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Biomedical subjects

M Lestani

Publications and source records attributed to M Lestani.

At least 37 records · Page 2Linked to original sources
PubMed1993

A CD5+ leukemic lymphoma with monocytoid features: an unusual B-cell lymphoma mimicking hairy-cell leukemia.

A case of lymphoma presenting with features shared by hairy cell leukemia (HCL) and its variant, intermediate lymphocytic lymphoma (ILL) and monocytoid B-cell lymphoma (MBCL) is described. Clinical presentation and the morphological findings observed in peripheral blood and in bone marrow biopsy suggested an HCL; however, the tartrate-resistant acid phosphatase negativity of peripheral blood lymphocytes, the histologic pattern observed in the spleen, and the immunophenotyping of peripheral blood, spleen and bone marrow neoplastic lymphocytes (expression of CD5 and lack of CD25), were strongly against this hypothesis. The clinical course was aggressive. This report emphasizes the concept of the equivocal presentation of some 'low-grade' B-cell lymphomas. It is further pointed out that, even with complete and exhaustive morphological and immunological analyses, atypical cases may be encountered.

Aged↗
PubMed1993

Constitutive expression of tenascin in T-dependent zones of human lymphoid tissues.

Tenascin is a major extracellular matrix glycoprotein that can interfere with the action of fibronectin by inhibiting cell adhesion and spreading. Although tenascin is able to exert important immunomodulatory activities on T and B cells and macrophages, little is known about its distribution in different lymphohemopoietic tissues. In this study we have analyzed tenascin immunoreactivity on cryostat and paraffin sections of normal and pathological lymphoid tissues using two different monoclonal antibodies. We demonstrated strong tenascin expression in all peripheral lymphoid tissues, whereas it was barely detectable in the thymus and in bone marrow. In reactive lymph nodes, tenascin was mainly found in T-dependent zones, forming a variably close-woven reticular network corresponding to fibroblastic reticulum cells and blood vessels basal laminae, showing a partial co-localization with fibronectin. In B-dependent zones, tenascin was restricted to blood vessels. Using double-marker analysis, we performed a thorough study comparing tenascin expression in different compartments of lymphoid microenvironments. Tenascin network appeared much thicker in chronically stimulated tissues, where CD4+ lymphocytes with "memory" phenotype (CD45RO+/CD45RA-) were predominant, and at sites of ongoing inflammation. In particular, a striking increase of tenascin was observed in sarcoid lymph node, as well as in myasthenic hyperplastic thymuses. In addition, tenascin can be abnormally synthesized in tissue involved by various types of lymphomas, including Hodgkin's disease and hairy cell leukemia.

Bone Marrow↗
PubMed1992

Detection of calbindin-D immunoreactivity in human follicular dendritic cells.

The calcium-binding protein calbindin-D (28 kD) has been analysed immunohistochemically in different human lymphoid tissues. Combined immunohistochemical staining showed that calbindin-D (28 kD) is expressed by only a proportion of dendritic cells within the light zone of germinal centres, where antigens in the form of immune complexes are trapped and presented to B lymphocytes. All other cell types including macrophages, interdigitating cells, and various lymphocyte populations were negative. The expression of calbindin-D in this functionally relevant subset of follicular dendritic cells could have a role in the regulation of proliferation and selection of memory B-cells by modulating the concentration of calcium ions. Calbindin-D may be a useful marker for analysing in situ the phases of follicular development in different physiological and pathological conditions.

Calbindins↗
PubMed1992

Neoplastic epithelial cells in a subset of human thymomas express the B cell-associated CD20 antigen.

A series of 36 human thymomas have been immunohistochemically analyzed using a panel of antibodies recognizing B-cell markers including CD20. Most thymomas exhibiting the cortical pattern, according to the criteria of Marino and Muller-Hermelink, were characterized by areas of medullary differentiation containing variable numbers of CD20+ B lymphocytes, thus mimicking the medulla of normal thymus. On the other hand, B cells were absent or rare in thymomas recognized as mixed using the same morphological criteria. Surprisingly, we observed in most mixed thymomas variable numbers of CD20+ spindle cells, characterized by long slender processes. Using double-marker analysis we could demonstrate the epithelial nature of these cells (expression of keratin and lack of lymphoid and B-cell-related markers). The immunoreactivity of thymoma epithelial cells with L26, an antibody widely used in the characterization of B-cell lymphomas, can represent a drawback of practical relevance in the differential diagnosis of mediastinal tumors.

Antibodies, Monoclonal↗
PubMed1992

Transbronchial biopsy in sarcoidosis: the role of immunohistochemical analysis for granuloma detection.

In this study 27 transbronchial biopsy specimens obtained from patients with clinical and/or laboratory features suggestive for sarcoidosis were analysed with conventional morphology and immunohistochemistry comparing the sensitivity and reproducibility of the two methods. A limited panel of monoclonal antibodies recognizing epitopes resistant to conventional fixation and embedment procedures were used (CD45R0, CD68, anti-cheratin, anti-collagen IV). All specimens were independently observed by two different pathologists. On the basis of the recognition of bona-fide noncaseating granulomas, 9 cases were uniformly judged as positive, 10 cases as negative, but 8 cases were considered doubtful. Immunohistochemical analysis reliably demonstrated the presence of epithelioid cells in 3 of these cases and absence in 5. These data suggest that the use of a limited immunohistochemical analysis can significantly improve histological diagnosis of sarcoidosis on small transbronchial biopsies using conventional routine material.

Antigens, CD↗
PubMed1990

Multimarker immunohistochemical staining of calgranulins, chloroacetate esterase, and S100 for simultaneous demonstration of inflammatory cells on paraffin sections.

Mac387 monoclonal antibody (MAb) recognizes two calcium binding, myeloid-associated proteins, now termed calgranulins, expressed at high levels by neutrophils and monocytes. Calgranulins are related to migration inhibitory factor (MIF) and are lost in a few days from monocytes differentiated in vitro. This marker is therefore potentially useful to analyze macrophage heterogeneity and turnover in tissue sections. In this study, we developed an immunohistochemical multimarker technique, including calgranulin demonstration, suitable for analyzing different inflammatory cells on paraffin-embedded material. The technique was carried out in subsequent steps demonstrating (a) naphthol AS-D chloroacetate esterase (CAE); (b) S100 immunoreactivity using a rabbit antibody in peroxidase-antiperoxidase (PAP) staining; and (c) Mac387 immunoreactivity using the alkaline phosphatase-anti-alkaline phosphatase (APAAP) technique. CAE staining was introduced in this method to distinguish Mac387+/CAE- macrophages from Mac387+/CAE+ neutrophils, and Mac387-/CAE+ mast cells. S100 protein is strongly expressed within lymphoid tissues by dendritic accessory cells and was then applied to distinguish these cells from S100-macrophages. We have also verified the possibility of reducing the staining time for this time-consuming procedure by use of microwave irradiation. The technique was applied to a representative variety of normal and pathological samples to assess its usefulness for study of cell heterogeneity. Our results showed the multimarker technique to be highly informative in the study of inflammatory lesions (e.g., rheumatoid arthritis, sarcoid and cat-scratch granulomas, dermathopathic lymphadenopathy), and is of wide potential value as an aid to histopathological diagnosis of several diseases.

Antibodies, Monoclonal↗
PubMed1988

Immunohistochemical characterization of osteoclasts and osteoclast-like cells with monoclonal antibody MB1 on paraffin-embedded tissues.

In this study we provide evidence that MB1, a newly developed monoclonal antibody which reacts with B lymphocytes and a proportion of T cells and monocytes, can be successfully used for the direct immunohistochemical identification of osteoclasts on paraffin-embedded surgical specimens. The antigen(s) recognized by MB1 is present at high density in the cytoplasm of osteoclasts of fetal bone and in the multinucleated cells of human giant cell tumour of bone (osteoclastoma), but is weakly expressed or absent in the giant cells of granulomas. MB1 is thus proposed as a new immunohistochemical marker for osteoclasts on paraffin-embedded material.

Acid Phosphatase↗
PubMed1988

Immunohistochemical analysis of sarcoid granulomas. Evaluation of Ki67+ and interleukin-1+ cells.

Proliferating cells have been immunophenotypically characterized in lymph node and bronchoalveolar lavage (BAL) samples obtained from patients with active and inactive sarcoidosis with the cell-cycle-related antigen Ki67. Ki67 monoclonal antibody was used by combined immunohistochemical methods together with antibodies recognizing macrophage- and T-cell-subset-related antigens using avidin-biotin peroxidase (ABC) and alkaline phosphatase-anti-alkaline phosphatase (APAAP) systems. Many proliferating Ki67+ cells were found in affected mediastinal lymph nodes. These cells were mainly located around granulomas and exhibited phenotypical markers of helper/inducer T cells (CD3+, CD4+). Ki67+ macrophages could not be detected in the same lesions with this technique. A different picture was found in BAL preparations where proportions of both T lymphocytes and macrophages were Ki67+. The presence of replicating lymphocytes could be correlated to disease activity, whereas the proportions of Ki67+ macrophages did not show significant differences between active and inactive disease. Interleukin-1 (IL-1) expression was investigated in the same samples with a specific antiserum. Epithelioid macrophages in granulomas and BAL macrophages in all cases exhibited cytoplasmic staining revealing an activated status. Interestingly, giant cells in granulomas were mainly devoid of IL-1 immunoreactivity. These studies support the concept that activated cells at different sites of ongoing inflammation play a central role in the mechanisms accounting for granuloma formation.

Adult↗
PubMed1987

Mediastinal large-cell lymphoma with sclerosis. Genotypic analysis establishes its B nature.

The Southern blot hybridization technique has been applied to study the configuration of immunoglobulin and T-cell receptor genes in 6 cases of the so called mediastinal large cell lymphoma with sclerosis. This lymphoma has been recently recognized as a separate entity among non-Hodgkin lymphomas mainly affecting young adult patients. The B-cell origin of this neoplasm was suggested by means of immunohistochemical analysis. However, the immunophenotypical B-cell related markers used do not always exhibit lineage fidelity. The Southern blot analysis demonstrated the presence of unique heavy and k-light chain immunoglobulin gene rearrangements, establishing genotypically their B-cell origin.

B-Lymphocytes↗
PubMed1987

Immunohistochemical evidence of active thymocyte proliferation in thymoma. Its possible role in the pathogenesis of autoimmune diseases.

Eight cases of human thymoma have been analyzed on cryostat sections with the monoclonal antibody Ki67, which reacts with cells in the proliferative phases of the cell cycle. The aim was to assess the proportion of proliferating thymocytes among lymphoid cells in the thymoma samples. In all cases a large number of cells (mean, 58.75%; range, 35-80%), recognized as thymocytes by morphology and lack of cytokeratin expression in a combined immunohistochemical assay, exhibited nuclear Ki67 staining. These findings differ from the reactivity pattern observed in age-matched nonneoplastic thymuses where lower growth activity of cortical thymocytes was observed (15-20% Ki67+ cells). Intensive thymocyte proliferation in thymomas may represent one of the factors which lead to autoimmunity in myasthenia gravis and thymomas.

Adult↗
PubMed1987

Hyaline-vascular type of Castleman's disease (angiofollicular lymph node hyperplasia) with monotypic plasma cells. An immunohistochemical study with monoclonal antibodies.

A case of angiofollicular lymph node hyperplasia (Castleman's disease) characterized by monotypic (IgG+, lambda+) plasmacytosis is described. Fresh tissue was available and a thorough immunohistochemical analysis of lymphoid and non-lymphoid cells was performed on cryostat sections. Although lymphoid follicles were numerous and exhibited some abnormal features they did not appear part of the monoclonal cell proliferation. Follicular lymphocytes were mixtures of Kappa+ and lambda+ cells. Vessels penetrating within these abnormal follicles expressed reduced levels of FVIII and Leu-M5 antigens and exhibited thicker layer of collagen type IV. The analysis of T-cell subsets showed a normal (3:1) T4/T8 ratio. This case extends to the mixed variant of hyaline-vascular Castleman's disease, the neoplastic potential previously associated to the plasma cell variant of the disease.

Adult↗
PubMed1987

Soluble interleukin-2 receptors in the sera of patients with hairy cell leukemia: relationship with the effect of recombinant alpha-interferon therapy on clinical parameters and natural killer in vitro activity.

In this study we provide evidence that the sera of patients with hairy cell leukemia (HCL) contain a factor that can prevent the binding of a monoclonal antibody specific for interleukin-2 receptor (IL-2R) to its target. This factor corresponds to the soluble form of IL-2R (sIL-2R), as assessed by a specific enzyme-linked immunosorbent assay test, and appears to be released by neoplastic hairy cells. The serum sIL-2R levels were very high at diagnosis and significantly reduced during recombinant alpha-interferon (rIFN alpha 2) therapy. Values of sIL-2R appeared to be inversely related to the natural killer in vitro function displayed by peripheral blood mononuclear cells from the same patients. The presence of sIL-2R in the serum of patients with HCL might be involved in the impairment of cell-mediated immunity observed in these patients and could represent a valuable marker for monitoring different phases of the disease and for modulating IFN therapy.

Antibodies, Monoclonal↗
PubMed1986

Mediastinal large-cell lymphoma of B-type, with sclerosis: histopathological and immunohistochemical study of eight cases.

Eight cases of mediastinal non-lymphoblastic large-cell lymphoma have been studied by histopathological and immunohistochemical methods. A common clinical, morphological and immunophenotypic pattern was identified. Six of eight cases proved to be of B-cell origin by the expression of B-associated antigens detected by specific monoclonal antibodies. Cells of large size with nuclei of varying morphology and a peculiar type of fine compartmentalizing fibrosis were observed in all specimens. Clinically the disease was characterized by the young age of the patients, primary mediastinal involvement, aggressive behaviour and spread to unusual sites (kidneys in four cases). This seems to be a hitherto unrecognized entity in the field of non-Hodgkin's lymphomas, often misdiagnosed because of location and a morphology uncommon for B-cell malignancies. Immunohistochemical analysis on frozen tissue sections appears to be mandatory for a correct diagnosis. Nevertheless, this type of lymphoma could be suspected also on the basis of its peculiar clinicopathological characteristics.

Adolescent↗
PubMed1986

Blastic OKT6-positive proliferation preceding malignant histiocytosis.

A 45-year old male presented latero-cervical lymphoadenopathy. Biopsy revealed a malignant proliferation of immature "lymphoid" cells bearing T6 antigen and HLA-DR but negative for other lymphoid markers, suggesting a phenotype similar to Langerhans cells. The patient did not receive any therapy and six months later developed a histologically typical malignant histiocytosis, involving spleen and liver. Other reported cases of lymphoid malignancies (two bearing the T6 antigen on blast cells) preceding malignant histiocytosis were found and compared with ours. Most of these cases were characterized by the pediatric age of the patients and were presented as acute leukemias exhibiting, in at least some of them, reliable T-cell markers. Our case appears to represent, on the other hand, a blastic proliferation of precursors of both histiocytes and Langerhans dendritic cells which eventually progressed to malignant histiocytosis. The relevance of this observation in the debate on the origin of Langerhans cells and the relationships existing between macrophages and dendritic cells is discussed.

Antigens, Differentiation, T-Lymphocyte↗