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Apology.

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L Perlman. 1988-06-16. Apology.. https://doi.org/10.1038/333586b0

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Epstein-Barr virus and a cellular signaling pathway in lymphomas from immunosuppressed patients.

BACKGROUND: Epstein-Barr virus (EBV) is associated with various malignant and benign lymphoproliferative disorders. It also efficiently transforms human B lymphocytes in vitro. The latent membrane protein 1 (LMP1) of EBV-infected cells plays a central part in this process by mimicking members of the family of tumor necrosis factor (TNF) receptors, thereby transmitting growth signals from the cell membrane to the nucleus through cytoplasmic TNF-receptor-associated factors (TRAFs). I sought evidence of LMP1-mediated signal transduction through TRAFs in tumor tissue from patients with post-transplantation lymphoproliferative disease and non-Hodgkin's lymphomas related to the acquired immunodeficiency syndrome (AIDS). METHODS: The association of LMP1 with TRAF-1 or TRAF-3 in tumor tissue was studied with double-immunofluorescence microscopy and immunoprecipitation assays. Evidence of LMP1-TRAF signaling was sought with an electrophoretic mobility shift assay for the nuclear factor-kappaB (NF-kappaB) transcription factor. RESULTS: Tumors from eight patients with post-transplantation lymphoproliferative disease, two patients with AIDS-associated non-Hodgkin's lymphoma, and three patients with endemic Burkitt's lymphoma were analyzed. Tumors from six of the patients with post-transplantation lymphoproliferative disease were positive for EBV and expressed LMP1; two samples were EBV-negative. Tumors from both patients with AIDS-associated non-Hodgkin's lymphoma were EBV-positive and expressed LMP1, whereas tumors from all three patients with Burkitt's tumors were positive for EBV but negative for LMP1. Double-immunofluorescence microscopy showed that LMP1 localized with and immunoprecipitated with TRAF-1 and TRAF-3 in all eight of the EBV-positive, LMP1-positive samples. An electrophoretic mobility shift assay revealed activated NF-kappaB in all eight EBV-positive, LMP1-positive samples as well, but not in either of the EBV-negative, LMP1-negative samples or in the three EBV-positive, LMP1-negative samples. CONCLUSIONS: LMP1-mediated signaling through the TRAF system has a role in the pathogenesis of the EBV-positive lymphomas that arise in immunosuppressed patients.

Acquired Immunodeficiency Syndrome

In vitro cytopathogenicity of the human immunodeficiency virus (HIV)-1 predicts survival in HIV-infected hemophiliacs independent from CD4 cell count.

In addition to quantification of viral load the graded cytopathogenicity of the human immunodeficiency virus may provide prognostic information for the course of HIV infection. However, the prognostic value of graded cytopathogenicity in addition to the CD4 count has not been evaluated in a large longitudinal study. Therefore a total of 216 HIV-seropositive hemophiliacs have been followed up from 1985 to 1998 (mean follow-up 70.4 +/- SD 26 months, median 72, range: 12 to 120 months). In vitro virulence was determined according to cytopathic effects on freshly isolated PBMC of healthy donors and graded from A (strongest cytopathogenic effect) to D (no cytopathic isolate effect). Survival was analyzed among patients with different virus isolates by Kaplan-Meier statistics (log rank) and factors independently associated with decreased survival were analyzed by Cox hazard regression analysis. - A virus isolate A was found in 22 (10.2%) patients, a virus isolate B was found in 21 (9.3%) patients, a virus isolate C was found in 9 (4.2%) and a virus isolate D was found in 10 (4.2%) patients. Mean survival times were 48 months (95% Confidence Interval (CI) = 36 - 60) in patients with isolate A, 72 months (CI = 36 - 108) with isolate B, 84 months (CI = 48-120) with isolate C, 72 months (60 - 96) with isolate D and 96 months (CI = 96 - 108) in patients with a negative virus culture (p < 0.001). Cox regression analysis indicated significant associations with outcome for young age (p <0.001), positive virus culture (p < 0.0001) and CD4 count (p < 0.0001) as independent predictors of survival. The presence of an isolate A revealed the strongest odds ratio (6.3, 95% CI 2.9-13.2). Our data indicate that the presence of a virus isolate A represents a strong risk factor for mortality in the course of HIV infection. Besides quantification of viral load and CD4 count, the graded cytopathogenicity may provide additional information for early and aggressive antiretroviral treatment, since the mean survival in patients with cytopathogenic virus isolates is reduced significantly.

Acquired Immunodeficiency Syndrome