摘要:

CD20 is a membrane-embedded 35-37 kDa nonglycosylated phosphoprotein that is a restricted B-cell antigen. CD20 antibodies are available for paraffin and frozen section immunohistochemistry and for flow cytometric analysis. Its clinical utility is greatest for identifying B-lineage non-Hodgkin's lymphomas, but it can also aid in the diagnosis of nodular lymphocyte predominance Hodgkin's disease and acute lymphoblastic neoplasms. CD20 immunotoxins have also been used experimentally to treat B-cell lymphomas that do not respond to conventional chemotherapy or radiation therapy.

ISSN:1062-3345    

出版商:OVID    

年代:1996

数据来源: OVID

摘要:

We tested a variety of techniques to optimize the immunolocalization of p110RBin deparaffinized formalin- and methacarn-fixed tissue, including the use of heat-induced epitope retrieval (HIER) using a microwave oven and DNase as pretreatments. By testing a number of commercially available antibodies and employing a series of different buffers at different pHs, as well as varying microwave exposure times, we obtained optimal nuclear immunostaining comparable to that observed in snap-frozen tissue sections and cell blocks. Employing very low pH buffers (pH 1.6) resulted in the highest signal-to-noise ratio, but also resulted in nonspecific nuclear immunostaining that could be duplicated with monoclonal antibodies to cell-surface antigens (e.g., CD20) using similar conditions. Even in optimally preserved tissues using optimal immunostaining techniques, a range of p110RBimmunostaining patterns was noted in normal tissues, including a subset of cells in which p110RBwas not reliably detectable. We conclude that whereas HIER techniques can permit the immunolocalization of p110RBin deparaffinized sections of human tissues and tumors, given the large variations in apparent p110RBimmunostaining intensities, immunohistochemistry must be used with great caution as a method of assessing alterations of retinoblastoma (RB) protein function and should be used only in the context of adequate internal controls and corroborative methods of assessment of p110RBstatus.

ISSN:1062-3345    

出版商:OVID    

年代:1996

数据来源: OVID

摘要:

We studied 39 vertical growth phase malignant melanomas, minimum Clark level III, with antibodies to proliferating cell nuclear antigen (PCNA), Ki-67 (MIB-1), and p53 (clones PAB 1801 and D07) in formalin-fixed, paraffin-embedded tissue. Twenty-four (62%) of the primary tumors had synchronous or metachronous metastases, which were also evaluated. Tumor proliferation and p53 expression were correlated with patient survival, disease-free interval, and tumor stage at presentation and subsequent progression. PCNA, Ki-67 (MIB-1), and p53 (clones 1801/D07) immunoreactivity did not differ in primary malignant melanomas without metastases (20.7, 9.1, 3.5/2.6%) compared to primary malignant melanomas with metastases (20.9, 8.7, 2/4%) but was significantly higher in the metastatic tumors (38.5, 13.2, 5.4/7.8%). Both PCNA immunoreactivity in primary malignant melanoma and patient age were significantly correlated with survival in patients with malignant melanomas who developed metastases. Patients surviving 60 months or longer were younger (p = 0.036; mean, 51 years) and had lower PCNA staining in the primary tumor (p = 0.007) (mean, 15.8%) compared with patients surviving for less than 60 months (mean age, 59.6 years; mean PCNA, 25.9%). PCNA immunoreactivity in metastatic malignant melanomas and Ki-67 (MIB-1) and p53 immunoreactivity in both primary and metastatic malignant melanomas were not predictive of survival. No significant correlation was found between disease-free interval and PCNA, Ki-67 (MIB-1), or p53 immunoreactivity in the primary tumors of patients who developed subsequent metastases. We conclude that (a) PCNA immunoreactivity in primary malignant melanomas and patient age correlate with aggressive biologic behavior in patients with subsequent metastases; (b) metastatic melanoma has elevated PCNA, Ki-67 (MIB-1) and p53 expression compared to primary melanomas with or without metastases; and (c) PCNA, Ki-67 (MIB-1), and p53 expression in primary malignant melanomas are not predictive of subsequent metastases or disease-free interval.

ISSN:1062-3345    

出版商:OVID    

年代:1996

数据来源: OVID

摘要:

The diagnosis of thymic neoplasms and their distinction from mediastinal lymphoproliferative disorders or other tumors is often difficult, particularly if only fixed tissue is available. Cortical thymocytes and a number of other normal cell types may be detected in paraffin sections using O13, a monoclonal antibody that recognizes CD99, the p30/32MIC2gene product. To determine whether this marker represents a diagnostic discriminant in assessing mediastinal neoplasms, O13 immunoreactivity was determined for a series of benign and malignant thymomas and mediastinal lymphoproliferative disorders. Small lymphocytes (cortical thymocytes) exhibited strong membrane staining for CD99 in 16 of 16 benign thymomas (including lymphocyte-predominant, epithelial-predominant, mixed lymphoepithelial, and spindle-cell types) and in five of five invasive thymomas (malignant thymoma type I; epithelial predominant subtype). Thymic epithelial cells were negative for CD99 staining. One case of well-differentiated thymic carcinoma, a subtype of thymic carcinoma (malignant thymoma type II), contained numerous CD99-positive thymocytes. Another case of thymic carcinoma (malignant thymoma type II) contained CD99-positive thymocytes focally, whereas the remaining six cases were nonreactive for CD99. Of 34 mediastinal non-Hodgkin's lymphomas, only cases of lymphoblastic lymphoma exhibited strong membrane staining for CD99 (three of four mediastinal cases; four of four extramediastinal cases). Weak to moderate, nonuniform, predominantly membrane staining for CD99 was seen in six of 30 cases of other types of non-Hodgkin's lymphoma (five large-cell, B-cell type and one large-cell, T-cell type). Immunologic evidence failed to support a thymic origin for the CD99-positive non-lymphoblastic B-cell lymphomas. Occasional Reed-Sternberg cells or variants exhibited membrane staining for CD99 in three of eight cases of mediastinal Hodgkin's disease and in three of eight extramediastinal cases. For certain diagnostic problems, inclusion of CD99 as part of the immunohistochemical staining profile of mediastinal neoplasms may be helpful in differential diagnosis.

ISSN:1062-3345    

出版商:OVID    

年代:1996

数据来源: OVID

摘要:

Antibodies recognizing the p30/32MIC2glycoprotein (CD99) are consistently positive in Ewing's sarcoma/peripheral neuroepithelioma and in most lymphoblastic lymphomas and acute lymphocytic leukemias. However, CD99 expression in other nonlymphoblastic non-Hodgkin's lymphomas (NHL) and Hodgkin's disease (HD) subtypes remains incompletely studied. We tested 11 lymphoblastic lymphomas as well as 19 low-grade, 16 intermediate-grade, and eight high-grade NHLs and 15 HD (10 nodular sclerosis, one lymphocyte predominant, three mixed cellularity, and one lymphocyte depleted). Among the NHLs, there were three “maltomas,” one monocytoid B-cell lymphoma, and one anaplastic largecell lymphoma. We used the commercially available paraffin-reactive monoclonal antibody O13, with enzyme retrieval only or combined with heat-induced epitope retrieval (HIER). Without HIER, lymphoid cells were immunoreactive in lymphoblastic lymphomas in 73% of cases; in low-grade NHLs, in 42% of cases; in intermediate-grade NHLs, in 19% of cases; and in high-grade NHLs, in 0% of cases. Of the HD subtypes, 70% of nodular sclerosis and the single case of lymphocyte predominant lymphomas contained positive cells, whereas the three mixed cellularity and single lymphocyte-depleted lymphoma tested negative. All three “maltomas” had positive cells, but neither case of monocytoid B-cell lymphoma or anaplastic large-cell lymphoma was positive. However, with the exception of one colonic low-grade NHL, all lymphoblastic and nonlymphoblastic NHLs and HD subtypes had positive cells with O13 following HIER, with most showing strong cytoplasmic membrane reactivity. Also, with HIER, three nodular sclerosis HD demonstrated strong cytoplasmic Golgi staining in a minority of Reed-Sternberg cells and variants. This increased sensitivity with HIER was associated with increased background staining. Yet these findings demonstrate that O13 immunoreactivity does not reliably discriminate between the various NHLs or HD, especially following HIER. Moreover, when using O13 in the differential diagnosis of Ewing's sarcoma/peripheral neuroepithelioma, specific and sensitive antihematolymphoid markers should be used concomitantly to identify CD99-positive leukemias and lymphomas.

ISSN:1062-3345    

出版商:OVID    

年代:1996

数据来源: OVID

摘要:

This report describes the usefulness of immunohistochemistry using anti-mb-l/CD79a monoclonal antibody JCB117 on paraffin sections to detect minimal residual disease after chemotherapy in testicular biopsies from 45 patients with acute lymphoblastic leukemia (ALL). The results obtained on paraffin sections were similar to those previously described on frozen sections using a large panel of monoclonal anti-B and anti-T antibodies. Five of 45 cases showed the presence of residual disease; one in five cases had obvious blast-cell infiltration; in four of five cases, involvement was diagnosed only after immunostaining. However, on paraffin sections, anti-mb-l/C79a (JCB117) antibody could detect blasts of B-cell phenotype at different levels of B-cell differentiation (in five of five cases); anti-CD20/L26 antibody, used for comparison, failed to react with early pre-B blasts (in four of five cases). In testicular biopsies with residual disease, an increased number of reactive T cells was also noted by reaction with anti-CD3 antibody. Anti-terminal deoxyribonucleotidyl transferase (TdT) staining was positive in two of five cases; the negative staining in the three remaining cases was probably the result of antigen alteration during fixation. Immunohistochemical evaluation (with prior antigen retrieval) using anti-mb-l (CD79a), anti-CD20/L26, anti-CD3, and anti-TdT antibodies is therefore an accurate alternative in the detection of residual blast cell involvement in treated ALL.

ISSN:1062-3345    

出版商:OVID    

年代:1996

数据来源: OVID

摘要:

A panel of immunohistochemical markers was employed to evaluate its utility in distinguishing between well-differentiated adenocarcinoma of the lung, bronchioloalveolar type, and reactive hyperplasia of type 2 pneumocytes. We studied 20 cases of bronchioloalveolar carcinoma, 10 with separate areas of pneumocyte hyperplasia, and 19 cases of non-neoplastic lung conditions with pneumocyte hyperplasia. The panel of markers included Leu M-1, B72.3, carcinoembryonic antigen (CEA), both monoclonal and polyclonal, and human milk-fat globule protein. The sensitivities and specificities of these antibodies as “tumor markers” are as follows: Leu M-1, sensitivity 85%, specificity 97%; B72.3, sensitivity 80%, specificity 100%; monoclonal CEA, sensitivity 50%, specificity 90%; and polyclonal CEA, sensitivity 50%, specificity 76%. The human milk-fat globule protein was positive in most reactive and neoplastic processes, with a sensitivity of 70% and a specificity of only 3%. The best combination of markers for discriminating between carcinoma and reactive pneumocytes was Leu M-1 and B72.3, with 13 of the bronchioloalveolar carcinomas positive for both, but none of the hyperplasias positive for both.

ISSN:1062-3345    

出版商:OVID    

年代:1996

数据来源: OVID

摘要:

The current study extends the principles of the antigen retrieval technique for formalin-fixed, paraffin-embedded tissues to transmission electron microscopy. Specimens prepared for both routine and immunoultrastructural studies were examined for the effects of microwave treatment on the immunolabeling of tissue antigens. Specimens of normal rat tongue mucosa and human oral mucosa were microwaved before immunogold labeling was done using six types of antibody (types I, III, IV, and VI collagen, laminin, and cytokeratin). Sections were cut from tissue blocks that had been fixed and embedded for either ultrastructural immunocytochemistry in L.R. White resin or routine electron microscopic morphology in TAAB resin. Compared with nonmicrowaved sections, microwave-treated, immunolabeled sections of both types of embedded tissues revealed markedly enhanced gold labeling for type IV collagen in the oral epithelial basal lamina. Moreover, microwave-treated L.R. White sections showed greater label density for type III and VI collagens and for cytokeratin compared with nonmicrowaved sections. There was variable gold labeling for laminin in both TAAB and L.R. White sections with or without microwave pretreatment and no improvement in type I collagen detection in microwave-treated sections. We concluded that postembedding microwave treatment of plastic ultrathin sections on sodium citrate buffer enhances some tissue antigens by increasing the likelihood of reexposing epitopes encrypted by a fixative-denaturative milieu. This microwave technique offers the potential of combining immunocytochemistry with enhanced exposure of antigenic markers of ultrastructural morphology in a number of extracellular sites.

ISSN:1062-3345    

出版商:OVID    

年代:1996

数据来源: OVID

ISSN:1062-3345    

出版商:OVID    

年代:1996

数据来源: OVID