B-cell Chronic Lymphocytic Leukemia with Aberrant CD8 Expression: Genetic and Immunophenotypic Analysis of Prognostic Factors

CD4+ chronic lymphocytic leukemia in an 86-year-old male veteran: A case report

CD4+ chronic lymphocytic leukemia (CLL) represents an extremely rare example of phenotypic aberrancy within CLL. We present a case of an 86-year-old male veteran with a history of multiple comorbidities who was incidentally diagnosed with CD4+ CLL during a routine peripheral blood workup. This case highlights the diagnostic challenges and characteristic features of CD4+ CLL, including flow cytometric analysis, molecular, and fluorescence in situ hybridization findings. The patient was classified as asymptomatic CLL Rai stage 0, warranting regular monitoring without a need for treatment intervention.

Clinical and prognostic significance of aberrant T-cell marker expression in 225 cases of de novo diffuse large B-cell lymphoma and 276 cases of other B-cell lymphomas

Expression of T-cell markers, generally investigated for immunophenotyping of T-cell lymphomas, is also observed in several types of B-cell lymphomas, including diffuse large B-cell lymphoma (DLBCL). We previously reported that CD5 expression in DLBCL is an inferior prognostic factor in the era of rituximab. However, data regarding the frequencies, histological relevance, and prognostic importance of T-cell markers other than CD5 are currently unavailable. In the present study, we comprehensively evaluated the expression of T-cell markers (CD2, CD3, CD4, CD5, CD7, and CD8) in 501 B-cell lymphomas, including 225 DLBCLs, by flow cytometry and subsequent immunohistochemistry. T-cell markers other than CD5, such as CD2, CD4, CD7, and CD8, were expressed in 27 (5%) patients, and notably, all of these cases were classified as large B-cell lymphoma subtypes: 25 DLBCLs and 2 intravascular large B-cell lymphomas. CD5 and other T-cell markers were expressed in 15% (31/225) and 10% (25/225) of DLBCL cases, respectively. Five of them co-expressed CD5 and other T-cell markers. Retrospectively analyzing the prognostic relevance of T-cell markers in 169 patients with primary DLBCL treated with rituximab-based chemotherapy, we showed that only CD5 was a strong predictor of poor survival. This study provides information about the occurrence of T-cell markers other than CD5 in B-cell lymphomas, their frequent histological subtypes, and their prognostic significance in DLBCL. CD5 was reconfirmed as a negative prognostic marker in DLBCL patients receiving rituximab-inclusive chemotherapy, whereas T-cell markers other than CD5 were found to have no impact on clinicopathological and survival analyses.

CD8 expression in B chronic lymphocytic leukemia: A case of immuno-phenotypic aberrancy

Immuno-phenotyping forms an integral part of laboratory work up of Chronic lymphocytic leukemia (CLL). Aberrant antigen expressions are a known phenomenon in leukemic blasts, however cross lineage antigen expression is rarely seen in mature B cell leukemia, the reported percentages varying from 1% to 3% in Europe and North America.

CASE DETAILS

We report a case of Rai stage 1 CLL showing aberrant expression of CD8 on flow cytometry. The patient had stable disease at a follow up of 9 months with no requirement of initiation of treatment.

DISCUSSION

CD8 expression in CLL is rare and approximately 120 cases have been reported from Western population. To the best of our knowledge, this is the first case to be reported from India. The prognostic significance has been variably reported from favorable to poor. At present, our case reflects the phenotypic heterogeneity of leukemia. Long term follow up and evaluation of more cases is required to predict the prognostic role in our patient population. © 2017 International Clinical Cytometry Society.

Surface profiles for subclassification of chronic lymphocytic leukemia

Chronic lymphocytic leukemia (CLL) has a variable clinical course. Some patients have stable disease while others progress and require treatment. Levels of several cluster of differentiation (CD) antigens are known to correlate with prognosis and may be used to stratify patients according to risk. In this review, we summarize current information on surface CD antigens found on CLL, their pathological significance and their detection using CD antibody microarrays. The use of extensive immunophenotypic patterns or surface profiles as disease signatures for CLL subclassification, prognosis and patient management is discussed with a focus on triaging patients with CLL with progressive disease.

Investigating the role of CD38 and functionally related molecular risk factors in the CLL NOD/SCID xenograft model

We explored the role of CD38 and functionally associated molecular risk factors in a recently described chronic lymphocytic leukemia (CLL) nonobese diabetic/ severe combined immunodeficient xenograft model. Intravenous injection of peripheral blood mononuclear cells from 73 patients with CLL into 244 mice resulted in robust engraftment of leukemic cells into the murine spleens detected 4 wks after transplantation. Leukemic cell engraftment correlated significantly (P < 0.05) with markers reflecting disease activity, e.g., Binet stage and lymphocyte doubling time, and the expression of molecular risk factors including CD38, CD49d, ZAP-70, and IgVH mutational status. Increased engraftment levels of CD38+ as compared to CD38- CLL cells could be attributed, in part, to leukemic cell proliferation as evidenced by combined immunostaining of murine spleen sections for Ki-67 and CD20. In short-term (24 h) homing assays, CD38+ CLL cells migrated more efficiently to the bone marrow of the recipient animals than their CD38- counterparts. Finally, CD38 expression by the leukemic cells was found to be dynamic in that it was regulated not only by elements of the murine microenvironment but also by co-engrafting non-malignant human T cells. This model could be useful for evaluating the biological basis of CLL growth in the context of the hematopoietic microenvironment as well as preclinical testing of novel compounds.

Using gene co-expression network analysis to predict biomarkers for chronic lymphocytic leukemia

BACKGROUND

Chronic lymphocytic leukemia (CLL) is the most common adult leukemia. It is a highly heterogeneous disease, and can be divided roughly into indolent and progressive stages based on classic clinical markers. Immunoglobin heavy chain variable region (IgVH) mutational status was found to be associated with patient survival outcome, and biomarkers linked to the IgVH status has been a focus in the CLL prognosis research field. However, biomarkers highly correlated with IgVH mutational status which can accurately predict the survival outcome are yet to be discovered.

RESULTS

In this paper, we investigate the use of gene co-expression network analysis to identify potential biomarkers for CLL. Specifically we focused on the co-expression network involving ZAP70, a well characterized biomarker for CLL. We selected 23 microarray datasets corresponding to multiple types of cancer from the Gene Expression Omnibus (GEO) and used the frequent network mining algorithm CODENSE to identify highly connected gene co-expression networks spanning the entire genome, then evaluated the genes in the co-expression network in which ZAP70 is involved. We then applied a set of feature selection methods to further select genes which are capable of predicting IgVH mutation status from the ZAP70 co-expression network.

CONCLUSIONS

We have identified a set of genes that are potential CLL prognostic biomarkers IL2RB, CD8A, CD247, LAG3 and KLRK1, which can predict CLL patient IgVH mutational status with high accuracies. Their prognostic capabilities were cross-validated by applying these biomarker candidates to classify patients into different outcome groups using a CLL microarray datasets with clinical information.

CD4 and CD8: an inside-out coreceptor model for innate immune cells

CD8 and CD4 are expressed by several cell types that do not express TCR. These include DCs, macrophages, monocytes, and NK cells. CD8(+) monocytes and macrophages are abundant at the site of pathology in many rat disease models, particularly those involving immune complex-mediated pathology. Indeed, in some disease models, CD8(+) macrophages correlate with severity of pathology or directly cause pathology or tumor cell killing. Evidence suggests CD8 or CD4 can enhance FcgammaR-dependent responses of human monocytes. Building on data that key components of TCR and FcgammaR signaling can substitute one another efficiently, we postulate that CD4 and CD8 operate with FcgammaR and potentially other receptors to enhance responses of T cells and various innate immune cells. Our model suggests CD8 on myeloid cells may contribute directly to tumor killing and tissue pathology by enhancing FcgammaR responses. Moreover, the model suggests a role for CD8 in cross-presentation of antibody-associated antigen by DCs and a new mechanism to regulate TCR sensitivity.

Correlation of ZAP-70 expression in B cell leukemias to the ex vivo response to a combination of fludarabine/genistein

The role of ZAP-70 expression on the ex vivo response of blood cells from CLL and PLL patients to a combination of fludarabine, a purine analog, and genistein, a tyrosine kinase inhibitor was studied. Patient cells were studied for the expression of ZAP-70 mRNA and its relation to the induction of apoptosis in response to treatment with genistein 15-60 muM and/or fludarabine 3 muM. The combination of genistein and fludarabine resulted in a significantly increased induction of apoptosis relative to the fludarabine alone. The ex vivo patient cells with a high ZAP-70 expression underwent more apoptosis in response to genistein than did patient cells with a low ZAP-70 mRNA expression. In contrast, basal IL-10 mRNA expression correlated negatively with apoptosis induction in response to genistein (P < 0.01). These studies suggest that, in malignant B cells that express elevated levels of the ZAP-70 signaling molecule, genistein may inhibit the ZAP-70 tyrosine kinase activity, resulting in cell death. The ZAP-70 may serve as a target for therapy. In addition, these studies suggest that the IL-10 expression by malignant B cells may not only suppress anti-tumor T cell responses in vivo, but also promote the survival of malignant B cells despite treatment with chemotherapeutic agents.

The GNAS1 T393C polymorphism is associated with disease progression and survival in chronic lymphocytic leukemia

PURPOSE

B-cell chronic lymphocytic leukemia (B-CLL) is characterized by the accumulation of monoclonal mature B cells. The G protein Galphas subunit has been linked to proapoptotic processes in cancer cell lines. The TT genotype of the GNAS1 T393C polymorphism is associated with increased Galphas transcript levels and a more favorable clinical course in different solid cancers.

EXPERIMENTAL DESIGN

We retrospectively genotyped 144 patients with B-CLL to examine a potential association between T393C genotypes with progression-free survival (time from diagnosis to initiation of chemotherapy) and overall survival.

RESULTS

The C-allele frequency in the patient group was 0.57 and not significantly different from that of healthy blood donors. Median progression-free survival was significantly different between genotypes (TT 130 months; TC 100 months; CC 31 months; P = 0.0066). Multivariable analysis showed that besides of ZAP-70 (P = 0.005) and Binet stage (P < 0.001), the T393C polymorphism was an independent prognostic factor for progression-free survival [hazard ratio (HR) CC versus TT 2.7; P = 0.010]. In Binet A stages, ZAP-70-positive patients with CC genotypes had a HR of 4.4 to receive first therapy compared with ZAP-70-negative patients with T-alleles (P = 0.0001). Regarding overall survival, CC genotypes (median overall survival, 197 months) were at highest risk for death compared with T-alleles (median overall survival, 310 months) in both univariate (HR, 4.8; P < 0.0001) and multivariable analysis (HR, 5.6; P = 0.002).

CONCLUSIONS

Here, we show that the GNAS1 T393C status is a novel independent prognostic marker in patients with B-CLL. These results could help to define patients who could benefit from an early individualized therapy.

Immunophenotypic and genetic characterization of a CD8 positive Mantle Cell Lymphoma in a patient with concomitant Mycosis Fungoides

Mantle cell lymphoma (MCL) is immunophenotypically characterized by cell surface co-expression of CD19, CD20, CD5, IgM and FMC7. However, the concomitant presence of other antigens distinctive of a particular leukocyte subset, e.g. T-lymphocytes, is an exceptional finding in MCL. Here, the first case of a blastic MCL in leukaemic phase with aberrant expression of the T-cell associated antigen CD8 occurring in a patient with concomitant Mycosis fungoides is described. Comprehensive immunophenotypic analysis showed that the MCL cells expressed the typical B-lymphocytic markers, were CD5 and CD8 positive, but did not express other T-cell proteins, such as CD2, CD3, CD4, CD7, TCRalphabeta and TCRgammadelta. The MCL cells expressed both CD8alpha and CD8beta chains indicating cell surface presence of CD8alphabeta heterodimers. Intriguingly, expression of the cytotoxic enzymes perforin and granzyme A was detected by RT-PCR. Cytogenetic and molecular genetic analysis of the lymphoma cells confirmed cyclin D1 overexpression secondary to the t(11;14)(q13;32) chromosomal translocation. Furthermore, trisomy 11, trisomy 14 and extra copies of t(11;14) translocated chromosomes were detected in sub clones of the analyzed MCL cells. Clinically, an aggressive course of disease including cerebral lymphoma involvement was noted in the reported patient. Hence, systematic studies addressing the incidence, biology and clinical behavior of this form of MCL seem to be justified in future.

Combined analysis of ZAP-70 and CD38 expression as a predictor of disease progression in B-cell chronic lymphocytic leukemia

Prognostic predictions in B-cell chronic lymphocytic leukemia (B-CLL) at early clinical stage are based on biological disease parameters, such as ZAP-70 and CD38 protein levels, genomic aberrations as well as immunoglobulin variable heavy chain gene (IgV(H)) mutation status. In the current study, ZAP-70 and CD38 expressions were examined by flow cytometry in 252 patients with B-CLL. Cytoplasmic ZAP-70 expression in more than 20% (ZAP-70(+)) and surface CD38 expression on more than 30% (CD38(+)) of B-CLL cells were associated with an unfavorable clinical course. The levels of ZAP-70 and CD38 did not change over time in the majority of patients where sequential samples were available for analysis. Combined analysis of ZAP-70 and CD38 yielded discordant results in 73 patients (29.0%), whereas 120 patients (47.6%) were concordantly negative and 59 patients (23.4%) were concordantly positive for ZAP-70 and CD38 expression. Median treatment-free survival times in patients whose leukemic cells were ZAP-70(+)CD38(+) was 30 months as compared to 130 months in patients with a ZAP-70(-)CD38(-) status. In patients with discordant ZAP-70/CD38 results, the median treatment-free survival time was 43 months. Thus, ZAP-70 and CD38 expression analyses provided complementary prognostic information identifying three patient subgroups with good, intermediate and poor prognosis. Over-representation of high-risk genomic aberrations such as 17p deletion or 11q deletion and distribution of the IgV(H) mutation status in B-CLL discordant for ZAP-70/CD38 pointed toward a distinct biologic background of the observed disease subgroups. This finding was also supported by microarray-based gene expression profiling in a subset of 35 patients. The expression of 37 genes differed significantly between the three groups defined by their expression of ZAP-70 and CD38, including genes that are involved in regulation of cell survival and chemotherapy resistance.