Diagnostic role and prognostic significance of a simplified immunophenotypic classification of mature B cell chronic lymphoid leukemias

Subtype Distribution, Clinical Features, and Survival in B-cell Chronic Lymphoproliferative Disorders in China: A Review of 1592 Cases

BACKGROUND

B-cell chronic lymphoproliferative disorders (B-CLPDs) are characterized by the sustained accumulation of monoclonal B cells. Limited studies have systematically described the clinical features and outcomes of the whole patient group, especially in Eastern populations.

PATIENTS AND METHODS

A total of 1592 patients with newly diagnosed B-CLPD were enrolled. Chronic lymphocytic leukemia (CLL) accounted for 39%, and Waldenström macroglobulinemia (WM), leukemic marginal zone lymphoma, follicular lymphoma (FL), and mantle cell lymphoma (MCL) constituted 13%, 13%, 9%, and 8% of cases, respectively.

RESULTS

The median age at diagnosis was 58 years, and the male/female ratio was 1.8:1. The 17p and 11q deletions were most common in MCL (36% and 17%, respectively), and 13q deletion and trisomy 12 were most frequent in CLL (35% and 21%, respectively). Patients with leukemic MCL had significantly worse survival than that of patients with other disease entities, with a 3-year overall survival (OS) of 58%, followed by 68.2% for WM/lymphoplasmacytic lymphoma. Those with CLL, leukemic marginal zone lymphoma, and FL had relatively favorable outcomes, with a 5-year OS > 80%. The survival of patients with B-CLPDs has improved over time with the emergence of novel drugs (3-year OS improvement from 82.1% to 92.2%). The improvement in survival mainly resulted from improvement among patients with MCL, WM/lymphoplasmacytic lymphoma, and FL. On multivariate analysis, only hemoglobin, lactate dehydrogenase, and 17p deletion were independently associated with survival (hazard ratio, 1.6, 2.0, and 3.1, respectively).

CONCLUSIONS

Comprehensive analysis of the clinical characteristics, immunophenotypic profiles, and cytogenetic features can be helpful in the differential diagnosis, especially for patients without a non-bone marrow biopsy specimen available. Universal prognostic factors could help with the early detection of high-risk patients and stratification for risk-adapted therapy.

Expression of CD43 in chronic lymphoproliferative leukemias

BACKGROUND

CD43 has been used on histological samples for the differential diagnosis of lymphoproliferative disorders but there is scarce data on its use by flow cytometry (FC). We set out to characterize the expression of CD43 by FC in B-cell lymphoproliferative disorders and to determine its possible role in the differential diagnosis of these malignancies.

METHODS

We analyzed the expression of CD43 in clonal B-cell lymphoproliferative disorders with exclusive peripheral blood and/or bone marrow involvement based on their Moreau chronic lymphocytic leukemia (CLL) score with particular emphasis on Moreau CLL score 3 (MS3) cases, which often present a diagnostic challenge. The cohort included 433 CLL (score 4-5), 34 MS3 and 166 lymphoproliferative disorders with lower scores.

RESULTS

Generally, the higher the Moreau CLL score, the higher CD43-positivity (425/443 [96%] for CLL, 23/34 [67%] for MS3 and 18/166 [11%] for cases with lower scores). MS3 cases constituted 5.4% of all cases and were more frequently CD5, CD200, CD43-positive and had del(q13) than score 0-2 cases. Among MS3 cases, del(13q) cases were predominantly CD43-positive (12/13).

CONCLUSIONS

The frequency of CD43-positivity increases sharply with the Moreau score. MS3 cases seem to include both CLL and non-CLL lymphoproliferative disorders and CD43 could aid in the differential diagnosis between the two. However, studies analyzing the correlation between CD43 expression and the underlying biologic changes of these cases are warranted. © 2017 International Clinical Cytometry Society.

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

Flow cytometric immunophenotyping (FCI) aids in the differentiation of chronic lymphocytic leukemia (CLL) from mantle cell lymphoma (MCL); however, overlapping phenotypes may occur. CD11c expression has been reported in up to 90% of CLL cases but has rarely been reported in MCL. Whether CD11c can be used to exclude MCL has not been directly addressed. FCI reports were reviewed for 90 MCL cases (44 patients) and 355 CLL/small lymphocytic lymphoma (SLL) cases (158 patients). MCL cases were confirmed by cyclin D1 immunoreactivity and/or t(11;14) detection by karyotyping or fluorescence in situ hybridization. Cases with typical MCL immunophenotypes did not express CD11c. The 2 MCL cases displaying dim CD11c positivity (2 of 44 patients) expressed other markers not typical of MCL. CD11c was detected in 96 (27.0%) of 355 cases of CLL/SLL representing 53 of 158 patients. CD11c expression is rare in MCL and may aid in differentiation of CD5+ B-cell neoplasms, particularly when small samples limit further ancillary testing.

The clinical and biological features of a series of immunophenotypic variant of B-CLL

OBJECTIVES

To describe the clinical and biological features of a series of immunophenotypic variant of B-CLL (v-CLL) characterised by intermediate RMH score, in the absence of t(11;14)(q13;q32) in FISH analysis in comparison with a series of typical CLL.

METHODS

We studied the clinical and biological features of 63 cases of v-CLL and 130 cases of CLL.

RESULTS

We observed significant differences in terms of age <70 yr (P < 0.001), lymphocytosis <20 x 10(9)/L (P < 0.001), lymphocyte doubling time <or=12 months (P = 0.02), high serum beta2-microglobulin levels (P < 0.001) and splenomegaly (P = 0.002); CD38, CD49d, CD1c were more expressed in v-CLL, CD43 in CLL (P < 0.001). IgV(H) mutation and trisomy 12 were more frequent in v-CLL group (P = 0.001; P < 0.001); del13q14 in CLL (P = 0.008). Gene expression profiling of nine v-CLL and 60 CLL indicated that the atypical group presented a specific molecular pattern. After a median follow-up of respectively, 55 (4-196) and 60 months (6-180), 25/42 patients with v-CLL (48%) and 55/93 patients with CLL (59%) were treated. Time to treatment was significantly shorter in IgV(H)-mutated v-CLL vs. mutated CLL (P = 0.006). The median overall survival was worse in v-CLL-mutated cases (P = 0.062).

CONCLUSION

v-CLL should be identified and dealt with separately from classic CLL. In particular, the prognostic markers that are routinely used to characterise classical B-CLL should not be interpreted as having the same meaning.

CD26 expression in mature B-cell neoplasia: its possible role as a new prognostic marker in B-CLL

CD26 (dipeptidyl peptidase IV, DPP IV) is widely expressed by T and natural killer (NK) cells, epithelial and endothelial cells of different tissues, and it is strongly upregulated in activated B-cells; moreover it plays a regulatory role in the neoplastic transformation and progression of various types of tumours. CD26 expression was evaluated by means of flow cytometry in various peripheral B-cell lymphoid tumours: 12 follicular and 12 mantle cell lymphomas, 20 multiple myelomas (MMs), 12 hairy cell leukaemias (HCLs), 112 chronic lymphocytic leukaemias (CLLs), 20 CD5(negative) B-cell chronic lymphoproliferative diseases (CD5(neg) B-CLPDs) and 12 diffuse large cell lymphomas (DLCLs). CD26 expression was absent or barely detectable in follicular and mantle cell lymphomas, high in MMs and HCLs, and variable in CLLs, in CD5(neg) B-CLPDs and in DLCLs. CD26 significantly correlated with CD49d and CD38 expressions (p < 0.0001) in B-CLLs, and there was a significant correlation between CD26 and ZAP-70 expressions or IgVH mutational status (p < 0.0001). After a median follow-up of 36 months, 65 B-CLL patients were treated; taking 10% as the best CD26 cut-off value, Kaplan-Meier curves revealed a significantly shorter time to treatment in the CD26-positive cases (p < 0.0001). Overall, our data indicate that CD26 expression may identify subsets of B-CLL patients with an unfavourable clinical outcome in terms of therapeutic need, thus suggesting its potential role as a marker (together with CD38 and CD49d) in a future routine cytofluorimetric panel to be validated for the prognostic stratification of B-CLLs.

The cut-off levels of CD23 expression in the differential diagnosis of MCL and CLL

Flow cytometric analysis of CD23 expression in CD5-positive B-cells is a widely applied method in the differential diagnosis of chronic lymphocytic leukaemia (CLL) and mantle cell lymphoma (MCL). According to the most accepted criteria, the leukaemic cell population is CD19/CD5/CD23 triple positive in CLL but CD23-negative in MCL. Recently, several groups have reported CD23-positive MCL cases; however, these studies mostly analysed only CD23 positivity but not intensity. To determine the role and the cut-off levels of CD23 positivity and intensity in the differential diagnosis of CLL and MCL, 26 cases of MCL and 84 cases of CLL were compared using flow cytometric analysis. Our results suggest that high values of CD23 positivity (>92.5%) and/or high fluorescence intensity (>44.5 mean fluorescence intensity (MFI)) of CD23 are related to CLL, whereas low CD23 positivity (<30%) is related to MCL. However, cases with intermediate CD23 positivity (between 30 and 92.5%) and lower intensity (<44.5 MFI) can either belong to CLL or MCL. In these cases, additional tests such as FISH analysis of the translocation t(11;14) or immunohistochemical detection of cyclin D1 overexpression are required to differentiate CLL from MCL.

2006 Bethesda International Consensus recommendations on the flow cytometric immunophenotypic analysis of hematolymphoid neoplasia: medical indications

The clinical indications for diagnostic flow cytometry studies are an evolving consensus, as the knowledge of antigenic definition of hematolymphoid malignancies and the prognostic significance of antigen expression evolves. Additionally the standard of care is not routinely communicated to practicing clinicians and diagnostic services, especially as may relate to new technologies. Accordingly there is often uncertainty on the part of clinicians, payers of medical services, diagnostic physicians and scientists as to the appropriate use of diagnostic flow cytometry. In an attempt to communicate contemporary diagnostic utility of immunophenotypic flow cytometry in the diagnosis and follow-up of patients with hematolymphoid malignancies, the Clinical Cytometry Society organized a two day meeting of international experts in this area to reach a consensus as to this diagnostic tool. This report summarizes the appropriate use of diagnostic flow cytometry as determined by unanimous approval of these experienced practitioners.

Predictive value of blood and bone marrow flow cytometry in B-cell lymphoma classification: comparative analysis of flow cytometry and tissue biopsy in 252 patients

OBJECTIVE

To study the effectiveness of peripheral blood (PB) and bone marrow flow cytometric immunophenotyping (FCIP) in predicting the histologic B-cell lymphoma type.

PATIENTS AND METHODS

We studied the FCIP results and tissue histopathology from 252 patients with B-cell lymphoma seen at Mayo Clinic's site in Rochester, MN, between January 1, 1997, and January 1, 2004, who had positive results on PB, bone marrow, or body fluid FCIP and a corresponding diagnostic tissue biopsy specimen.

RESULTS

Most of the B-cell lymphomas studied were low grade, with chronic lymphocytic leukemia (CLL)/small lymphocytic lymphoma being most common. Flow cytometric immunophenotyping histogram analysis was more informative than tabulated percentage antigen positivity; surface immunoglobulin and CD20 staining intensity, CD5 and CD23 positivity, CD10 positivity, and the coexpression of CD11c/CD22 and CD103 were the most pertinent markers. Using these FCIP parameters and strict immunophenotypic definitions for CLL, mantle cell lymphoma (MCL), and hairy cell leukemia, we obtained greater than 95% specificity for each diagnosis. However, we encountered the following exceptions to standard paradigms of B-cell lymphoma-associated FCIP: (1) CD5 expression by disorders distinct from CLL and MCL, (2) lack of uniform CD5 positivity in some CLL and MCL cases, (3) absence of CD10 in approximately 50% of follicular lymphomas, and (4) expression of CD103 by occasional marginal zone lymphomas.

CONCLUSION

Stringent interpretation of PB and bone marrow FCIP results enables identification of certain B-cell lymphoma types. However, the observed exceptions to accepted immunophenotypic paradigms highlight the occasional phenotypic overlap among diseases and emphasize that a systematic approach to FCIP interpretations is key to providing clinically useful diagnostic information.

A multicenter retrospective clinical study of CD5/CD10-negative chronic B cell leukemias

CD5-negative chronic B cell lymphoproliferative disorders in leukemic phase (B-CLPD) are heterogeneous and relatively uncommon pathologies that often lack a histopathological definition because of the absence of accessible pathological tissue. We describe the clinical features and evolution-related variables of 156 patients with CD5/CD10-negative B-CLPD (median age 66 years, range 25-86). The median follow-up was 51 months (range 6-216), and overall 3- and 5-year survival was respectively 87 and 76%; 50 patients needed therapy at diagnosis, 56 during follow-up, and 50 remained untreated until the last control. A combined clinical, histological, cytomorphological, immunophenotypical, and cytogenetic diagnostic approach allowed the complete classification of only a minority of patients as being affected by splenic marginal zone or lymphoplasmacytic lymphoma; the majority of cases remained unclassifiable. Multivariate analysis showed that the clinicohematological variables adversely related to overall survival were serum LDH levels and age, whereas high serum LDH levels, hemoglobin levels of <11 g/dl, and splenomegaly related to treatment-free time (in "wait and see" cases); only splenomegaly related to time to progression (in treated patients). In conclusion, our retrospective study describes the clinical features and variables related to evolution in a large group of patients with CD5/CD10-negative chronic B-cell lymphoid leukemias and underlines the fact that a probable lymphoplasmacytic or marginal zone normal cell origin can be supposed in such leukemic forms, but never surely demonstrated.

Outcomes in patients with splenic marginal zone lymphoma and marginal zone lymphoma treated with rituximab with or without chemotherapy or chemotherapy alone

BACKGROUND

The optimal management of patients with splenic marginal zone lymphoma/marginal zone lymphoma (SMZL) is controversial. The objective of this retrospective study was to compare the outcomes of patients with SMZL who received treatment with rituximab, rituximab plus chemotherapy, or chemotherapy alone.

METHODS

The Leukemia Service database was searched for patients with splenic lymphoma who were registered between May 1995 and October 2004. The indications for treatment were the same as those used for patients with chronic lymphocytic leukemia.

RESULTS

SMZL was confirmed in 70 patients. The median age was 64 years. The median number of CD20 molecules per cell was 69 x 10(3). Forty-three patients required systemic therapy; rituximab in 26 patients, chemotherapy plus rituximab in 6 patients, and chemotherapy alone in 11 patients. Ten additional patients underwent splenectomy, and 17 patients were in the observation group. The overall response rates were 88% with rituximab, 83% with rituximab plus chemotherapy, and 55% with chemotherapy alone; the 3-year survival rates were 95%, 100%, and 55%, respectively. The 3-year failure-free survival (FFS) rates were 86%, 100%, and 45% in the rituximab, rituximab plus chemotherapy, and chemotherapy alone groups, respectively. Rituximab treatments resulted in longer survival and FFS compared with chemotherapy. Rituximab alone resulted in disappearance of splenomegaly in 92% of patients and normalization of absolute lymphocyte counts. In univariate analysis, younger age and rituximab-based therapy were predictive of longer FFS.

CONCLUSIONS

Rituximab with or without chemotherapy was found to have major activity in patients with SMZL. These results may be associated with high levels of cellular CD20 antigen sites. Rituximab should be the treatment of choice, at least in older patients with SMZL who have comorbid diseases.

Histopathology of B-cell chronic lymphocytic leukemia

Histologic and immunohistologic findings of B-cell chronic lymphocytic leukemia/small lymphocytic leukemia are revised in the light of the more recent knowledge on the pathobiology of the disease. The guidelines for the optimal handling of the bioptic samples are provided. The relevance of the examination of trephines and surgical specimens is outlined with special reference to the identification of risk factors in individual patients.

De novo CD5 positive diffuse large B-cell lymphomas with bone marrow involvement in Korean

In CD5 positive (CD5+) mature B-cell lymphomas, newly recognized CD5+ diffuse large B-cell lymphoma (DLBCL) has been characterized by aggressive features. We studied twenty-five cases with CD5+ lymphomas involving bone marrow. Eleven cases were diagnosed as chronic lymphocytic leukemia, six cases were diagnosed as mantle cell lymphoma (MCL), and three cases with morphologic characteristics of MCL and without both the cyclin D1 expression and IGH/CCND1 rearrangement were unclassifiable. The remaining five cases, showing large to medium-sized lymphoid cells with prominent nucleoli and a moderate amount of cytoplasm, were diagnosed as DLBCL. Five DLBCL cases were positive for CD5, CD20, surface immunoglobulin, but negative for CD23. Patients with CD5+ DLBCL showed a high age of onset (median, 68 yr) and two patients expired one month after the diagnosis. Since CD5+ DLBCL forms a distinct subgroup of DLBCL, a study of CD5 expression in DLBCL would be helpful to predict prognosis and to determine future therapeutic strategy. To the best of our knowledge, this is the first report on de novo CD5+ DLBCL in Koreans.

Classification systems for acute and chronic leukaemias

Modern classification systems for acute and chronic leukaemias are based on cytomorphology, cytochemistry, immunophenotyping, immunogenetics and molecular cytogenetics. Morphology forms the initial diagnosis of leukaemia, but generally is not sufficient to identify biologically and clinically relevant subsets within the main categories of leukaemia. Immunophenotyping precisely defines the lineage and stage of differentiation of malignantly transformed haematopoietic cells. This is usually sufficient for precise classification of mature lymphoid malignancies, although immunogenetic and (molecular) cytogenetic studies might be helpful to confirm the diagnosis of disseminated non-Hodgkin's lymphomas. However, certain categories of disease that are clearly defined by cytomorphology and immunophenotyping, particularly acute leukaemias, are still heterogeneous, mainly owing to different underlying leukaemogenic events. Immunophenotyping can reveal subgroups highly suggestive of certain chromosome aberrations but reliable identification of such aberrations requires cytogenetic or molecular studies. Such combined diagnostic information forms the basis of current WHO classification of tumours of haematopoietic and lymphoid tissues. This will be complemented in the near future with novel criteria revealed by microarray gene expression profiling. This chapter summarizes and comments on the currently used immunophenotypic classification systems of acute and chronic leukaemias and on the added value of molecular diagnostics.

Comments on the 2001 WHO proposal for the classification of haematopoietic neoplasms

In the preface, the World Health Organization (WHO) classification vows to offer pathologists, oncologists and geneticists worldwide a system of classification for human neoplasms based on histopathological and genetic features. Standardization of nomenclature and agreed-upon criteria for definition of the various types of cancer are felt to be a prerequisite for progress in clinical oncology, multicentre therapy trials and comparative studies in different countries. In fact, the WHO effort represents the first worldwide comprehensive consensus classification of the haematological malignancies. Consensus was reached among a subgroup of investigators, carefully selected for their experience and contributions to existing classifications. In the present climate of daily new discoveries that yield a constant stream of fascinating insights into the biology of leukaemias and lymphomas and, above all, resulting in an explosion of potential therapeutic targets, the WHO system has taken the stand of compiling established classification approaches and providing order to known facts. This furnishes an essential skeleton upon which to build in the future. The WHO committee decided that sorting neoplasms according to prognosis was neither practical nor necessary and could be misleading. While justifiable at the present time, it is important to realize that the classifications of the haematological malignancies are a moving target and that the trend is to move away from currently accepted gold standards, such as morphological evaluations, in favour of genetic characterizations, especially those with therapeutic relevance. The goal of this chapter is to fill in some gaps that, as per the author's opinion, exist in the WHO classification, predominantly, where it concerns the role of immunophenotyping as a complementary discipline for genotyping through its potential to generate surrogate marker profiles for molecular lesions. By introducing some state-of-the-art classification modalities, some of which are still awaiting confirmation, this chapter also aims to spark excitement and provide a glimpse at the future.