Epidemiology of human T cell leukemia virus type I infection in East Sepik Province, Papua New Guinea

A serological survey of 317 healthy residents of rural Papua New Guinea (PNG) showed a 26% prevalence of antibodies to human T cell leukemia virus type I (HTLV-I). Antibody to HTLV-I was detected in 16% of children less than or equal to 10 years old (including an 18-month-old child) and increased to greater than or equal to 24% in subjects greater than 20 years old. Prospective examination for antibody in 104 residents of one village revealed a seroconversion rate of 13% over a one-year period. The mean titer of antibody in these subjects (1:183) was lower (P less than .0005) than that in persons who were persistently seropositive (1:718). Analysis for clustering of infected subjects suggested that personal contact within the home played a role in the horizontal spread of HTLV-I. These data indicate that HTLV-I infection has a higher prevalence in PNG than in other endemic parts of the world, exposure occurs at an early age, and infection and/or seroconversion is common in adults as well as in children.     

Antibodies to human herpes virus-6 and clinical course in patients with Hodgkin's disease.

Serial serum samples from 37 patients with Hodgkin's disease (HD) and 39 healthy controls were studied for antibodies to human herpes virus-6 (HHV-6) using ELISA and indirect immunofluorescent antibody (IFA) tests and to the Epstein-Barr virus (EBV) using a radio-complement fixation assay. Antibodies to HHV-6 in the pre-treatment sera from the HD patients were not significantly different from those of controls, but significant changes in titers related to clinical course were noted among the HD patients. HHV-6 IFA titers increased significantly in the course of follow-up in patients who relapsed and decreased significantly over time in patients who did not. These serologic studies support tissue-based investigations indicating that EBV plays a greater etiologic role in HD than HHV-6, although HHV-6 serology may be of prognostic value or may assist in identifying individuals with immunologic abnormalities. The identification of diverse HHV-6 antibody patterns using different assays may reflect the presence of a number of antibodies with varying implications, similar to those identified for EBV.     

Nucleic Acid Hybridization with RNA Immobilized on Filter Paper

RNA has been immobilized in a manner suitable for use in molecular hybridization experiments with dissolved RNA or DNA by a nonaqueous solid-phase reaction with carbonyldiimidazole and RNA "dry coated" on cellulose or, preferably, on previously activated phosphocellulose filters. Immobilization of RNA does not appear to alter its chemical character or cause it to acquire affinity for unspecific RNA or DNA. The versatility and efficiency of this method make it potentially attractive for use in routine analytical or preparative hybridization experiments, among other applications.     

Functional and phenotypic comparison of human T cell leukemia/lymphoma virus positive adult T cell leukemia with human T cell leukemia/lymphoma virus negative Sézary leukemia, and their distinction using anti-Tac. Monoclonal antibody identifying the human receptor for T cell growth factor.

Adult T cell leukemia (ATL) and Sézary leukemia are malignant proliferations of T lymphocytes that share similar cell morphology and clinical features. ATL is associated with HTLV (human T cell leukemia/lymphoma virus), a unique human type C retrovirus, whereas most patients with the Sézary syndrome do not have antibodies to this virus. Leukemic cells of both groups were of the T3, T4-positive, T8-negative phenotype. Despite the similar phenotype, HTLV-negative Sézary leukemic cells frequently functioned as helper cells, whereas some HTLV-positive ATL and HTLV-positive Sézary cells appeared to function as suppressors of immunoglobulin synthesis. One can distinguish the HTLV-positive from the HTLV-negative leukemias using a monoclonal antibody (anti-Tac) that appears to identify the human receptor for T cell growth factor (TCGF). Resting normal T cells and most HTLV-negative Sézary cells were Tac-negative, whereas all ATL cell populations were Tac-positive. The observation that ATL cells manifest TCGF receptors suggests the possibility that an abnormality of the TCGF-TCGF receptor system may partially explain the uncontrolled growth of these cells.     

Type-I HTLV antibody in urban and rural Ghana, West Africa

The prevalence of antibodies against the newly described human T-cell lymphoma virus, type I (HTLV-I) in two communities in Ghana, West Africa, is described. There was no difference by community (urban, 3.6% and rural, 4.0%). Prevalence increased with age, being 5.9% among persons greater than 10 years old, but did not differ by sex. There was no difference when data were analysed by housing status or crowding. Non-confirmed reactions in the assay system were frequent and correlated with both prevalence and titer of antibody against malaria. Possible explanations include vector-borne transmission like that of malaria, but the relationship is more probably due to a polyclonal stimulation of B cells, enhancing the potential for detecting reactivity in the assay. Because assay systems vary and because most laboratories do not routinely use a confirmation assay, results presented by different groups must be interpreted cautiously.     

Molecular epidemiology of HTLV-I-associated non-Hodgkin's lymphomas in Jamaica

As part of epidemiologic studies of human T-lymphotropic virus (HTLV)-I-associated malignancies in Jamaica, the authors evaluated 26 patients with non-Hodgkin's lymphoma for the presence of integrated HTLV-I provirus in their malignant cells. Fifteen of 26 patients had integrated provirus. All 15 also were HTLV-I antibody positive. Eleven patients did not have integrated provirus, and all 11 were antibody negative. All of the antibody-positive cases had onset of their disease in adulthood (age range, 21-57 years) as opposed to the broad age range of negative cases (4-66 years). Clinical features which were more common in provirus positive than negative patients included leukemic phase, skin involvement, and hypercalcemia, which are all features frequently seen in HTLV-I-associated adult T-cell leukemia/lymphoma (ATLL). The presence of skin involvement, circulating malignant cells, abnormal liver function tests, or the presence of two or more of these four features were statistically significantly different between virus-positive and virus-negative cases. Although the survival of positive cases (6 months) was shorter than that of negative cases (9 months), this was not statistically significant. The only significant determinant of survival was hypercalcemia, with those who developed hypercalcemia at some point in their disease course, independent of their HTLV-I status, surviving a mean of 5 months as compared to a mean of 17.5 months in those who never became hypercalcemic. The six HTLV-I-positive lymphomas that underwent cell typing were all primarily OKT4 positive, whereas two HTLV-I antibody-negative cases that were typed were B-cell lymphomas.