الفهرس 
Clinical Features of HHV-6Only 14 pages are availabe for public view
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Abstract
Human herpes virus-6 (HHV-6) was first isolated from peripheral blood leucocytes of patients with lymphoproliferative disorders, including lymphoma and leukemia (Salahuddin et al, 1986). HHV-6 is predominantly a CD4+ T-lymphotropic virus, although other cell types such as B and CD8+ T-lymphocytes, monocytes/macrophages, megakaryocytes and natural killer (NK) cells can be infected in vitro. As for other herpesviruses, primary infection occurs mainly in childhood, being the causative agent of exanthem subitum. HHV-6 probably remains latent in the host after primary infection since it can be reactivated in immunocompromised patients such as those receiving a bone marrow transplant or those infected with HIV; such patients may present a broad spectrum of clinical disorders in response to infection ranging from asymptomatic infection to illnesses such as interstitial pneumonia or encephalitis. A role for HHV-6 in haematological malignancies, such as lymphomas has been suggested, though it is primarily a lytic virus; the transforming potential of its DNA has been demonstrated in vitro. Genomic DNA and several subgenomic clones from HHV-6 variant A can produce malignant transformation of NIH 3T3 cells and human keratinocytes. HHHHV-6 genome integration has been found in peripheral blood mononuclear cell DNA (PBMCs). HHV-6 DNA sequences have been identified in the pathologic tissue of Hodgkin’s disease, non-Hodgkin’s lymphoma. And also in PBMCs from patients with acute lymphoblastic leukemia (ALL) and acute myeloid leukemia (AML). As well as in T-cell chronic lymphoproliferative disease. Moreover, HHV-6 seroprevalence was shown to be higher in patients with Hodgkin’s disease or acute myeloid leukemia (AML) as compared withcontrols. In the present study, we are aiming to investigate the relationship between acute pediatric leukemic patients either AML or ALL and HHV-6 infection.The study was conducted on a total of 90 patients with acute pediatric leukemia: (1) 60 patients with evidence of infection with febrile illness, 35 patients with ALL and 25 patients with AML, and (2) 30 patients with apparently no evidence of febrile illness, 18 patients with ALL and 12 patients with AML. All patients were presented through treatment to the Medical Oncology Department of the National Cancer Institute, Cairo University; during the period of January 2005 to January 2008.The study also included 10 non-cancer control (healthy persons) subjects: (1) 7 withevidence of febrile illness, and (2) 3 with apparently no evidence of febrile illness. Both patients and control group were matched for age and gender, and examining their clinical status.