Human T-cell leukemia (lymphotropic) retroviruses and their causative role in T-cell malignancies and acquired immune deficiency syndrome

Hematopoietic and lymphoproliferative cancer among male veterans using the Veterans Administration Medical System

Hematopoietic and lymphoproliferative cancer risk among the 3.7 million United States male veterans who use the Veterans Administration (VA) medical system annually was assessed using age-specific incidence curves and cumulative incidence rates. Relative risk comparing the VA with general population risk estimates from the Surveillance, Epidemiology, and End Results (SEER) data were increased significantly for all malignancies examined. The VA sample showed risk increases of 93% for Hodgkin's disease, 20% for non-Hodgkin's lymphomas, 51% for multiple myelomas, and 40% for all leukemias. Among the leukemia subtypes, the observed risk increases were 54%, 23%, 80%, and 46% for lymphocytic, granulocytic, monocytic, and other forms of leukemia, respectively. The large size of the sample and the consistency of risk estimates with two different methods confer validity and strength to these findings. The possible relevance of the high prevalence of tobacco and alcohol use in this population sample to the current findings is discussed and the need for further analytic investigations to explain the increases in risk is emphasized.

Novel membrane-interactive ether lipid analogs that inhibit infectious HIV-1 production and induce defective virus formation

A new class of membrane-active ether lipid (EL) analogs of platelet-activating factor were studied for in vitro anti-HIV-1 activity. Human T-cell (CEM-ss) monolayers or suspension cultures were used to determine effects of structural modifications of Type A phosphorus-containing and Type B nonphosphorus EL analogs on (a) the inhibitory concentration50 (IC50) for HIV-1 syncytial plaque formation and cell growth, and, (b) virus budding at the cell plasma membrane. Results indicate that representative Type A and Type B EL inhibit HIV-1 but not herpes simplex virus type 2 plaque formation when added before or up to 2 days after viral infection. Anti-HIV-1 activity does not involve direct inactivation of virus infectivity. Type A EL (IC50 range = 0.2-1.4 microM) with alkyoxy, alkylthio, or alkyamido substitution at glycerol position 1 and ethoxy or methoxy substitution at position 2, and Type B compounds (IC50 range = 0.33-0.63 microM) with an inverse choline or nitrogen heterocyclic substitution at position 3 have selective activity against HIV-1-infected T-cells. EL treatment of HIV-1-infected cells is associated with subsequent release of reverse transcriptase activity, but infectious virus production is inhibited with time after infection. Electron microscopic examination of HIV-1-infected and EL-treated cells revealed absence of detectable budding virus at the plasma membrane but presence of intracytoplasmic vacuolar virus particles. In summary, these data suggest that EL analogs are a novel class of agents that induce defective intracytoplasmic vacuolar HIV-1 formation in T-cells. Being membrane interactive, EL are ideally suited for combination chemotherapy with DNA-interactive anti-HIV nucleoside analogs.

T-lymphoblastic and peripheral T-cell lymphomas in the northern part of The Netherlands. An immunologic study of 29 cases

The morphologic type, immunophenotypes, and clinical presentation of 12 cases of T-lymphoblastic lymphoma and 17 cases of peripheral T-cell lymphoma were studied. The lymphoblastic cases were subclassified according to intrathymic stages of T-cell differentiation. Two cases had an early intrathymic immunophenotype (CD4-negative, CD8-negative, CD1-negative), seven cases had an intermediate intrathymic immunophenotype (CD1-positive, CD4-positive, CD8-positive), and two cases had a late intrathymic immunophenotype (CD1-positive, CD8-positive, CD4-negative); one case expressed T-cell and B-cell markers. The peripheral T-cell lymphomas were morphologically subclassified according to the updated Kiel classification. T-cell lymphomas of low-grade malignancy--chronic lymphocytic lymphoma, T-zone lymphoma, and pleomorphic small cell lymphoma--in general had a complete immunophenotype matching the immunophenotypes of normal peripheral T-cells. In addition these cases were CD38-positive and HLA class II-positive. The T-cell lymphomas of high-grade intermediate and large cell, immunoblastic and large cell anaplastic lymphoma--were characterized by loss of T-cell markers. For their establishment as T-cell lymphoma a panel of monoclonal antibodies is needed.

AIDS update: oral findings, diagnosis, and precautions

The dimensions of AIDS continue to increase. The number of people infected with the AIDS virus (HIV) grows and no effective vaccine or curative treatment is expected in the near future. This article describes the oral findings of AIDS and AIDS-related complex (ARC). It will help dentists in recognition, diagnosis, consultation, and office precautions. These oral findings are important considerations in treatment planning and staging for patients with AIDS and ARC.

Familial Hodgkin's disease. A clinical and laboratory investigation

A three to sevenfold increased risk of Hodgkin's disease has been noted in families of patients. We report the first family in which all four of a four member sibship had Hodgkin's disease. In these four sibling cases, we were able to explore markers of infectious etiologic factors by measuring antibodies to Epstein-Barr virus (EBV) and human T-cell lymphotropic virus (HTLV), and possible genetic risk factors by human leukocyte antigen (HLA) typing and chromosome analysis. All three men were diagnosed within six months of their 30th birthday. HLA typing revealed that all four siblings share the DR5 antigen, and two siblings share HLA-B27. Chromosome analysis on peripheral lymphocytes revealed no abnormalities. A detailed, structured interview failed to elicit evidence of unusual exposures. The EBV antibody titers are probably within the normal range and none of the family had antibodies to HTLV-III. Observations on this family suggest that genetic factors play a greater role than environmental factors in the etiology of familial Hodgkin's disease.

The value of lymph node biopsy in patients with the acquired immunodeficiency syndrome (AIDS) and the AIDS-related complex (ARC): a morphological and immunohistochemical study of 90 cases

The morphological and immunohistochemical findings in lymph nodes of nine patients with the acquired immunodeficiency syndrome (AIDS) and 81 patients with the AIDS-related complex (ARC) are presented. Three basic histological patterns were observed: follicular hyperplasia (29 cases), mixed hyperplasia (49 cases) and lymphocyte depletion (12 cases). While the first two variants were detected in typical ARC patients, lymphocyte depletion was always associated with AIDS. Immunohistochemistry on frozen sections showed that the number of B-cells varied throughout the series, being higher in the follicular type and significantly lower in the lymphocyte depletion nodes. The content of T-lymphocytes of the helper/inducer (T4) phenotype was reduced in all instances; this reduction was more pronounced in the germinal centres in follicular hyperplasia, while it involved all compartments of the node in the mixed and lymphocyte depletion types. In contrast the cytotoxic/suppressor (T8) subset was increased in the follicular and mixed hyperplasias only. Partial disintegration of the dendritic network in at least some of the follicles could be demonstrated in all lymph nodes. In the follicular and mixed hyperplasias there was a high number of proliferating B-cells in the germinal centres. Our data indicate the usefulness of grading the changes occurring in lymph nodes of patients with ARC and AIDS, and allow speculation as to the pathophysiology of these conditions.

Characteristic regional prevalence of HTLV-I in Shimane Prefecture

Serological survey for human T-lymphotropic virus type I (HTLV-I) was performed in Shimane Prefecture, Japan, located on the coast of Japan sea. The rates of anti-adult T-cell leukemia-associated antigen-positive sera were 4.2% and 6.9% respectively for males and females. The rate increased with age, particularly in females. From the geographical point of view, the Oki Islands and a very small focus in Shimane-cho had high rates of anti-adult T-cell leukemia-associated antigen positives. Even within the Oki Islands, there was a big difference in the rate of seropositives between Dozen and Dogo which are only 10 km apart. The focus, Shimane-cho, has a population of 299. Even within a small area, there is a tendency of HTLV-I carriers to form a very narrow focus.

Oral findings in people with or at high risk for AIDS: a study of 375 homosexual males

A total of 375 homosexual males were studied to assess the dental findings, life-style, and risk factors during a 4-year period. At baseline, 136 of the patients were diagnosed as having AIDS, 116 were considered at risk for AIDS, and 123 were considered healthy. In a mean follow-up time of 23 months, nine of the patients at risk for AIDS and five of the patients considered healthy were diagnosed as having AIDS. Kaposi's sarcoma was the most common oral neoplasm, and candidiasis was the most frequent oral infection. Hairy leukoplakia was found in 28% of the patients, and periodontal disease was found in 17% of the patients. Carriers of the AIDS virus may not be identified easily and control measures in the dental office must be followed.

Infectious and sexually transmitted diseases: implications for dental public health

The Acquired Immunodeficiency Syndrome (AIDS) has stimulated renewed attention toward infectious diseases and dental public health. Currently, AIDS is defined as individuals with Kaposi's sarcoma and/or pneumocystis carinii pneumonia and/or other life-threatening opportunistic infections (e.g., specific forms of tuberculosis or meningitis, candidal esophagitis), and associated immunosuppression that cannot be accounted for by another disease process and/or medications. As of January 1986, the AIDS epidemic has afflicted over 16,000 persons in the United States and has taken over 8,000 lives. All present indications point toward a much more extensive epidemic based on the lack of a vaccine and effective forms of treatment, the large number of carriers in the population, and variable modes of transmission.

Serologic studies in hairy cell leukemia: high prevalence of Epstein-Barr and cytomegalovirus antibodies and absence of human T-cell lymphotrophic viruses antibodies

Serum from 60 patients with hairy cell leukemia (HCL) were studied for the presence and the titers of antibodies to Epstein-Barr virus (EBV), cytomegalovirus (CMV) and human T-cell lymphotrophic viruses (HTLV). Eighty-three percent of the patients were seropositive for EBV, with a (reciprocal) geometric mean titer (GMT) of 960. Seventy-eight percent of the patients had antibodies to CMV with a GMT of 435. All 21 patients tested for HTLV I and HTLV III were seronegative; only one patient showed detectable antibodies to HTLV II. The potential role of these infections in the physiopathology of HCL is discussed.

Suppression of retroviral propagation and disease by suramin in murine systems

Retroviral propagation crucially depends on reverse transcriptase (RT). We have developed murine models to test the biological effectiveness of the RT inhibitor suramin. The drug was active in our assay system, which includes (i) inhibition of RT activity in the murine T-cell tropic virus SL3-3 and Rauscher murine leukemia virus (MuLV), (ii) inhibition of plaque formation in the XC plaque assay, (iii) inhibition of viral infection of cultured murine T cells, and (iv) inhibition of splenomegaly induced by Rauscher MuLV in BALB/c mice. Suramin decreases viral titers significantly, even if started 36 hr after infection. Viral titers and number of infected cells increased to control levels after removal of the drug. BALB/c mice treated i.v. with 40 mg of suramin per kg twice per week following infection with Rauscher MuLV showed a 35% decrease in splenomegaly. Suramin is an active antiretroviral agent whose effect on retroviral propagation is reversible. We conclude that it acts as a virustatic drug and that long-term administration of suramin will be necessary if it is used for experimental treatment of human retroviral illnesses such as the acquired immune deficiency syndrome.