The role of CD11c expression in the diagnosis of mantle cell lymphoma

The unnecessary use of short tandem repeat testing on bone marrow samples in patients after 1 year following allogeneic hematopoietic stem cell transplant

OBJECTIVES

To determine whether the information provided by short tandem repeat (STR) testing and bone marrow (BM) biopsy specimens following hematopoietic stem cell transplant (HSCT) provides redundant information, leading to test overutilization, without additional clinical benefit.

METHODS

Cases with synchronous STR and flow cytometric immunophenotyping (FCI) testing, as part of the BM evaluation, were assessed for STR/FCI concordance.

RESULTS

Of 1199 cases (410 patients), we found the overall concordance between STR and FCI was 93%, with most cases (1063) classified as STR-/FCI-. Of all discordant cases, 75 (6%) were STR+/FCI-, with only 5 (6.7%) cases best explained as identification of disease relapse. Eight cases were STR-/FCI+, representing relapsed/residual disease. Analysis of cases 1 year or more from transplant (54% of all cases) indicated only 9 (1.5%) were STR+/FCI-, and none uniquely identified relapse.

CONCLUSIONS

These data suggest that STR analysis performed 1 year or more post-HSCT does not identify unknown cases of relapse. Furthermore, while STR testing is critical for identifying graft failure/rejection within the first year posttransplant, FCI appears superior to STR at detecting late relapses with low-level disease. Therefore, STR testing from patients 1 year or more post-HSCT may be unnecessary, as BM biopsy evaluation is sufficient to identify disease relapse.

Implementation of International Prognostic Index with flow cytometry immunophenotyping for better risk stratification of chronic lymphocytic leukemia

BACKGROUND

Current chronic lymphocytic leukemia (CLL) International Prognostic Index (IPI) stratifies patients based on clinical, molecular, and biochemical features; however, B-cell markers also influence CLL outcomes. Here, prognostic roles of CD11c, CD38, and CD49d were first evaluated, and then an immunophenotypic score was combined with CLL-IPI for risk stratification of CLL patients.

METHODS

A total of 171 CLL subjects were included, and surface marker expression was assessed by flow cytometry. Levels ≥30% were chosen as cut-off of positivity to a marker; then values of 1 (for CD11c and CD38) or 3 (for CD49d) were assigned and scores determined for each patient's clone immunophenotype.

RESULTS

CD49d positivity was significantly associated with simultaneous expression of CD11c and/or CD38, unmutated IGHV status, and higher β2-microglobulin levels compared to those with CD49d negativity. Moreover, CD49d⁺ patients experienced a shorter progression-free survival and time to treatment. When the immunophenotypic score was combined with CLL-IPI, patients with high-risk immunophenotype had a significantly lower time-to-treatment regardless CLL-IPI.

CONCLUSIONS

Our results suggested clinical utility of an integrated prognostic score for better risk stratification of CLL patients. These results require further validation in prospective larger studies.

Rituximab leads to early elimination of circulating CD20+ T and B lymphocytes in patients with iTTP despite ongoing TPEx

How TPEx impacts rituximab effectiveness in iTTP patients is not fully understood. In iTTP patients on therapeutic plasma exchange, rituximab eliminates circulating CD20+ B and T cells in 24 hours for at least 1 week.

Gamma-Delta T-Cell Acute Lymphoblastic Leukemia/Lymphoma: Immunophenotype of Three Adult Cases

Gamma-delta (γδ) T-cell acute lymphoblastic leukemia/lymphoma (T-ALL) is not commonly observed in adult patients. We report three adult cases and describe their immunophenotypes. Two of these cases were diagnosed as γδ T-ALL; one was diagnosed as a mixture of T-ALL and T-cell non-Hodgkin lymphoma (T-NHL). We also discussed the differential diagnoses.

Blastoid Variant Mantle Cell Lymphoma Expressing Aberrant CD3 and CD10 with Concurrent Small Lymphocytic Lymphoma: Establishment of a Clonal Relationship by B- and T-Cell Receptor Gene Rearrangements

Mantle cell lymphoma (MCL) is an aggressive non-Hodgkin B-cell lymphoma typically expressing CD19, CD20, CD5, FMC-7, CyclinD1, and SOX-11 and harboring the IgH/CCND1 translocation. We report a blastoid variant of mantle cell lymphoma (MCL) involving an inguinal lymph node that, in addition to classical phenotypic and genetic findings, also aberrantly coexpresses surface CD10 and cytoplasmic CD3. Small lymphocytic lymphoma (SLL) was also present in the same lymph node and in the bone marrow. B- and T-cell gene rearrangement studies by PCR show the MCL and SLL to be clonally related. Expression of multiple aberrant antigens and concurrent lymphomas of different classifications can cause a diagnostic challenge. Awareness of such a presentation and integration of the data from morphologic evaluation, flow cytometry, immunohistochemistry, and FISH studies is required for proper diagnosis, prognosis, and therapy.

Expression of aberrant antigens in hematological malignancies: A single center experience

Background and Objective

Aberrant phenotype is a phenomenon of abnormal expression or loss of expression of cell specific lineage marker not associated with specific cell type. Aberrant phenotype expression due to genetic defects may be associated with unfavorable outcome. It can be used to determine minimal residual disease status. The purpose of the study was to find out the occurrence of aberrant phenotypes in leukemia/lymphoma patients.

Methods

One milliliter peripheral blood or bone marrow samples were analyzed on FACS Calibur flowcytometer. The cells were lysed and stained following standard protocol. Data was acquired and analyzed by CellQuest-Pro software. The Antigenic expression was rated as positive when the percentage of positive blast cells was ≥ 20%. In that manner, aberrant phenotype was considered positive when 20% of blast cells show expression of markers.

Results

Of a total 145 cases analyzed, 26 were acute myeloid leukemia, 71 of acute lymphoblastic leukaemia, 48 were of Chronic Lymphoid leukemia on the basis of morphological features and confirmed by flow cytometry. Overall, 19% (28) cases showed aberrant expression of antigens. In 32% (9/28) AML patients, CD5, CD7, CD64dim, CD10, CD117, CD25 and TdT were expressed while in 25% (7/28) ALL patients CD33, CD13, HLA-DR and CD3 were detected. Among chronic leukemia, all aberrant expressions were seen in cases of B-CLL (10/28) only; with CD11c, CD3 and CD10 as the aberrantly expressed markers.

Conclusion

Variability in aberrant phenotype expression was observed in different types of acute and chronic leukemia patients with no prognostic implications on treatment response.

The Role of CD200 and CD43 Expression in Differential Diagnosis between Chronic Lymphocytic Leukemia and Mantle Cell Lymphoma

Objective:

Atypical chronic lymphocytic leukemia (CLL) is most frequently confused with mantle cell lymphoma (MCL). Several markers may contribute to the diagnosis of CLL. However, there is no consensus on which markers are needed to be used in flow cytometry for the diagnosis of CLL. The aim of the present study was to investigate the role of CD43 and CD200 markers in the differential diagnosis between CLL and MCL.

Materials and Methods:

To address this issue, 339 consecutive patients with CLL and MCL were included in the flow cytometry lymphoproliferative disease panel for evaluation of CD43 and CD200 expressions, but not in the Matutes scoring system.

Results:

CD200 was expressed in 97.3% of atypical CLL cases, whereas it was dimly expressed in only 6.1% of MCL cases. CD43 expression was 95.7% in atypical CLL cases. In the MCL cases, its expression rate was 39.4%.

Conclusion:

CD43 and CD200 were found to be more valuable markers than CD22, CD79b, and FMC7. CD43 and CD200 could also be considered as definitive markers in atypical CLL patients, for whom the Matutes scoring system remains ineffective.

Multimodality Technologies in the Assessment of Hematolymphoid Neoplasms

Accurate assessment of tissues for hematolymphoid neoplasms requires an integrated multiparameter approach. Although morphologic examination by light microscopy remains the mainstay of initial assessment for hematolymphoid neoplasms, immunophenotypic analysis by immunohistochemistry and/or flow cytometry is essential to determine the pattern of differentiation and to detect minimal disease when morphology is inconclusive. In some cases, immunophenotypic analysis provides additional information for targeted immunotherapy and prognostication. Genotypic studies, including cytogenetics, fluorescence in situ hybridization, DNA microarray, polymerase chain reaction, and/or next-generation sequencing, are also imperative for subclassification of the genetically defined disease entities in the current World Health Organization classification of hematolymphoid neoplasms. Moreover, genotypic studies can establish clonality, stratify patients to determine appropriate treatment, and monitor patients for treatment response.

Diagnosis of chronic lymphoproliferative disorders by flow cytometry using four-color combinations for immunophenotyping: A proposal of the brazilian group of flow cytometry (GBCFLUX)

BACKGROUND

Multiparametric flow cytometry (MFC) is a powerful tool for the diagnosis of hematological malignancies and has been useful for the classification of chronic lymphoproliferative disorders (CLPD) according to the WHO criteria. Following the purposes of the Brazilian Group of Flow Cytometry (GBCFLUX), the aim of this report was to standardize the minimum requirements to achieve an accurate diagnosis in CLPDs, considering the different economic possibilities of the laboratories in our country. Most laboratories in Brazil work with 4-fluorescence flow cytometers, which is why the GBCFLUX CLPD Committee has proposed 4-color monoclonal antibody (MoAb) panels.

METHODS/RESULTS

Panels for screening and diagnosis in B, T and NK lymphoproliferative disorders were developed based on the normal differentiation pathways of these cells and the most frequent phenotypic aberrations. Important markers for prognosis and for minimal residual disease (MRD) evaluation were also included. The MoAb panels presented here were designed based on the diagnostic expertise of the participating laboratories and an extensive literature review.

CONCLUSION

The 4-color panels presented to aid in the diagnosis of lymphoproliferative neoplasms by GBCFLUX aim to provide clinical laboratories with a systematic, step-wise, cost-effective, and reproducible approach to obtain an accurate immunophenotypic diagnosis of the most frequent of these disorders. © 2016 International Clinical Cytometry Society.

Rituximab-Induced Splenic Rupture and Cytokine Release

Patient: Female, 55

Final Diagnosis: Mantle cell lymphoma

Symptoms: Cytokine release syndrome • hypoglycemia • hypotension • splenic rupture • splenomegaly • vision loss

Medication: —

Clinical Procedure: Case Report

Specialty: Oncology

Immunophenotypic analysis reveals heterogeneity and common biologic aspects in monoclonal B-cell lymphocytosis

Monoclonal B-cell lymphocytosis (MBL) is the presence of small B-cell clones in the peripheral blood of healthy subjects. Most MBL have the characteristic phenotype of chronic lymphocyte leukemia (chronic lymphocytic leukemia (CLL)-like MBL), and depending on the number of monoclonal B-cells, may characterize a preclinical stage of the CLL. However, there are also MBL with an atypical (CD5(+) CD20(+/bright) CD23(dim/-) ) or a CD5(neg) phenotype, which remain largely unexplored. We performed an extended immunophenotypic, cytogenetic, and hematologic analysis in 75 CLL-like, 39 atypical, 50 CD5(neg) , and 7 biphenotypic MBL cases to detect differences or similarities among the MBL subsets. The phenotypic analysis showed expression variations in many surface markers and a wide spectrum of disease-specific phenotypes within each MBL subtype. Interphase fluorescent in situ hybridization analysis showed a different panel of aberrations according to the phenotype. Overall, del(13q14) and +12 were the most common abnormalities (39%), whereas del(11q13), del(17p13), and del(6q23) were detected only in 3, 1, and 0 cases, respectively. A comparison of MBL with overt chronic lymphoproliferations revealed common aspects in the preclinical state, regarding both the kind of cytogenetic aberrations detected and the lymphocyte composition. Our findings highlight not only the heterogeneity among MBL subsets but also indicate common biologic features which differentiate MBL from clinical disease.

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.

Mantle cell lymphoma: a clinically heterogeneous disease in need of tailored approaches

BACKGROUND

Mantle cell lymphoma (MCL) remains incurable using conventional chemotherapeutic approaches. New clinical data show that some patients have a chronic/indolent course and others have a more fulminant course and short survival, similar to that of patients with acute leukemias.

METHODS

This review presents an overview of this aggressive disease, including the diagnosis, epidemiology, prognosis, and management of this protean and challenging condition.

RESULTS

Distinguishing indolent MCL from in situ MCL is important but can be challenging. Molecular exploration has identified SOX11 and HDAC11 as potential candidate genes for discrimination of indolent cases. Improvements in the prognosis in MCL are likely the result of earlier identification of more indolent cases and the application of modern modalities, including rituximab and autologous transplantation. Younger patients may be able to tolerate more intensive therapy, while treatment for elderly or frail patients may focus on maintenance to prolong remission. For patients with relapsed disease, some agents have shown promise, such as lenalidomide and bortezomib. Emerging drugs such as PCI37625 and CAL-101 are being explored in phase I and II studies.

CONCLUSIONS

Although patients with MCL continue to experience poor outcomes, new treatment approaches for various stages of disease are showing promise in improving survival.

Scoring systems in mantle cell lymphoma: a critical point of view

A proposal for a scoring system in the diagnosis of chronic lymphoproliferative diseases other than CLL has been recently published in Cytometry Part B. The authors apply this score for deciding whether or not FISH evaluation for the detection of IGH/CCND1 rearrangements must be performed to exclude Mantle Cell Lymphoma (MCL). In their validation series, no MCL scored <3. We have applied their system to our cases of MCL and also to a small series of Marginal Zone lymphomas. In our hands, the scoring system as has been published does not discriminate adequately between both entities. We propose using the negativity of a marker, CD11c, instead of the platelet count to improve the results. However, we believe that given the clinical and prognostic implications of the diagnosis of MCL, scoring systems should be greatly ameliorated prior to their generalized use.