood was used to validate the test. Flow cytometric analysis of LEF1 was performed in 64 patient samples qualitatively and quantitatively by comparing the staining intensity and the ratios of the median fluorescence intensities (MFIs) of LEF1 in B cells of interest to the internal reference cell populations. The results were correlated with the pathologic diagnosis.

RESULTS

Proper sample processing ensured sufficient separation of positive LEF1 staining in T cells from negative staining in normal B and natural killer (NK) cells. Qualitative analysis of patient samples showed that all 25 cases of CLL/SLL but none of the other small B-cell lymphomas were positive for LEF1. Using a B/NK MFI ratio of 1.5 and B/T MFI ratio of 0.45 separated CLL/SLL cases from non-CLL lymphomas.

CONCLUSIONS

Flow cytometric analysis of LEF1 is sufficient to differentiate CLL/SLL from other small B-cell lymphomas and may serve as a useful tool in the diagnosis of CLL/SLL.

Differential expression of CD200 in B-cell neoplasms by flow cytometry can assist in diagnosis, subclassification, and bone marrow staging

OBJECTIVES

To analyze CD200 expression by flow cytometry in a large series of B-cell neoplasms in a variety of tissue types in comparison with benign B-lineage cells.

METHODS

We measured CD200 expression levels in 505 peripheral blood (PB), bone marrow (BM), and lymphoid tissue biopsy specimens, including 364 cases positive for B-cell leukemias and lymphomas.

RESULTS

CD200 expression in chronic lymphocytic leukemia cases was as bright as or brighter than normal PB B cells in nearly all cases, while mantle cell lymphoma (MCL) cases were usually dim or negative. However, rare MCL cases (about 5%) were moderately bright for CD200. Marginal zone lymphomas varied by subtype, with nodal cases brighter, splenic cases dimmer, and extranodal cases heterogeneous for CD200 expression. Follicular lymphoma (FL) cells were brighter for CD200 in BM specimens than in lymph nodes. In some BM specimens, dim CD200 could distinguish FL cells from background hematogones. Large B-cell lymphomas of the non-germinal center type tended to be brighter for CD200 than those of the germinal center type, while Burkitt lymphomas were negative.

CONCLUSIONS

CD200 staining by flow cytometry can be useful in the differential diagnosis of B-cell neoplasms and in their detection in the BM.

New Immunohistochemistry for B-Cell Lymphoma and Hodgkin Lymphoma

Context

B-cell non-Hodgkin lymphoma is a heterogeneous group of lymphoproliferative malignancies with different clinical behaviors and treatments. It is important to differentiate individual B-cell lymphoma to apply the best treatment and management. Morphology and immunohistochemistry are the primary tools used for diagnosing lymphoma. There is a characteristic pattern of expression with immunohistochemical antibodies in most well-defined B-cell lymphomas. Some cases of B-cell lymphoma, however, show unusual morphologic and immunophenotypic features. The new and sometimes more specific antibodies have been developed recently, which may further define those lymphomas. Only with use of the antibodies over time does their true nature and specificity become evident.

Objectives

To present new antibodies for B-cell lymphoma that enhance the probability for diagnosis or can act as alternate markers in unusual cases, in which a B-cell lymphoma does not present with characteristic immunohistochemical staining, and to present prognostic markers that allow for better management of patients with specific B-cell lymphomas.

Data Sources

Data were obtained from literature review and figures from slides in personal practice.

Conclusions

The immunohistochemical antibodies presented in this article increase our ability to understand, diagnosis, and manage patients with B-cell lymphoma.

Gene expression profile for predicting survival of patients with meningioma

Current staging methods are inadequate for predicting the overall survival of meningioma. DNA microarray technologies improve the understanding of tumour progression. We analysed genome wide expression profiles of 119 meningioma samples from two previous published DNA microarray studies. The Cox proportional hazards regression models were applied to identify overall survival related gene signature. A total of 449 genes (109 upregulated and 340 downregulated) were identified as differentially expressed in meningioma. Among these differentially expressed genes, 37 genes were identified to be related to meningioma overall survival. Our 37-gene signature is closely associated with overall survival among patients with meningioma. This gene expression profile could provide an optimization of the clinical management and development of new therapeutic strategies for meningioma.

The role of tumor expression of CD200 in tumor formation, metastasis and susceptibility to T lymphocyte adoptive transfer therapy

CD200 is a cell surface glycoprotein that has been implicated in a variety of human cancer cells and has been thought to play a pro-tumor role. However, in our recent study we have revealed that CD200 on cancer cells inhibits tumor formation and metastasis through inhibition of myeloid cells.

Diagnostic and prognostic significance of CD200 expression and its stability in plasma cell myeloma

Aim

Previous studies showed that CD200 expression is a prognostic factor for plasma cell myeloma (PCM), but the prognostic effect is conflicting between studies. We studied CD200 protein expression and the stability of expression in PCM to clarify its potential utility in diagnosis, prognosis and monitoring of disease.

Method

CD200 expression was studied in 77 cases of PCM by immunohistochemistry on paraffin sections from decalcified bone marrow biopsies.

Result

There were 16 newly diagnosed cases and 61 post-treatment cases from 54 patients: 37 men and 17 women, with a median age of 62 years (range, 41–88 years). CD200 demonstrated moderate to strong membrane expression in positive cases. Fifty-six of 77 cases (73%) showed CD200 expression. Twenty of the 22 (91%) patients with serial specimens demonstrated stable CD200 expression (n=15) or lack of CD200 expression (n=5). One patient lost CD200 expression, while another one gained CD200 expression during treatment. The clinical, pathologic and cytogenetic features between the CD200+ group and the CD200− group were similar in most instances. However, CD200 expression was associated with lower serum β2-microglobulin (p=0.03). There was no significant difference in overall survival and progression-free survival between the CD200+ and CD200− patients (p>0.05).

Conclusions

CD200 is expressed in a majority of PCM cases, and the expression is stable during the treatment process. Therefore, immunohistochemical expression of CD200 is a useful marker for the diagnosis and follow-up of PCM.

Immunological dysregulation in multiple myeloma microenvironment

Multiple Myeloma (MM) is a systemic hematologic disease due to uncontrolled proliferation of monoclonal plasma cells (PC) in bone marrow (BM). Emerging in other solid and liquid cancers, the host immune system and the microenvironment have a pivotal role for PC growth, proliferation, survival, migration, and resistance to drugs and are responsible for some clinical manifestations of MM. In MM, microenvironment is represented by the cellular component of a normal bone marrow together with extracellular matrix proteins, adhesion molecules, cytokines, and growth factors produced by both stromal cells and PC themselves. All these components are able to protect PC from cytotoxic effect of chemo- and radiotherapy. This review is focused on the role of immunome to sustain MM progression, the emerging role of myeloid derived suppressor cells, and their potential clinical implications as novel therapeutic target.

Atypical case of B-cell Chronic Lymphocytic Leukemia presenting with extreme hyperleukocytosis / Hiperleucocitoză extremă într-un caz atipic de leucemie limfatică cronică cu celulă B

Very few cases of chronic lymphocytic leukemia (CLL) presenting with extreme hyperleukocytosis are reported in the literature. We describe the case of a 66 years old woman, with newly diagnosed CLL presenting with extreme hyperleukocytosis of 774.2 x 109/liter, Rai stage III and Binet stage C. The patient has no comorbidities and the CIRS score (cumulative illness rating scale) is well below 6, with normal creatinine clearance. Some other interesting aspects related with this case are the atypical immunophenotype, the expression of Cyclin D1, and the B hepatitis viral infection, which made her diagnosis and treatment challenging. The patient was tested for NOTCH1 mutation and it was positive. There is important evidence that NOTCH1 mutations are associated with rapidly progressive disease and resistance to treatment. The distinction of CLL from mantle cell lymphoma (MCL) is not always easy because some MCLs may mimic CLL clinically, histologically, and/or phenotypically. The hepatitis B prophylaxis for viral reactivation was not available an in the end the patient was treated only with fludarabine and cyclophosphamide, without rituximab. CD200 should be introduced in the routine panel for flow cytometry to distinguish CLL from mantle cell lymphoma and NOTCH1 mutation is associated with poor prognosis and should be evaluated at diagnosis. CLL with extreme hyperleukocytosis presentation is very rare and sometimes an atypical CLL may represent a diagnostic pitfall.

CD200 has an important role in the differential diagnosis of mature B-cell neoplasms by multiparameter flow cytometry

BACKGROUND

Multiparameter flow cytometry is a useful tool for the diagnostic evaluation of mature B-cell neoplasms (MBN). Recently, it has been shown that CD200 may improve the distinction between chronic lymphocytic leukemia (CLL; CD200+) and mantle cell lymphoma (MCL; CD200-), but the role of CD200 expression in atypical CLL and other MBN remains to be established.

METHODS

To address this issue, we investigated the expression of CD200 in 159 consecutive cases of MBN.

RESULTS

CD200 was strongly expressed in CLL and was revealed to be an excellent marker to distinguish CLL from MCL, even in cases of atypical CLL. However, lack of CD200 was not an exclusive finding of MCL, being also observed in other MBNs. Furthermore, CD200 was highly expressed in hairy cell leukemia, being useful in the differential diagnosis of lymphomas with villous lymphocytes. Herein, we propose an algorithm to classify CD5+ MBNs based on the expression of CD200, CD11c, heavy chain immunoglobulins, and Matutes score.

CONCLUSIONS

These results expand the understanding of the CD200 expression in MBNs, giving further support for the inclusion of this marker in the routine investigation by flow cytometry.

CD200 flow cytometric assessment and semiquantitative immunohistochemical staining distinguishes hairy cell leukemia from hairy cell leukemia-variant and other B-cell lymphoproliferative disorders

OBJECTIVES

To evaluate CD200 expression in B-cell proliferative disorders.

METHODS

We analyzed 180 recent specimens of B-cell neoplasms for CD200 expression by flow cytometric immunophenotypic analysis, which is better able to assess relative intensity of staining than immunohistochemical staining.

RESULTS

We found that hairy cell leukemia exhibits a high level of staining for CD200 in comparison to other B-cell lymphoproliferative disorders, including hairy cell leukemia-variant (HCL-V), marginal zone lymphoma, and lymphoplasmacytic lymphoma. We confirmed this observation by semiquantitative immunohistochemical staining.

CONCLUSIONS

Assessment of the CD200 expression level is helpful to distinguish HCL from HCL-V and other B-cell lymphoproliferative disorders and in the differential diagnosis of B-cell neoplasms in general.

Coinhibitory molecules in cancer biology and therapy

The adaptive immune response is controlled by checkpoints represented by coinhibitory molecules, which are crucial for maintaining self-tolerance and minimizing collateral tissue damage under physiological conditions. A growing body of preclinical evidence supports the hypothesis that unleashing this immunological break might be therapeutically beneficial in the fight against cancer, as it would elicit an effective antitumor immune response. Remarkably, recent clinical trials have demonstrated that this novel strategy can be highly effective in the treatment of patients with cancer, as shown by the paradigmatic case of ipilimumab (a monoclonal antibody blocking the coinhibitory molecule cytotoxic T lymphocyte associated antigen-4 [CTLA4]) that is opening a new era in the therapeutic approach to a chemoresistant tumor such as cutaneous melanoma. In this review we summarize the biology of coinhibitory molecules, overview the experimental and clinical attempts to interfere with these immune checkpoints to treat cancer and critically discuss the challenges posed by such a promising antitumor modality.

First molecular cloning and gene expression analysis of a teleost CD200 (OX-2) glycoprotein from rock bream, Oplegnathus fasciatus

CD200 plays an important role in delivering an immunoregulatory signal to the immune system through interaction with its receptor. However, CD200 has not been characterized and its function in teleosts is unknown. In this study, the rock bream (Oplegnathus fasciatus) CD200 gene (RbCD200) was cloned and its expression profile was analyzed after infection with Edwardsiella tarda, Streptococcus iniae or red seabream iridovirus (RSIV). The coding region of RbCD200 cDNA was 855 bp, encoding 284 amino acid residues. The gene consisted of two extracellular Ig-like domains and a transmembrane domain. RbCD200 was highly expressed in the brain, erythrocytes, intestine and stomach of healthy rock bream. In the spleen, RbCD200 gene expression was down-regulated until 48 h after E. tarda exposure, except at 12 h RbCD200 gene expression was down-regulated then up-regulated at 12 h and 24 h after infection with S. iniae and RSIV, respectively. In the whole kidney, the RbCD200 gene was down-regulated in response to infection with E. tarda and S. iniae. However, RSIV infection increased RbCD200 gene expression in whole kidney until 48 h. These results suggest that RbCD200 is differentially expressed in the spleen and whole kidney after infection with different pathogens.

Utility of CD200 immunostaining in the diagnosis of primary mediastinal large B cell lymphoma: comparison with MAL, CD23, and other markers

CD200, an immunoglobulin superfamily membrane glycoprotein, is expressed in a number of B cell lymphoproliferative disorders, including primary mediastinal large B cell lymphoma, but not diffuse large B cell lymphoma, based on a preliminary study. Here, we compare the expression of CD200 with other markers of primary mediastinal large B cell lymphoma, including MAL and CD23, in formalin-fixed, paraffin-embedded histologic sections from a series of 35 cases of primary mediastinal large B cell lymphoma and 30 cases of diffuse large B cell lymphoma. CD200 exhibits the greatest staining sensitivity of the markers studied: 94%, compared with CD23 (69%), MAL (86%), TRAF (86%), and REL (77%). It exhibits staining specificity of 93%, similar to that of CD23 (93%) and MAL (97%), and greater than that of TRAF (77%) and REL (83%). We conclude that CD200 is a practical and useful marker for the diagnosis of primary mediastinal large B cell lymphoma.

CD200 expression in plasma cells of nonmyeloma immunoproliferative disorders: clinicopathologic features and comparison with plasma cell myeloma

The majority of plasma cell myelomas (PCMs) are positive for CD200, a membrane protein with immunosuppressive function. There are no flow cytometry data in the literature on plasma cell CD200 expression in other immunoproliferative disorders. Therefore we used flow cytometry to study the expression of CD200 on plasma cells in diagnostic bone marrow aspirates from 61 patients with monoclonal gammopathy of undetermined significance (MGUS) and 10 patients with lymphoplasmacytic lymphoma (LPL). For comparison, we evaluated CD200 expression in 74 PCM bone marrow biopsies. Thirty-three (54.1%) of 61 MGUS cases and 2 (20.0%) of 10 LPL cases were CD200+. Comparative clinicopathologic parameters for MGUS cases, based on CD200 expression status, showed no differences between the 2 groups. The proportion of CD200+ PCMs (73.0%) in our series was significantly higher than that of CD200+ MGUS (P = .030) and CD200+ LPL (P = .002) cases.

CD 200 - A useful marker in chronic B lymphoprolipherative disorders

Background: The diagnosis and management of the patients with chronic lymphoproliferative diseases have become dependent on immunological criteria. Flow cytometry immunophenotyping is used for rapid and specific diagnosis but there are cases when we are not facing a typical immunophenotype, so there is a constant need to find new markers and new combinations of markers that would allow the improvement and the development of our diagnosis. Aim: Our aim was to evaluate CD 200 expression in different B-cell chronic lymphoproliferative disorders. CD200 is a membrane glycoprotein belonging to the immunoglobulin superfamily and the over-expression of CD200 has been reported in a number of malignancies, including CLL, as well as on cancer stem cells. Methods: We analyzed the CD200 expression in 122 patients diagnosed with chronic lymphoproliferative disorders (100 patients with CLL, 10 patients with splenic marginal zone lymphoma (SMZL), 10 patients with MCL and 2 patients with hairy cell leukemia), in the Department of Hematology of the University Emergency Hospital, Bucharest. We performed immunophenotypical analysis of peripheral blood and bone marrow aspiration on BD FACS Calibur flowcytometer. Results: CD200 was brightly expressed in all 100 CLL patients (100%). In SMZL patients, CD200 was dim positive (40%-60%), in patients with HCL. CD200 was also bright positive (96% and 97%) and in patients with MCL CD200 was negative (1-10%); CD 200 was significantly higher in CLL patients compared with other B-cell chronic lymphoproliferative disorders. We found 14 patients with CD19, CD5 positive population and CD23- , but with high expression of CD 200. Cyclin D1 was negative on bone marrow biopsy in 13/14 of these patients. (1/14 patients were without bone marrow involvement); Conclusions: CD200 has a great impact in diagnosing B- chronic lymphoproliferative disorders, especially when we want to determine the origin of a CD19, CD5 positive population and distinguish between CLL and MCL. CD 23 is a reliable marker in those cases, but, as we showed, CD23 might have a lower specificity than CD200 for CLL. We added CD200 in our panels in order to diagnose chronic lymphoproliferative disorders, not to replace CD 23, but to improve and save time in our diagnostic process. The high expression of CD200 in CLL and HCL could open the option for new- targeted therapy (anti-CD200).