High incidence of EBV genome in CD30-positive non-Hodgkin's lymphomas.

In Hodgkin's disease, Epstein-Barr virus (EBV) is found in CD30-positive Reed-Sternberg cells. We therefore studied 60 CD30-positive non-Hodgkin's lymphomas (NHLs) for the presence of EBV by the polymerase chain reaction (PCR) and DNA in situ hybridization (DISH), and by immunohistochemistry for the latent EBV proteins LMP and EBNA-2. CD30-negative NHLs and reactive lymph nodes served as controls. The CD30-positive cases comprised 17 anaplastic large cell lymphomas (ALCLs) (> 75 per cent CD30-positive cells) and 43 non-ALCLs (with 5-35 per cent CD30-positive cells). By PCR, 40 of 60 CD30-positive NHLs (67 per cent) were EBV-positive; in CD30-negative cases, 6/29 (21 per cent) were EBV-positive, as were 12/50 (24 per cent) reactive lymph nodes. The DISH procedure demonstrated the EBV genome exclusively in the nuclei of tumour cells in 23 of the 37 PCR EBV-positive cases that were tested. PCR-negative cases were always DISH-negative, as were the PCR-positive reactive lymph nodes and CD30-negative NHLs. Immunohistochemistry demonstrated LMP in neoplastic cells of 7/47 (15 per cent) CD30-positive NHLs, both ALCL and non-ALCL always in PCR EBV-positive cases, but never in the two control groups. EBNA-2 staining could not be detected. It is concluded that EBV is present (and transcriptionally active) in a sizeable number of NHLs and an association between the presence of the EBV genome and CD30 expression seems likely.

Immunohistochemical detection of retroviral-P15E-related material in carcinomas of the head and neck.

As has been reported previously, head and neck carcinomas produce low molecular weight factors (H/N ca LMWFs); a molecular weight less than 25000 daltons is capable of inhibiting the chemotaxis of mononuclear phagocytes. The effect of the factors could be neutralized by antibodies to P15E, one of the structural envelope proteins of Murine Leukemia Viruses (MuLV). This indicates that these low molecular weight factors derived from the tumors are related to P15E. In this study, 35 biopsy specimens of head and neck carcinomas were subjected to an indirect immunoperoxidase assay, in order for P15E-like material to be detected morphologically. All head and neck carcinomas gave positive results. Sixty-three percent of other carcinomas (used as controls) were positive as well. P15E-like material was also expressed in epithelia-overlaying inflammatory responses. Healthy epithelia were not positive. This report thus supports the view that P15E-like molecules can be easily detected in cancerous disease--not only by way of biologic isolation, but also by use of immunohistochemical techniques. Since the factor is not specific for the malignant state, it cannot be used as a tumor marker. Possibly involved in the pathogenesis of cancerous disease, its relationship to growth factors, oncogenes, and the immune system needs further clarification.

Identification of a new lymphocyte subset surface antigen, the expression of which disappears after in vitro and in vivo stimulation. Distribution, biochemistry, and functional studies.

Two monoclonal antibodies (MoAbs) are described (MD 2.6, IgG1 and MD 4.3, IgG2a) that react with a nonlineage specific lymphocyte subset surface antigen. This antigen is expressed on B cells, a subset of both T8+ and T4+ cells, cells that exert killer and natural killer cell activity in vitro, B cells in lymph nodes, and a small percentage of thymocytes. Expression of the antigen was found to be variable on T cells but not on B cells among individuals. Following polyclonal activation, expression of the determinant detected was lost from the cell surface. Both MD+ and MD+ cells responded to PHA and in MLC. MLC resulted in the generation of cytotoxic T lymphocytes and primed T lymphocytes in both the MD+ and MD+ subpopulations. In contrast, the response to soluble antigens was found to reside almost exclusively in the MD-subset. Immunoprecipitation indicates that the MoAbs react with an antigen that has a molecular weight of 220-240 KD which can be cleaved into subunits of 70-80 kD by beta-mercaptoethanol.

HLA-DR antigens in epithelioid cell granulomas of sarcoidosis, using semithin frozen sections. A concept about granuloma formation.

Mediastinal lymph nodes of 11 patients with Sarcoidosis were studied. The immunoperoxidase technique using monoclonal antibody to HLA-DR antigen revealed on conventional frozen sections epithelioid cell granulomas with intense staining. Localization of this HLA-DR + material on or in cells in these granulomas was possible with 1 mu semithin frozen sections. Epithelioid cells as well as multi nuclear giant cells were seen in these sections with membrane bound HLA-DR antigens. Some problems about HLA-DR antigens in relation with antigen handling, the presence on epithelioid, (and) giant cells and granuloma formation will be discussed.

Mononuclear phagocyte function in head and neck cancer. Chemotactic responsiveness of blood monocytes in correlation between histologic grade of the tumor and infiltration of these cells into the tumor area.

The chemotactic responsiveness of peripheral monocytes and the acid-phosphatase activity of tumor-infiltrating macrophages, as well as the ultrastructural appearance, were studied in 40 patients with squamous cell carcinoma of the head and neck. The chemotactic responsiveness was found to be decreased in carcinoma patients, and this value appeared to be positively correlated in individual patients with the number of tumor-infiltrating macrophages, as well as with the histologic grade of the tumor. Patients with poorly differentiated malignancies showed impaired monocyte chemotactic responsiveness and low numbers of tumor-infiltrating macrophages. Macrophages present in the parenchyma of the tumor showed a weak and diffuse pattern of acid phosphatase activity. The acid phosphatase activity of stromal macrophages was much stronger and distributed in foci. Electron microscopic examination of the parenchymal macrophages revealed low numbers of lysosomes and the presence of tumor cell debris in the cytoplasm of the cell, without any sign of a surrounding phagosomal membrane. Together with the weak cytochemical reactivity, this probably indicates the poor functional state of the phagocyte when infiltrated in the parenchyma of the tumor. Low molecular weight factors derived from the tumor are known to decrease chemotactic responsiveness of peripheral monocytes. The poor functional state of the macrophages infiltrated within tumor parenchyma might be explained by assuming that a high concentration of such factors in the near vicinity of malignant cells causes toxic effects in macrophages.

Production and traffic of B lymphocytes in the extracortical central area of the guinea pig thymus.

Lymphocytes in the stroma and lymphatics of the extra-cortical central area (ECCA) of the guinea pig thymus have been studied with light microscopy, quantitative microscopy, colchicin-induced mitotic arrest, EA (IgG) and EA (IgM) C adherence, surface immunoglobulins (Ig total, IgM, IgG), alkaline phosphatase activity and the effect of cyclophosphamide administration. The results suggest, that AP-positive, SIg-positive EAC-negative lymphocytes in the ECCA proliferate and maturate into AP-negative, SIg-positive, EAC-positive lymphocytes. The latter leave the thymus through the lymphatics. Calculations show that daily 8-9 X 10(6) B lymphocytes are produced in the ECCA and leave this area through the lymphatics. As this number is more than 10% of the number of T cells which daily leave the thymus, we conclude that in the ECCA a considerable number of B lymphocytes is produced.