A comparison of flow cytometry, bone marrow biopsy, and bone marrow aspirates in the detection of lymphoid infiltration in B cell disorders

Rare central nervous system lymphomas

Central nervous system (CNS) lymphomas are rare malignancies characterised by lymphoid infiltration into the brain, spinal cord, cranial nerves, meninges and/or eyes in the presence or absence of previous or concurrent systemic disease. Most CNS lymphomas are of the diffuse large B-cell lymphoma (DLBCL) subtype for which treatment strategies, particularly the use of high-dose methotrexate-based protocols and consolidation with autologous stem cell transplantation, are well established. Other histopathological subtypes of CNS lymphoma are comparatively less common with published data on these rare lymphomas dominated by smaller case series and retrospective reports. Consequently, there exists little clinical consensus on the optimal methods to diagnose and manage these clinically and biologically heterogeneous CNS lymphomas. In this review article, we focus on rarer CNS lymphomas, summarising the available clinical data on incidence, context, diagnostic features, reported management strategies, and clinical outcomes.

Clinically Undetected Hodgkin Lymphoma Diagnosed Initially on Bone Marrow Biopsy: A Large Retrospective Observational Study from a Tertiary Care Center

Introduction Hodgkin lymphoma (HL) involving the bone marrow (BM) is relatively rare with an incidence ranging from 4% to 18%. The incidence of primary HL of marrow is 0.25%. To the best of our knowledge, the present study is the largest study on HL diagnosed initially on marrow biopsy.

Objective To establish diagnostic criteria based on clinicopathological and histological features in HL diagnosed first on the marrow.

Materials and Methods This was a retrospective study done from January 2012 to December 2020 that included 36 cases of HL diagnosed initially on BM. Based on the presence of large mononuclear or binucleate Reed–Sternberg (RS)-like cells in a polymorphous inflammatory background, HL was suspected and immunohistochemistry (IHC) with CD15 and CD30 was done. Correlation with subsequent lymph node biopsies was done, wherever possible.

Results Fever (94.4%) was the most common symptom, followed by loss of weight (66.7%). Twenty-one cases (58.4%) had uni/bicytopenia and 15 cases (41.6%) had pancytopenia. Only one case showed suspicious mononuclear RS cells on aspirates and the rest of the cases were diagnosed on trephine biopsy alone. Trephine imprints showed variable cellularity in 13 (36%) cases. Diffuse involvement was seen in 24 cases (66.7%), and focal nodular aggregates were seen in 12 cases (33.3%). Out of 36 cases, 26 cases (19 cases on marrow and 7 cases on lymph node) were confirmed as HL with IHC. Immunophenotype of the RS cells on the marrow was CD30+/CD15+ in (6/29) (20.7%) cases, CD30+/CD15− in (7/29) (24.1%) cases and CD30−/CD15+ in (6/29) (20.7%) cases. Seven cases (26.9%) were diagnosed on subsequent lymph node biopsy as mixed cellularity HL with IHC confirmation. Marrow fibrosis was seen in 16 cases (44.4%), and granulomas were seen in 8 cases (22.2%).

Conclusion In cases presenting with long-standing fever and cytopenias, HL must always be suspected, even if there are no palpable lymph nodes. Bone marrow biopsy is preferable over aspiration in such cases and IHC plays a major role in diagnosing the cases.

Optimal panel of immunohistochemistry for the diagnosis of B-cell non-Hodgkin lymphoma using bone marrow biopsy: a tertiary care center study

Background

Morphological diagnosis of non-Hodgkin lymphoma (NHL) is usually based on lymph node biopsy. Bone marrow biopsy (BMB) is important for staging, and morphology alone can be challenging for subtyping. Immunohistochemistry (IHC) allows a more precise diagnosis and characterization of NHL using monoclonal antibodies. However, there is a need for a minimal panel that can provide maximum information at an affordable cost.

Methods

All newly diagnosed cases of B-cell NHL with bone marrow infiltration between 2017 and 2019 were included. BMB was the primary procedure for diagnosing B-cell NHL. Subtyping of lymphomas was performed by immunophenotyping using a panel of monoclonal antibodies on IHC. The primary diagnostic panel of antibodies for B-cell NHL included CD19, CD20, CD79, CD5, CD23, CD10, Kappa, and Lambda. The extended panel of antibodies for further subtyping included CD30, CD45, CD56, Cyclin D1, BCL2, and BCL6.

Results

All cases of B-cell NHL were classified into the chronic lymphocytic leukemia (CLL) and non-CLL groups based on morphology and primary IHC panel. In the CLL group, the most significant findings were CD5 expression, CD23 expression, dim CD79 expression, and weak surface immunoglobulin (Ig) positivity. In the non-CLL group, they were CD5 expression, positive or negative CD23 expression, strong CD79 expression, and strong surface Ig expression. An extended panel was used for further subtyping of non-CLL cases, which comprised CD10, Cyclin D1, BCL2, and BCL6.

Conclusion

We propose a two-tier approach for immunophenotypic analysis of newly diagnosed B-cell NHL cases with a minimum primary panel including CD5, CD23, CD79, Kappa, and Lambda for differentiation into CLL/non-CLL group and Kappa and Lambda for clonality assessment. An extended panel may be used wherever required for further subtyping of non-CLL.

Comparison of bone marrow aspiration cytology with bone marrow trephine biopsy histopathology: An observational study

INTRODUCTION:

Bone marrow examination is a useful investigative tool for the diagnosis of many hematological and nonhematological disorders. Bone marrow aspiration (BMA) provides information about the numerical and cytological features of marrow cells, whereas bone marrow trephine biopsies (BMB) provide excellent appreciation of spatial relationships between cells and of overall bone marrow structure. We conducted this study with the objective of comparing the accuracy of BMA with BMB in the diagnosis of various hematological disorders.

MATERIALS AND METHODS:

Both BMA and BMB were performed on a total of 130 cases and a comparative evaluation was performed in 100 cases to see the complementary role of both the procedures. However, 30 cases were excluded due to inadequate BMA, BMB, or both. Immunohistochemistry (IHC) was employed whenever required.

RESULTS:

In our study of 100 cases, 87% of cases were confirmed on bone marrow biopsy and in remaining 13% of cases final diagnosis was achieved with the help of other ancillary investigations. These cases were excluded for calculation of concordance rate between BMA and BMB. The concordance and disconcordance rate between BMA and BMB was 72.4% and 27.6%, respectively.

CONCLUSION:

BMA cytology and trephine biopsy histopathology complement each other and the superiority of one method over the other depended on the underlying disorder. Furthermore, application of ancillary techniques such as flow cytometery and IHC proved to be an additional advantage in further typing of various diseases.

The Minimal Residual Disease in Non-Hodgkin's Lymphomas: From the Laboratory to the Clinical Practice

Minimal residual disease (MRD) in non-Hodgkin's lymphomas (NHLs) still represents matter of interest and debate: indeed, the new available treatments offer higher rates of complete responses and MRD negativity than in the past, with a positive impact on the long-term survival. Furthermore, the introduction of more sensitive and accurate molecular techniques, such as digital PCR (ddPCR) and the next generation sequencing techniques (NGS), increased the possibility of identifying molecular targets to be followed after therapy (such as rearrangement of immunoglobulins, fusion genes, or mutations). This review focused on how molecular biology can help to detect MRD in different types of NHLs and how MRD can change the clinical practice in 2019. In follicular lymphoma (FL), contamination of the grafts and molecular disease persistence after transplantation represent a negative prognostic factors. The combination of Rituximab or Obinutuzumab with Bendamustine seems to be the most effective way to clear MRD in FL patients receiving chemo-immunotherapy (further studies are in progress), and also ⁹⁰Yttrium-Ibritumomab-Tiuxetan offers a deep clearance of molecular disease. Finally, molecular MRD can further stratify PET-negative cases, with subjects both PET- and MRD-negative presenting the best outcome. In aggressive lymphomas, MRD has a relevant prognostic power and can represent the platform for immunotherapy (such as CAR-T). In diffuse large B-cell lymphoma (DLBCL), the assessment of MRD in the plasma (where cell-free DNA and exosomes circulate) seems to be more predictive than the bone marrow analysis or peripheral blood mononuclear cells. Finally, NGS technologies could be more useful than the classical "patient allele-specific PCR" because they can identify any possible clone emerging during the treatment or follow-up, even if different from that identified at diagnosis, thus predicting relapse. After all, the present available molecular approaches can move MRD from the bench side to the clinical practice.

Comparative Analysis of Multicolor Flow Cytometry and Immunohistochemistry for the Detection of Disseminated Tumor Cells

Disseminating cells of a primary solid tumor may represent the origin of metastases and relapses. We aimed at comparing the diagnostic efficacy of multicolor flow cytometry (MFC) and morphology/immunohistochemistry (IHC) in the detection of disseminated tumor cells in the bone marrow (BM) and body fluids of patients with solid tumors, and in pediatric neuroblastoma cases. We investigated 72 samples retrospecively from 50 patients by MFC. Morphology/IHC data were available in 48 cases. In the first cohort, 36 samples derived from 34 patients with various forms of suspected and proven solid tumors and in the second cohort, 36 samples of 16 children with suspected and proven neuroblastoma were analyzed at diagnosis or during follow-up in a 4-color setting by MFC, and the results were compared with those obtained by IHC. In the group of various solid tumors, we found 91% concordance between IHC and MFC, and it was 65% in the neuroblastoma group, and 77% overall. Detection of disseminated tumor cells was found to be more effective by MFC in de novo neuroblastoma samples (100% vs. 86%). The advantage of MFC was even more pronounced when minimal residual disease was evaluated (efficacy, 92% vs. 68%). In contrast, efficacy of IHC was 100% in the group of various solid tumors, whereas it was 91% for MFC. We conclude that MFC and IHC are both essential tools for examining infiltration of BM and body fluids by disseminating solid tumor cells. In the case of neuroblastoma, however, minimal residual disease detection by MFC in a hypoplastic/aplastic BM environment was more effective than IHC, as considerably more cells could be analyzed.

Minimal residual disease in chronic lymphocytic leukemia: A consensus paper that presents the clinical impact of the presently available laboratory approaches

Chronic lymphocytic leukemia (CLL) is a malignancy defined by the accumulation of mature lymphocytes in the lymphoid tissues, bone marrow, and blood. Therapy for CLL is guided according to the Rai and Binet staging systems. Nevertheless, state-of-the-art protocols in disease monitoring, diagnostics, and prognostics for CLL are based on the assessment of minimal residual disease (MRD). MRD is internationally considered to be the level of disease that can be detected by sensitive techniques and represents incomplete treatment and a probability of disease relapse. MRD detection has been continuously improved by the quick development of both flow cytometry and molecular biology technology, as well as by next-generation sequencing. Considering that MRD detection is moving more and more from research to clinical practice, where it can be an independent prognostic marker, in this paper, we present the methodologies by which MRD is evaluated, from translational research to clinical practice.

Rapid and label-free identification of single leukemia cells from blood in a high-density microfluidic trapping array by fluorescence lifetime imaging microscopy

The rapid screening and isolation of single leukemia cells from blood has become critical for early leukemia detection and tumor heterogeneity interrogation. However, due to the size overlap between leukemia cells and the more abundant white blood cells (WBCs), the isolation and identification of leukemia cells individually from peripheral blood is extremely challenging and often requires immunolabeling or cytogenetic assays. Here we present a rapid and label-free single leukemia cell identification platform that combines: (1) high-throughput size-based separation of hemocytes via a single-cell trapping array, and (2) leukemia cell identification through phasor approach and fluorescence lifetime imaging microscopy (phasor-FLIM), to quantify changes between free/bound nicotinamide adenine dinucleotide (NADH) as an indirect measurement of metabolic alteration in living cells. The microfluidic trapping array designed with 1600 highly-packed addressable single-cell traps can simultaneously filter out red blood cells (RBCs) and trap WBCs/leukemia cells, and is compatible with low-magnification imaging and fast-speed fluorescence screening. The trapped single leukemia cells, e.g., THP-1, Jurkat and K562 cells, are distinguished from WBCs in the phasor-FLIM lifetime map, as they exhibit significant shift towards shorter fluorescence lifetime and a higher ratio of free/bound NADH compared to WBCs, because of their glycolysis-dominant metabolism for rapid proliferation. Based on a multiparametric scheme comparing the eight parameter-spectra of the phasor-FLIM signatures, spiked leukemia cells are quantitatively distinguished from normal WBCs with an area-under-the-curve (AUC) value of 1.00. Different leukemia cell lines are also quantitatively distinguished from each other with AUC values higher than 0.95, demonstrating high sensitivity and specificity for single cell analysis. The presented platform is the first to enable high-density size-based single-cell trapping simultaneously with RBC filtering and rapid label-free individual-leukemia-cell screening through non-invasive metabolic imaging. Compared to conventional biomolecular diagnostics techniques, phasor-FLIM based single-cell screening is label-free, cell-friendly, robust, and has the potential to screen blood in clinical volumes through parallelization.

A unique bone marrow lymphoma patient presenting with an isolated mass: A case report

Bone marrow lymphoma with the onset of an isolated mass in the bone marrow is extremely rare. The present case report described a unique case of B cell lymphoblastic lymphoma (LBL) presenting with an isolated mass in the bone marrow cavity, without any organopathy or lymphadenopathy. An isolated mass in bone marrow is a rare primary manifestation of LBL. The patient in the present case report presented with pain in the right elbow, a fever, pancytopenia and splenomegaly. Additionally, no abnormality was determined in the lymph nodes, the bone marrow karyotype or a computed tomography scan of the humerus. Positron emission tomography (PET) examination revealed an increased uptake of ¹⁸F-fluorodeoxyglucose in right distal humerus. An isolated mass in the bone marrow cavity was removed by surgery. Pathological findings revealed B cell LBL. The patient received an acute lymphocytic leukemia chemotherapy regimen and achieved complete remission. However, 4 months following the initial diagnosis, the patient succumbed due to a relapse. The present case highlighted the importance of PET examination and biopsy, and the requirement to identify appropriate treatments for LBL. Additionally, it is important to broaden the differential diagnosis when an isolated mass is identified in the bone marrow cavity.

Accuracy and Relative Value of Bone Marrow Aspiration in the Detection of Lymphoid Infiltration in non-Hodgkin Lymphoma

Aims and background

In hematologic malignancies, bone marrow aspiration is considered complementary to bone marrow biopsy for the detection of tumor infiltration. The present study evaluated the accuracy of bone marrow aspiration and the relative contributions of bone marrow aspiration and bone marrow biopsy in detecting bone marrow involvement by non-Hodgkin lymphomas.

Methods and study design

We compared 51 simultaneous marrow aspirates and core biopsies from non-Hodgkin lymphoma patients for sensitivity, specificity, concordance, quality and clinical relevance.

Results

The agreement level of bone marrow biopsy and bone marrow aspiration was 80%, and the overall sensitivity and specificity for bone marrow aspiration were 69% and 86%, respectively. When considering only the indolent non-Hodgkin lymphoma samples, the sensitivity of bone marrow aspiration was 82% and the specificity was 85%, whereas the sensitivity and specificity were 40% and 86%, respectively, in the aggressive non-Hodgkin lymphoma specimens. Five cases (10%) were reported in which bone marrow biopsy did not detect lymphoid infiltration even though the bone marrow aspiration was positive. In one of these, lymphoid infiltration was documented by a second bone marrow biopsy performed thereafter.

Conclusions

The data from the current study show that bone marrow aspiration is a useful procedure with which to detect bone marrow infiltration by lymphoma. Although it cannot be a substitute for examination of the marrow by core biopsy, the utility of adding an aspirate to bone marrow biopsy is supported by its earlier and easier availability for bone marrow examination, the larger amounts of marrow that can be examined with both procedures, and the percentage, although small, of potentially true-positive bone marrow aspirates with negative biopsies.

Vortex-dislodged cells from bone marrow trephine biopsy yield satisfactory results for flow cytometric immunophenotyping

INTRODUCTION

A good bone marrow (BM) sample is essential in evaluating many hematologic disorders. An unsuccessful BM aspiration (BMA) procedure precludes a successful flow cytometric immunophenotyping (FCI) in most hematologic malignancies. Apart from FCI, most ancillary diagnostic techniques in hematology are less informative. We describe the feasibility of FCI in vortex-dislodged cell preparation obtained from unfixed trephine biopsy (TB) specimens.

METHODS

In pancytopenic patients and dry tap cases, routine diagnostic BMA and TB samples were complemented by additional trephine biopsies. These supplementary cores were immediately transferred into sterile tubes filled with phosphate-buffered saline, vortexed, and centrifuged. The cell pellet obtained was used for flow cytometric immunophenotyping.

RESULTS

Of 7955 BMAs performed in 42 months, 34 dry tap cases were eligible for the study. Vortexing rendered a cell pellet in 94% of the cases (32 of 34), and FCI rendered a rapid diagnosis in 100% of the cases (32 of 32) where cell pellets were available.

CONCLUSION

We describe an efficient procedure which could be effectively utilized in resource-limited centers and reduce the frequency of repeat BMA procedures.

Analytical and diagnostic validation of a flow cytometric strategy to quantify blood and marrow infiltration in dogs with large B-cell lymphoma

BACKGROUND

Lymph node (LN), peripheral blood (PB), and bone marrow (BM) samples are commonly analyzed by flow cytometry (FC) for the immunophenotyping and staging of canine lymphomas. A prognostic value for FC BM infiltration in dogs with large B-cell lymphoma (LBCL) was demonstrated. Aim of this study was to define the analytical performances of this technique, and to establish a cutoff suitable to safely discriminate between infiltrated and noninfiltrated PB and BM samples.

METHODS

Large B-cells were added to control PB and BM samples, to achieve twelve different large B-cells concentrations, ranging from 0 to 50%. The percentage of large B-cells was recorded for each dilution, using a BD Accuri C6 FC. Accuracy was evaluated by Passing-Bablok regression analysis. Intra-assay precision was assessed at 0%, 1, 3, and 10% dilutions evaluating the CVs of 10 repeated acquisitions. ROC curves were drawn to identify the cutoffs most suitable to discriminate between 25 infiltrated (PARR-positive) and 25 noninfiltrated (PARR-negative) PB and BM samples, respectively.

RESULTS

Optimal analytical accuracy and precision were achieved. Almost all CVs were <10%. Negative controls had up to 0.5% large B-cells, with 50 and 22% CV in PB and BM samples, respectively, 0.56 and 2.45% cutoffs were selected based on the ROC curves for PB and BM samples, respectively.

CONCLUSIONS

Quantification of large B-cells in PB and BM samples by FC is reliable and analytical performances met the acceptance criteria. Assessment of performances of different instruments and protocols is warranted. © 2016 International Clinical Cytometry Society.

Involvement of bone marrow in lymphoma: pathological investigation in a single-center from northern China

OBJECTIVES

This study aimed to evaluate key features of bone marrow trephine biopsy (BMT) involvement of lymphoma in Northern China.

METHODS

950 cases were assessed for the occurrence of bone marrow involvement and architectural features including volume percentage, involvement pattern (diffuse, nodular, focal, para trabecular, or interstitial), and presence/absence of background changes (granuloma, stromal fibrosis or necrosis). Correlations with bone marrow aspirate (BMA) and flow cytometry (FCM) findings were made in a subset of paired cases (359 BMA and 364 FCM).

RESULTS

153 (16.1%) cases involved BMT. The most frequent type was mantle cell lymphoma (28/153, 18.3%). Architectural features were similar to previous studies except that diffuse large B-cell lymphoma (DLBCL) preferred focal pattern (16/22 cases, 72.7%) most of all. BMA and BMT agreed in 84.1% of cases (302 of 359: 277 both negative, 25 both positive), while FCM and BMT agreed in 80.8% of cases (294 of 364: 242 both negative, 52 both positive). Both varied widely among different subgroups.

CONCLUSIONS

Occurrence of BMT involvement by lymphoma in Northern China is relatively low. The volume percentage, distribution patterns and background changes may be useful pointers towards a particular lymphoma type in Chinese. FCM is more sensitive and reliable than BMA in China.

Bone marrow trephine biopsy involvement by lymphoma: review of histopathological features in 511 specimens and correlation with diagnostic biopsy, aspirate and peripheral blood findings

AIMS

This study aimed to evaluate the key features of bone marrow trephine (BMT) biopsy involvement by lymphoma.

METHODS

511 cases were assessed for percentage of marrow involvement, pattern of involvement (diffuse, nodular, paratrabecular, interstitial or intrasinusoidal), presence/absence of granulomas, stromal fibrosis and necrosis, presence/absence of neoplastic/reactive follicles and discordance with other biopsy sites. Correlation with aspirate and peripheral blood findings was made in a subset of 345 patients (167 aspirates, 178 blood).

RESULTS

The most frequent subtype was follicular lymphoma (26.2%) followed by extranodal marginal zone (23.1%), lymphoplasmacytic (19.2%), diffuse large B cell (DLBCL) (12.5%), Hodgkin (HL) (5.7%) and mantle cell lymphomas (4.3%). The predominant pattern in follicular lymphoma was paratrabecular. Marginal zone lymphomas of all types and lymphoplasmacytic lymphoma showed a relatively even distribution between diffuse, interstitial, paratrabecular and nodular patterns. The majority of mantle cell lymphoma cases showed either diffuse or nodular patterns. A diffuse pattern was common in DLBCL and Burkitt lymphomas. An intrasinusoidal pattern was seen only in extranodal and splenic marginal zone lymphomas. Granulomas and fibrosis were uncommon in small cell B cell lymphomas but frequent in DLBCL and HL. Aspirate and trephine results concurred in 73.8% of cases overall, but this varied widely between subtypes. Peripheral blood involvement rates by lymphoma also varied, with a mean of 37.1%.

CONCLUSIONS

Different lymphomas often demonstrate reliably characteristic architectural patterns of marrow involvement which can help differentiate them even when cytological features do not permit this, and marrow stromal and other background changes may also be useful pointers towards a particular lymphoma subtype.

Analysis of immunoglobulin and T cell receptor gene rearrangement in the bone marrow of lymphoid neoplasia using BIOMED-2 multiplex polymerase chain reaction

The evaluation of bone marrow (BM) involvement is important for diagnosis and staging in patients with lymphoid neoplasia. We evaluated of immunoglobulin (Ig) and/or T-cell receptor (TCR) gene rearrangements in the BM using the standardized BIOMED-2 multiplex PCR clonality assays and compared the results with microscopic findings such as histology and CD10, CD20, CD79a, CD3 and CD5 immunohistochemistry. A total of 151 samples were enrolled; 119 B cell neoplasia, 29 T cell neoplasia, and 3 Hodgkin's lymphoma. The molecular clonality assay and microscopic diagnosis were concordant in 66.9% (n=101) and discordant in 33.1 % (n=50). Ig/TCR gene clonality assay detected 43 cases of BM involvement which was not presented in the morphology. Two cases among them turned into microscopic BM involvement during a close follow up. Clonal TCR gene rearrangements were detected in 12.6% of B cell neoplasia and Ig gene rearrangement were found in 3.4% of T cell neoplasia. This molecular clonality assay is valuable particularly in diagnosing BM involvement of lymphoid neoplasia if it is morphologically uncertain. But it should be carefully interpreted because molecular clonality may be present in the reactive lymphoproliferation. Therefore, comprehensive analysis with morphologic analysis should be important to reach a final diagnosis.

Immunophenotyping of chronic B-cell neoplasms: flow cytometry versus immunohistochemistry

Morphological differentiation between benign and malignant lymphoproliferative disorders (LPDs) can be challenging. Immunophenotyping (IPT) by either technique, flow cytometry or immunohistochemistry (IHC), is an important step in solving such difficulty. Thirty-five newly diagnosed patients with chronic B-cell neoplasms (11 chronic lymphocytic leukemia, 22 non Hodgkin lymphoma and 2 hairy cell leukemia) were included in this study with age range from 20 to 70 years. Monoclonal antibodies surface expression using lymphoproliferative disorders panel (CD45, CD19, CD5, CD10, CD11c, CD20, CD22, CD23, CD38, CD79b, FMC7, CD103, CD25, kappa and lambda light chains) by flow cytometry was done on bone marrow samples. CD20, CD5, CD23, Bcl-2, Bcl-6, kappa and lambda light chain immunostaining were performed on fixed bone marrow trephine biopsy specimen. The sensitivity of IHC was 81.8% in chronic lymphocytic leukemia (CLL) and 100% in non Hodgkin lymphoma (NHL) as regards CD20, 100% in both groups as regards CD5, 46% in CLL and 66.7% in NHL as regards CD23, 33.3% in CLL and 50% in NHL as regards kappa chain, 20% in CLL and 33.3% in NHL as regards lambda chain. We found that IHC and flow cytometry are equally effective in diagnosing CLL; however, IHC might be slightly more sensitive than flow cytometry in detecting bone marrow infiltration in NHL and hairy cell leukemia (HCL).

The diagnostic value of CD1d expression in a large cohort of patients with B-cell chronic lymphoproliferative disorders

Immunophenotyping is indispensable in the differential diagnosis of B-cell chronic lymphoproliferative disorders (B-CLPDs). However, B-CLPDs often show overlapping immunophenotypic profiles and may be diagnostically challenging. CD1d is an HLA class I-like molecule that presents glycolipids to invariant natural killer T cells. Normal mature B cells constitutively express CD1d, but with the exception of some conflicting data, its expression in B-CLPDs is unknown. We demonstrate that in 222 B-CLPD cases, CD1d expression of less than 45% is strongly predictive of CLL (likelihood ratio, 32.3; specificity, 97.4%; sensitivity, 84.1%). In addition, CD1d showed significantly higher staining intensity in splenic marginal zone lymphoma compared with atypical hairy cell leukemia, lymphoplasmacytic lymphoma, and mantle cell lymphoma, thus allowing the discrimination of the former from the latter immunophenotypically overlapping B-CLPDs. It is important to note that in a given patient, CD1d expression on malignant B cells was similar between tissues and remained unaffected by disease stage and treatment status. Our findings strongly argue for the incorporation of CD1d into routine lymphoma panels.

Prognostic factors in chronic lymphocytic leukemia-what do we need to know?

Of all leukemias, chronic lymphocytic leukemia (CLL) shows the highest variability in its clinical presentation and course. CLL can present as an aggressive and life threatening leukemia or as an indolent form that will not require treatment over decades. The currently available clinical staging systems for CLL are simple and inexpensive but lack accuracy to predict disease progression and survival on an individual basis. The increased understanding of the key events of molecular pathogenesis has provided a plethora of novel molecular and biological factors that correlate with the outcome of CLL. This Review provides a concise discussion of the most important discoveries and gives guidance on how to implement novel prognostic tools in the clinical management of CLL by applying the criteria of evidence, relevance, and simplicity to the selection of prognostic markers.

Routine use of ancillary investigations in staging diffuse large B-cell lymphoma improves the International Prognostic Index (IPI)

BACKGROUND

The International Prognostic Index (IPI) is used to determine prognosis in diffuse large B-cell lymphoma (DLBCL). One of the determinants of IPI is the stage of disease with bone marrow involvement being classified as stage IV. For the IPI, involvement on bone marrow is traditionally defined on the basis of histology with ancillary investigations used only in difficult cases to aid histological diagnosis. This study aimed to determine the effect of the routine use of flow cytometry, immunohistochemistry and molecular studies in bone marrow staging upon the IPI.

RESULTS

Bone marrow trephines of 156 histologically proven DLBCL cases at initial diagnosis were assessed on routine histology, and immunohistochemistry using two T-cell markers (CD45RO and CD3), two B-cell markers (CD20 and CD79a) and kappa and lambda light chains. Raw flow cytometry data on all samples were reanalysed and reinterpreted blindly. DNA extracted from archived paraffin-embedded trephine biopsy samples was used for immunoglobulin heavy chain and light chain gene rearrangement analysis. Using immunophenotyping (flow cytometry and immunohistochemistry), 30 (19.2%) cases were upstaged to stage IV. A further 8 (5.1%) cases were upstaged using molecular studies. A change in IPI was noted in 18 cases (11.5%) on immunophenotyping alone, and 22 (14.1%) cases on immunophenotyping and molecular testing. Comparison of two revised IPI models, 1) using immunophenotyping alone, and 2) using immunophenotyping with molecular studies, was performed with baseline IPI using a Cox regression model. It showed that the revised IPI model using immunophenotyping provides the best differentiation between the IPI categories.

CONCLUSION

Improved bone marrow staging using flow cytometry and immunohistochemistry improves the predictive value of the IPI in patients with DLBCL and should be performed routinely in all cases.

Staging bone marrow in diffuse large B-cell lymphoma: the role of ancillary investigations

Diffuse large B-cell lymphoma (DLBCL) is an aggressive non-Hodgkin's lymphoma (NHL) that requires treatment at initial diagnosis. Treatment decisions may be guided by staging investigations, which include assessment of bone marrow (BM). Traditionally this assessment has included light microscopic examination of the bone marrow aspirate and trephine biopsy. Ancillary testing--including immunophenotyping using flow cytometry on BM aspirates, immunohistochemistry (IHC) on BM trephines and molecular studies using immunoglobulin heavy (IgH) or light (IgL) chain gene rearrangements--are performed as required to aid histological diagnosis. This review examines the evidence for the routine use of ancillary tests in the initial staging of DLBCL, including the limitations, potential pitfalls and possible clinical implications of their use in this setting.

Assessment of expression of selected Bcl-2 family proteins in lymphoid infiltration in patients with B-cell chronic lymphocytic leukaemia treated with nucleoside analogues

B-cell chronic lymphocytic leukaemia (B-CLL) is characterized by clonal growth and accumulation of mature lymphoid cells due to disturbance in genetically regulated form of cell death called apoptosis. The intrinsic mechanism of apoptosis is controlled by Bcl-2 family proteins. Purine nucleoside analogues induce the apoptosis in cells in a state of quiescence. The aim of the study was to assess expression of selected Bcl-2 family proteins in neoplastic infiltration in bone marrow in patients with B-CLL treated with nucleoside analogues. The study comprised examination of bone marrow obtained routinely by trephine biopsy from 18 patients with B-CLL diagnosed before administration of purine nucleoside analogues treatment and after its completion. Expression of Bcl-2, Bcl-x and Bax proteins was examined. Lymphoid cells in bone marrow were present in all patients before administration of treatment. After treatment in two patients bone marrow was infiltrated in diffuse pattern, whereas other patients presented nodular pattern of infiltration. The difference between stage of infiltration before and after treatment was statistically significant (p<0.002). High percentage of infiltration cells with positive anti Bcl-2 reaction from 42.0% in one patient to 85.33+/-3.06% in four patients before treatment was observed. After treatment percentage of infiltration cells with positive anti Bcl-2 antibody reaction was from 33.0+/-18.38% in two patients to 99.0% in one patient. Positive correlation between stage of infiltration and expression of Bcl-2 protein was confirmed before and after treatment. Such correlations were not observed in case of Bax and Bcl-x. Strong staining of immunohistochemical reaction of cells in lymphoid infiltration with Bcl-2 antibody was confirmed. There was a difference between Bcl-/Bax ratio before and after treatment. Immunohistochemical assessment of expression of Bcl-2 family proteins in cells of lymphoid infiltration in bone marrow of patients with CLL is an important method in detection of minimal residual disease (MRD) after treatment.

Clinical outcome of low-grade NHL patients with bone marrow involvement

BACKGROUND

Bone marrow (BM) involvement in low-grade non-Hodgkin's lymphoma (NHL) has a clear impact on patients' survival. The standard practice is morphological examination of BM biopsy at diagnosis. The clinical significance of flow cytometry (FC) analysis of BM aspirates is largely unknown.

MATERIALS AND METHODS

The medical charts of 70 low-grade NHL patients, who underwent BM biopsy and FC analysis between 1994 and 2004, were reviewed.

RESULTS

Forty-three patients (61.4%) were BM+ by morphology, while in those without morphological involvement by lymphoma FC was positive in 9 (BM-FC+, 12.9%) and negative in 18 (BM-FC-, 25.7%). The median treatment-free period was shorter in the BM+ and BM-FC+ groups compared with the BM-FC- group (1 and 4 months vs. 31 months, respectively) (log-rank test, P = 0.0195). The median survival time was not reached for the BM-FC- patients, whereas for BM+ and BM-FC+ patients it was 129 and 89 months, respectively, with no significant difference between them [the difference between the BM-FC- and the two other groups was statistically significant (log-rank test, P = 0.029)].

CONCLUSIONS

The outcome of low grade NHL in patients who had BM involvement by FC alone or by morphology was similar. If confirmed, these findings suggest a modification in the workup and management of localized low grade NHL.

Flow cytometric analysis of lymphomas: current status and usefulness

CONTEXT

Immunophenotyping has become a routine practice in the diagnosis and classification of most cases of non-Hodgkin lymphoma, and flow cytometry is often the method of choice in many laboratories. The role that flow cytometry plays, however, extends beyond just diagnosis and classification.

OBJECTIVE

To review and evaluate the current roles of flow cytometry in non-Hodgkin lymphoma, to compare it with immunohistochemistry, and to discuss its potential future applications in the molecular diagnostic era.

DATA SOURCES

The information contained herein is derived from peer-reviewed articles on the subject published in the English-language medical literature during the years 1980 to 2005 that were identified using PubMed (http://www.ncbi.nlm.nih.gov/entrez/query.fcgi, 1980-2005) search, various books and other sources on flow cytometry, and the author's personal experience of more than 10 years with flow cytometric analysis of lymphomas and leukemia using Becton-Dickinson (San Jose, Calif) and Beckman-Coulter (Miami, Fla) flow cytometers.

STUDY SELECTION

Studies were selected based on adequate material and methods, statistically significant results, and adequate clinical follow-up.

DATA EXTRACTION

The data from various sources were compared when the methods used were the same or similar and appropriate controls were included. Most of the studies employed 2-color, 3-color, or 4-color flow cytometers with antibodies from Becton-Dickinson, Beckman-Coulter, or DakoCytomation (Carpinteria, Calif). Results were evaluated from studies utilizing the same or similar techniques and flow cytometers. Only objective data analyses from relevant and useful publications were included for reporting and discussion.

DATA SYNTHESIS

Flow cytometry serves a variety of roles in the field of lymphoma/leukemia including rapid diagnosis, proper classification, staging, minimal residual disease detection, central nervous system lymphoma detection, evaluation of prognostic markers, detection of target molecules for therapies, ploidy analysis of lymphoma cell DNA, and evaluation of multidrug-resistance markers. It offers many advantages in comparison to immunohistochemistry for the same roles and provides uses that are either not possible or not preferable by immunohistochemistry such as multiparameter evaluation of single cells and detection of clonality in T cells.

CONCLUSIONS

By virtue of its ability to evaluate not only surface but also cytoplasmic and nuclear antigens, flow cytometry continues to enjoy widespread use in various capacities in lymphoma evaluation and treatment. Additional roles for flow cytometry are likely to be invented in the future and should provide distinctive uses in the molecular era.

ZAP-70 expression, as detected by immunohistochemistry on bone marrow biopsies from early-phase CLL patients, is a strong adverse prognostic factor

Zeta-associated protein-70 (ZAP-70), mostly assessed by flow-cytometry (FC), recently emerged as reliable prognostic factor in chronic lymphocytic leukaemia (CLL) at presentation. We evaluated ZAP-70 expression in 156 CLL patients by immunohistochemistry (IHC) on formalin-fixed bone marrow (BM) biopsies at diagnosis. At presentation, 117 patients (75%) were with Binet stage A, 27 (17%) stage B and 12 (8%) stage C. Median follow-up was 61 months (range 6-242). ZAP-70 was expressed in neoplastic lymphocytes of 69 patients (44%). Concordance between ZAP-70 by IHC and ZAP-70 by FC, immunoglobulin heavy chain variable genes (IGHV) mutational status and CD38 expression was found in 41/46 (89%), 41/49 (80%) and in 60/88 (68%) tested cases, respectively. ZAP-70 expression significantly correlated with advanced Binet stage (B-C), diffuse BM infiltration, increased lactate dehydrogenase (LDH) and beta2-microglobulin serum levels and lymphocyte doubling time <12 months. ZAP-70 positivity was significantly related to poorer time to progression (median 16 months vs 158 of ZAP-70-negative cases) (P<0.0001) and overall survival (median 106 months vs not reached) (P=0.0002); this correlation was confirmed at multivariate analysis. ZAP-70 expression correlated with poorer outcome also when evaluated only in the 117 stage A patients. In conclusion, immunohistological detection of ZAP-70 on formalin-fixed BM biopsies at diagnosis appears a useful methodological approach to identify patients with poor prognosis in CLL.

Bone marrow infiltration pattern in B-cell chronic lymphocytic leukemia is related to immunoglobulin heavy-chain variable region mutation status and expression of 70-kd ζ-associated protein (ZAP-70)

B-cell chronic lymphocytic leukemia (B-CLL) consists of at least 2 subtypes with either somatically mutated or unmutated immunoglobulin heavy-chain variable region (IgVH) genes. A prognostic significance of the infiltration pattern in bone marrow trephine biopsy has been described before. The combined pattern analysis and detection of 70-kd zeta-associated protein (ZAP-70) expression in formalin-fixed, paraffin-embedded bone marrow trephines has not been investigated so far. To evaluate the relationship between ZAP-70 expression, mutation status, and the infiltration pattern in B-CLL, we analyzed bone marrow trephine biopsies from B-CLL patients (n = 35). The expression of ZAP-70 was related to the infiltration type: in all samples with diffuse infiltration pattern, the leukemic cells showed ZAP-70 staining, whereas leukemic cells in a nodular infiltration pattern were negative. By contrast, the mixed-pattern type showed a variable ZAP-70 expression. Besides definitely negative or positive ZAP-70 expression, a few samples showed a faint ZAP-70 staining, and the classification into the positive or negative group was difficult. In addition, the infiltration type was related to the mutation status in a subset of samples: mutation of the IgVH gene was restricted to the nondiffuse infiltration pattern and was not found in cases with diffuse infiltration of bone marrow. The expression of ZAP-70, detected by an immunohistochemical assay and also by real-time quantitative reverse transcriptase-polymerase chain reaction assigned 83% of the chronic lymphocytic leukemia cases to the suspected immunoglobulin mutation subtype. In 2 patients with ZAP-70 expression, a mutated IgVH status was found. These cases exhibited a mixed pattern of infiltration. We conclude that the pure nodular type of marrow infiltration in B-CLL is associated with IgH hypermutation and ZAP-70 negativity, whereas the predominantly diffuse type of infiltration reveals unmutated IgH genes with ZAP-70 overexpression. The mixed type of infiltration is displayed by mutated as well as unmutated cases with a varying pattern of ZAP-70 expression.

Potential predictive patterns of minimal residual disease detected by immunohistochemistry on bone marrow biopsy specimens during a long-term follow-up in patients treated with cladribine for hairy cell leukemia

CONTEXT

Minimal residual disease (MRD) in patients treated for hairy cell (HC) leukemia as assessed by immunohistochemistry has not been included routinely in evaluation of treatment results.

OBJECTIVE

To assess the presence of persistent HCs after treatment, as detected by immunohistochemistry, and to evaluate the correlation between the level of MRD and clinical outcome.

DESIGN

Percentages of DBA.44-positive HCs were assessed on 116 biopsy specimens from 17 patients. The patients had a median follow-up of 55.4 months.

RESULTS

Minimal residual disease was seen in 3 patterns. Group 1 (7 patients) had MRD levels ranging from "rare scattered suspicious HCs" to less than 1%. The MRD levels were stable throughout follow-up, and all patients remained in complete remission. Group 2 (6 patients) had MRD levels ranging from 1% to 5%, and 3 patients were in complete remission at 77.9, 63.8, and 108.0 months. Another patient showed evidence of disease activity (partial remission) at 47.6 months. Two other patients relapsed at 12.3 months and at 25.7 months, respectively, with greater than 1% HCs. Group 3 (4 patients) had MRD levels greater than 5%. Three patients relapsed at 11.3, 12.1, and 29.6 months, respectively, with greater than 5% HCs. The fourth patient had MRD levels of 5% at 14.6 months and 2% at 20.0 months but was subsequently lost to follow-up.

CONCLUSIONS

Quantitative assessment of MRD may be of value in identifying patients at risk for relapse of hairy cell leukemia.

Application of BIOMED-2 primers in fixed and decalcified bone marrow biopsies: analysis of immunoglobulin H receptor rearrangements in B-cell non-Hodgkin's lymphomas

The detection of clonality in lymphomas was recently improved by the BIOMED-2 approach, but analysis of fixed tissues is limited. Here, we adapted the BIOMED-2 protocol for examining immunoglobulin H (IgH) receptor rearrangements in fixed, decalcified bone marrow biopsies (BMBs) for clonality analysis in B-cell non-Hodgkin's lymphomas (B-NHL). The study included 111 decalcified BMBs (12 formalin fixed and 99 glutardialdehyde fixed), with B-NHL (n = 85), T-NHL (n = 8), or reactive infiltrates (n = 18). Initially, IgH FRIII polymerase chain reaction (PCR) analysis of crude DNA extracts from 75 glutardialdehyde-fixed BMBs (B-NHLs) using a standard seminested PCR resulted in clonal peaks in 46 of 75 (61.3%) BMBs compared with 19 of 70 (27.1%) for the original BIOMED-2 protocol. Modifications to both DNA extraction and PCR reaction improved the detection rate to 26 of 36 (72.2%) for BIOMED-2 primers, including 10 of 15 (66.7%) cases not detected by our standard IgH analysis. Moreover, introducing the same modifications for analysis of the FRII region by BIOMED-2 primers revealed clonal peaks in 19 of 36 (52.8%) B-NHLs compared with 5 of 70 (7.1%) for the original BIOMED-2 protocol. Together, analysis of FRII and FRIII regions by the modified BIOMED-2 protocol increased the detection rate to 31 of 36 (86.1%), particularly for BMBs with histological evidence of follicular lymphoma (FRIII, 70%; FRII, 90%). In summary, this study provides an improved protocol for detection of clonality by IgH-specific BIOMED-2 primers in fixed, decalcified bone marrow biopsies.

How we process trephine biopsy specimens: epoxy resin embedded bone marrow biopsies

Improved cytomorphology of semithin resin sections over paraffin wax embedded sections may be important in diagnostic haematopathology. However, resin embedding can make immunohistochemical antigen detection or DNA isolation for clonal gene rearrangement assays difficult. This review describes the processing of bone marrow biopsies using buffered formaldehyde based fixation and epoxy resin embedding, with or without EDTA decalcification. Traditional semithin resin sections are completely rehydrated after etching in home made sodium methoxide solution. Resin elimination allows high resolution staining of tissue components with common histological stains. Efficient antigen retrieval and the Envision-HRP system permit the immunohistological detection of many antigens of diagnostic relevance, with retention of high quality cytomorphology. Furthermore, DNA can be extracted for clonality analysis. The technique can be completed within a similar time period to that of paraffin wax processing with only approximately 30% increase in cost. This technique has been used for diagnosis in over 4000 bone marrow biopsies over the past 14 years. By meeting traditional and contemporary demands on the haematopathologist, it offers a powerful alternative to paraffin wax processing for diagnosis and research.

Definition and diagnosis of sporadic and familial chronic lymphocytic leukemia

This article describes the main defining criteria for chronic lymphocytic leukemia (CLL) and its differential diagnosis from closely related B-cell disorders. In addition to the morphology of circulating lymphocytes, the key diagnostic aid is the "CLL score" based on the typical immunophenotype of CLL as ascertained with five reagents: CD5, CD23, CD79b (or CD22), FMC7, and intensity of SmIg staining. The concepts of polyclonal and monoclonal B-cell lymphocytosis are defined with focus on the latter and its incidence in elderly individuals and its significant increase in healthy relatives from CLL families. The value of flow cytometry in the analysis of minimal residual disease after therapy also is discussed with a comparison with findings in bone marrow trephine biopsies. No candidate gene has been linked to the high incidence of CLL (10%) seen in families of patients with this disease.