KSHV (OR) HHV8

Controversy has plagued tumor virology since the first tumor viruses were described over 100 years ago. Methods to establish cancer causation, such as Koch's postulates, work poorly or not at all for these viruses. Kaposi's sarcoma herpesvirus (KSHV/HHV8) and Merkel cell polyomavirus (MCV) were both found using nucleic acid identification methods but they represent opposite poles in the patterns for tumor virus epidemiology. KSHV is uncommon and has specific risk factors that contribute to infection and subsequent cancers...

Gastrointestinal Kaposi sarcoma (KS) is classical, but rare. The AKT signaling pathway plays a central role in G protein-coupled receptor, key protein of KS histogenesis, encoded by KSHV/HHV8. There is increasing evidence that rapamycin, acting on AKT pathway, may be useful in the treatment of KS, including in HIV patients. We aimed to study the expression pattern of AKT pathway proteins in gastrointestinal KS. Expression of AKT, 4EBP1, PTEN, mTOR was assessed in 19 gastrointestinal KS biopsies by immunohistochemistry (17 patients)...

SESSION TYPE: Cancer Case Report Posters IIPRESENTED ON: Tuesday, October 23, 2012 at 01:30 PM - 02:30 PMINTRODUCTION: PEL is a rare form of Non-Hodgkin lymphoma that involves serous body cavities with lymphomatous effusions in absence of lymphadenopathy or organomegaly. Extracavity involvement is a rarity and only two cases have been described since its recognition in 1995. We report PEL presenting with hemolytic anemia, hepatomegaly and abdominal lymphadenoapthy and bowel wall thickening.CASE PRESENTATION: A 53 yr old male with HIV on ART presented with sudden onset of generalized weakness...

Kaposi sarcoma (KS) is a low-grade vascular tumor associated with Kaposi sarcoma herpesvirus/human herpesvirus 8 (KSHV/HHV8) infection. Kaposi sarcoma lesions predominantly present at mucocutaneous sites, but may involve all organs and anatomic locations. Recognized epidemiologic-clinical forms of KS include classic, African (endemic), AIDS-associated (epidemic), and iatrogenic KS. New clinical manifestations have been described, such as antiretroviral therapy-related KS regression or flares. Kaposi sarcoma lesions evolve from early (patch stage) macules into plaques (plaque stage) that grow into larger nodules (tumor stage)...

Human herpesvirus-8 (HHV8)-positive effusion-based lymphomas have been termed primary effusion lymphoma (PEL) in the WHO Classification of Tumours of Haematopoietic and Lymphoid Tissues. Kaposi sarcoma herpesvirus (KSHV)/HHV8-negative effusion-based lymphomas (KSHV/HHV8-negative EBLs) resembling PELs have been reported in the literature and in many cases have been (mis)classified as PEL-like lymphomas. Herein, we present a series of cases and a review of KSHV/HHV8-negative EBLs. This lymphoma, although cytomorphologically resembling PEL, is a distinct entity with characteristic clinical and pathologic features...

Kaposi sarcoma (KS) is a complex cancer that arises from the initial infection of an appropriate endothelial or progenitor cell by Kaposi Sarcoma Herpesvirus/Human Herpesvirus-8 (KSHV/HHV8). However, the majority of KS cases occur when infected patients also suffer from some coincident form of immune deregulation, providing a favorable microenvironment for tumor development. Cellular hallmarks of KS progression include both the hyper-proliferation of KSHV-infected cells and the infiltration of immune modulatory cells into KS lesions, which together result in chronic inflammation, the induction of angiogenesis and tumor growth...

We report a case of left atrial cardiac myxoma harbouring an incidental atypical B-cell lymphoid proliferation. Histology disclosed classic myxoma cells embedded in a mucopolysaccharide-rich matrix and a micronodular atypical lymphoid proliferation under the surface of the mass. Myxoma cells were immunoreactive for calretinin, while lymphoid cells expressed B lineage markers (CD 20+, CD79a), without evidence of clonality. Moreover, they were LMP1 positive; EBNA2 negative; KSHV/HHV8 negative; and, by in situ hybridization, EBER/Epstein-Barr virus (EBV) positive and Kappa and Lambda negative...

Posttransplantation human herpesvirus-8 (HHV8)/Kaposi sarcoma herpesvirus (KSHV) primary infection and/or reactivations are associated with uncommon and sometimes fatal, neoplastic, and non-neoplastic diseases. HHV8-related clinical manifestations notably range from Kaposi sarcoma (KS) to either primary effusion lymphoma or multicentric Castleman disease B-cell malignancies, and from polyclonal HHV8-positive plasmacytic lymphoproliferative disorders to bone marrow failure and peripheral cytopenias, associated or not with hemophagocytic syndromes, and to acute hepatitis syndromes...

KSHV inflammatory cytokine syndrome (KICS) is a newly described condition characterized by systemic illness as a result of systemic, lytic KSHV infection. We used Illumina sequencing to establish the DNA vironome of blood from such a patient. It identified concurrent high-level viremia of human herpesvirus (HHV) 8 and 6a. The HHV8 plasma viral load was 5,300,000 copies/ml, which is the highest reported to date; this despite less than five skin lesions and no HHV8 associated lymphoma. This is the first report of systemic HHV6a/KSHV co-infection in a patient...

Primary effusion lymphoma (PEL) is a rare lymphoma associated with Kaposi sarcoma-associated herpesvirus (KSHV), also known as human herpesvirus 8 (HHV8), and characterized by a malignant body cavity effusion without solid organ or nodal involvement. Prognostic factors in patients with PEL have not been systematically studied. We conducted a literature search for patients with HHV8-positive PEL to identify potential prognostic factors for survival. Our search identified 147 patients, among which 104 patients were HHV8-positive...

We describe three cases of lymph proliferative diseases characterized by the presence of lymphoma cells expressing the KSHV/HHV-8 antigen with or without EBV expression. The patients were HIV seronegative without serous effusions. One case was diagnosed as KSHV-germinotropic lymphoproliferative disorder due to the presence of atypical plasmablasts involving germinal centers. These plasmablasts were positive for MUM1 and vIL6, co-expressed EBV and LNA-1 of HHV-8/KSHV, and showed a polyclonal pattern of Ig gene rearrangements on PCR...

Kaposi's sarcoma-associated herpesvirus (KSHV; or human herpesvirus 8 [HHV8]) is implicated in the pathogenesis of many human malignancies including Kaposi's sarcoma (KS), multicentric Castleman's disease (MCD), and primary effusion lymphoma (PEL). KSHV infection displays two alternative life cycles, referred to as the latent and lytic or productive cycle. Previously, we have reported that the replication and transcription activator (RTA), a major lytic cycle transactivator, contributes to the development of KSHV latency by inducing latency-associated nuclear antigen (LANA) expression during early stages of infection by targeting RBP-Jκ, the master regulator of the Notch signaling pathway...

Kaposi's sarcoma (KS) remains among the most common causes of oral cancer in HIV-infected individuals. Infection with the KS-associated herpesvirus (KSHV/HHV8) is a necessary event for disease development. Emerging evidence suggests that KSHV infects vascular endothelial (or endothelial progenitor) cells promoting the formation of the KS tumor (or spindle) cell. These cells elaborate angiogenic growth factors and cytokines that promote the dysregulated angiogenesis and profuse edema that characterizes this unusual vascular tumor...

BACKGROUND: Infection with Kaposi's sarcoma-associated herpesvirus (KSHV/HHV8) often results in the development of fatal tumors in immunocompromised patients. Studies of renal transplant recipients show that use of the immunosuppressant drug rapamycin, an mTOR inhibitor, both prevents and can induce the regression of Kaposi's sarcoma (KS), an opportunistic tumor that arises within a subset of this infected population. In light of rapamycin's marked anti-KS activity, we tested whether the drug might directly inhibit the KSHV life cycle...

Kaposi sarcoma-associated herpesvirus (KSHV, also called Human herpesvirus 8 or HHV8) is a γ-2 herpesvirus that causes Kaposi sarcoma. KSHV seroprevalence rates vary geographically with variable rates recorded in different sub Sahara African countries, suggesting that effects of genetic and/or environmental factors may influence the risk of infection. One study conducted in South Africa, where KSHV seroprevalence is relatively low, found that carriage of human leukocyte antigen (HLA) alleles HLA-A*6801, HLA-A*30, HLA-A*4301, and HLA-DRB1*04 was associated with increased shedding of KSHV DNA in saliva...

In recent years, infectious agents have been increasingly recognised as an important pathogenetic factor for various malignant tumours of the ocular adnexa. Many of these viruses and bacteria affect the cell cycle and physiological apoptosis. Ocular adnexal lymphoma (OAL), especially extranodal marginal cell lymphoma, is associated with Chlamydophila psittaci and Helicobacter pylori in certain geographic regions. Epstein-Barr virus seems to play a role in the natural killer/T-cell lymphoma subtype of the orbit, as has long been described for Burkitt lymphoma...

BACKGROUND: Kaposi sarcoma-associated herpesvirus (KSHV), or human herpesvirus type 8 (HHV8), is consistently identified in 2 human immunodeficiency virus (HIV)-associated lymphoproliferative disorders: primary effusion lymphoma (PEL) and multicentric Castleman disease. Rarely, KSHV/HHV8-positive extracavitary solid tissue lymphomas occur, often at extranodal sites, which are not associated with an effusion. These solid variants of PEL are similar morphologically, immunophenotypically, clinically and genetically to classic PEL...

Tumor viruses can induce cell transformation by overcoming cellular defense mechanisms and promoting the ungoverned proliferation of infected cells. To this end, functionally related viral oncogenes have evolved in disparate viruses to over-ride key proliferative and survival intracellular pathways, thus assuring efficient viral replication and contributing to tumor formation. Indeed, the study of viral oncogenes has been a powerful tool for disclosing fundamental insights into these basic cellular processes...

For Kaposi's sarcoma-associated herpesvirus (KSHV; also called human herpesvirus 8 [HHV8]), the switch from latency to active lytic replication requires RTA, the product of open reading frame 50 (ORF50). RTA activates transcription from nearly 40 early and delayed-early viral promoters, mainly through interactions with cellular DNA binding proteins, such as CSL/RBP-Jkappa, Oct-1, C/EBPalpha, and c-Jun. Reliance on cellular coregulators may allow KSHV to adjust its lytic program to suit different cellular contexts or interpret signals from the outside...

MicroRNAs (miRNAs) are involved in sequence-specific cleavage, translational repression or deadenylation of specific target mRNAs resulting in post-transcriptional gene silencing. Epstein-Barr Virus (EBV) infection induces cellular non-coding (nc)RNAs e.g., the "vault" RNAs or miRNAs such as miR-21, miR-155 or miR-146a. MiR-146a is upregulated in various tumours and plays a role in innate immunity. We show that the EBV-encoded latent membrane protein 1 (LMP1) induces the expression of miR-146a via NFkappaB...