[Show abstract][Hide abstract] ABSTRACT: To study the expression of CD2-associated protein (CD2AP), an adaptor protein involved in T-cell signalling and renal function, in normal, reactive and neoplastic human lymphoid tissues.
We used immunohistochemical techniques to evaluate monoclonal antibodies against CD2AP on over 400 formalin fixed paraffin embedded tissue blocks retrieved from the host institutions of three authors. The samples tested included normal, reactive and neoplastic lymphoid tissue. In lymphoid tissues, strong CD2AP staining was observed in plasmacytoid dendritic cells (pDCs), weak and variable in mantle zone B cells and moderate in rare germinal center cells. CD2AP labeled cortical and rare medullary thymocytes and isolated mononuclear cells in bone marrow trephines. Furthermore, epithelial and endothelial cells expressed CD2AP. Among neoplasms, the greatest number of CD2AP-positive cases were found in diffuse large B cell (21/94), NK T-cell lymphomas (7/67), "blastic plasmacytoid dendritic cell neoplasms" (9/10) and some types of solid tumor.
Our finding that mature peripheral T cells are CD2AP-negative but immature cortical thymocytes are positive may prove useful for diagnostic purposes. Moreover, our results demonstrate that CD2AP represents a useful marker of normal and neoplastic pDC and may be used in a diagnostic panel in reactive or neoplastic lymphoid proliferations.
[Show abstract][Hide abstract] ABSTRACT: Sixty-four cases of mainly lymphoid lesions were investigated by fine needle aspiration. Both conventional smears and cytospin preparations were made from this material. Diagnoses based on cytological and immunocytological criteria were made in 57 of these cases and include reactive hyperplasia, non-Hodgkin's and Hodgkin's lymphoma and metastatic carcinoma. Five cases were inadequate for diagnostic purposes and in 2 cases no definite diagnosis could be made. These diagnoses were confirmed using tissue sections in 48/51 cases (with only 3 cytological diagnoses significantly altered by histology) and supported by supplementary clinical information in 8 cases. These results demonstrate the value of FNA biopsy in the investigation of lymphoid lesions using both conventional cytology and immunocytochemistry.
No preview · Article · Jun 2009 · Leukemia and Lymphoma
[Show abstract][Hide abstract] ABSTRACT: Renal biopsies were taken from 42 patients at seven and 21 days after renal transplantation. Paraffin sections from these specimens were examined immunocytochemically for the presence of platelet microthrombi in glomerular capillaries using the monoclonal antibody Y2/51. Patients were treated by one of four different immunosuppressive regimes, three of which included cyclosporin A, either alone or in combination with steroids and azathioprine. Microthrombi were detected in approximately 30% of biopsies and were much commoner in patients receiving multi-drug therapy. We conclude that, contrary to previous suggestions, glomerular capillary thromboses are not frequent in patients on cyclosporin A alone. They are found mainly in patients on multiple drug therapy, particularly when steroids are included. The detection of microthrombi is unlikely to be of assistance in the earlier detection of cyclosporin toxicity.
[Show abstract][Hide abstract] ABSTRACT: Leukemia is one of the leading journals in hematology and oncology. It is published monthly and covers all aspects of the research and treatment of leukemia and allied diseases. Studies of normal hemopoiesis are covered because of their comparative relevance.
[Show abstract][Hide abstract] ABSTRACT: Jaw1, also known as lymphoid-restricted membrane protein (LRMP), is an endoplasmic reticulum-associated protein. High levels of Jaw1/LRMP mRNA have been found in germinal centre B-cells and in diffuse large B-cell lymphomas of 'germinal centre' subtype. This paper documents Jaw1/LRMP expression at the protein level in human tissues by immunohistochemical and western blotting analysis using an antibody reactive with paraffin-embedded tissues. Jaw1/LRMP was highly expressed in germinal centre B-cells (in keeping with gene expression data), in 'monocytoid B-cells', and in splenic marginal zone B-cells. It was absent, or present at only low levels, in mature T-cells, although cortical thymocytes were weakly positive. Among lymphoid neoplasms, Jaw1/LRMP was found in germinal centre-derived lymphomas (follicle centre lymphoma, Burkitt's lymphoma, lymphocyte-predominant Hodgkin's disease) but not in T-cell neoplasms (with the exception of a single T lymphoblastic lymphoma). Classical Hodgkin's disease and myeloma lacked Jaw1/LRMP but many cases of chronic lymphocytic leukaemia (but not mantle zone lymphoma) were Jaw1/LRMP-positive. Approximately half of the marginal zone lymphomas were Jaw1/LRMP-positive. In diffuse large B-cell lymphomas, Jaw1/LRMP was found in three-quarters (24/32) of the cases classified phenotypically as being of 'germinal centre' type, but it was also expressed in almost half (13/28) of the 'non-germinal centre' cases. A similar proportion of 'non-germinal centre' cases were positive for the protein products of two other genes expressed highly in germinal centre cells (HGAL/GCET2 and PAG). The fact that all three of these proteins are expressed in a significant proportion of diffuse large B-cell lymphomas assigned to the 'non-germinal centre' category indicates that the immunophenotypic categorization of diffuse large B-cell lymphoma according to cellular origin may be more complicated than currently understood. Finally, the expression of Jaw1/LRMP in other types of lymphoma and in non-lymphoid tissues/tumours may be of interest in differential diagnosis and research.
No preview · Article · Aug 2006 · The Journal of Pathology
[Show abstract][Hide abstract] ABSTRACT: To investigate whether an antibody against an intracellular epitope can detect CD19 in routine biopsy specimens and thus to document in detail its expression in human lymphomas.
A polyclonal antibody to the C terminus of CD19 was used to immunostain paraffin-embedded samples of normal and neoplastic lymphoid tissues. CD19 was widely expressed in normal B cells and in extramedullary plasma cells. It was found in most B-cell neoplasms, but expression in follicular lymphoma was weak (33/69) or negative (four cases). Similarly, CD19 expression in diffuse large B-cell lymphomas was weak (28/56) or negative (eight cases). In T-cell-rich B-cell lymphomas, CD19 was also weak (4/10) or negative (three cases). CD19 was often absent in post-transplant B lymphoproliferative disease, classical Hodgkin's disease and plasma cell neoplasms. An unexpected finding was the frequent absence of CD19 in the neoplastic cells in lymphocyte predominant Hodgkin's disease.
CD19 can now be detected in routine biopsy specimens. In contrast to the classical pan-B marker CD20, CD19 is not always strongly expressed in B-cell neoplasms. Furthermore, the lymphocytic and histiocytic (L&H) cells of lymphocyte predominant Hodgkin's disease (which express most B-cell-associated markers) commonly lack CD19.
[Show abstract][Hide abstract] ABSTRACT: The use of interphase fluorescence in situ hybridisation (FISH) to study cytogenetic abnormalities in routinely fixed paraffin wax embedded tissue has become commonplace over the past decade. However, very few studies have applied FISH to routinely fixed bone marrow trephines (BMTs). This may be because of the acid based decalcification methods that are commonly used during the processing of BMTs, which may adversely affect the suitability of the sample for FISH analysis. For the first time, this report describes the simultaneous application of FISH and immunofluorescent staining (the FICTION technique) to formalin fixed, EDTA decalcified and paraffin wax embedded BMTs. This technique allows the direct correlation of genetic abnormalities to immunophenotype, and therefore will be particularly useful for the identification of genetic abnormalities in specific tumour cells present in BMTs. The application of this to routine clinical practice will assist diagnosis and the detection of minimal residual disease.
Full-text · Article · Jan 2006 · Journal of Clinical Pathology
[Show abstract][Hide abstract] ABSTRACT: Langerhans’cells are intraepithelial dendritic cells believed to be important in the recognition and processing of exogenous antigens. They were demonstrated by immunohistological methods in cervical tissue obtained from 10 subjects ranging in age from 30 weeks gestational age to 62 years. Langerhans’cells were clearly delineated in all tissue sections and appear to form a relatively constant component of both the transformation zone and ectocervical epithelium. In addition to Langerhans’cells, a population of T lymphocytes characterized as predominantly T-cytotoxic/suppressor cells have also been demonstrated. The interaction between Langerhans’cells, T lymphocytes and stromal macrophages and their relation to antigen recognition is discussed.
No preview · Article · Aug 2005 · BJOG An International Journal of Obstetrics & Gynaecology
[Show abstract][Hide abstract] ABSTRACT: Two microarray studies of mediastinal B cell lymphoma have shown that this disease has a distinct gene expression profile, and also that this is closest to the pattern seen in classical Hodgkin's disease. We reported previously an immunohistologic study in which the loss of intracellular B cell-associated signaling molecules in Reed-Sternberg cells was demonstrated, and in this study we have investigated the expression of the same components in more than 60 mediastinal B cell lymphomas. We report that these signaling molecules are frequently present, and in particular that Syk, BLNK and PLC-gamma2 (absent from Reed-Sternberg cells) are present in the majority of mediastinal B cell lymphomas. The overall pattern of B cell signaling molecules in this disease is therefore closer to that of diffuse large B cell lymphoma than to Hodgkin's disease, and is consistent with a common cell of origin as an explanation of the similar gene expression profiles.
[Show abstract][Hide abstract] ABSTRACT: The expression of cytokeratin intermediate filaments by a tumour has been accepted as evidence of an epithelial origin. Although there have been anecdotal reports of cytokeratin expression within tissues and neoplasms of non-epithelial origin, particularly muscle, there have been no comprehensive studies of its frequency and distribution. In order to investigate this we have studied 51 cases of normal smooth muscle and benign and malignant smooth muscle tumours using a panel of monoclonal antibodies against a range of intermediate filaments (cytokeratins, desmin and vimentin). Cytokeratin expression was noted overall in 50% of normal, benign and malignant smooth muscle tissues. Such expression tended to have a focal or patchy distribution. No case expressed cytokeratins in the absence of both desmin and vimentin. The implication of these findings for diagnostic immunocytochemistry is that intermediate filaments alone are not completely reliable markers of tumour histogenesis and should be used as part of a larger panel of monoclonal antibodies.
[Show abstract][Hide abstract] ABSTRACT: Neoplasms of histiocytes and dendritic cells are rare, and their phenotypic and biological definition is incomplete. Seeking to identify antigens detectable in paraffin-embedded sections that might allow a more complete, rational immunophenotypic classification of histiocytic/dendritic cell neoplasms, the International Lymphoma Study Group (ILSG) stained 61 tumours of suspected histiocytic/dendritic cell type with a panel of 15 antibodies including those reactive with histiocytes (CD68, lysozyme (LYS)), Langerhans cells (CD1a), follicular dendritic cells (FDC: CD21, CD35) and S100 protein. This analysis revealed that 57 cases (93%) fit into four major immunophenotypic groups (one histiocytic and three dendritic cell types) utilizing six markers: CD68, LYS, CD1a, S100, CD21, and CD35. The four (7%) unclassified cases were further classifiable into the above four groups using additional morphological and ultrastructural features. The four groups then included: (i) histiocytic sarcoma (n=18) with the following phenotype: CD68 (100%), LYS (94%), CD1a (0%), S100 (33%), CD21/35 (0%). The median age was 46 years. Presentation was predominantly extranodal (72%) with high mortality (58% dead of disease (DOD)). Three had systemic involvement consistent with 'malignant histiocytosis'; (ii) Langerhans cell tumour (LCT) (n=26) which expressed: CD68 (96%), LYS (42%), CD1a (100%), S100 (100%), CD21/35 (0%). There were two morphological variants: cytologically typical (n=17) designated LCT; and cytologically malignant (n=9) designated Langerhans cell sarcoma (LCS). The LCS were often not easily recognized morphologically as LC-derived, but were diagnosed based on CD1a staining. LCT and LCS differed in median age (33 versus 41 years), male:female ratio (3.7:1 versus 1:2), and death rate (31% versus 50% DOD). Four LCT patients had systemic involvement typical of Letterer-Siwe disease; (iii) follicular dendritic cell tumour/sarcoma (FDCT) (n=13) which expressed: CD68 (54%), LYS (8%), CD1a (0%), S100 (16%), FDC markers CD21/35 (100%), EMA (40%). These patients were adults (median age 65 years) with predominantly localized nodal disease (75%) and low mortality (9% DOD); (iv) interdigitating dendritic cell tumour/sarcoma (IDCT) (n=4) which expressed: CD68 (50%), LYS (25%), CD1a (0%), S100 (100%), CD21/35 (0%). The patients were adults (median 71 years) with localized nodal disease (75%) without mortality (0% DOD). In conclusion, definitive immunophenotypic classification of histiocytic and accessory cell neoplasms into four categories was possible in 93% of the cases using six antigens detected in paraffin-embedded sections. Exceptional cases (7%) were resolvable when added morphological and ultrastructural features were considered. We propose a classification combining immunophenotype and morphology with five categories, including Langerhans cell sarcoma. This simplified scheme is practical for everyday diagnostic use and should provide a framework for additional investigation of these unusual neoplasms.
[Show abstract][Hide abstract] ABSTRACT: In a previous study, we showed that the high level of protein tyrosine phosphorylation present in lymphomas containing an anaplastic lymphoma kinase (ALK) can be demonstrated in routinely processed paraffin tissue sections using immunolabelling techniques. In the present study we investigated whether oncogenic tyrosine kinase activation also occurs in other categories of lymphoma by staining 145 cases of lymphoma covering those tumours with a range of different subtypes including those with morphological similarity to ALK-positive anaplastic large cell lymphoma (ALCL). Twelve cases of the borderline malignant disorder lymphomatoid papulosis were also studied. Twenty seven of the 28 cases of ALK-positive ALCL showed the extensive cytoplasmic labelling for phosphotyrosine in the neoplastic cells. The remaining case containing moesin-ALK exhibited membrane-associated phosphotyrosine expression. There was no nuclear phosphotyrosine labelling in any of the ALK-positive ALCL, even though ALK was present within the cell nuclei in 23 of the tumours. Variable degrees of phosphotyrosine labelling, usually membrane-restricted, were observed in 7/40 cases of ALK-negative ALCL, 9/29 cases of diffuse large B-cell lymphoma, 3/6 cases of mediastinal B-cell lymphoma, 2/7 cases of Hodgkin's lymphoma, 3/6 cases of peripheral T-cell lymphomas unspecified, 4/6 cases of B-cell chronic lymphocytic leukaemia, 2/6 cases of follicular lymphomas and 2/12 cases of lymphomatoid papulosis studied. However none of these phosphotyrosine-positive cases showed the strong cytoplasmic labelling comparable to that seen in ALK-positive lymphoma. We conclude that activation of a tyrosine kinase is probably not a major oncogenic event in lymphomas other than ALK-positive ALCL.
No preview · Article · Feb 2002 · The Histochemical Journal
[Show abstract][Hide abstract] ABSTRACT: The JC12 monoclonal antibody recognizes a previously unknown nuclear protein that showed a restricted distribution in normal tonsil and was also overexpressed in a subset of diffuse large B-cell lymphomas. Using this reagent, we expression cloned cDNAs encoding its antigenic target and identified this protein as a novel putative transcription factor, FOXP1. The FOXP1 protein sequence contains predicted domains characteristic of transcription factors, including a winged helix DNA-binding motif, a second potential DNA-binding motif, a C(2)H(2) zinc finger, nuclear localization signals, coiled-coil regions, PEST sequences, and potential transactivation domains. The FOXP1 gene has been mapped to chromosome 3p14.1, a region that commonly shows loss of heterozygosity in a wide range of tumors and which is reported to contain a tumor suppressor gene(s). Using tissue arrays and immunohistochemistry, we demonstrate that both the FOXP1 mRNA and protein are widely expressed in normal tissues. The levels of FOXP1 mRNA were compared in paired normal and tumor tissues (from the same patient) using a tissue array containing cDNAs extracted from 68 samples taken from kidney, breast, prostate, uterus, ovary, cervix, colon, lung, stomach, rectum, small intestine, and from nine cancer cell lines. Differences in FOXP1 mRNA expression between normal and tumor samples were observed in 51% of cases. Most striking was the comparative loss of expression in 73% of colon tumors and comparative overexpression of FOXP1 mRNA in 75% of stomach tumors. Analysis of the FOXP1 mRNA expression in normal tissues (not taken from cancer patients) indicated that loss of FOXP1 expression may occur in some histologically normal tissues adjacent to tumors. Immunohistochemical analysis of FOXP1 protein expression was performed on 128 solid tumors, including 16 renal, 9 breast, 12 lung, 20 colon, 21 stomach, 10 head and neck, 35 prostate, and 5 pancreatic cases. Complete loss of expression, increased expression, and cytoplasmic mislocalization of the predominantly nuclear FOXP1 protein were frequently observed in neoplastic cells. Our study identifies FOXP1 as a new candidate tumor suppressor gene localized to the chromosome 3p14.1 region.
[Show abstract][Hide abstract] ABSTRACT: Anaplastic large cell lymphoma (ALCL) was proposed as a clinicopathologic entity over 14 years ago, but has been somewhat controversial due to the variability of its defining features and variable occurrence in different age-groups. To evaluate this entity in a pediatric population, 36 cases of childhood large cell lymphoma were evaluated for abnormalities of the anaplastic lymphoma kinase (ALK) gene that has been associated with ALCL morphology and immunophenotype. ALK abnormalities were evaluated by assay for the t(2;5)(p23;q35) translocation by RT-PCR and/or expression of NPM-ALK fusion protein by immunohistochemistry. Results showed 17 patients to have evidence of ALK gene expression. All of these children (mean age, 9.3 years) had tumors that were of T-cell phenotype (with the exception of a single case of null phenotype) and that expressed CD30. In contrast, 19 children with no evidence of ALK expression were older (mean, 12.7 years), and the majority (12/19) had tumors of B-cell phenotype. CD30 was also diffusely expressed in 8 of these 19 tumors. The difference in mean age between the two groups was statistically significant (P = 0.015). In three cases tested for both ALK and the t(2;5), ALK protein was detected in the absence of the t(2;5) translocation but no cases showed the reverse pattern, consistent with ALK fusion to genes other than NPM or activation of the ALK gene by another mechanism. These findings provide further support that ALK-positive ALCL is a distinct pathologic entity among pediatric large cell lymphomas primarily characterized by expression of T-cell markers, CD30, and EMA, and by a younger mean age.
No preview · Article · Jan 2001 · Pediatric and Developmental Pathology
[Show abstract][Hide abstract] ABSTRACT: The 5q- syndrome is a distinct subtype of myelodysplastic syndrome (MDS) characterized by refractory anemia, deletion of the long arm of chromosome 5, del(5q), as the sole cytogenetic abnormality, and a low frequency of transformation to acute leukemia. Using combined immunophenotyping and fluorescence in situ hybridization (FISH), studies were carried out on bone marrow smears of three 5q- syndrome cases to identify the cell lineages carrying the 5q deletion. In all three cases, the granulocytic, monocytic, and erythroid lineages possessed the del(5q) clonal marker, whereas the T-lymphocytes did not. Interestingly, in one case, cells of B-lymphoid lineage also showed the presence of the del(5q). This is the first report to date showing involvement of an acquired 5q deletion associated with MDS in B-cells. This result suggests that in some cases, MDS arises in a multipotent cell with a capacity to differentiate into both myeloid and lymphoid cells.
No preview · Article · Dec 2000 · Genes Chromosomes and Cancer
[Show abstract][Hide abstract] ABSTRACT: Oncogenic anaplastic lymphoma kinase (ALK) fusion proteins (nucleophosmin-ALK [NPM-ALK] and other variants) are expressed in many cases of anaplastic large-cell lymphoma (ALCL) but are absent from normal tissues. The possibility that ALK proteins are immunogenic was investigated with the use of an immunocytochemical technique to screen plasma from ALK-positive ALCL on transfectants expressing ALK proteins and by an in vitro kinase assay. Circulating antibodies against NPM-ALK protein were present in all ALK-positive ALCL patients (11 out of 11 cases) studied while 10 patients also had antibodies recognizing normal ALK protein. Weak antibodies reactive with NPM-ALK (which may represent anti-NPM autoantibodies) were detected by the in vitro kinase assay in 3 of the 10 control samples (but not by immunocytochemistry). The presence of anti-ALK antibodies may be relevant to the relatively good prognosis of ALK-positive ALCL. The immunocytochemical technique for detecting anti-ALK activity is simple and semiquantative and may provide a means of detecting B-cell responses to other tumor-associated molecules. (Blood. 2000;96:1605-1607)