Harry L. Ioachim

EBV-associated Primary Lymphomas in Salivary Glands of HIV-infected Patients

The lymph nodes within and around salivary glands are commonly involved in inflammatory processes, but rarely the site of primary lymphomas. We observed six cases of primary salivary gland lymphoma in HIV-infected patients and studied them in parallel with three cases of primary salivary gland lymphoma unrelated to HIV and three cases of HIV-related salivary gland lymphadenopathies in order to characterize this new entity. We found that all salivary gland lymphomas in HIV-infected patients were of high histologic grade while salivary gland lymphomas unrelated to HIV were predominantly of low grade MALT type. All lymphomas in both categories expressed the B-cell phenotype. Just as HIV-unrelated lymphomas frequently arise on the background of chronic inflammatory lymphoid processes, lesions characteristic of HIV-lymphadenopathy were still present in some lymphomas of HIV-infected patients. EBV RNA transcripts (EBER) were demonstrated in three, and latent membrane protein (LMP) in two of the six HIV-related and in none of the three HIV-unrelated lymphomas. The three EBER-positive lymphomas were of the histologic types known to express the virus in most cases. The presence of HIV in the form of the core protein p24 and envelope glycoprotein gp41 on the dendritic reticular cells of germinal centers was ascertained in the cases of HIV-related lymphadenopathies but also in the coexistent lymphadenopathies of lymphomas. The practical importance of diagnosing the salivary lymphadenopathies and lymphomas associated with the HIV-infection resides in avoiding their misdiagnosis and surgical removal as tumors of salivary glands.

Correlations between Tumor Antigenicity, Malignant Potential, and Local Host Immune Response

In the process of induction and growth of tumors, complex interrelationships are established between tumor and host. Among the multiple participating factors, some are particularly important in determining the outcome of tumor growth. To understand this complex interrelationship, it is therefore necessary to identify the determinant factors of tumor-host interaction and to study their functions.

Lymphoid proliferations and lymphomas associated with gastric metaplasia, dysplasia, and carcinoma.

Gastric carcinomas are invariably accompanied by lymphoid proliferations. We studied their features in 22 resected gastric carcinomas in which the lymphoid proliferations ranged from reactive lymphoid follicles to mucosa-associated lymphoid tissue (MALT) lymphomas. In most cases, the collections of lymphocytes were abundant, which is remarkable considering the lack of lymphoid tissue in the normal stomach. They were not haphazardly located but in direct contact with the metaplastic, dysplastic, and neoplastic epithelial cells, in positions suggestive of defense barriers. They consisted of newly formed lymphoid follicles with reactive germinal centers sometimes high up in the superficial mucosa, collections of plasma cells beneath the surface epithelium, and large aggregates of B cells above and below the muscularis mucosae as well as abundant T cells. The latter, both CD4+ and CD8+, were seen within metaplastic epithelial cells as well as within carcinomatous glands that were partially destroyed, resembling apparent neoplastic lympho-epithelial lesions (LEL). In three cases, the B cells infiltrating the gastric muscular layers represented MALT-lymphomas adjacent to gastric carcinomas, as confirmed by polymerase chain reaction (PCR) analysis in two cases. In a case of lymphoepithelioma-like carcinoma, the excessive lymphoid cells were predominantly of T-CD8+ type. In this case, EBV identified by EBV-encoded RNA and latent membrane protein was present in large amounts. Helicobacter pylori was seen in only six cases in areas of chronic gastritis that were distant from carcinoma. H. pylori was not present in the areas of metaplasia, dysplasia, or carcinoma. It appears that the lymphoid proliferations accompanying these gastric changes do not arise in response to the pathogenic agent H. pylori, which caused the persistent infection leading to them yet is no longer present, but rather in response to the existence of the abnormal epithelial cells. Thus the lymphoid proliferations consistently associated with gastric metaplasia, dysplasia, and neoplasia may be regarded as immune reactions to the long-term cellular changes triggered by the initial chronic gastritis. On rare occasions, the exaggerated lymphoid proliferations may reach the end of the spectrum, resulting in MALT lymphomas coexistent with gastric carcinomas.

Ovarian cancer-associated antibodies recovered from ascites: Their use for the isolation of ovarian cancer-associated antigen to produce monoclonal antibodies

Immune complexes (ICs) were recovered from the ascites of a patient with stage IV endometrioid ovarian cancer by sequential precipitation with 33% saturated ammonium sulfate and 2.5% polyethylene glycol 6000 (PEG 6000), followed by affinity chromatography on protein A-Sepharose CL-4B. The IgG-containing ICs were dissociated using 8 M urea, separated by ion-exchange chromatography on Sephadex QAE-50, and subsequently analyzed for purity by immunoelectrophoresis (IEP) and radial immunodiffusion (RID). Recovered antibody was tested for reactivity by immunohistologic techniques against paraffin-embedded tumor tissue and acetone-fixed cell suspensions of epithelial tumors. The antibody which demonstrated ovarian cancer-associated activity was absorbed with antigen extracts of breast, colon, and lung cancers as well as keratin to reduce cross-reactivity. The absorbed endometrioid ovarian cancer-associated antibody (OCAAb) was used to produce an immunoadsorbent column for the recovery of tumor-associated antigens. A mouse monoclonal antibody designated FEN-1 was produced using this antigen-containing fraction, and preliminary screening has demonstrated ovarian tumor-associated reactivity. The use of autologous ICs as reagents for preparing tumor antigen-rich immunogens may provide a valuable tool in the search for tumor-associated antigens.

Neoplastic transformation of rat thymic cells induced in vitro by Gross leukemia virus.

Cultures of embryonal rat thymus infected initially with Gross leukemia virus have, at the present time, abundantly replicated infectious virus particles for 20 months. Cells from these cultures, after 3 months in vitro, displayed morphological changes and induced formation of tumors upon isotransplantation. The tumors were serially transplantable, and subsequent transplants continue to carry the initial Gross leukemia virus.

Cultures grown and embedded in situ on Spurr discs, a low viscosity epoxy resin for electron microscopy☆

Abstract The ultrastructural study of cellular inter-relationships in vitro requires methods of embedding in situ. The present technic combines the advantages of growing the cells directly on the substrate with subsequent embedding in situ. In addition it uses Spurr medium which provides qualities of low viscosity, high penetrability and easy handling.

Description of an endometrioid ovarian cancer cell line

Abstract A human cell line, designated L-1, has been established from the ascites of an untreated patient with stage IV (FIGO) endometrioid ovarian cancer. This cell line initially grew uninterrupted for 6 months without fibroblast contamination and contact inhibition, and has been subcultured weekly for the past 7 years. L-1 does not contain steroid hormone receptors nor does it demonstrate the presence of oncofetal antigens by immunohistochemical techniques. The doubling time of L-1 is 11.8 hr. Flow cytometric analysis reveals an aneuploid DNA peak, and an abnormal karyotype demonstrates hyperdiploidy, translocations, and deletions. Morphology, growth patterns, cytogenetic analysis, and other features of L-1 are characterized.

Anti HTLV-III and Anti T-Cell Antibodies in AIDS and ARC Patients

The number of surface immunoglobulins (SIg)-positive lymphocytes was found to increase when normal lymphocytes were incubated with sera of AIDS or ARC patients. These circulating antilymphocyte antibodies were selectively reactive with 0KT4- but not with 0KT8-staining T-cells. In the present study, AIDS, ARC and control patients were evaluated for antilymphocyte antibodies, anti HTLV-III antibodies and helper/suppressor (h/s) T-cell ratios. In the AIDS group, 23 of 24 patients had circulating HTLV-III antibodies, 24 of 24 showed markedly decreased h/s T-cell ratios and 19 of 21 patients showed marked elevation of anti-lymphocyte antibodies. In contrast, in control patients, none of 14 had HTLV-III antibodies, 13 of 14 had normal h/s T-cell ratios and 3 of 11 showed small increases in antilymphocyte antibodies. In the ARC group, 16 of 16 had circulating anti HTLV-III antibodies. 11 of 15 had decreased h/s T-cell ratios and 6 of 11 showed elevated anti T-cell antibodies. The correlations obtained between these tests and clinical diagnoses indicate their potential usefulness in the detection and monitoring of AIDS and ARC patients.