Atypical lymphocyte morphology: an adverse prognostic factor for disease progression in stage A CLL independent of trisomy 12

The kappa/lambda ratio of surface immunoglobulin light chain as a valuable parameter for MRD assessment in CLL with atypical immunophenotype

In recent years, the significance of detecting minimal/measurable residual disease (MRD) in chronic lymphocytic leukemia (CLL) has increased due to the availability of highly effective therapeutic agents. Flow cytometry provides notable cost-effectiveness and immediacy, with an expected sensitivity level of approximately 10-4. The critical aspect of MRD detection via flow cytometry lies in accurately defining the region containing tumor cells. However, a subset of CLL, known as CLL with atypical immunophenotype, exhibits a distinct cell surface marker expression pattern that can make MRD detection challenging, because these markers often resemble those of normal B cells. To enhance the sensitivity of MRD detection in such atypical cases of CLL, we have capitalized on the observation that cell surface immunoglobulin (sIg) light chains tend to be expressed at a higher level in this subtype. For every four two-dimensional plots of cell surface markers, we used a plot to evaluate the expression of sIg kappa/lambda light chains and identified regions where the kappa/lambda ratio of sIg light chains deviated from a designated threshold within the putative CLL cell region. Using this method, we could detect atypical CLL cells at a level of 10-4. We propose this method as an effective MRD assay.

Atypical Chronic Lymphocytic Leukemia-The Current Status

A diagnosis of typical chronic lymphocytic leukemia (CLL) requires the presence of ≥5000 clonal B-lymphocytes/μL, the coexistence of CD19, CD20, CD5, and CD23, the restriction of light chain immunoglobulin, and the lack of expression of antigens CD22 and CD79b. Atypical CLL (aCLL) can be distinguished from typical CLL morphologically and immunophenotypically. Morphologically atypical CLL cells have been defined mainly as large, atypical forms, prolymphocytes, or cleaved cells. However, current aCLL diagnostics rely more on immunophenotypic characteristics rather than atypical morphology. Immunophenotypically, atypical CLL differs from classic CLL in the lack of expression of one or fewer surface antigens, most commonly CD5 and CD23, and the patient does not meet the criteria for a diagnosis of any other B-cell lymphoid malignancy. Morphologically atypical CLL has more aggressive clinical behavior and worse prognosis than classic CLL. Patients with aCLL are more likely to display markers associated with poor prognosis, including trisomy 12, unmutated IGVH, and CD38 expression, compared with classic CLL. However, no standard or commonly accepted criteria exist for differentiating aCLL from classic CLL and the clinical significance of aCLL is still under debate. This review summarizes the current state of knowledge on the morphological, immunophenotypic, and genetic abnormalities of aCLL.

The morphology of CLL revisited: the clinical significance of prolymphocytes and correlations with prognostic/molecular markers in the LRF CLL4 trial

Historically, an increase in the percentage and number of circulating prolymphocytes in chronic lymphocytic leukaemia (CLL) has been associated with strong expression of surface immunoglobulin, trisomy 12 and a poor outcome. This study re‐examines the biological and clinical significance of increased peripheral blood prolymphocytes in 508 patients at entry into the randomized UK Leukaemia Research Fund CLL4 trial. It also investigates the associations between increased prolymphocytes and a comprehensive array of biomarkers. 270 patients (53%) had <5% prolymphocytes, 167 (33%) had 5–9%, 60 (12%) had 10–14% and 11 (2%) had ≥15% prolymphocytes. We show that a higher proportion of prolymphocytes (≥10%) was independently associated with NOTCH1 mutations (P = 0·006), absence of 13q deletion (P = 0·001), high CD38 expression (P = 0·02) and unmutated IGHV genes (P = 0·01). Deaths due to Richter syndrome were significantly more common amongst patients who had ≥10% vs <10% prolymphocytes (13% vs 2%) respectively (P < 0·0001). ≥10% prolymphocytes was also associated with a shorter progression‐free survival (Hazard ratio [HR] 1·50 [95% confidence interval [CI]: 1·16–1·93], P = 0·002) and overall survival (HR 1·99 [95% CI: 1·53–2·59], P < 0·0001). Our data support the routine examination of blood films in CLL and suggest that a finding of an increased proportion of prolymphocytes may be a trigger for further evaluation of clinical and laboratory features of progressive disease.

Del(20q) in patients with chronic lymphocytic leukemia: a therapy-related abnormality involving lymphoid or myeloid cells

Deletion 20q (Del(20q)), a common cytogenetic abnormality in myeloid neoplasms, is rare in chronic lymphocytic leukemia. We report 64 patients with chronic lymphocytic leukemia and del(20q), as the sole abnormality in 40, a stemline abnormality in 21, and a secondary abnormality in 3 cases. Fluorescence in situ hybridization (FISH) analysis revealed an additional high-risk abnormality, del(11q) or del(17p), in 25/64 (39%) cases. In most cases, the leukemic cells showed atypical cytologic features, unmutated IGHV (immunoglobulin heavy-chain variable region) genes, and ZAP70 positivity. The del(20q) was detected only after chemotherapy in all 27 cases with initial karyotypes available. With a median follow-up of 90 months, 30 patients (47%) died, most as a direct consequence of chronic lymphocytic leukemia. Eight patients developed a therapy-related myeloid neoplasm, seven with a complex karyotype. Combined morphologic and FISH analysis for del(20q) performed in 12 cases without morphologic evidence of a myeloid neoplasm localized the del(20q) to the chronic lymphocytic leukemia cells in 5 (42%) cases, and to myeloid/erythroid cells in 7 (58)% cases. The del(20q) was detected in myeloid cells in all 4 cases of myelodysplastic syndrome. In aggregate, these data indicate that chronic lymphocytic leukemia with del(20q) acquired after therapy is heterogeneous. In cases with morphologic evidence of dysplasia, the del(20q) likely resides in the myeloid lineage. However, in cases without morphologic evidence of dysplasia, the del(20q) may represent clonal evolution and disease progression. Combining morphologic analysis with FISH for del(20q) or performing FISH on immunomagnetically selected sub-populations to localize the cell population with this abnormality may help guide patient management.

Prospective study of prognostic factors in asymptomatic patients with B-cell chronic lymphocytic leukemia-like lymphocytosis: the cut-off of 11 × 10(9)/L monoclonal lymphocytes better identifies subgroups with different outcomes

The arbitrary threshold of 5 × 10(9)/L chronic lymphocytic leukemia (CLL)-like lymphocytes differentiates monoclonal B lymphocytosis (MBL) from CLL. There are no prospective studies that search for the optimal cut-off of monoclonal lymphocytes able to predict outcome and simultaneously analyze the prognostic value of classic, immunophenotypic, and cytogenetic variables in patients with asymptomatic clonal CLL lymphocytosis (ACL), which includes MBL plus Rai 0 CLL patients. From 2003 to 2010, 231 ACL patients were enrolled in this study. Patients with 11q deletion and atypical lymphocyte morphology at diagnosis had shorter progression-free survival (PFS) (p = 0.007 and p = 0.015, respectively) and treatment-free survival (TFS) (p = 0.009 and p = 0.017, respectively). Elevated beta-2 microglobulin (B2M) also correlated with worse TFS (p = 0.002). The optimal threshold of monoclonal lymphocytes independently correlated with survival was 11 × 10(9)/L (p = 0.000 for PFS and p = 0.016 for TFS). As conclusion, monoclonal lymphocytosis higher than 11 × 10(9)/L better identifies two subgroups of patients with different outcomes than the standard cut-off value of 5 × 10(9)/L. Atypical lymphocyte morphology, 11q deletion and elevated B2M had a negative impact on the survival in ACL patients.

ZAP-70 expression and proliferative activity in chronic lymphocytic leukemia

The expression of 70 kDa protein zeta-associated protein (ZAP-70) in chronic lymphocytic leukemia (CLL) has been used to detect those patients with more aggressive disease. The aim of this study was to determine the proliferative activity of ZAP-70(+) leukemic cells by immunocytochemical methods. The study was undertaken on native blood marrow (BM) and peripheral blood (PB) smears from 65 patients with CLL. ZAP-70 was expressed in leukemic cells of 35 patients (54%). We demonstrated that ZAP-70 immunoreactivity correlated with Rai 0-IV (p = 0.002) and Binet A-C stages (p < 0.001), total tumor mass (TTM score) (p < 0.001), β2-microglobulin (p = 0.006), atypical lymphocytes (p < 0.001) and proliferative activity in bone marrow and peripheral blood (p = 0.014, p = 0.002, respectively) using χ(2) test and Mann-Whitney test. ZAP-70 protein expression is in direct correlation with the poorer prognostic parameters, which additionally confirms the successful method of detection of ZAP-70 expression. Higher Ki-67 expression in BM and PB smears of patients with ZAP-70(+) disease indicates higher proliferating compartments, which may contribute to poorer prognosis.

Sustained high level of serum VEGF at convalescent stage contributes to the renal recovery after HTNV infection in patients with hemorrhagic fever with renal syndrome

To investigate the role of vascular endothelial growth factor (VEGF) in the increased permeability of vascular endothelial cells after Hantaan virus (HTNV) infection in humans, the concentration of VEGF in serum from HTNV infected patients was quantified with sandwich ELISA. Generally, the level of serum VEGF in patients was elevated to 607.0 (542.2-671.9) pg/mL, which was dramatically higher compared with healthy controls (P < 0.001). There was a rapid increase of the serum VEGF level in all patients from the fever onset to oliguric stage, at which the serum creatinine reached the peak level of the disease, indicating that VEGF may be involved in the pathogenesis of renal hyper-permeability. Moreover, the serum VEGF level at convalescent stage was positively correlated with the degree of the disease severity. The sustained high level of serum VEGF at convalescence was observed in critical HFRS patients, suggesting that VEGF would probably contribute to the renal recovery after the virus clearance. Taken together, our results suggested that the VEGF would be involved in the pathogenesis of renal dysfunction at the oliguric stage after HTNV infection, but may function as a recovery factor during the convalescence to help the body self-repair of the renal injury.

Clinical and Laboratory Prognostic Indicators in Chronic Lymphocytic Leukemia

Background

The clinical course of patients with chronic lymphocytic leukemia (CLL) is heterogeneous, with some patients experiencing rapid disease progression and others living for decades without requiring treatment. The Rai and Binet clinical staging systems are used to define disease extent and predict survival. The pathology laboratory also provides important prognostic information.

Methods

A review of the literature was performed on the subject of staging in CLL from clinical and pathologic standpoints. This article also reviews currently available diagnostic approaches related to disease prognosis and to timing of treatment and follow-up in patients with CLL.

Results

Novel biological and cytogenetic features such as immunoglobulin heavy-chain variable gene segment [IgVH], genomic aberrations including del(17p13), del(11q23), del(13q14), and trisomy 12, serum markers (thymidine kinase and beta-2 microglobulin), and cellular markers (CD38 and ZAP70) have become increasingly important in predicting prognosis at the time of diagnosis.

Conclusions

Current prognostic factors directly or indirectly influence the management of patients with CLL and help to predict treatment-free and overall survival.

Prospective study of clinical and biological prognostic factors at diagnosis in patients with early stage B-cell chronic lymphocytic leukemia

Retrospective series have reported many clinical and biological significant prognostic factors in chronic lymphocytic leukemia (CLL). We describe a prospective cohort of 135 patients with CLL homogeneously studied at diagnosis for prognostic factors. Biological variables analyzed were CD38 and ZAP-70 expression, fluorescence in situ hybridization (FISH) for 13q-, +12, 11q-, and 17p-, and conventional cytogenetics. Univariate and multivariate analysis for progression-free survival (PFS) were performed in patients with early stage (Rai 0-1) CLL. CD38 was positive in 42 (31.6%) patients and ZAP-70 in 47 (35.9%). The most frequent FISH finding was isolated 13q- in 50 (38.5%) patients, and 17p- -was found in 11 (8.4%). Among 135 patients, 114 (84.4%) were Rai 0-1 at diagnosis and 39 (28.9%) presented adenopathies. With a median follow-up of 39 months, the presence of lymphadenopathy in patients with Rai 0-1 stage CLL was the only significant variable for predicting PFS in multivariate analysis (odds ratio [OR] 7, 95% confidence interval [CI] 2.2-22, p = 0.001). When only biological factors were analyzed, CD38 expression (OR 3.2, 95% CI 1.1-9.3, p = 0.03) and 17p- (OR 3.5, 95% CI 0.95-13.1, p = 0.05) correlated with worse PFS. A longer follow-up is necessary to analyze the prognostic value of these variables regarding overall survival.

Diagnostic issues in chronic lymphocytic leukaemia (CLL)

The diagnosis of chronic lymphocytic leukaemia (CLL) is based on clinical and laboratory features. Morphology and immunophenotype are the initial diagnostic investigations. In atypical cases, these tests should be complemented with molecular genetics and/or histology to exclude other B-cell disorders of small lymphocytes. Morphologically, CLL can be classified into typical and atypical. Immunophenotyping is the only method that can establish or confirm the diagnosis as CLL lymphocytes have a distinct immunophenotypic signature. A scoring system compounding the results with a set of markers allows firming up the diagnosis. Other immunological markers such as CD38 and ZAP-70 have an important prognostic impact. Fluorescence in situ hybridization (FISH) analysis, chiefly by detecting 17p (TP53 locus) and 11q (ATM) deletions and mutational status of the IgVH gene, also provides prognostic information and may determine the type of therapy. In atypical CLL, histology and/or molecular genetics may be required to exclude other B-cell disorders.

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.

B-cell chronic lymphocytic leukemia risk in association with serum leptin and adiponectin: a case-control study in Greece

AIM

Leptin and adiponectin are two well-studied adipokines in relation to malignancies. In this study, we examined the association between leptin/adiponectin and risk of B-cell chronic lymphocytic leukemia (B-CLL), as well as the relationships between adipokines and several established prognostic factors of B-CLL.

METHODS

Ninety-five patients with incident B-CLL and 95 hospital controls matched on age and gender were studied between 2001 and 2007, and blood samples were collected. Leptin, total and high molecular weight adiponectin, and prognostic markers of B-CLL were determined.

RESULTS

Cases had a higher body mass index (BMI) than controls (p = 0.01) and lower levels of leptin (p < 0.01). Significantly more cases than controls presented a family history of lymphohematopoietic cancer (LHC) (p = 0.01). Higher serum leptin levels were associated with lower risk of B-CLL adjusting for age, gender, family history of LHC, BMI and serum adiponectin; the multivariate odds ratio comparing highest to lowest tertile was 0.05 (95% CI 0.01-0.29, p trend < 0.001); Adiponectin was not significantly different between cases and controls.

CONCLUSION

Leptin was found to be inversely associated with risk of CLL but in contrast to prior studies of CLL and hematologic malignancies, this study found no significant association between CLL and adiponectin.

The leukemias of mature lymphocytes

The leukemias of mature B cells and T cells are a limited set of diseases in which blood and bone marrow are the primary sites of involvement. Although they may superficially resemble one another, they have distinct clinical and pathologic features and must be distinguished from one another. In this article, the major clinical, morphologic, phenotypic, and molecular genetic features of the mature B- and T-cell leukemias are reviewed, and differential diagnostic considerations are discussed.

Chronic lymphocytic leukemia With t(2;14)(p16;q32) involves the BCL11A and IgH genes and is associated with atypical morphologic features and unmutated IgVH genes

The t(2;14)(p16;q32) has been reported previously in only 12 cases of chronic lymphocytic leukemia/small lymphocytic lymphoma (CLL/SLL). The clinicopathologic features have been incompletely described. We describe 6 new cases of CLL/SLL with t(2;14)(p16;q32). All had marrow involvement, 4 had absolute lymphocytosis, 4 had lymphadenopathy, and 3 had hepatosplenomegaly. All showed atypical lymphocyte morphologic features with plasmacytoid differentiation and irregular nuclei; 3 had increased prolymphocytes. Flow cytometry demonstrated typical immunophenotypes in 5 and an atypical immunophenotype in 1. All expressed ZAP70; 5 assessed showed unmutated IgV(H) genes. Karyotyping identified t(2;14)(p16;q32) as the sole abnormality in 1, primary abnormality in 2, and part of a complex karyotype in 3. Fluorescence in situ hybridization analysis revealed BCL11A/IgH rearrangement in all. After chemotherapy, 3 patients died of disease and 3 were alive with disease (median follow-up, 80 months). We conclude that CLL/SLL with t(2;14) (p16;q32) and BCL11A/IgH rearrangement is characterized by atypical morphologic features and unmutated IgV(H) genes.

Prognostic markers in chronic lymphocytic leukaemia

Rai and Binet staging of chronic lymphocytic leukaemia (CLL) is being superseded by new prognostic markers. The mutational status of the immunoglobulin variable region heavy-chain genes segregates the disease into more benign and more malignant versions, and has been confirmed as an important prognostic marker in prospective clinical trials. A search for surrogate markers for this difficult-to-perform assay has led to flow cytometric assays for CD38 and ZAP-70 expression, although in both cases there are problems with standardization and interpretation of the assays. A separate pathway of research has revealed two chromosomal aberrations--deletions of 11q and 17p--as important prognostic markers. Fluorescent in-situ hybridization has made their detection readily available. These five markers are in different stages of evaluation, but some of them are ready to be used for risk-adapted therapy in clinical trials. Other assays are in earlier stages of assessment.

Differential diagnosis in chronic lymphocytic leukaemia

The diagnosis of chronic lymphocytic leukaemia (CLL) is based on clinical and laboratory features. Morphology and immunophenotype are the key initial diagnostic tests. In cases with atypical features, these investigations should be complemented with cytogenetics and/or histology to confirm the diagnosis and to exclude other B-cell disorders. Morphologically, CLL can be classified into typical and atypical forms. Cell-marker studies provide a robust foundation to establish the diagnosis as the lymphocytes have a distinct immunophenotypic signature. Although no single antigen is exclusively expressed in CLL cells, when several markers are compounded into a scoring system the results allow firming up of the diagnosis. Other immunological markers, such as CD38 or ZAP-70, have an important prognostic impact. Fluorescence in-situ hybridization (FISH) analysis also provides prognostic information, chiefly by detecting 17 (p53 locus) and 11q deletion, and may determine the type of therapy.

CD45 expression in low-grade B-cell non-Hodgkin's lymphomas

CD45 is a glycoprotein expressed in all lymphohemopoietic cells. Its expression increases during B-lymphocyte ontogeny. Few data are available about CD45 expression in the various types of low-grade B-cell non-Hodgkin's lymphomas (NHL). Low levels of CD45 have been reported in pathologic lymphocytes from typical chronic lymphocytic leukemia (CLL) and higher levels of this antigen have been observed in some cases of atypical CLL and in some cases of other types of NHL. One hundred and seven bone marrow samples of NHL with bone marrow infiltration were investigated: 45 typical CLL, 15 atypical CLL, 9 mantle cell lymphomas (MCL), 1 MCL with CD23 expression, 18 marginal zone lymphomas (MZL), 6 lymphoplasmacytic lymphomas (LPL), 6 follicular lymphomas (FL), and 7 hairy cell leukemias (HCL). CD45 expression was evaluated by flow cytometry: pathologic lymphocytes were identified on the basis of specific immunophenotypic profile, CD19/K or CD19/lambda co-expression. Results were expressed as median fluorescence intensity (MFI) along a 1024 linear scale. CD45 expression was measured also on autologous T-lymphocytes and a "CD45 index" was calculated as the ratio MFI of pathologic B-lymphocytes/MFI of T-lymphocytes, to normalize the results obtained. We found four CD45 expression patterns: very low in typical CLL; relatively low in MCL; intermediate intensity in MZL, LPL, and FL; very high expression in HCL. Among the atypical cases, very high CD45 expression was found in one case of CD23-negative CLL, in CD23-positive MCL, and CLL with atypical morphology. The results indicate different levels of maturation in low-grade NHL and may help to characterize such neoplasias.

The t(14;19)(q32;q13)-positive small B-cell leukaemia: a clinicopathologic and cytogenetic study of seven cases

The t(14;19)(q32;q13), involving the BCL3 locus at chromosome 19q13 and the immunoglobulin heavy chain gene at 14q32, is a rare recurrent cytogenetic abnormality identified in B-cell neoplasms, most of which have been classified as chronic lymphocytic leukaemia (CLL) in the literature. We describe the clinicopathological, immunophenotypic and cytogenetic findings in seven patients with B-cell neoplasms associated with t(14;19)(q32;q13). There were five men and two women, with a median age of 48 years (range 33-68). All had absolute lymphocytosis, six had lymphadenopathy, and one had splenomegaly. Lymphocytes in blood and bone marrow aspirate smears were predominantly small and cytologically atypical. Flow cytometric immunophenotyping showed an atypical immunophenotype with low CLL scores. The growth pattern in bone marrow biopsy specimens was interstitial to diffuse; immunohistochemical stains were positive for bcl3 and negative for cyclin D1. Lymph node biopsy specimens of two patients revealed total architectural effacement by neoplasm with proliferation centres. In addition to t(14;19), cytogenetic studies demonstrated trisomy 12 in five patients. These results suggest that B-cell neoplasms with the t(14;19)(q32;q13) present frequently as leukaemia composed of small B-lymphocytes and share many features with CLL. However, these neoplasms also differ from CLL cytologically and in their immunophenotype.

Clinical and laboratory parameters that define clinically relevant B-CLL subgroups

B cell-type chronic lymphocytic leukemia (B-CLL) is a heterogeneous disease. This is reflected by the very wide-ranging clinical courses that B-CLL patients experience and by the marked variation in laboratory findings between patients. In this chapter, we will review the various clinical and laboratory parameters that divide B-CLL patients into "subgroups," and correlate the parameters that define them. When feasible, we will also link clinical features to the cellular and genetic characteristics recently defined for these leukemic cells. The discussion is limited to parameters that define phenotypes or subgroups that may relate to disease activity and clinical outcome.

ζ-Chain associated protein 70 and CD38 combined predict the time to first treatment in patients with chronic lymphocytic leukemia

BACKGROUND

Zeta-chain associated protein (ZAP)-70 has been proposed as a surrogate marker for immunoglobulin heavy-chain variable region (IgVH) mutation in chronic lymphocytic leukemia (CLL), but it is still not clear whether it is an independent prognostic factor.

METHODS

The authors evaluated ZAP-70 expression by flow cytometry in 201 untreated patients and correlated ZAP-70 levels with CD38 expression, genetic abnormalities detected by fluorescence in situ hybridization (FISH), and the time from diagnosis to first treatment.

RESULTS

Fifty-seven patients (28%) were positive for ZAP-70 (> or = 20%). Positive ZAP-70 status was associated with advanced disease stage, atypical morphology, CD38-positive status, trisomy 12, del(6q), or no detectable abnormalities; negative ZAP-70 status was correlated with del(13q) as a sole abnormality. The treatment-free interval (TFI) was 17.7 months for ZAP-70-positive patients and 44.6 months for ZAP-70-negative patients (P < 0.001). Multivariate analysis in 117 patients identified advanced stage, CD38 > or = 7%, and the absence of del(13q) as a sole abnormality as independent factors for short TFI. Excluding FISH, ZAP-70 status acquired independent prognostic value along with CD38 status. The authors proposed a risk model that combines ZAP-70 and CD38 to identify patients who are likely to progress. When both markers were positive, the TFI was 12 months; when both were negative, the median TFI was 54 months; a median TFI of 26 months was observed in patients who had discordant results (P < 0.00001).

CONCLUSIONS

The current findings suggested that both ZAP-70 and CD38 should be tested prospectively in all patients with early-stage CLL.

Economic assessment on the management of chronic lymphocytic leukaemia

In the last decade, several new promising treatments for chronic lymphocytic leukaemia (CLL) have been developed. Healthcare costs are increasing and new treatments tend to be very expensive; therefore, information about the cost effectiveness in treatments for CLL is urgently needed. The authors performed a literature review on the currently available economic evaluations on CLL treatments. A total of 65 articles were found, of which 11 could be included. These articles were evaluated on the basis of six methodological requirements for economic evaluations, enabling readers to judge the value of the studies. Only a small amount of information was available on the costs of CLL treatments. Future economic evaluations should be performed according to the methodological requirements for these studies, which should also be properly documented.

Aberrant morphology, proliferation, and apoptosis of B-cell chronic lymphocytic leukemia cells

B-cell chronic lymphocytic leukemia (CLL) has been traditionally described as a disease characterized by an accumulation of quiescent small lymphocytes with decreased susceptibility to apoptotic cell death. However, small numbers of "atypical" lymphocytes and prolymphocytes (PL) are frequently observed in the bone marrow (BM) of patients with CLL. In this study, we examined BM biopsy and aspirate specimens obtained from seven patients with atypical CLL. Using a double labeling (Ki-67+/CD20+) immunohistochemical method, we found that an appreciable number of the atypical CLL cells expressed the proliferation-associated protein Ki-67. Because CLL is characterized by a slow change in the peripheral blood (PB) lymphocyte count, we reasoned that a subpopulation of CLL cells probably undergoes spontaneous apoptosis. Using Western blot analysis, we observed expression of procaspase-9, procaspase-10, and poly(ADP-ribose) polymerase by the neoplastic cells in all seven cases of CLL, and procaspase-3 and procaspase-8 expression in six neoplasms. We also detected cleaved caspase-3 and cleaved poly(ADP-ribose) polymerase in four and five CLL cases, respectively. To determine whether CLL cells undergo spontaneous apoptosis, we performed the terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling (TUNEL) assay using BM biopsy specimens. We found TUNEL-positive lymphocytes in areas infiltrated by CLL. In summary, our data show that subpopulations of B-lymphocytes are proliferating or undergoing spontaneous apoptotic cell death in patients with atypical CLL.

Unique gene expression and clinical characteristics are associated with the 11q23 deletion in chronic lymphocytic leukaemia

Chromosome abnormalities influence prognosis and tumour progression in B-cell Chronic Lymphocytic Leukaemia (CLL). This study sought to determine whether these different disease subgroups were associated with unique gene expression patterns. Thirty-four cases of CLL were screened for the 11q23, 13q14, 17p13 deletions, and trisomy 12 by fluorescence in situ hybridization (FISH). Expression of 205 cell signalling and apoptosis genes were compared by cDNA array among cases with different chromosome abnormalities. A majority of the statistically differentially expressed genes were present in the 11q23 deletion group by hierarchical clustering. CDC2, a serine/threonine kinase, was overexpressed in the 11q23 deletion group (P = 0.0004) and confirmed by Taqman real-time polymerase chain reaction. Several other genes associated with cell signalling were overexpressed in the 11q23 deletion group. A strong overall correlation existed between the presence of different chromosome abnormalities and a number of prognostic factors including immunoglobulin heavy chain variable region mutation status (P = 0.011), time to treatment (P = 0.025) and lymphocyte doubling time (P = 0.034). This study confirmed the prognostic impact of chromosome abnormalities identified by FISH in CLL, particularly the 11q23 deletion and trisomy 12. In addition, the 11q23 deletion group was associated with a unique gene expression pattern involving cell signalling and apoptosis genes.

Advances in the diagnosis and classification of chronic lymphoproliferative disorders

In this review, we have highlighted recent advances in chronic lymphoproliferative disorders that commonly involve the peripheral blood. As we have seen, our concepts of certain diseases are changing. Molecular genetic and immunophenotypic studies are allowing more precise characterization of CLL and defining important biologic markers that predict clinical behavior. Prolymphocytic leukemia is now more narrowly defined and its relationship to nucleolated variants of MCL is now apparent. With new reagents and techniques applied to problems such as identification of Sezary cells and T-cell monoclonality determination, our ability to diagnose, monitor, and provide prognostic information is improving. Insight into the biology of these diseases also may provide new therapeutic targets in the future.

Chronic lymphocytic leukemia with 6q− shows distinct hematological features and intermediate prognosis

Cytogenetic and fluorescence in situ hybridization studies were successfully performed in 217 chronic lymphocytic leukemia (CLL). In all, 13 patients with 6q21 deletion were identified and characterized in comparison with 92 patients with 'favourable' karyotype (normal or 13q-), 69 cases with 'intermediate risk' (1-2 anomalies) and 43 cases with 'unfavourable' karyotype (complex, 11q- or 17p-). Six out of 13 cases with 6q- showed an excess of atypical lymphocytes, a finding confirmed at the histologic level; >20% CD38+ cells were seen in 5/6 cases. IGVH mutational status revealed >98% homology to the germline sequence in 4/10 cases. When compared with the 'favourable' group, patients with 6q- showed a higher white blood cell (WBC) count, frequent splenomegaly, atypical morphology, CD38+ and short time from diagnosis to first treatment and short survival. A higher median WBC count was found in the 6q- group vs the intermediate-risk group; survival was shorter in the unfavourable group. To ascertain if the 6q- anomaly was an independent factor predicting for an inferior outcome among those patients with 'favourable' cytogenetics, we performed an analysis of prognostic factors in 105 patients (92 'favourable' plus 13 with 6q-), showing that the 6q- chromosome maintained its prognostic significance at multivariate analysis (P=0.02) along with stage (P=0.01). We conclude that CLL with 6q- is characterized by a high incidence of atypical morphology, classical immunophenotype with CD38 positivity and intermediate incidence of IGVH somatic hypermutation. Clinicobiological features and outcome show that this cytogenetic subset of CLL should be allocated in an intermediate-risk category.

Update in the pathologic features of mature B-cell and T/NK-cell leukemias

Modern diagnosis of mature B- and T-cell leukemias requires integration of morphologic, immunophenotypic, and molecular genetic features. This integrative approach has allowed more precise definitions of specific disease entities. This in turn provides better information for clinicians to select proper therapy and determine prognosis. The characteristic pathologic features of these disorders are reviewed.

Correlation between cell size and CD38 expression in chronic lymphocytic leukaemia

Both CD38 expression and increased cell size are features of B-lymphocyte activation and have been implicated as adverse prognostic factors in B-cell chronic lymphocytic leukaemia (CLL). We therefore examined the relationship between these two variables by FACS analysis in 140 consecutive CLL patients. Using the mean forward-angle light scatter (FSC) as a measure of cell size, circulating B lymphocytes were found to be significantly larger in "CD38-positive" cases (those in which the antigen was expressed in at least 20% of the malignant cells) as compared with "CD38-negative" patients (p = 0.029). Furthermore, within individual cases B lymphocytes expressing CD38 were, on average, significantly larger than cells that did not express the antigen (p < 0.0001). Finally, when B lymphocytes of individual "CD38-positive" cases were arbitrarily divided into large and small subpopulations using their mean FSC as a cut-off, CD38 was found to be more frequently expressed on the larger cells (p < 0.0001). This strong positive correlation between CD38 expression and cell size implicates cell activation as a possible underlying determinant of both tumour-cell phenotype and clinical outcome in CLL.

Biological and clinical heterogeneity of B-cell chronic lymphocytic leukemia

B-cell chronic lymphoproliferative disorders have been recognized as a heterogeneous group of neoplastic diseases affecting the lymphoid system. They are frequently characterized by leukemic manifestations with peripheral blood and/or bone marrow involvement. B-cell chronic lymphocytic leukemia (B-CLL), a disease which is now accepted as derived from immunologicallycompetent antigen-activated B-cells, is the most common in the western countries. Although for several decades it was considered as a unique entity, a body of evidences is now emerging indicating the biological heterogeneity of B-CLL. Molecular and immunophenotypic data induce to consider two main subgroups of B-CLL exist at the cellular level: in fact, B-CLL cases can be divided into two categories according to IgV gene mutation status. One group develops from "memory" B-cells after antigenic stimulation in the germinal center of secondary follicles, displays mutated gene IgV and lacks CD38 expression; the second one derives from the so-called "naïve" antigen inexperienced B-cells, does not present IgV gene mutations and displays CD38 surface molecule. The two groups seem to be characterised by different clinical outcomes with the "mutated" group expected to have a more benign course than that arising from a "naïve" B-cell. Thus, the definition of the biological features of these different groups could be of help for clinicians in order to recognize patients needing more intensive therapeutic approaches.

Albumin enhanced morphometric image analysis in CLL

BACKGROUND

The heterogeneity of lymphocytes from patients with chronic lymphocytic leukemia (CLL) and blood film artifacts make morphologic subclassification of this disease difficult.

METHODS

We reviewed paired blood films prepared from ethylene-diamine-tetraacetic acid (ETDA) samples with and without bovine serum albumin (BSA) from 82 CLL patients. Group 1 adhered to NCCLS specifications for the preparations of EDTA blood films. Group 2 consisted of blood films containing EDTA and a 1:12 dilution of 22% BSA. Eight patients were selected for digital photomicroscopy and statistical analysis. Approximately 100 lymphocytes from each slide were digitally captured.

RESULTS

The mean cell area +/- standard error was 127.8 microm(2) +/- 1.42 for (n = 793) for group 1 versus 100.7 microm(2) +/- 1.39 (n = 831) for group 2. The nuclear area was 88.9 microm(2) +/- 0.85 for group 1 versus 76.4 microm(2) +/- 0.83 for group 2. For the nuclear transmittance, the values were 97.6 +/- 0.85 for group 1 and 104.1 +/- 0.83 for group 2. The nuclear:cytoplasmic ratios were 0.71 +/- 0.003 for group 1 and 0.78 +/- 0.003 for group 2. All differences were statistically significant (P < 0.001).

CONCLUSIONS

BSA addition results in the reduction of atypical lymphocytes and a decrease in smudge cells. BSA also decreases the lymphocyte area and nuclear area, whereas nuclear transmittance and nuclear:cytoplasmic ratio are increased. A standardized method of slide preparation would allow accurate interlaboratory comparison. The use of BSA may permit better implementation of the blood film-based subclassification of CLL and lead to a better correlation of morphology with cytogenetics and immunophenotyping. Published 2003 Wiley-Liss, Inc.

B-chronic lymphocytic leukemia: practical aspects

B-CLL is the most common adult leukemia in the Western world. It is a neoplasia of mature looking B-monoclonal lymphocytes co-expressing the CD5 antigen (involving the blood, the bone marrow, the lymph nodes and related organs). Much new information about the nature of the neoplastic cells, including chromosomal and molecular changes as well as mechanisms participating in the survival of the leukemic clone have been published recently, in an attempt to elucidate the biology of the disease and identify prognostic subgroups. For the time being, clinical stage based on Rai and Binet staging systems remains the strongest predictor of prognosis and patients' survival, and therefore it affects treatment decisions. In the early stages treatment may be delayed until progression. When treatment is necessary according to well-established criteria, there are nowadays many different options. Chlorambucil has been the standard regimen for many years. During the last decade novel modalities have been tried with the emphasis on fludarabine and 2-chlorodeoxyadenosine and their combinations with other drugs. Such an approach offers greater probability of a durable complete remission but no effect on overall survival has been clearly proven so far. Other modalities, included in the therapeutic armamentarium, are monoclonal antibodies, stem cell transplantation (autologous or allogeneic) and new experimental drugs. Supportive care is an important part of patient management and it involves restoring hypogammaglobulinemia and disease-related anemia by polyvalent immunoglobulin administration and erythropoietin respectively.

Immunophenotype does not correlate with lymph node histology in chronic lymphocytic leukemia/small lymphocytic lymphoma

The presence of prominent proliferation centers (PCs) in lymph nodes (LNs) involved with chronic lymphocytic leukemia/small lymphocytic lymphoma (CLL/SLL) has been associated with atypical blood smear morphology. Atypical CLL has in turn been associated with variant immunophenotypes and poor outcome. However, the significance of abundant PCs remains controversial. We have analyzed the flow cytometric immunophenotypic features of 54 CLL/SLL LNs and correlated these findings with the morphologic and clinical features. The LN histology was assigned to one of two groups based on the prominence of PCs: Group I LNs contained scattered small, sometimes ill-defined PCs in a background of monotonous small round lymphocytes. Group II LNs had increased numbers and sizes of PCs resulting in an obviously nodular appearance at low magnification. Flow cytometry was performed using broad three- or four-color antibody panels that included anti-CD5, CD19, CD20, CD23, CD38, FMC7, and surface immunoglobulin (sIg). The intensity of expression of all markers was scored semi-quantitatively using isotypic controls and internal positive and negative populations as standards. There were 32 group I and 22 group II LNs that, by definition, expressed CD19, CD5, and CD23. Little variability was seen in the intensity of expression of CD19, and the majority of cases expressed CD23 brightly. CD5 varied from very dim to an intensity similar to that of normal T cells; the majority had an intermediate level of CD5 expression. FMC7 was expressed to a significant extent in 11 cases (21%). CD20 was relatively bright in 17 cases (32%). sIg was dim in 29 cases (55%) and moderate or bright in 24 cases (45%). CD38 was expressed significantly in 25 cases (47%). There was no correlation between histologic group and intensity of expression of any individual marker or with an immunophenotypic atypia score based on FMC7, CD20, and sIg. There was also no correlation between morphology or immunophenotype and clinical features. These findings do not support the interpretation that the prominence of proliferation centers in CLL/SLL LNs defines biologically distinct subtypes.

Peripheral blood manifestations of lymphoma and solid tumors

Although the peripheral blood film has limited use in this age of technologic testing, most new tests are ancillary and cannot be interpreted accurately without examining the peripheral blood film. The peripheral smear plays a critical role in the diagnosis and management of many lymphoproliferative disorders, although playing more of a general function in nonlymphoid malignancies to evaluate cytopenias.

Cleaved lymphocytes in chronic lymphocytic leukemia: a detailed retrospective analysis of diagnostic features

Through a global analysis of diagnostic features, the aim was to profile CLL patients with circulating cleaved lymphocytes at diagnosis, a controversial prognostic factor. Although some of them could have been considered today as having Non-Hodgkin's lymphoma, all 106 patients of our retrospective series have had CLL treatments. Slide review distinguished seven lymphocyte morphotypes. With minimal a priori assumptions, excluding in particular clinical staging systems, forty-five diagnostic features were analyzed in 37 patients. CORICO (Correlations Iconography), a purely geometric method, deciphered the multidimensional structure of the raw data. Probabilistic monoparametric tests were made on the 106 patients. In ten patients (Binet stages: 3A, 6B, 1C), at least 8% of the lymphocytes were cleaved. Unrelated to the prolymphocytes, this morphotype had neither links with the CD5+CD23+ (9/10 vs 80/86), FMC7+ (5/10 vs 22/62), CD38 (1/7 vs 7/64) markers nor with any major CLL laboratory values; only three links characterized it: no cases of mixed marrow infiltrate (nodular: 1, interstitial: 6, diffuse: 3; ns), a lower percentage of eosinophils (ns), and predominance of CD11c (7/10 vs 20/66, p < 0.02). In conclusion, in contrast to the PLL morphotype, or to the lactic dehydrogenase (LDH) activity, which was a strong prognostic factor in this series, an independent detrimental value of the cleaved morphotype has not yet been found. Our study shows that free of modeling constraints, this method makes possible a rapid and objective insight into variable interrelations. If further explored in a prospective study, this approach may contribute to the understanding of discrepancies in the literature.

CD38 expression and secondary 17p deletion are important prognostic factors in chronic lymphocytic leukaemia

CD38 expression and chromosomal abnormalities are novel prognostic factors in chronic lymphocytic leukaemia (CLL). However, their value remains undetermined. CD38 was evaluated in 123 patients and chromosomal aberrations in 111 cases with fluorescence in situ hybridization (FISH). CD38 expression was found in 27% of the cases. In addition, seven out of 32 CD38- patients became CD38+ during evolution of the disease. Chromosomal abnormalities included isolated 13q deletion (40%), 12q trisomy (14%), 11q deletion (without 17p deletion) (14%) and 17p deletion (7%). CD38 expression was significantly associated with Binet stages B and C, atypical morphology and 11q deletion. On univariate analysis of survival estimates, advanced Binet stages, CD38+ phenotype, atypical morphology and 11q or 17p deletions were associated with shorter event-free survival (EFS), treatment-free interval (TFI) and overall survival (OS). Multivariate analysis identified both Binet stages and CD38 as independent prognostic factors with regard to EFS and TFI. However, CD38 appeared as an independent factor for OS when restricted to Binet stage A. Chromosomal aberrations were re-evaluated during evolution in 31 cases. The 17p deletion was the most frequent new chromosomal abnormality (35%) and significantly associated with death (64%). In conclusion, CD38 expression and secondary 17p deletion are important poor prognostic indicators, especially in Binet stage A CLL.

Laboratory, morphologic, and immunophenotypic correlates of surface immunoglobulin heavy chain isotype expression in B-cell chronic lymphocytic leukemia

We compared surface immunoglobulin heavy chain isotype expression with a number of laboratory, morphologic, and immunophenotypic features in a series of 76 cases of B-cell chronic lymphocytic leukemia (B-CLL). Fifty-five cases were IgM+/IgD+, a phenotype associated with antigenically naïve B cells; 16 cases expressed IgD without IgM, a phenotype seen in a subset of normal B cells with extensive somatic immunoglobulin variable region (IgV) gene mutations; and 5 cases were IgD-, a phenotype associated with memory B cells. WBC count, atypical morphologic features, atypical immunophenotypic characteristics, and CD38 expression were nonrandomly distributed among the 3 categories of heavy chain isotype expression. Moreover, a WBC count more than 30,000/microL (30 x 10(9)/L), atypical morphologic features, and CD38 expression in more than 30% of neoplastic cells (all adverse prognostic factors in B-CLL) were less common among IgD-only cases than among IgM+/IgD+ and IgD- cases. These data demonstrate that surface immunoglobulin heavy chain isotype expression is associated with several laboratory, morphologic, and immunophenotypic features in B-CLL. The subset of B-CLL with the IgD-only phenotype is associated with several favorable prognostic factors, suggesting the possibility that IgD-only B-CLL may be associated with a favorable prognosis.

Typical and atypical chronic lymphocytic leukemia differ clinically and immunophenotypically

We compared the features of 17 cases of atypical chronic lymphocytic leukemia (aCLL) with those of a clinical control group of 24 cases of CLL. Quantitative flow cytometric data, available for 12 cases, were compared with an immunophenotypic control group of 58 cases using a relative fluorescence indexfor CD5, CD23, CD79b, and surface immunoglobulin light chain (sIg). Compared with the clinical control group, patients with aCLL had a higher mean WBC count and a lower platelet count. Patients with aCLL had a significantly higher probability of disease progression. Compared with an immunophenotypic control group of 58 CLL cases, 12 cases of aCLL demonstrated significantly higher expression of CD23. There was no significant difference in expression of sIg, CD79b, or CD5 between the groups. CD38 expression was noted in only 1 (9%) of 11 tested cases; 2 (18%) of 11 cases had trisomy 12. aCLL can be distinguished from typical CLL morphologically, clinically, and immunophenotypically. Atypical morphologic features in CLL seem to be a marker of aggressive clinical behavior.

Comparative genomic hybridization and amplotyping by arbitrarily primed PCR in stage A B-CLL

Cytogenetic analysis is useful in the diagnosis and to assess prognosis of B-cell chronic lymphocytic leukemia (B-CLL). However, successful cytogenetics by standard techniques has been hindered by the low in vitro mitotic activity of the malignant B-cell population. Fluorescence in situ hybridization (FISH) has become a useful tool, but it does not provide an overall view of the aberrations. To overcome this hurdle, two DNA-based techniques have been tested in the present study: comparative genomic hybridization (CGH) and amplotyping by arbitrarily primed PCR (AP-PCR). Comparative genomic hybridization resolution depends upon the 400-bands of the human standard karyotype. AP-PCR allows detection of allelic losses and gains in tumor cells by PCR fingerprinting, thus its resolution is at the molecular level. Both techniques were performed in 23 patients with stage A B-CLL at diagnosis. The results were compared with FISH. The sensitivity of AP-PCR was greater than CGH (62% vs. 43%). The use of CGH combined with AP-PCR allowed to detect genetic abnormalities in 79% (15/19) of patients in whom G-banding was not informative, providing a global view of the aberrations in a sole experiment. This study shows that combining these two methods with FISH, makes possible a more precise genetic characterization of patients with B-CLL.

Morphometric and colorimetric analysis of peripheral blood smears lymphocytes in B-cell disorders: proposal for a scoring system

Distinguishing leukemic phases of B-cell disorders in peripheral blood smears is well recognized to be difficult in some cases since it depends on subtle and subjective criteria. In order to quantify cytological features and to assess objective descriptions, a morphometric analysis was performed on 83 peripheral blood smears of B-cells disorders (n = 77) and healthy donors (n = 6). Using standardized May-Grunwald Giemsa staining, standardized image acquisition system and well defined microscopic fields, we have analyzed lymphoid cells, measuring morphometric and color parameters. By combining seven relevant morphometric criteria (the nuclear shape, the cellular shape and area, the nucleo-cytoplasmic ratio, the nuclear red/blue ratio, the cytoplasmic green/blue ratio and the proportion of cells with nucleolus), we have established a score that could range from a minimum of -3 (large B-CLL type) to a maximum of +8 (large MCL type): negative scores corresponds to different types of B-CLL (n = 30), including "atypical B-CLL" (n = 6), the score zero correspond to healthy donors (n = 6) used as baseline, the positive score values correspond to +1 for Follicular lymphoma (n = 2), +3 for Splenic Lymphoma with Villous Lymphocytes (n = 12), +4 for Hairy Cell Leukemia (n = 7), for Hairy Cell Leukemia-variant (n = 2), +6 for B-prolymphocytic leukemia (n = 6) and +7 and +8 for most Mantle Cell Lymphoma (n = 18). Testing T-cell disorders samples (n = 10) using the same protocol, the profile is different and cannot be confused with B-cell diseases. Our scoring system indicates that measurement of some common morphologic features in standardized conditions provides objective criteria to characterize those diseases and might be helpful for diagnosis.

The influence of cytogenetic aberrations on gene replication in chronic lymphocytic leukemia patients

Chronic lymphocytic leukemia (CLL) is the most common leukemia in humans, with the major cytogenetic aberrations of trisomy 12 and deletion of 13q14. This study examined the influence of these aberrations on general gene replication. The study group included three subgroups: (1) 15 CLL patients, (2) 4 CLL patients with trisomy 12, (3) 3 CLL patients with deletions in 13q14. Five healthy individuals served as a control group. Monocolor fluorescence in situ hybridization (FISH) with probes for c-myc, HER-2/neu, and p53 was applied to lymphocyte nuclei for the evaluation of replication timing. Asynchronous replication (SD) rate was significantly higher in all CLL patients (P < 0.01) when compared to the control group and was even higher in the group of CLL patients with trisomy 12 and 13q14 deletion (P < 0.01). The asynchrony rate was significantly higher in cells with trisomy 12 for all three probes analyzed, compared to "healthy" cells in the same patients (P < 0.001). To conclude, in CLL patients with a chromosomal aberration such as trisomy 12 and 13q14 deletion we were able to demonstrate a high rate of asynchrony of replication. The high correlation between cells with trisomy 12 and SD pattern could reflect direct influence of the aberration on gene replication and cell cycle control.

Achieving Optimal Outcomes in Chronic Lymphocytic Leukaemia

Chronic lymphocytic leukaemia (CLL) is a disease of late middle age and older. The majority of patients are diagnosed because of a lymphocytosis of at least 5 x 10(9)/L on an incidental blood count. It needs to be distinguished from mantle cell lymphoma and splenic marginal zone lymphoma by lymphocyte markers. The immunophenotype of CLL is sparse surface immunoglobulin, CD5+, CD19+, CD23+, CD79b-, and FMC7-. The disease is staged according to the presence of lymphadenopathy and/or splenomegaly and the features of bone marrow suppression. Most patients have an early stage of disease when diagnosed and perhaps 50% will never progress. This group of patients have a normal life expectancy and do not require treatment beyond reassurance. Progression involves an increasing white cell count, enlarging lymph nodes and spleen, anaemia and thrombocytopenia. Complications of progression include autoimmune haemolytic anaemia and thrombocytopenia, immunodeficiency, and the development of a more aggressive lymphoma. A range of prognostic factors is available to predict progression, but most haematologists rely on close observation of the patient. Intermittent chlorambucil remains the first choice treatment for the majority of patients. Combination chemotherapy offers no advantage. Intravenous fludarabine is probably more effective than chlorambucil, but no trial has yet shown a survival advantage for using it first rather than as a salvage treatment in patients not responding to chlorambucil. It is at least 40 times as expensive as chlorambucil. Cladribine may be as effective as fludarabine, although it has been used less and is even more expensive. Patients who relapse after chlorambucil should be offered retreatment with the same agent and if refractory should be switched to fludarabine, which may also be offered for retreatment on relapse. For patients refractory to both drugs, a variety of options are available. High dose corticosteroids, high dose chlorambucil, CHOP (cyclophosphamide, prednisolone, vincristine and doxorubicin), anti-CD52, anti-CD20 and a range of experimental drugs which are being evaluated in clinical trials. Younger patients should be offered the chance of treatment with curative intent, preferably in the context of a clinical trial. Autologous stem cell transplantation after achieving a remission with fludarabine has relative safety and may produce molecular complete remissions. Only time will tell whether some of these patients are cured but it seems unlikely. Standard allogeneic bone marrow transplant is probably too hazardous for most patients, but non-myeloablative regimens hold out the hope of invoking a graft-versus-leukaemia effect without a high tumour-related mortality. Trials of immunotherapy are exciting options for a few patients in specialised centres.

Atypical lymphocytes in B-cell chronic lymphocytic leukemia and trisomy 12 studied by conventional staining combined with fluorescence in situ hybridization

Trisomy 12 is one of the most frequent chromosomal abnormalities in B-cell chronic lymphocytic leukemia (CLL), and is predominantly found in CLL with atypical morphology (aCLL). It has been suggested that the atypical morphology might be a feature of the abnormal trisomy 12 clone, but so far it has been difficult to allocate chromosomal aberrations to individual leukemic cells identified by cytomorphology. We therefore wanted to use our MGG/FISH method, which combines fluorescence in situ hybridization (FISH) and standard cytomorphology, to study if the trisomy 12 clone in CLL was restricted to lymphocytes with atypical morphology. Peripheral blood specimens of four patients with aCLL were studied using a DNA probe against the pericentromeric region of chromosome 12. Trisomy 12 was found in 10-34 % of the lymphocytes. In three patients, the proportion of atypical and typical lymphocytes with trisomy 12 was quite comparable, and so was the percentage of atypical cells with lymphoplasmacytoid morphology and those with cleaved nucleus showing trisomy 12. Only one patient differed, since we found an overrepresentation of trisomy 12 among the atypical lymphocytes. However, this could be fully explained by the diluting effect of contaminating T-cells after chemotherapy. The results of the present study show that despite the strong association of trisomy 12 and atypical morphology in CLL, this chromosomal abnormality is not confined to lymphocytes with atypical morphology, but is also found in typical CLL cells. This supports that both cell types have the same clonal origin and that different cell morphology cannot be explained alone by the acquisition of an additional chromosome 12.

Morphological and immunophenotypic features of chronic lymphocytic leukemia

In this review, we summarize the morphological features and immunophenotypic profile of chronic lymphocytic leukemia (CLL) cells, discuss the value of these investigations as front line diagnostic tests, and emphasize their correlation with the clinical features, disease progression, molecular genetics and pathogenesis of CLL. In CLL, the morphology of the circulating cells is characteristic and typical in the majority of cases. However, 15% of patients, either at diagnosis or during the course of the disease, show atypical morphology reflected by either (1) an increased (> 10%) number of circulating prolymphocytes, designated CLL/PL, or (2) an increased (> 15%) number of circulating lymphoplasmacytic and cleaved cells, designated 'atypical' CLL. There is strong evidence of a close association between atypical morphology (CLL/PL) and atypical (CLL) and clinical features, e.g. disease progression, advanced stage and survival, molecular genetics, particularly trisomy 12, but also the rare cases with t(11;14) or t(14;19), p53 abnormalities, unmutated immunoglobulin (Ig) VH genes and origin of the cell (naive, pregerminal center cell). CLL cells have a distinct immunological repertoire different from that of other lymphoproliferative disorders. The typical CLL phenotype is CD5+, CD23+, FMC7-, weak expression of surface Ig (sIg) and weak or absent expression of membrane CD22 and CD79b. The latter marker identifies an extracellular epitope of the B-cell receptor (BCR) beta chain and its weak or absent expression in CLL may derive from the expression of a truncated form. This, together with the low expression of CD22, might explain the abnormal signal transduction of CLL cells similar to that of anergic B lymphocytes. Because no single marker is specific for CLL, a composite phenotype considering this set of 5 or 6 markers compounded into a scoring system helps to distinguish CLL from the other B-cell malignancies. Immunophenotypic analysis has also been shown to be useful for minimal residual disease detection and adds valuable prognostic information because the expression of certain markers, such as FMC7 or CD38, seems to be associated with a poor outcome. In addition, CLL cells express a variety of Bcl-2 family proteins with a profile that favors inhibition of apoptosis which, together with the interaction with microenvironmental (e.g. stromal) cells and the release of cytokines, explains the long life span and subsequent accumulation of CLL cells in various organs. Despite controversies relating to the expression of adhesion molecules (selectins and integrins) in CLL cells, it appears that some of these molecules do play a role in the pathogenesis, biology and clinical patterns of the disease. In conclusion, morphology and immunophenotype are the two essential investigations, which must be carried out in all cases of CLL. Both provide relevant information in terms of diagnosis, course of the disease, prognosis and pathogenesis.

Chronic lymphoproliferative disorders: an integrated point of view for the differential diagnosis

Morphology is regarded as the principle basis for the identification of lymphoid neoplasms. Sometimes, however, it fails to discriminate among several chronic lymphoproliferative disorders (CLDs). Improved immunophenotyping has resulted in a better characterization of a number of variants of these diseases, some of which may benefit from different therapeutic approaches. In particular, the proposal of scoring systems using a panel of monoclonal antibodies (MoAbs) has represented a critical step in this field. In fact, to date, some MoAbs (CD5, CD23, FMC7, CD22, CD79b, and surface immunoglobulin density) are able to distinguish among several entities, thus allowing for a correct diagnosis in the majority of cases. However, there is still a small percentage of patients where the combined diagnostic approach (morphology and immunophenotyping) should be further refined by other techniques, such as cytogenetic and molecular characterization. Here numerous questions are raised indicating the need to more accurately differentiate the disease entities under discussion and better understand some of their clinical manifestations.