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Biomedical subjects

B Falini

Publications and source records attributed to B Falini.

At least 37 records · Page 2Linked to original sources
PubMed2000

A new variant anaplastic lymphoma kinase (ALK)-fusion protein (ATIC-ALK) in a case of ALK-positive anaplastic large cell lymphoma.

Anaplastic lymphoma kinase (ALK)-positive lymphomas ("ALKomas") constitute a distinct molecular and clinicopathological entity within the heterogeneous group of CD30-positive large cell lymphomas. In 80-85% of cases tumor cells express a Mr 80,000 hybrid protein comprising the nucleolar phosphoprotein nucleophosmin (NPM) and the ALK. We report here the cloning and expression of a novel ALK-fusion protein from an ALK-positive lymphoma. This case was selected for molecular investigation because of (a) the absence of NPM-ALK transcripts; (b) the atypical staining patterns for ALK (cytoplasm-restricted) and for NPM (nucleus-restricted); and (c) the presence of a Mr 96,000 ALK-protein differing in size from NPM-ALK. Nucleotide sequence analysis of ALK transcripts isolated by 5'-rapid amplification of cDNA ends revealed a chimeric mRNA corresponding to an ATIC-ALK in-frame fusion. ATIC is a bifunctional enzyme (5-aminoimidazole-4-carboxamide ribonucleotide transformylase and IMP cyclohydrolase enzymatic activities) that catalyzes the penultimate and final enzymatic activities of the purine nucleotide synthesis pathway. Expression of full-length ATIC-ALK cDNA in mouse fibroblasts revealed that the fusion protein (a) possesses constitutive tyrosine kinase activity; (b) forms stable complexes with the signaling proteins Grb2 and Shc; (c) induces tyrosine-phosphorylation of Shc; and (d) provokes oncogenic transformation. These findings point to fusion with ATIC as an alternative mechanism of ALK activation.

3T3 Cells↗
PubMed2000

Defective recruitment and activation of ZAP-70 in common variable immunodeficiency patients with T cell defects.

We have previously identified a subset of common variable immunodeficiency (CVID) patients with defective T cell function associated with impaired activation of the TCR-dependent tyrosine phosphorylation cascade. Here we have assessed the structural and functional integrity of the principal components involved in coupling the TCR/CD3 complex to intracellular tyrosine kinases in two of these patients. We show that ZAP-70 fails to bind the signaling-competent CD3zeta tyrosine phosphorylation isoform and to become activated following TCR engagement, suggesting that defective recruitment of ZAP-70 might underlie the TCR signaling dysfunction in these patients. Determination of the nucleotide sequences encoding the intracellular domains of the CD3/zeta subunits and ZAP-70 did not reveal any mutation. Furthermore, ZAP-70 from these patients could interact in vitro with recombinant phospho-zeta, ruling out genetic defects at the immunoreceptor tyrosine-based activation motif/SH2 domain interface responsible for ZAP-70 recruitment to the activated TCR. No defect was found in expression, activity or subcellular localization of Lck, which is thought to be primarily responsible for CD3zeta phosphorylation. Hence, while the T cell defect in these CVID patients can be pinpointed to the interaction between ZAP-70 and CD3zeta, the integrity in the components of the signaling machinery involved in this process suggests that additional components might be required for completion of this step.

Animals↗
PubMed2000

Primary eyelid plasmacytoma.

We report a case of eyelid plasmacytoma. The patient presented with a superficial lesion on the upper left eyelid, 10x7 mm in size. Histological and immunohistochemical findings were indicative of plasmacytoma with slightly abnormal sub-epidermic plasma cell infiltrates. Immunoperoxidase staining was strongly positive for intracytoplasmic kappa light chains. No infiltration by atypical plasma cells could be documented in the bone marrow biopsy and aspirate. Skeletal survey showed no osteolytic lesions or osteoporosis. The tumor on the left eyelid was surgically removed. No radiotherapy was administered.

Adult↗
PubMed2000

Immunophenotypic and genotypic markers of follicular center cell neoplasia in diffuse large B-cell lymphomas.

Diffuse large B-cell lymphomas (DLBCL) are a biologically and clinically heterogeneous entity. Although some DLBCL represent transformation of follicular lymphomas (FL), the proportion that is of follicular center cell (FCC) origin remains uncertain. Immunophenotypic and genotypic markers used to suggest a FCC origin for a lymphoma (bcl-6 and CD10 expression, lack of CD138 expression, bcl-2 rearrangements [R]) or to subdivide DLBCL (bcl-2 expression, bcl-6 R) were therefore investigated in 22 FL and 44 DLBCL using paraffin section immunostains and Southern blot/polymerase chain reaction analysis. All FL tested were bcl-6+ (19) and CD138- (22) with 16/19 also bcl-2 and CD10+ (classic phenotype), one bcl2+, CD10- (grade III) and two bcl2-, CD10+ (grade II or III). Bcl-2R was identified in 4/5 FL-GrI, 3/6 FL-GrII, and 1/3 FL-GrIII. Bcl-6R was found in 0/5, 2/4, and 0/3 FL, respectively. All but 3/41 DLBCL were bcl-6+ with 17/37 also bcl-2+ and CD10+. Three of these cases were also CD138+. Twelve bcl-6+ cases were bcl-2+, CD10-, six bcl-2-, CD10+, and two bcl-2-, CD10-. The three bcl-6- cases were bcl-2+, CD138- and two were CD10+. Bcl-2R was identified in 5/27 DLBCL with 4/5 bcl-2+, 3/4 tested CD10+ and 4/4 bcl-6+. Bcl-6R was identified in 7/26 including three with a classic FL phenotype. The vast majority of DLBCL in this study have an immunophenotype that supports a FCC origin. Although the proportion of DLBCL that co-expressed bcl-6, CD10 and bcl-2 was lower than for the FL, absence of bcl-2 or CD10 may be associated with higher grade FL It is also possible that bcl-6 expression is not completely specific for a FCC origin. Only a minority of cases suggested postfollicular differentiation. Only a minority of DLBCL show bcl-2R, suggesting that many have a different molecular pathogenesis than most low-grade FL. Bcl-6R did not exclude a FCC origin.

B-Lymphocytes↗
PubMed2000

ALK expression in extranodal anaplastic large cell lymphoma favours systemic disease with (primary) nodal involvement and a good prognosis and occurs before dissemination.

AIMS: In anaplastic large cell lymphoma (ALCL), the site of origin has been described as an important prognostic factor. Recently, a fusion protein containing anaplastic lymphoma kinase (ALK) was described in systemic nodal ALCL, and shown to be associated with a good prognosis. The aims of this study were to investigate whether the presence of ALK protein differs between ALCL of different sites of origin; to determine whether ALK expression occurs before dissemination to other sites; and, finally, to investigate whether the site of origin remains a prognostic parameter in ALK negative ALCL. METHODS: ALK expression, as detected by immunohistochemistry using the monoclonal antibodies ALK1 and ALKc, was studied in 85 ALCLs from different sites of origin. In 22 patients, ALK expression was studied in multiple biopsies from different sites (including 13 skin, 16 lymph node, and nine other). Overall survival time was analysed using the Kaplan Meier method. RESULTS: ALK expression was found in 20 of 51 systemic ALCLs with (primary) nodal involvement. No ALK expression was found in 15 primary cutaneous, 14 gastrointestinal, and five nasal ALCLs. Multiple and subsequent biopsies of patients showed ALK expression to be identical to that seen in the primary diagnostic biopsy. Kaplan Meier survival curves showed that in ALK negative ALCLs originating from different sites, primary cutaneous cases are associated with an excellent overall survival, whereas the other cases show a comparable five years survival of less than 40%. CONCLUSIONS: If present, ALK expression favours systemic ALCL with (primary) nodal involvement, and can be used in differentiating between extranodal involvement of systemic (nodal) ALCL and primary extranodal ALCL. ALK is expressed consistently in multiple biopsies of a given patient, indicating that the chromosomal abnormality leading to aberrant ALK expression occurs before dissemination to other sites. Finally, in ALK negative non-cutaneous ALCLs, different sites of origin show comparable poor survival.

Adolescent↗
PubMed2000

Rapid diagnosis of acute promyelocytic leukemia by analyzing the immunocytochemical pattern of the PML protein with the monoclonal antibody PG-M3.

The fusion protein, promyelocytic leukemia-retinoic acid receptor (PML-RAR)alpha, generated by the t(15;17) translocation has an abnormal cellular distribution with colocalization of RARalpha and PML proteins. We analyzed the immunostaining pattern of PML protein using the PG-M3 monoclonal antibody directed against the amino terminal portion of PML (retained in wild-type PML and PML-RARalpha fusion protein) in the diagnosis of acute promyelocytic leukemia (APL). In addition, we compared this test with other methods for detecting the PML-RARalpha fusion gene. A normal immunostaining pattern was observed in nonmyeloid disorders and in 78 of 111 acute myeloid leukemias (AMLs). A microgranular pattern was observed in 25 AMLs, all corresponding to APL. These results were concordant with the reverse transcriptase-polymerase chain reaction results for PML-RARalpha fusion gene. Only 1 case positive for the PML-RARalpha transcript showed a normal protein pattern by immunocytochemistry. PML immunostaining was helpful to rapidly differentiate 7 cases with borderline characteristics and to obtain the diagnosis in 2 cases with scarce material. The effectiveness and low cost of this technique support its routine use as a first-line procedure in the differential diagnosis of AML.

Antibodies, Monoclonal↗
PubMed2000

Anaplastic lymphoma kinase expression as a marker of malignancy. Application to a case of anaplastic large cell lymphoma with huge granulomatous reaction.

Anaplastic large cell lymphoma (ALCL) shows a wide morphologic spectrum, including the occurrence of reactive components obscuring the neoplastic population. This makes its distinction from hyperimmune reaction difficult. The authors describe an ALCL in a girl wha had a tick bite 20 days prior to clinical presentation. She developed a huge epithelioid reaction (an unprecedented finding for this tumor). The diagnostic controversies were solved by applying the ALKc antibody against anaplastic large cell lymphoma kinase (ALK), in conjunction with reagents anti-nucleophosmin (NPM), which showed the typical staining pattern observed in ALCL carrying t(2;5). Comprised within the epithelioid component there were large anaplastic cells and small-medium sized atypical elements displaying strong nuclear and cytoplasmic positivity for ALK and NPM (N-terminal region). This pattern, never observed in normal lymphocytes, corresponds to the presence of the product of the hybrid gene NPM/ALK produced by t(2;5). Following the diagnosis, the patient - whose general conditions were critical - underwent aggressive chemotherapy, achieving complete remission.

Anaplastic Lymphoma Kinase↗
PubMed2000

The pathologist's view point. Part I--indolent lymphomas.

BACKGROUND AND OBJECTIVES: The REAL/WHO classification constitutes a new tool for the better understanding and treatment of malignant lymphomas. The authors focus on the key features of B-cell lymphomas with an indolent behavior, aiming to contribute to the cross-talk between pathologists and clinicians. DATA SOURCES AND METHODS: Each lymphoma entity is analyzed on the basis of the most representative contributions in the literature and the authors' experience gained in studying more than 20,000 lymphoid tumors over a 20-year period. RESULTS: Guidelines for diagnosis and areas of interest for future clinico-pathologic studies are identified and discussed. Within this context, selected data obtained by the application of novel markers are presented. INTERPRETATION AND CONCLUSIONS: The present know- ledge and organization of malignant lymphomas now make the development of tailored therapies a feasible goal.

Humans↗
PubMed2000

The pathologist's view point. Part II --aggressive lymphomas.

BACKGROUND AND OBJECTIVES: The REAL/WHO classification constitutes a new tool for the better understanding and treatment of malignant lymphomas. The authors focus on the key features of aggressive B- and T-cell lymphomas, aiming to contribute to the cross-talk between pathologists and clinicians. DATA SOURCES AND METHODS: Each lymphoma entity is analyzed on the basis of the most representative contributions in the literature and the authors' experience gained in studying more than 20,000 lymphoid tumors over a 20-year period. RESULTS: Guidelines for diagnosis and areas of interest for future clinico-pathologic studies are identified and discussed. Within this context, selected data obtained by the application of novel markers are presented. INTERPRETATION AND CONCLUSIONS: The present know- ledge and organization of malignant lymphomas now make the development of tailored therapies a feasible goal.

Humans↗
PubMed1999

Lymphomas expressing ALK fusion protein(s) other than NPM-ALK.

The tumor cells in ALK-positive lymphoma ("ALKoma") usually express the product of the NPM-ALK chimeric gene, generated by the t(2;5) chromosomal translocation. However, 10% to 20% of ALK-positive lymphomas express ALK fusion protein(s) other than NPM-ALK, and in this report, we describe the immunohistologic and clinicopathologic features of 15 such cases. The absence of the NPM-ALK fusion gene was confirmed by reverse transcriptase-polymerase chain reaction (RT-PCR) in 8 cases and by fluorescence in situ hybridization (FISH) analysis in a further 2 cases. In each case, ALK staining was restricted to the cytoplasm and the N-terminus of NPM to the nucleus (contrasting with lymphomas expressing NPM-ALK in which cytoplasmic as well as nuclear labeling is seen). However, in the course of screening 53 ALK-positive lymphomas, 2 biopsies were found that had a "cytoplasm-only" ALK staining pattern but that nevertheless were shown to carry the (2;5) (by NPM staining and RT-PCR). The 15 cases resembled typical NPM-ALK-positive lymphomas in that all were of T or null phenotype, usually occurred in young male patients, and frequently presented with advanced disease associated with systemic symptoms and extranodal involvement. Moreover, their prognosis was excellent and indistinguishable from that of classical t(2;5)-positive tumors, but was clearly different from that of ALK-negative anaplastic large-cell lymphomas. These results suggest that lymphomas carrying variants of the NPM-ALK fusion protein can be detected by immunostaining for ALK and NPM and also that they can be grouped with classical t(2;5)-positive tumors as a single entity (ALK-positive lymphoma or "ALKoma") that shows a better prognosis than ALK-negative anaplastic large-cell lymphoma.

Adolescent↗
PubMed1999

TRK-fused gene (TFG) is a new partner of ALK in anaplastic large cell lymphoma producing two structurally different TFG-ALK translocations.

Anaplastic large cell lymphoma (ALCL) is associated with the t(2;5)(p23;q35), which generates the NPM-ALK fusion gene encoding an 80-kD protein. Several studies have suggested that genes other than NPM may be fused to the ALK gene. Here we have identified TRK-fused gene (TFG) as a new ALK partner in 2 ALCL, 1 of which exhibited a t(2;3)(p23;q21). In these cases, TFG was involved in 2 different fusion genes, TFG-ALK(S) and TFG-ALK(L), coding respectively 85-kD and 97-kD chimeric proteins. The ALK breakpoint in these translocations was the same as in the classic t(2;5) translocation. These 2 proteins were both active in an in vitro tyrosine kinase assay showing that the new cloned cDNA sequences are translated into chimeric proteins with functional activity. These findings indicate that TFG can provide an alternative to NPM as a fusion partner responsible for activation of the ALK and the pathogenesis of ALCL.

Adult↗
PubMed1999

Elderly aggressive-histology non-Hodgkin's lymphoma: first-line VNCOP-B regimen experience on 350 patients.

Age is a risk factor and a prognostic parameter in elderly aggressive-histology non-Hodgkin's lymphoma (NHL) patients. Several adapted chemotherapeutic regimens have recently been designed and tested on elderly patients. Several of these trials have shown that older aggressive-histology NHL patients can benefit from specific and adequate treatment capable of curing a percentage of these patients. Between January 1992 and September 1997, 350 previously untreated aggressive-histology NHL patients greater than 60 years of age were treated with a combination therapy including cyclophosphamide, mitoxantrone, vincristine, etoposide, bleomycin, and prednisone (VNCOP-B). Complete remission (CR) was achieved by 202 (58%) patients and partial remission (PR) by 87 (25%), whereas the remaining 61 (17%) patients were nonresponders. The overall response rate (CR + PR) was 83%. Clinical and hematologic toxicities were modest, because 71% of the patients received granulocyte colony-stimulating factor (G-CSF). The CR rates for the three age groups (60 to 69, 70 to 79, and >/=80 years) were similar: 61%, 59%, and 56%, respectively. At 5 years, the relapse-free survival rate was 65%, the overall survival rate was 49%, and the failure-free survival rate was 33%. In the multivariate analysis, prognostic factors associated with longer survival or longer relapse-free survival turned out to be localized disease stage (P =.001) and good performance status (P =.0002). Application of the International Prognostic Factor Index was significantly associated with outcome (P =.001). These data confirm on a large cohort of patients that the VNCOP-B regimen is effective in inducing good CR and relapse-free survival rates with only moderate toxic effects in elderly aggressive-histology NHL.

Aged↗
PubMed1999

ALK+ lymphoma: clinico-pathological findings and outcome.

A distinct pathologic entity (ALK+ lymphoma) that is characterized by expression of the anaplastic lymphoma kinase (ALK) protein has recently emerged within the heterogeneous group of CD30(+) anaplastic large-cell lymphomas. Information on clinical findings and treatment outcome of ALK+ lymphoma is still limited, and no data are available concerning the value of the International Prognostic Index when applied to this homogeneous disease entity. To clarify these issues, a recently developed monoclonal antibody ALKc (directed against the cytoplasmic portion of ALK) was used to detect expression of the ALK protein in paraffin-embedded biopsies from 96 primary, systemic T/null anaplastic large-cell lymphomas, and the ALK staining pattern was correlated with morphological features, clinical findings, risk factors (as defined by the International Prognostic Index), and outcome in 78 patients (53 ALK+ and 25 ALK-). Strong cytoplasmic and/or nuclear ALK positivity was detected in 58 of 96 ALCL cases (60.4%), and it was associated with a morphological spectrum (common type, 82.7%; giant cell, 3.5%; lymphohistiocytic, 8. 6%; and small cell, 5.2%) that reflected the ratio of large anaplastic elements (usually showing cytoplasmic and nuclear ALK positivity) to small neoplastic cells (usually characterized by nucleus-restricted ALK expression). Clinically, ALK+ lymphoma mostly occurred in children and young adults (mean age, 22.01 +/- 10.87 years) with a male predominance (male/female [M/F] ratio, 3.0) that was particularly striking in the second-third decades of life (M/F ratio, 6.5) and usually presented as an aggressive, stage III-IV disease, frequently associated with systemic symptoms (75%) and extranodal involvement (60%), especially skin (21%), bone (17%), and soft tissues (17%). As compared with ALK+ lymphoma, ALK- cases occurred in older individuals (mean age, 43.33 +/- 16.15 years) and showed a lower M/F ratio (0.9) as well as lower incidence of stage III-IV disease and extranodal involvement at presentation. Overall survival of ALK+ lymphoma was far better than that of ALK- anaplastic large-cell lymphoma (71% +/- 6% v 15% +/- 11%, respectively). However, within the good prognostic category of ALK+ lymphoma, survival was 94% +/- 5% for the low/low intermediate risk group (age-adjusted International Prognostic Index, 0 to 1) and 41% +/- 12% for the high/high intermediate risk group (age-adjusted International Prognostic Index, >/=2). Multivariate analysis identified ALK expression and the International Prognostic Index as independent variables that were able to predict survival among T/null primary, systemic anaplastic large-cell lymphoma. Thus, we suggest that such parameters should be taken into consideration for the design of future clinical trials.

Adult↗
PubMed1999

Human immunodeficiency virus-associated Hodgkin's disease derives from post-germinal center B cells.

Human immunodeficiency virus-associated Hodgkin's disease (HIV-HD) displays several peculiarities when compared with HD of the general population. These include overrepresentation of clinically aggressive histologic types and frequent infection of Reed-Sternberg (RS) cells by Epstein-Barr virus (EBV). Recently, we have reported that the histogenesis of HD of the general population may be assessed by monitoring the expression pattern of BCL-6, a transcription factor expressed in germinal center (GC) B cells, and of CD138/syndecan-1 (syn-1), a proteoglycan associated with post-GC, terminal B-cell differentiation. In this study, we have applied these two markers to the study of HIV-HD histogenesis and correlated their expression status to the virologic features of this disease. We have found that RS cells of all histologic categories of HIV-HD consistently display the BCL-6(-)/syn-1(+) phenotype and thus reflect post-GC B cells. Although BCL-6(-)/syn-1(+) RS cells of HIV-HD express CD40, they are not surrounded by CD40 ligand-positive (CD40L+) reactive T lymphocytes, which, in HD of the general population, are thought to regulate the disease phenotype through CD40/CD40L interactions. Conversely, RS cells of virtually all HIV-HD express the EBV-encoded latent membrane protein 1 (LMP1), which, being functionally homologous to CD40, may contribute, at least in part, to the modulation of the HIV-HD phenotype.

B-Lymphocytes↗
PubMed1999

Detection of normal and chimeric nucleophosmin in human cells.

In anaplastic large-cell lymphoma (ALCL), the (2;5) chromosomal translocation creates a fusion gene encoding the 80-kD NPM-ALK hybrid protein. This report describes three new monoclonal antibodies, two of which recognize, by Western blotting, the N-terminal portion of NPM present in the NPM-ALK fusion protein and also in two other NPM fusion proteins (NPM-RARalpha and NPM-MLF1). The third antibody recognizes the C-terminal portion (deleted in NPM-ALK) and reacts only with wild-type NPM. The three antibodies immunostain wild-type NPM (in paraffin-embedded normal tissue samples) in cell nuclei and in the cytoplasm of mitotic cells. Cerebral neurones, exceptionally, show diffuse cytoplasmic labeling. In contrast to normal tissues, the two antibodies against the N-terminal portion of NPM labeled the cytoplasm of neoplastic cells, in four ALK-positive ALCL, reflecting their reactivity with NPM-ALK fusion protein, whereas the antibody to the C-terminal NPM epitope labeled only cell nuclei. Immunocytochemical labeling with these antibodies can therefore confirm that an ALK-positive lymphoma expresses NPM-ALK (rather than a variant ALK-fusion protein) and may also provide evidence for chromosomal anomalies involving the NPM gene other than the classical (2;5) translocation.

Animals↗
PubMed1999

Gene rearrangements in T-cell lymphoblastic lymphoma.

This study presents an examination of the Ig heavy chain (IgH) and T-cell receptor gamma (TCRgamma) genes in a series of 39 CD3-positive T-cell acute lymphoblastic leukaemia (ALL) cases with and without co-expression of CD79a; 30/39 cases had a rearrangement of the TCRgamma genes and two of these 30 cases also demonstrated an IgH rearrangement. No cases had solely an IgH rearrangement. The conclusion of the study is that lymphoblastic lymphoma cases that are positive for CD3 are of T-cell lineage, regardless of CD79a expression.

Adolescent↗