I Araujo

Freie Universität Berlin, Berlin, Land Berlin, Germany

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Publications (11)78.54 Total impact

  • Article: ALK+ lymphoma: clinico-pathological findings and outcome.
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    ABSTRACT: 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.
    Blood 04/1999; 93(8):2697-706. · 9.90 Impact Factor
  • Article: Frequent expansion of Epstein-Barr virus (EBV) infected cells in germinal centres of tonsils from an area with a high incidence of EBV-associated lymphoma.
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    ABSTRACT: Burkitt's lymphoma (BL) and Hodgkin's disease (HD) occurring in developing regions are frequently associated with Epstein-Barr virus (EBV) infection and have a high incidence in childhood. Recent genotyping studies indicate that the tumour cells of both neoplasms represent B cells that contain somatically mutated immunoglobulin heavy chain genes. This implies that the precursors of these neoplasms have participated in the germinal centre (GC) reaction. We therefore presumed that normal lymphoid tissues from children living in developing regions would harbour an increased number of EBV-infected cells within the GC, when compared with children living in industrialized nations. To test this hypothesis, hyperplastic tonsils from 40 children living in Bahia (Brazil) and 40 from German children were analysed for the presence of EBV-encoded small nuclear RNA (EBER) and EBV-encoded proteins by in situ hybridization and immunohistology, respectively. Although the overall EBV infection rate was similar in both groups (50 per cent of Bahian vs. 45 per cent of German cases), a significantly higher number of EBER-positive lymphoid cells were found in the GCs of 8/20 EBV-positive tonsils from Brazil (9-89 cells/GC; mean: 14.5 cells/GC per case), while only 3/18 tonsils from Germany displayed a few EBER positive cells (1-9 cells/GC; mean: 0.5 cell/GC per case) in this compartment (p < 0.007). In addition, the EBV-infected GC cells in Bahian samples resembled centroblasts, exhibited mitotic activity, and in two cases showed expression of EBV-encoded latent membrane protein (LMP)-1, findings not present in German samples. These data show that latently EBV-infected cells participate more frequently in GC reactions in developing regions than in industrialized countries and may abnormally express the oncogenic protein LMP-1. This could in part explain the higher incidence in this region of EBV association with lymphomas related to GC cells or their progeny, such as BL and HD.
    The Journal of Pathology 03/1999; 187(3):326-30. · 6.32 Impact Factor
  • Article: Expression of vascular endothelial growth factor in lymphomas and Castleman's disease.
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    ABSTRACT: Vascular endothelial growth factor (VEGF) is one of the main angiogenic cytokines in human solid tumours and inhibition of VEGF-induced angiogenesis suppresses tumour growth. Some groups of malignant lymphoma, including peripheral T-cell lymphomas and Hodgkin's disease, are characterized by a conspicuous proliferation of small vessels. To test the hypothesis that VEGF may also be involved in the angiogenesis in lymphomas and other lesions of the lymphoid system, VEGF expression was analysed in tissues, employing in situ hybridization with a 35S-labelled RNA probe specific for this cytokine. Significant expression of VEGF transcripts was observed in Hodgkin's disease and peripheral T-cell lymphomas, particularly of the angioimmunoblastic type. In contrast, expression of this cytokine was minimal or absent in follicle centre lymphoma and chronic lymphocytic leukemia of B-cell type. VEGF was mainly observed in reactive non-lymphoid CD68-negative cells, which probably represent fibroblasts or myofibroblasts. In normal and ulcerated tonsils, VEGF was expressed in the squamous epithelium but only rarely found in the lymphoid tissue. Although infectious mononucleosis tonsils contained high numbers of VEGF-positive cells in the interfollicular zone, expression of this cytokine was not found in Epstein-Barr virus (EBV)-infected cells, as determined by simultaneous in situ hybridization for VEGF and EBV-encoded small nuclear RNAs (EBER). In 5/8 cases of Castleman's disease, germinal centres containing small vessels also showed expression of VEGF, in contrast to normal tonsillar germinal centres which are devoid of both vessels and VEGF transcripts. It is concluded that VEGF may be involved in the induction of the angiogenesis of both peripheral T-cell lymphomas and Hodgkin's disease, but not in low-grade B-cell lymphomas. In contradistinction to solid tumours, in which this cytokine is commonly secreted by the tumour cells themselves, in malignant lymphoma VEGF is not a product of neoplastic cells. Vascularization of germinal centres in Castleman's disease may also be a consequence of abnormal local expression of VEGF.
    The Journal of Pathology 10/1997; 183(1):44-50. · 6.32 Impact Factor
  • Article: Expression of cytotoxic molecules in intestinal T-cell lymphomas. The German Study Group on Intestinal Non-Hodgkin Lymphoma.
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    ABSTRACT: Intestinal T-cell lymphoma (ITCL) represents a subgroup of peripheral T-cell lymphomas which is thought to arise from alpha beta intraepithelial T-lymphocytes. Since these lymphocytes may contain cytotoxic molecules, the question of whether this also holds true for ITCL arises. Twenty ITCL cases were examined for the presence of granzyme B, perforin, and T-cell-restricted intracellular antigen (TIA-1)/granule membrane protein of 17 kD (GMP-17). Two molecules with restricted expression in cytotoxic cells, granzyme B and perforin, were detected by immunocytochemistry and by in situ hybridization with an isotopically labelled RNA probe, respectively. Immunocytochemistry was also performed with the antibody 2G9, which recognizes two molecules, one expressed by cytotoxic cells (TIA-1) and the other found in granulocytes and cytotoxic cells (GMP-17). Granzyme B, TIA-1/GMP-17, and perforin were found in the neoplastic cells of 16/19 cases, 19/20 cases, and 16/17 cases, respectively, of ITCL, but not in the tumour cells of the control group, which consisted of intestinal B-cell lymphomas (five cases) and CD8-negative peripheral nodal T-cell lymphomas (six cases). At least one of these molecules was expressed in the tumour cells of all ITCL cases. 2G9 proved to be the most sensitive immunohistological marker, since reactivity with this antibody was not only observed in the highest number of cases, but also found in high numbers of neoplastic cells in positive cases. In conclusion, ITCL appears to show cytotoxic differentiation in all cases. In conjunction with immunophenotypic and genotypic data, our results support a uniform derivation of this tumour from intraepithelial alpha beta cytotoxic T-lymphocytes.
    The Journal of Pathology 08/1997; 182(3):311-7. · 6.32 Impact Factor
  • Article: Uniform expression of cytotoxic molecules in anaplastic large cell lymphoma of null/T cell phenotype and in cell lines derived from anaplastic large cell lymphoma.
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    ABSTRACT: We recently provided ample evidence that anaplastic large cell lymphomas of T/null phenotype (T-/null-ALCL) genotypically represent peripheral T cell lymphomas which in up to 90% have a phenotype of cytotoxic cells with expression of granzyme B protein and perforin transcripts. However, the issue of granzyme B expression in T-/null-ALCL is still controversial due to differing results from another laboratory. To verify our earlier immunohistochemical stainings for granzyme B, we looked for granzyme B transcripts by in situ hybridization (ISH). In addition, we investigated our previously analyzed cases by immunohistology (IH) with another antibody (2G9), which reacts with two molecules known to be expressed in cytotoxic cells: T-cell-restricted intracellular antigen (TIA)-1 and granule membrane protein-17 (GMP-17). We also extended our studies to homogenous tumor cell populations provided by ALCL-derived cell lines. As evidenced by ISH, transcripts for perforin, TIA-1 and granzyme B were found in all ALCL-derived cell lines. Similarly, proteins of TIA-1/GMP-17, granzyme B and perforin were expressed in all of these lines as shown by IH. In biopsy specimens, TIA-1/GMP-17 were detected by IH in 14/16 cases of T-/null-ALCL, and granzyme B transcripts were found in 13/13 T-/null-ALCL cases, but not in 6 B-ALCL cases. The detection of granzyme B transcripts yielded results largely identical to those of IH for granzyme B protein, thus confirming our earlier data and suggesting that the regulation of the expression of this molecule largely occurs at the transcriptional level. Our data further confirm the almost uniform expression of cytotoxic molecules in both primary ALCL cases and ALCL-derived cell lines and therefore suggest that the derivation from cytotoxic T cells may be the unifying characteristic for T-/null-ALCL.
    Pathobiology 02/1997; 65(2):83-90. · 1.18 Impact Factor
  • Article: Anaplastic large-cell lymphomas of T-cell and null-cell phenotype express cytotoxic molecules.
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    ABSTRACT: To further specify the cellular origin and nature of anaplastic large-cell lymphoma (ALCL) and its relationship to other lymphoid neoplasms, particularly Hodgkin's disease (HD), we investigated the presence of cytotoxic molecules in a large well-characterized series of these tumors. For expression of the cytotoxic molecules perforin and granzyme B, in situ hybridization (ISH) and immunohistology were used, respectively. Overall, 23 of 25 ALCLs of T/null phenotype and five (three mixed cellularity and two nodular sclerosis) of 57 HD cases showed the presence of perforin transcripts and/or granzyme B molecules in neoplastic cells. Polymerase chain reaction (PCR) analysis of ALCLs showed that most (10 of 11) cases of null-cell ALCL (null-ALCL) contained a clonal rearrangement of T-cell receptor beta-chain genes, as did T-cell ALCL (T-ALCL; 9 of 10 cases). However, both cytotoxic molecules and clonally rearranged T-cell receptor beta-chain genes were absent in seven of seven and eight of nine cases of B-cell ALCL (B-ALCL), respectively. These data show that all or nearly all T-ALCLs, irrespective of the clinical subform or the lack of T-cell-associated molecules, are derived from activated cytotoxic T cells. The same appears to be true for the neoplastic cells of rare HD cases. These findings indicate that T-ALCLs are different from B-ALCLs and the majority of HD cases, and suggest that some HD cases, especially those with T-cell antigen-positive tumor cells, may be closely related to T-ALCL, at least in terms of cellular origin.
    Blood 12/1996; 88(10):4005-11. · 9.90 Impact Factor
  • Article: Expression of Epstein-Barr virus-gene products in Burkitt's lymphoma in Northeast Brazil.
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    ABSTRACT: The Epstein-Barr Virus (EBV) is consistently found in tumor cells of Burkitt's lymphoma (BL) endemic in central Africa and malaria is considered a pathogenic cofactor. In contrast, fewer than 20% of BL cases occurring in Western countries are EBV-associated. We have investigated 54 BL cases from Bahia, a tropical region of Northeast Brazil, for expression of EBV gene products by in situ hybridization and immunohistology and performed typing of the EBV by polymerase chain reaction. Ten pediatric BL cases from Germany served as controls. New cases of malaria were not observed in the period and area of our study. Small nuclear EBV encoded transcripts, EBER, were found in tumor cells of 47 of 54 Brazilian cases (87%) but in only 2 of 10 German cases (20%). Type I latency of the EBV infection with absence of EBV-encoded proteins LMP1 and EBNA2 was found in 45 of 47 of the EBER-positive Brazilian cases. In two cases, occasional LMP1-containing tumor cells were found in the neighborhood of small Schistosoma mansoni granulomas and scars. BHLF1 transcripts associated with lytic EBV infection could be detected in few cells in 3 of the 40 EBER-positive Brazilian cases investigated. EBV type A was found in the majority of Brazilian BL cases (20 of 30 A-type, 7 of 30 B-type, and 3 of 30 not amplifiable). Our results indicate that the association of Bahian BL with EBV, but not the regional prevalence of malaria, is similar to endemic African BL. In two cases, type II latency was found in association with schistosomiasis, suggesting a role of this parasitosis in the induction of an EBV expression pattern that is unusual for BL. Because chronic schistosomiasis is associated with elevated Th2 cytokine expression resulting in reduced cell-mediated cytotoxicity, it seems possible that altered local immunity is responsible for this peculiar phenotype.
    Blood 07/1996; 87(12):5279-86. · 9.90 Impact Factor
  • Article: Monokine expression in Langerhans' cell histiocytosis and sinus histiocytosis with massive lymphadenopathy (Rosai-Dorfman disease)
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    ABSTRACT: Langerhans' cell histiocytosis (LCH) is a clonal proliferation of Langerhans cells (LC) showing histologically an abundant reactive infiltrate composed of macrophages and lymphocytes, as well as eosinophilic and neutrophilic granulocytes. Rosai-Dorfman disease (RDD) shows a sinusoidal accumulation of large histiocytic cells with an immunophenotype similar to LC of LCH. The histological picture of LCH is reminiscent of an inflammatory disorder and LC may produce cytokines and are influenced by these soluble factors. This study set out to establish the monokine expression pattern in LCH in comparison with those of RDD; dermatopathic lymphadenopathy, which also shows a proliferation of S100-positive dendritic cells; and LC in normal skin specimens. Isotopic in situ hybridization was used for the detection of transcripts of tumour necrosis factor-alpha (TNF-alpha), interleukin-6 (IL-6), and IL-1 beta, in some cases combined with immunohistology for the S100 protein or CD68. In all 11 tissue samples from eight patients, LC of LCH expressed TNF-alpha; in two cases IL-1 beta transcripts were additionally noted in some LC, whereas IL-6 was found in reactive cells. Large histiocytic cells of RDD expressed all three monokines, whereas minimal or no expression of these cytokines could be detected in interdigitating reticulum cells in dermatopathic lymphadenopathy. In two out of five normal skin samples, only TNF-alpha specific signals were observed in LC. These data suggest that histologically different lesions of the histiocytic/dendritic cell system display distinct cytokine profiles. The expression of monokines, which have been demonstrated to influence various functions of epidermal LC, may play a role in the pathogenesis of LCH. Systemic symptoms in RDD may be related to enhanced production of monokines in these lesions.
    The Journal of Pathology 06/1996; 179(1):60-5. · 6.32 Impact Factor
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    Article: Frequent expression of interleukin-10 by Epstein-Barr virus-harboring tumor cells of Hodgkin's disease.
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    ABSTRACT: Tumor cells of Epstein-Barr virus (EBV)-associated Hodgkin's disease (HD) express the viral protein, latent infection membrane protein-1 (LMP1), but evade cytotoxic responses normally directed at this antigen. We tested whether local production of the immunoregulatory interleukins (IL)-4 and -10 may have a role in this process. IL-4 RNA was not detectable in any of the HD cases. By contrast, isotopic in situ hybridization and correlation with the presence of EBV gene products showed significantly higher proportions of cases with IL-10 expressing tumor cells in LMP1-positive (17 of 26, 66%) as compared with LMP1-negative HD cases (six of 37, 16%). Absence of EBV BCRF1 RNA indicated that the transcripts originated from the cellular IL-10 gene. Similarly, an association between IL-10 expression and EBV-infection of tumor cells was found in AIDS-related malignant non-Hodgkin lymphomas (ARL). Very small proportions of EBV-infected cells, mainly blasts, expressed IL-10 in infectious mononucleosis tonsils. Thus, although not entirely exclusive to EBV-positive cases, IL-10 expression is frequently associated with EBV-infection in HD and ARL and appears to be upregulated by EBV, most likely through LMP1. In view of the established inhibitory effects of IL-10 on cell mediated immunity, it is suggested that IL-10 expression may contribute to evasion of LMP1-positive cells from cytotoxicity directed at viral antigens.
    Blood 05/1996; 87(7):2918-29. · 9.90 Impact Factor
  • Article: Inflammatory pseudotumors of lymph node origin show macrophage- derived spindle cells and lymphocyte-derived cytokine transcripts without evidence of T-cell receptor gene rearrangements. Implications for pathogenesis and classification as an idiopathic retroperitoneal fibrosis-like sclerosing immune reaction.
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    ABSTRACT: Sclerosing pseudotumorous immune reactions of the retroperitoneum have been shown to consist of HLA-DR-positive spindle-shaped fibroblasts and macrophages that resemble fibroblasts, and in some instances they contain clonal populations of T lymphocytes not found in granulation tissue, keloids, nodular fasciitis, or fibromatoses. In patients who are iatrogenically immunosuppressed, circulating monocytes may be induced in vitro to transform into spindle-shaped macrophages, and secrete collagen after stimulation by conditioning medium from activated T lymphocytes. The authors investigated a series of five inflammatory pseudotumors (IPT) of lymph node origin for identification of spindle-shaped macrophages, T-cell receptor gene rearrangements, and lymphocyte-derived cytokine mRNA production. All cases of IPT demonstrated spindle-shaped macrophages resembling fibroblasts or myofibroblasts characterized by vimentin, CD45 (LCA), CD68 (KP1) or HAM-56, and HLA-DR(LN3) immunoreactivity and demonstrated production of procollagen-alpha1 (I) mRNA by in situ hybridization. Clonal T-cell receptor chain gene rearrangements were undetectable by polymerase chain reaction. Strong specific lymphocyte-derived interleukin-1beta and interleukin-6 mRNA cytokine transcripts were identified. Although all patients with IPT were managed with steroids and nonsteroidal anti-inflammatory medication, some had treatment-refractory disease. Because all-trans retinoic acid has been demonstrated to inhibit the in vitro transformation of monocytes into collagen-producing spindle-shaped macrophages ("neofibroblasts"), it may be of benefit for patients with IPT.
    American Journal of Clinical Pathology 05/1996; 105(4):430-9. · 2.60 Impact Factor
  • Article: Patterns of cytokine gene expression in infectious mononucleosis.
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    ABSTRACT: Primary infection with Epstein-Barr virus (EBV) may arise as infectious mononucleosis (IM) in adolescents and young adults. Morphologically, IM-affected lymphoid tissue is characterized by expanded interfollicular areas with formation of atypical lymphoid blasts. It is assumed that morphology and clinical presentation of IM are related to characteristic patterns of cytokine production by EBV-infected and reactive cells. We studied IM tonsils of eight patients and six normal tonsils with a double in situ hybridization procedure using [35S]-labeled RNA probes specific for various cytokines and digoxigenin-labeled probes for the detection of the nuclear EBV encoded RNA transcripts, EBER 1 and 2. All of the IM cases displayed the same distinct cytokine gene expression pattern. When compared with interfollicular areas of normal tonsils, expression of lymphotoxin (LT), tumor necrosis factor-alpha (TNF-alpha), interleukin-6 (IL-6), and IL-1 beta, but not IL-8 or IL-1 alpha was strongly enhanced in interfollicular areas in IM tonsils. LT was expressed predominantly by EBV-infected cells. TNF-alpha transcripts were also present in EBV-infected cells, although in smaller proportions. IL-6 specific signals were only found in few EBV-infected cells. IL-1 alpha-, IL-1 beta-, and IL-8-specific signals were not observed in EBV-infected cells, but were present at high signal intensity in many cells within and around foci of EBV-infected cells (IL-1 beta), next to areas of necrosis (IL-8, IL-1 beta), or in epithelial cells (IL-1 alpha). These data suggest that EBV infection in form of IM results in induction of specific sets of cytokine genes in EBV-infected and in neighboring EBV-negative cells contributing to the characteristic morphology and cellular arrangement of the lesion as well as the clinical presentation.
    Blood 03/1994; 83(3):707-12. · 9.90 Impact Factor