Analysis of chronic lymphoid leukaemias according to FAB.

We have studied the immunophenotypic features in patients with chronic lymphoid leukaemia and investigated the suitability of classification according to guidelines of the French-American-British (FAB) group. Immunophenotyping was carried out on cytocentrifuge preparations of mononuclear blood leukocytes using the alkaline phosphatase-antialkaline phosphatase (APAAP) method. The 114 leukaemias, including 58 cases of B-chronic lymphocytic leukaemia (B-CLL), 3 Waldenstr?m's macroglobulinaemia, 6 prolymphocytic leukaemia (B-PL), 13 B-CLL/PL, 4 B-CLL of mixed cell type, 8 splenic lymphoma with villous lymphocytes (SLVL), 8 hairy cell leukaemia (HCL), two HCL variant, three leukaemic phase of follicular lymphoma, two leukaemic phase of intermediate lymphoma, two plasma cell leukaemia and two chronic T-cell leukaemia, were investigated. The 111 of 112 B-chronic lymphoid leukaemias (B-CLL + B-PL + B-CLL/PL + SLVL + HCL etc.) showed monotypic light chains. The antibody HML1 was highly specific for HCL. The antibodies CD11c and CD25 were positive in all HCL cases, but were not specific for this disease. CD5 positivity and CD22s negativity were found in most patients with B-CLL, B-CLL/PL and B-CLL of mixed type. This marker type has a limited value for differentiation from the other chronic lymphoid leukaemias. We also studied three patients with chronic lymphoid leukaemia which were not described by the FAB classification. We conclude that a study of the morphology of the leukaemic cells was the most useful basis for the diagnosis of these leukaemias, whereas immunotyping was apparently valuable only in individual cases.     

The significance of soluble HLA-G plasma levels as well as messenger HLA-G for B-cell chronic lymphocytic leukemia (B-CLL)

The immunosuppression accompanies B-cell chronic lymphocytic leukemia (B-CLL) but might be also responsible for disease progression by enabling CLL cells to escape from the immunosurveillance. Some particles involved in the regulation of an immune system might represent prognostic value for B-CLL. Recently we found no correlation between HLA-G on messenger and protein level, suggesting that HLA-G is released in soluble form. To confront this hypothesis we characterized soluble HLA-G (sHLA-G) by the prognostic factors in the first cohort of 34 CLL patients. No correlation was observed between sHLA-G levels in ZAP-70(+) and ZAP-70(−) CLL as well as in CD38(+) CLL and CD38(−) CLL patients. Next, we wondered whether gene expression of HLA-G, which represent the whole HLA-G pool in the cell, posses prognostic value for CLL. In the second cohort of 41 CLL patients we assessed messenger levels of HLA-G by the strongest prognostic factors in CLL including cytogenetics, IgVH mutational status, ZAP-70 as well as CD38. No changes of HLA-G expression levels were found in different CLL groups characterized by IgVH gene mutational status, ZAP-70 as well as CD38. We observed no differences in expression of HLA-G in various cytogenetic groups of CLL including del17p, del13q, del11q, +8q, +3q, del14q and del6q when compared to those with normal karyotype or with 12+. Both, mRNA expression of HLA-G and levels of its soluble form in plasma bring no additional prognostic value for B-CLL patients.     

Expression of the CD11c antigen in B-cell chronic lymphoproliferative disorders

This study analyzed the expression of the beta2 integrin CD11c in 155 patients with well-characterized B-cell chronic lymphoproliferative disorders: 106 B-cell chronic lymphocytic leukemias (B-CLL), 21 hairy cell leukemias (HCL), 9 B-cell prolymphocytic leukemias (PLL) and 19 low grade non-Hodgkin's lymphomas (NHL) in leukemic phase. CD11c was expressed in 100% of patients with HCL and B-PLL, while in B-CLL and NHL it was expressed in only 49 and 57%, respectively. Furthermore, in B-CLL the expression of CD11c was found mainly in patients with early stage of disease. In addition, when the fluorescence intensity of CD11c, calculated by MFI, was evaluated, it proved significantly higher in HCL and B-PLL compared to the values recorded in B-CLL and NHL (325 and 387 vs 34 and 56, respectively) (p < 0.05). Our results demonstrate that the evaluation of CD11c, both in terms of overall positivity and of fluorescence intensity, represents an additional useful parameter for a more precise differential diagnosis within the spectrum of B-cell chronic lymphoproliferative disorders.     

Surface Phenotype and Adhesion Activity of B-Cell Chronic Lymphoid Leukemias

Surface phenotypes and adhesion activity to human umbilical vein endothelial cells (HUVECs) were studied using leukemic cells from 12 Japanese patients with B-cell chronic lymphoid leukemias including 7 with chronic lymphocytic leukemia (CLL), 1 with prolymphocytic leukemia (PLL), 2 with hairy cell leukemia (HCL) and 2 with HCL variant (HCL-V). CD 13 and CD23 were found to be characteristically positive in CLL, whereas they were not expressed in non-CLL cases except for positivity of CD23 in two such cases. Except for CDl lb, all other leukocyte integrins examined (CDlla, CD11c and CD18) and their ligand (CD54) were highly expressed in non-CLL cases. Adhesion activity of leukemic cells to HUVECs after co-culture with HUVECs was well correlated with the expression of CD11b lb, CD18 and CD54, but showed no predilection for any leukemia subtype. Positivity for CD5, CD21, CD23 and CD13 changed after the co-culture with HUVEC. These results suggest that adhesion activity after co-culture does not correlate with the leukemia subtype and that endothelial cells activate or differentiate leukemic cells.     

Immunophenotyping of subtypes of B-chronic (mature) lymphoid leukemia. A study of 242 cases.

BACKGROUND. The French-American-British group's proposal for the classification of chronic lymphoid leukemias is unique at this time. Testing, expanding, and adding to the theory by immunophenotyping will help to additionally characterize this group of diseases. METHODS. Peripheral blood samples from 242 patients with chronic lymphoid leukemias were analyzed for immunologic evaluation of the following subtypes: typical chronic lymphocytic leukemia (CLL), 189; CLL with pleomorphic lymphocytes (CLL-pleo), 19; CLL of mixed cell type (CLL/PL), 20; prolymphocytic leukemia (PLL), 22; hairy cell leukemia (HCL), 10; HCL-variant, 1; and splenic lymphoma with villous lymphocytes, 1. RESULTS. The phenotype of CLL and CLL-pleo was weak surface immunoglobulin (SIg) with positive results of mouse rosettes (MR+), CD5+, and CD22-. Of PLL and HCL, it was strong SIg, MR-, CD5-, and CD22+. By analyzing the four markers and accepting the relevant results of two or more as sufficient for diagnosis, all cases (100%) of CLL, CLL-pleo, PLL, and HCL were diagnosed. CLL/PL showed the phenotype of CLL in 66.67% and of PLL in 33.33% of patients. The frequency of cases with weak fluorescence in decreasing order was CLL, CLL-pleo, CLL/PL, and PLL and HCL. The same sequence applied to the mean percentage of mouse rosette-forming cells and CD5 cells, but the sequence was reversed for CD22 cells. CONCLUSIONS. SIg intensity, MR, CD5, and CD22 constitute the minimum number of immune markers for the differential diagnosis of the subtypes of chronic lymphoid leukemia. The frequency of the four markers among the subtypes suggested that CLL and CLL-pleo have identical phenotypes and that the five subtypes follow a continuous range of B-cell differentiation from early mature (CLL and CLL-pleo) to late mature pre-plasma cell stages (PLL followed by HCL), with CLL/PL of intermediate maturity.     

Occurrence of particular isoenzymes in fresh and cultured leukemia-lymphoma cells. I. Tartrate-resistant acid phosphatase isoenzyme

The cells from 87 leukemia-lymphoma cell lines, 14 B-lymphoblastoid cell lines, 459 cases of leukemia-lymphoma, normal specimens, 22 leukemia-lymphoma cell lines treated with 12-O-tetradecanoylphorbol 13-acetate (TPA) and 14 cases of chronic lymphocytic leukemia (CLL) and chronic myelocytic leukemia (CML) treated with TPA were analyzed for the expression of tartrate-resistant acid phosphatase (TracP) isoenzyme separated by isoelectric focusing. The TracP isoenzyme was seen in the following leukemia-lymphoma cell lines: 4 of 30 T-cell, 2 of 35 B-cell, 1 of 6 non-T/non-B-cell, 1 of 8 myelomonocytic, 3 of 4 erythroleukemia, and 3 of 4 Hodgkin's disease-derived cell lines. The expression of the TracP band could be induced by treatment with TPA in 3 myelomonocytic leukemia cell lines. Among the different types of leukemia-lymphoma cells freshly obtained from patients, the TracP isoenzyme was detected at a high incidence in cases of B-CLL, hairy cell leukemia (HCL), and B-lymphoma. Of the myeloid leukemias, 10% to 20% displayed the TracP isoenzyme. TracP positivity was detected in the peripheral blood, tonsil, bone marrow, spleen, and liver obtained from healthy donors, but not in the thymus. The expression of the TracP band could be newly induced by TPA in cases of CLL and in cases of CML. It is concluded that TracP activity is not specific for HCL, but is found at high incidences in cases of HCL, B-CLL and B-lymphoma. The TracP isoenzyme is not expressed by very immature lymphoid leukemia cells, but by cells arrested at later stages of differentiation of the T- or B-cell lineage, and by some myeloid cells.     

The importance of surface immunoglobulin, mouse rosettes, and CD5 in the immunophenotyping of chronic lymphocytic leukemia and reactive lymphocytosis

Peripheral blood from 167 B-chronic lymphocytic leukemia (B-CLL) and 119 reactive lymphocytosis (RLC) patients were analyzed to evaluate the immunophenotypic diagnostic value of mouse rosettes (M-rosette), and weak expression of monoclonal surface immunoglobulin (SIg). In B-CLL, 145 cases were M-rosette+ (86.83%), 135 surface immunoglobulin (SIg)+ (80.84%), and 117 M-rosette+ SIg+ (70.06%). Of 32 SIg- cases, 28 were M-rosette+; and of 22 M-rosette-cases, 18 were SIg+. By combining results of the two assays and accepting positivity of either one or both as sufficient for diagnosis, B-CLL was diagnosed in 163 cases (97.60%). CD5 was performed in 49 cases of the 167 with paired data for SIg and M-rosettes. By combining the results of the three assays and accepting positivity of any two or all three as sufficient for diagnosis, all 49 cases (100%) were diagnosed. Correlation analysis showed no significant association between M-rosette, SIg, and CD5 expression. The results demonstrate the independent expression of the three markers, and their complementary role in immunophenotyping B-CLL. In RLC, all 119 cases were T-lineage and SIg-, and 115 were M-rosette-, indicating the role of the two markers in differentiating B-CLL from RLC. Three of the four M-rosette+ T-RLC were subsequently diagnosed as B-CLL, suggesting the necessity of follow-up of such cases.     

Differential expression of TRAP Isoenzyme in B-CLL Cells Treated with Different Inducers

Purified B-cells from normal tonsils and from the peripheral blood of eight patients with B-chronic lymphocytic leukemia (B-CLL) were treated in vitro with the protein kinase C (PKC) activators TPA, Bryostatin 1 (Bryo), mezerein, with the calcium ionophore A23187, and with the cytokines interleukin-1/2, interferon-alpha/gamma, tumor necrosis factor. The induction of the lysosomal enzyme tartrate-resistant acid phosphatase (TRAP) was examined at the RNA (by Northern blotting analysis) and the protein level (by isoelectric focusing). TRAP mRNA and protein were induced by treatment with PKC activators while the combination of PKC stimulator and calcium ionophore was not effective, TRAP mRNA was detected as early as 2 hours after initiation of the culture. This induction of positivity for TRAP which is the enzymatic hallmark of hairy cell leukemia (HCL) by TPA or Bryo is consistent with the previously reported acquisition of HCL-type cellular features in TPA-driven CLL cells; CLL cells exposed to the double stimulus of TPA or Bryo + A23187 have previously been described to differentiate to plasmacytoid cells which is in accord with their remaining TRAP negative. The present data provide evidence that 1) B-CLL cells can be induced by direct stimulation of PKC to convert to HCL-type cells; 2) TPA/Bryo-exposed B-CLL cells display phenotypes different from those of cells treated with combinations containing calcium ionophore; 3) the phosphoinositol signal transduction pathway distal to PKC can be activated effectively in B-CLL cells; 4) Bryo, a new natural PKC activator, induces responses in CLL similar to those caused by TPA; 5) TRAP is an inducible indicator of cellular activation. These observations provide support for the idea that HCL and HCL-like cells might differentiate along a separate branch of B-cell lineage and might represent mature “activation end stage” cells.     

Hybrid form of hairy cell leukemia and chronic lymphocytic leukemia

We report a case with mixed features of hairy cell leukemia (HCL) and chronic lymphocytic leukemia (CLL), which may represent a hybrid form of these two entities. Hairy projections were demonstrated on leukemic cells in the peripheral blood. Surface marker studies of blood and spleen specimens by flow cytometry and immunohistochemistry showed immunophenotype characteristic of HCL, namely, monoclonal IgG-kappa, positive reactions to CD 11c, CD 19, CD 20, Cd 22, and HLA-DR, but negative reactions to CD 3, CD 5, CD 7 and CD 10. The only atypical finding was the absence of CD 25. Immunogenotyping showed rearrangement of heavy-chain and kappa light chain genes. Leukemic cells were also positive for tartrate-resistant acid phosphatase (TRAP). A pseudosinus pattern was demonstrated in the spleen. However, the leukemic cells in the spleen showed atypical cytologic features. Clinically, the patient had generalized lymphadenopathy, high leukocyte counts, Coombs' negative hemolysis, hypoimmunoglobulinemia and IgG-kappa monoclonal gammopathy, features more consistent with CLL than HCL. Although only CD 11c, CD 22, CD 25 and TRAP are characteristic for HLC and CD 5, characteristic for CLL, a panel of eight markers is recommended for the differential diagnosis of HCL, CLL and other low-grade B-cell neoplasms, which may share some common features, making a clear-cut diagnosis difficult.     

Successful treatment of extranodal Hodgkin's lymphoma in a patient with longstanding hairy cell leukemia

Purine analogs, particularly pentostatin and cladribine, are highly effective in hairy cell leukemia (HCL). Both of these drugs induce responses in approximately 80 - 95% of patients. However, it is not yet determined if treatment with these drugs can induce second malignancies. Hodgkin's lymphoma is very rare as a second malignancy and there are only 3 reported cases concerning the association of this lymphoma with HCL. We describe a patient with longstanding HCL in complete remission after cladribine, in whom extranodal Hodgkin's lymphoma appeared 8 years after the diagnosis of HCL. Magnetic resonance imaging revealed diffuse intra-osseal neoplastic infiltration of the corpora of the whole spinal column and extra-osseal propagation from the fifth thoracic vertebra into the spinal canal with spinal cord compression. Histological and immunohistochemical analysis of the extradural tumor, which was completely excised, disclosed nodular sclerosis Hodgkin's lymphoma with typical Reed - Sternberg cells that were positive for CD30, CD15, bcl-6, Ki67, p53, EBV LPM-1 and IgG, and negative for CD45, CD20, DBA44, kappa, lambda light chains and IgM. In addition, immunohistochemical analysis of the bone marrow in 1999 showed infiltration with positivity for IgM and negative for kappa light chains and IgG. These findings (expression of different immunoglobulins and light chains on the cells) suggest an independent origin of these 2 B-cell neoplasms. After neurosurgery the patient received 6 courses of the MP-ABVD protocol and achieved a complete remission, which has lasted 16 months thus far.     

Soluble Interleukin-2 Receptor, Soluble CD8 and Soluble Intercellular Adhesion Molecule-1 Levels in Hematologic Malignancies

Plasma levels of soluble interleukin-2 receptor (sIL-2R), soluble CD8 (sCD8) and soluble intercellular adhesion molecule 1 (sICAM-1) were determined by ELISA assays in about 100 patients with hairy cell leukemia (HCL), acute myelomonocytic leukemia (AMMoL), acute myelocytic leukemia (AML), chronic lymphocytic leukemia (CLL), prolymphocytic leukemia (PLL), acute lymphoblastic leukemia (ALL), adult T-cell leukemia (ATL), and mycosis fun-goides (MF). Additionally, cultured AML, ALL, and CLL cells grown with and without 12-0-tetra-decanoyl-phorbol-13-acetate (TPA) were tested for IL-2R (CD25) expression by indirect immunofluorescence. Supernatants of these cultures were also tested for sIL-2R by ELISA.

Elevated sIL-2R levels were found in HCL patients at initial diagnosis and relapse, in AMMoL, in AML, in the accelerated and non-accelerated phases of B-CLL, in PLL, in non-T/non-B ALL, in B-ALL, in mixed lineage ALL, in T-CLL, in T-ALL, and in active MF. Reduced levels of sIL-2R were encountered in HCL patients in remission, in pre-T-ALL, and in MF patients in remission. Also, in non-accelerated CLL sIL-2R levels were less elevated than in later stages of the disease. In T-CLL, sIL-2R was only slightly elevated. Thus, we believe sIL-2R could prove to be a useful marker of disease stage, subtype, and prognosis in several hematologic malignancies.

The cultures with and without TPA suggested that the undetermined source of sIL-2R in HCL, ALL and AML could indeed be the malignant cells but perhaps not so in the case of B-CLL.

Plasma sCD8 was found to be below normal control levels in HCL, and lowest in relapsing cases. In addition, sCD8 levels were below normal in pre-T-ALL, and in MF. Levels in the non-accelerated phase of B-CLL approximated those of controls. Elevated levels of sCD8 were observed in AML, AMMoL, accelerated stage B-CLL, PLL, non-T/non-B ALL, B-ALL, mixed lineage ALL, T-ALL, T-CLL, and ATL. Thus, in a few instances, sCD8 may also correlate with disease subtype, as well as stage. Although sICAM-1 levels were elevated in all leukemias, its levels in CLL did not appear to be related to disease activity. Whether this is true or not for other leukemias would require additional work on sICAM-1 levels and its relationship to disease activity and prognosis.     

Relevance of a scoring system including CD11c expression in the identification of splenic diffuse red pulp small B‐cell lymphoma (SRPL)

‘Splenic red pulp lymphoma with numerous basophilic villous lymphocytes’ (SRPL), recently described, is characterized by clinical, morphologic, immunologic, cytogenetic and molecular features distinct from SMZL/SLVL and HCL. In particular, the intensity of CD11c staining (expressed as fluorescence intensity ‐RFI‐) in SRPL is significantly different from the RFI in SMZL/SLVL and HCL. Moreover the use of a scoring system based on the expression of CD11c, CD22, CD76, CD38 and CD27 appears to improve the differential diagnosis between SRPL and SMZL/SLVL and emphasizes that SRPL is an entity closed to but distinct from SMZL/SLVL. Copyright © 2010 John Wiley & Sons, Ltd.     

Differentiating Agents Do Not Induce a True Hairy Cell Phenotype in B-CLL Cells in Vitro

B-Chronic lymphocytic leukemia (B-CLL) and hairy cell leukemia (HCL) are both differentiated B-cell lymphoproliferative disorders. Prior studies have suggested that phorbol esters and the macro-cyclic lactone Bryostatin-1, which are both protein kinase-C activators, can induce the differentiation of B-CLL cells into HCL cells in vitro, as evidenced by morphology, phenotype and TRAP activity. The differentiating effect of all-trans retinoic acid on B-CLL cells has been less extensively studied. We studied the effects of incubating adherence purified B-CLL cells with phorbol myristic acetate (PMA), all-trans retinoic acid (ATRA), and Bryostatin-1. None of these agents induced a true HCL phenotype (CD5-, CD1 lc/CD25 coexpression) under the conditions studied.     

Splenic Lymphoma with Villous Lymphocytes

Splenic lymphoma with villous lymphocytes (SLVL) is a recently identified B cell lymphoproliferative disorder characterised by splenomegaly and the presence in the peripheral blood of lymphocytes with 'villous' projections. These villous lymphocytes are slightly larger than those found in CLL, have a round nucleus, a visible nucleolus in 50% of cases and have a variable amount of basophilic cytoplasm and characteristically, an irregular cell surface with thin, short membrane villi that are unevenly distributed and most often seen at the poles of the cell. Small numbers of plasmacytoid cells are present in most cases. There may be a variable degree of anaemia or thrombocytopenia. Immunologically the cells display a B cell phenotype with surface immunoglobulin of moderate to strong intensity, CD19, CD20, CD22, class II MHC antigens and FMC-7 expression, but they are often negative with CD5 and CD23, commonly positive in CLL, and they also are negative with CD25, HC2 and B-ly-7, typical markers in hairy cell leukaemia (HCL). The expression of CD11c, another HCL marker is variable. The bone marrow is easily aspirated and splenic infiltration is predominantly in the white pulp, both features distinct from HCL. A monoclonal gammopathy (M-band) is identified in the serum in two-thirds of patients, occasionally with free urinary light chains, but is generally less than 20 g/l. The disease usually follows a benign clinical course but may undergo transformation to large cell lymphoma in a minority of cases. When treatment is required, splenectomy is the treatment of choice and should be considered before splenic irradiation or chemotherapy which are less effective modalities.     

A Review on Splenic Diffuse Red Pulp Small B-Cell Lymphoma

Splenic diffuse red pulp small B-cell lymphoma (SDRPL) is a rare disease, representing <1% of all non-Hodgkin lymphomas (NHL). The most common clinical manifestations include splenomegaly, lymphocytosis, and hemocytopenia. A diagnosis of SDRPL can be challenging, as it shares multiple clinical and laboratory features with splenic marginal zone lymphoma (SMZL), hairy cell leukemia (HCL), and HCL variant (HCL-v). Obtaining splenic tissue remains the gold standard for diagnosis. In the cases where splenic tissue is not available, diagnosis can be established by a review of peripheral blood and bone marrow studies. SDRPL is characterized by a diffuse involvement of the splenic red pulp by monomorphous small-to-medium sized mature B lymphocytes effacing the white pulp. The characteristic immunophenotype is positive for CD20, DBA.44 (20 to 90%), and IgG, and typically negative for CD5, CD10, CD23, cyclin D1, CD43, annexin A1, CD11c, CD25, CD123, and CD138. The Ki-67 proliferative index is characteristically low. Cyclin D3 is expressed in the majority of SDRPL in contrast with other types of small B-cell lymphomas, thus facilitating the recognition of this disease. There is no standard treatment regimen for SDRPL. Initial treatment options include splenectomy, rituximab monotherapy, or a combination of both. Chemoimmunotherapy should be considered in patients with advanced disease at baseline or progression.     

Expression of the T1 (CD5, p67) surface antigen in B-CLL and B-NHL and its correlation with other B-cell differentiation markers

The T1 surface antigen (CD5,p67) expression on blood lymphocytes (PBL) and lymphoid cells from lymph node biopsies (LN) from 31 patients with B-cell chronic lymphocytic leukemia (B-CLL) and 79 with B non-Hodgkin lymphoma (B-NHL), was detected in 25 B-CLL (80 per cent) and in 11 B-NHL (13 per cent) belonging to the following histologic subtypes: lymphocytic of CLL type (DLWD) one case, lymphoplasmacytoid (DLWD) four cases, centrocytic (DLPD) five cases, immunoblastic (DH) one case. All B-CLL and the T1 + B-NHL were also tested with monoclonal antibodies against the Common Acute Lymphoblastic Leukemia Antigen, B cells (FMC7, FMC8, BA1, Y29-55), T cells (OKT11a), HLA-DR and HLA-DQ monomorphic determinants. All the B-CLL and the T1+ B-NHL were CALLA-, BA1+, Y29.55+. FMC7+ cells were detected in large numbers six B-CLL (three T1+ and three T1-) and in four centrocytic lymphomas. FMC8 reacted with 70 per cent of leukemias (where it stained 30 per cent of neoplastic cells) and with 8/9 T+ B-NHL. HLA-DR and HLA-DQ molecules were detected in 100 per cent and 90 per cent of cases respectively. In vitro treatment of HLA-DQ- or T1- B-CLL with phorbol ester TPA led to the expression of these antigens as well as of the receptors for Interleukin 2 and MLR3 activation antigen. Surface membrane Ig (SIg) was detected in 79 per cent of cases, its density measured by FACS analysis varied, even markedly, from case to case. Among the B-CLL, cells with high SIg content were either T1+ or T1- and more likely FMC7+. The SIg- cases were seven B-CLL (five T1+ and two T1-) and two B-NHL, in which, however, cytoplasmic IgM was detected. This study reveals the existence of four major B-CLL subgroups: T1- SIg-, T1+ SIg+, T1+ SIg+, T1- SIg+. It also indicates that the T1 antigen may be transitionally present during B-cell differentiation and that its expression may precede that of SIg as supported by the in vitro studies. In addition, the finding that some B-NHL are T1+ suggests that they derive similarly to the B-CLL from a common progenitor.     

IFN Gamma Gene Polymorphism May Contribute to the Susceptibility to CLL

The pathogenesis of B-cell chronic lymphocytic leukemia (B-CLL) has been linked with the production and activity of certain growth factors. However a significant proportion of CLL patients display immune abnormalities suggestive of aberrant cytokine secretion and/or response. In contrast to B lymphocytes, T cells of B-CLL patients characterise with the increased production of interferon-gamma (IFN-γ) and this cytokine has been indicated to prevent malignant cells from entering apoptosis including the slowly expanding population of CD5+ B cells that characterizes chronic lymphocytic leukemia. The aim of the present study was to assess whether functionally relevant interferon-gamma gene (IFNG) polymorphism (+847 A/T) contributes to the pathogenesis of B-CLL. In total 110 individuals was investigates, including 61 CLL patients and 50 healthy individuals. The presence of the IFNG AA genotype was found to be associated with susceptibility to CLL (23/61 vs. 7/50, p < 0.005, for patients and controls, respectively). This results suggest that individuals rather prone to the lower level of IFN-γ production (associated with the presence of the A allele) appear to be more susceptible to this malignant disease.     

Triggering of neoplastic B cells via surface IgM and the cell surface antigens CD20 and CDw40. Responses differ from normal blood B cells and are restricted to certain morphologic subsets

By raising monoclonal antibodies (MAbs) against B cells, a number of cell surface molecules have recently been identified which after binding by their specific antibody can trigger B cells, either alone or in co-operation with antibodies to surface immunoglobulin (sIg). The anti-CD20 (Bp35) MAb IF5 can deliver a strong activation signal to resting normal B cells, and the anti-CDw40 (Bp50) MAb G28-5 can promote activated G1 B cells to enter S phase. These antibodies were tested for their functional effects in vitro on suspended cells from 17 follicle-center-cell (FCC) lymphomas, 5 cases of chronic lymphatic B-cell leukemia (B-CLL) and 8 cases of various histological types. Changes in cellular volume, RNA and DNA synthesis were compared with the results obtained with a polyclonal anti-mu [F(ab')2] antiserum, a MAb to surface IgM (AF6), 12-O-tetradecanoyl-phorbol-13-acetate (TPA) and B-cell growth factor (low-molecular-weight BCGF). Our data reveal differences in the requirements for triggering of various B-cell subsets: cells from CLL responded strongly to TPA but not to anti-mu, which is a potent stimulator not only of normal B cells but also of cells from individual cases of FCC lymphomas. Our observations suggest that the differentiation stage of B-CLL cells is distinct from that of small resting B cells from peripheral blood. Centrocytic lymphomas could not be activated by any of the reagents. CD20-mediated triggering was seen in neoplastic B cells from only 4 of 30 cases, indicating that most B-cell neoplasias were not responsive to this activation pathway. In contrast, the anti-CDw40 MAb consistently stimulated DNA synthesis together with anti-mu or TPA in cells from FCC lymphomas, but not from CLL. Together, these results suggest that activation in different neoplastic B-cell subsets depends on distinct signal transduction mechanisms.     

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

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

Outline for Writing an Article for Current Treatment Options in Oncology: Splenic Lymphoma with Villous Lymphocytes

Two subtypes of splenic marginal zone lymphoma (SMZL) are identified in the World Health Organization (WHO) classification: SMZL without villous lymphocytes and SMZL with villous lymphocytes in the peripheral blood (SLVL). SLVL is a rare leukemic and indolent B-cell chronic lymphoproliferative disorder (B-CLPD) that we have to differentiate from hairy cell leukemia (HCL), B prolymphocytic leukemia (B-PLL) and follicular lymphoma (FL). Morphological examination associated with immunophenotyping is, in most cases, likely to distinguish these CD5 negative entities. However, the diagnosis can be difficult to make on morphological criteria, especially in patients without absolute lymphocytosis. Based on histologic, cytogenetic and molecular studies, SLVL emerges as a distinct entity. SLVL has a relatively clinical benign course but a few patients could require treatment, because of a symptomatic splenomegaly and/or a severe cytopenia. In symptomatic patients HCV negative, the frontline treatment remains questionable. Splenectomy, regarded as the most effective treatment, could be required for diagnostic purposes: however, relapse occur in 30% of cases. Fludarabine (FDR), a purine analogue and deoxycoformycin (DCF) can induce a maintained response in a substantial proportion of patients with SLVL and could be used as a first line treatment. In HCV + SLVL patients, antiviral treatment using alpha interferon and ribavirin can induce regression of SLVL.