Expression Of Human Herpesvirus-8 Research Articles

Immunohistochemistry expression of Human Herpes Virus-8 in cutaneous vascular lesions

Immunohistochemistry expression of Human Herpes Virus-8 in cutaneous vascular lesions

HPV Infection, but Not EBV or HHV-8 Infection, Is Associated with Salivary Gland Tumours.

Benign and malignant salivary gland tumours are clinically heterogeneous and show different histology. Little is known about the role of human herpes virus 8 (HHV-8), Epstein-Barr virus (EBV), and human papillomavirus (HPV) infection in salivary gland neoplasms. We investigated the presence of the three viruses in formalin-fixed, paraffin-embedded tissue samples in a cohort of 200 different salivary gland tumours. We performed EBV-LMP-1 and HHV-8 and p16 immunohistochemistry, a specific chip based hybridization assay for detection and typing of HPV and a chromogenic in situ hybridization for EBV analysis. Only one case, a polymorphic low-grade carcinoma, showed HHV-8 expression and one lymphoepithelial carcinoma was infected by EBV. In 17 cases (9%) moderate or strong nuclear and cytoplasmic p16 expression was detected. The HPV type was investigated in all of these cases and additionally in 8 Warthin's tumours. In 19 cases HPV type 16 was detected, mostly in Warthin's tumour, adenoid cystic carcinoma, and adenocarcinoma NOS. We concluded that HHV-8 infection and EBV infection are not associated with salivary gland cancer, but HPV infection may play a role in these tumour entities.

Kaposi sarcoma: The African HIV epidemic's partner in crime

Kaposi sarcoma: The African HIV epidemic's partner in crime

Synchronous Follicular Lymphoma, Kaposi Sarcoma, and Castleman’s Disease in a HIV-Negative Patient With EBV and HHV-8 Coinfection

The authors describe the case of a 65-year-old woman who was HIV negative and had a lymph node biopsy that showed concurrent follicular lymphoma (FL; grade 3A), Kaposi sarcoma (KS), and Castleman's disease (CD) with coinfection by human herpes virus-8 (HHV-8) and Epstein-Barr virus (EBV). The lymphoma was positive for CD20, CD10, and BCL6 and negative for BCL2. Flow cytometry showed a clonal lambda B-cell population, and polymerase chain reaction (PCR) showed a clonal immunoglobulin heavy chain gene rearrangement, confirming a neoplastic B-cell process. Focally, the FL component showed numerous EBER1-positive cells, with rare HHV-8-positive cells. The KS component showed strong HHV-8 expression with rare EBER1-positive cells. The CD component showed scattered HHV-8, viral interleukin-6, and EBER1-positive cells. The simultaneous occurrence of a FL, KS, and CD in an HIV-negative patient expands the spectrum of HHV-8-positive neoplasms and suggests the possibility of HHV-8 rendering mature B-cells hyperresponsive to antigenic stimulation, providing an expanded target for second site mutations or cytokine-driven hyperplasia, culminating in lymphoma.

LANA-1, Bcl-2, Mcl-1 and HIF-1α protein expression in HIV-associated Kaposi sarcoma

Human herpesvirus 8 (HHV8) is necessary for Kaposi sarcoma (KS) to develop, but whether the tissue viral load is a marker of KS progression is still unclear. Little is known about the level of expression of apoptosis-regulating proteins and of hypoxia-inducible factors (HIFs) in KS tumour cells relative to HHV8 expression. We therefore investigated the expression of the latency-associated nuclear antigen (LANA-1) of HHV8, Bcl-2, Mcl-1, Bax, Bcl-xL, caspase 3 and HIF-1alphain KS tissue specimens at different stages of the disease. The expression of these proteins was evaluated immunohistochemically using tissue microarrays (TMAs) in tissue specimens from 245 HIV-positive patients at different stages of the disease. Both LANA-1 and HIF-1alpha were expressed in KS biopsies taken at different stages, but their level increased throughout tumour progression. Additionally, the levels of Bcl-2 and Mcl-1 were higher in visceral KS lesions compared to levels observed in cutaneous and mucosal KS. This study demonstrates that late tumour stages of KS in tissues from HIV-positive patients are associated with high levels of LANA-1, HIF-1alpha and of the anti-apoptotic proteins, Bcl-2 and Mcl-1. Finally, the expression of these proteins can be potentially used as a tissue biomarker in defining patients with a higher risk of disease progression.

Clinical, histological and immunohistochemical findings in oral Kaposi's sarcoma in a series of Mexican AIDS patients. Comparative study

The origin of spindle cells (SC) in oral Kaposi's sarcoma (OKS) is still an intriguing aspect. Thus the aim of the present study was to compare the clinical, histological and immunohistochemical characteristics of OKS and oral pyogenic granuloma (OPG), in order to contribute to the knowledge of the cells involved in Kaposi's sarcoma pathogenesis. In this retrospective, observational and comparative study, 39 OKS and 30 OPG cases were included. Immunohistochemical studies were performed for vimentin, alpha SMA, desmin, C-kit, CD34, D2-40 and LANA-1 [human herpesvirus-8(HHV-8)]. Statistical comparisons were done using the chi-square and Wilcoxon-Mann-Whitney rank sum tests. Fourteen (35.9%) OKS cases also affected the skin, and 83.8% involved the palate. All OKS and OPG were positive for vimentin and CD34. OKS samples were positive for alpha SMA, and 25.6% expressed C-kit. All OKS cases were positive for HHV-8, and the number of positive cells increased significantly from early / intermediate to late histological stage. D2-40 was expressed in the cellular component and vascular walls of all OKS cases, but it was negative in OPG. HHV-8 expression was increased in late histological stages of OKS lesions. The expression of D2-40 marker in the vascular walls and SC supports the view of a lymphatic differentiation in neoplastic cells of OKS. Desmin, alpha SMA, D2-40, C-kit and HHV-8 were the main markers differently expressed in OKS and OPG.

KSHV/HHV8-Associated Intestinal Kaposi's Sarcoma in Patient with Ulcerative Colitis Receiving Immunosuppressive Drugs

Kaposi sarcoma-associated herpesvirus (KSHV), also known as human herpesvirus 8 (HHV8), has been identified in all four forms of Kaposi's sarcoma (classic, endemic, HIV-associated and iatrogenic). We report the rare case of an intestinal (small intestine and rectosigmoid) Kaposi's sarcoma in a 62-year-old HIV-negative man with ulcerative colitis. This patient was receiving immunosuppressive therapy with steroids and azathioprine. To date, the causative role of KSHV/HHV8 in the pathophysiology of Kaposi's sarcoma associated with ulcerative colitis has only been proven for cutaneous lesions but not for intestinal lesions of Kaposi's sarcoma. We report for the first time, the expression of HHV8 (by using immunohistochemistry) in colonic Kaposi's sarcoma in a patient with an ulcerative colitis-related tumor. The patient underwent a total proctocolectomy. At laparotomy, numerous Kaposi's sarcoma lesions were found in the small intestine, which were left in situ. Forty months after surgery and following withdrawal of immunosuppressive therapy, the patient had no evidence of any disease and a normal abdominal and thoracic CT scan. Cases of colorectal Kaposi's sarcoma complicating inflammatory bowel disease should be managed with a conservative approach and discontinuation of the immunosuppressive treatment. However, discontinuation of the immunosuppression is not always possible and in those cases chemotherapy may be indicated.

The effects of human herpesvirus 8 infection and interferon-γ response in cutaneous lesions of Kaposi sarcoma differ among human immunodeficiency virus-infected and uninfected individuals

Kaposi sarcoma (KS) is associated with human herpesvirus 8 (HHV-8). The cutaneous immune response in this tumour is not well established and a better understanding is necessary. To evaluate the HHV-8 expression and immune response in cutaneous lesions of classic KS (CKS) and AIDS-associated KS (AIDS-KS). We performed a quantitative immunohistochemical study of cells expressing HHV-8 latency-associated nuclear antigen (LANA), CD4, CD8 and interferon (IFN)-gamma in skin lesions from patients with CKS and AIDS-KS (with or without highly active antiretroviral therapy, HAART). CKS showed higher LANA expression compared with AIDS-KS, regardless of HAART. We also found higher LANA expression in nodules compared with patch/plaque lesions. The tissue CD4+ cell proportion was lower in AIDS-KS patients without HAART than in patients with CKS. In CKS lesions, CD4+ and CD8+ cells expressed IFN-gamma, as shown by double immunostaining. AIDS-KS presented low numbers of IFN-gamma-expressing cells. CD8+ cell numbers were similar in all groups, which appeared unrelated to the clinical or epidemiological type of KS. Our quantitative data on the pattern of KS lesions in selected groups of patients, as shown by in situ immune response, demonstrated a CD4+ T-cell involvement associated with IFN-gamma, an environment of immune response-modified human immunodeficiency virus (HIV) infection. In our sample, the promotion of KS in patients without HIV appears to be related to higher HHV-8 load or virulence than in those with AIDS. This higher resistance may be explained by a sustained immune response against this herpesvirus, that is only partially restored but effective after HAART.

Inflammatory myofibroblastic tumor of the central nervous system and its relationship to inflammatory pseudotumor

Inflammatory myofibroblastic tumor (IMT) is a distinctive spindle cell lesion and occurs primarily in soft tissue. Recent evidence suggests a neoplastic nature, although historically, both neoplastic and nonneoplastic processes were combined in this category. Originally described as a nonneoplastic process, the term inflammatory pseudotumor (IP) has been used synonymously with IMT. IMTs have been linked to ALK gene (2p23) rearrangements, and some have suggested an association with the human herpesvirus 8 (HHV-8). IMT in the central nervous system (CNS) is rare, its characteristics are poorly defined, and its relation to similar tumors at other sites is unclear. To better characterize IMT within the CNS, we studied clinicopathologic features of 6 IMTs and compared them with 18 nonneoplastic lesions originally classified as IP. The IMT group consisted of 2 male and 4 female patients with a median age of 29 years. Of the six IMTs, 5 occurred within the cerebral hemispheres, and one was in the posterior fossa. All tumors were composed of neoplastic spindle cells and a variable amount of inflammatory infiltrate. Eighteen IPs included in this study consisted of predominantly inflammatory masses occasionally seen in the setting of systemic diseases. Only 1 IMT and none of the IPs recurred during the follow-up period. Four IMTs had either ALK protein overexpression or 2p23 rearrangement, and 1 case demonstrated both. None of the IPs were positive for ALK. Neither IMT nor IP cases demonstrated HHV-8 expression. We suggest that IMT in the CNS is distinct from the nonneoplastic IP, and distinguishing IMT from nonneoplastic lesions should enable better decisions for patient management.

Retinoic Acid Analogues Inhibit Human Herpesvirus 8 Replication

Retinoids have a pronounced antiviral effect against several viruses. In this study we aimed to investigate the effect of retinoids on human herpesvirus 8 (HHV-8). A panel of retinoic acid compounds were tested for their antiviral activity against HHV-8 in human umbilical vascular endothelial cells (HUVECs) and in a human epithelial cell line. The presence, transcription and antigen expression of HHV-8 in infected cells - in the presence or absence of retinoic acid compounds - were evaluated by PCR, reverse transcriptase PCR and immunofluorescence assays; HHV-8 viral load was determined by real-time quantitative PCR. Angiogenesis induced by HHV-8 was also assessed using Cultrex basement membrane extract. The compounds tested specifically inhibited viral promoters, during the early and late phases of infection in both cell systems tested, and resulted in up to 100-fold reduction of viral titre and release of progeny virus. The inhibition of viral replication induced by retinoids in endothelial cells, the primary target of HHV-8-driven transformation in Kaposi's Sarcoma, prevented endothelial cells from developing spindle morphology and in vitro tube formation, characteristic changes associated with HHV-8 infection and transformation. We show that retinoids inhibit HHV-8 replication and identify new retinoid compounds with a strong antiviral effect. Selective retinoids, particularly those with retinoic acid receptor agonist activity, may be good candidates for the development of antiviral drugs.

Inflammatory myofibroblastic tumor in children: clinical review with anaplastic lymphoma kinase, Epstein-Barr virus, and human herpesvirus 8 detection analysis

Background/Purpose Inflammatory myofibroblastic tumor (IMT) is considered as an intermediate neoplasm that may present malignant features. Differential diagnosis with other tumor processes is sometimes difficult. Similar anaplastic lymphoma kinase (ALK) gene abnormalities as in anaplastic large cell lymphoma have been reported. Human herpesvirus 8 (HHV-8) DNA sequences have been described in adult pulmonary IMTs and Epstein-Barr virus (EBV) has been reported in splenic and hepatic IMTs, suggesting the importance of both viruses in IMT development. This article aims to evaluate ALK, EBV, and HHV-8 expression in children with IMT and to correlate our findings with clinical features. Methods Sixteen children (range, 1-15 years) who had surgery for IMT between 1978 and 2003 were evaluated retrospectively. Formalin-fixed, paraffin-embedded archival tissues were stained for HHV-8 and ALK with immunohistochemistry. Epstein-Barr virus was detected by in situ hybridization (EBER probes). Results Tumors were located in the pulmonary lobe (n = 4), urinary tract (n = 4), mesentery or bowel (n = 4), hepatic lobe (n = 1), vena cava (n = 1), spinal cord (n = 1), and soft tissue (n = 1). Five children were treated with steroids and/or antibiotics before surgery, with no substantial result. IMT was excised totally in all but 2 cases. Four patients presented aggressive IMT with recurrence or metastasis requiring new surgery. ALK was positive in 3 (18.8%) cases and EBV in 1 pulmonary and 1 bladder tumor, all of them without recurrence or metastasis. None of the cases were positive for HHV-8. All patients are now disease-free with a mean follow-up of 4.2 years. Conclusions Considering the present lack of efficient medical treatment, surgery should still be considered as the mainstay therapy in IMT, even in cases of recurrence or metastases. Larger multicentric studies would be necessary to understand the prognostic significance of ALK, EBV, and HHV-8 and their relationships with the origins of the tumor.

Posttransplant Kaposi's sarcoma: Report from a single center

Posttransplant Kaposi's sarcoma (KS) is not uncommon. This study investigated the clinical manifestations, impact of immunosuppression, and presence of HHV-8 antigen in our patients. Methods Among 568 renal transplant recipients, four developed KS. The physical findings, radiologic studies, immunosuppressive regimens, and the clinical outcomes were reviewed. In two patients, the expression of human herpes virus-8 was examined with polymerase chain reaction and in situ hybridization. Results The incidence of KS was 0.7% in our recipients. The intervals between the transplantation and the development of KS ranged from 2 months to 8.4 years. All KS patients had calcineurin inhibitor-based antirejection therapies. Peripheral lymphadenopathy was the initial manifestation in three of four patients; the fourth presented with violaceous papules over his lower legs. Besides lymphadenopathy, KS in one patient also involved internal visceral organs. One patient died at the time of diagnosis because of Salmonellosis; the other three experienced tumor regression after discontinuation of calcineurin inhibitors. HHV-8 expression was detected in two examined specimens. Conclusion Lymph node involvement is the most common clinical presentation in our posttransplant KS patients. HHV-8 infection is associated with the development of KS. Early withdrawal of calcineurin inhibitors produces a favorable outcome in posttransplant KS.

Benign dermal angioproliferation mimicking Kaposi’s sarcoma: report of two cases

Kaposi’s sarcoma and angiosarcoma are malignant endothelial neoplasms with a progressive clinical course and distinctive histopathology. We present two adult renal dialysis patients who developed violaceous, non-tender, poorly demarcated plaques on the scalp and thigh respectively that clinically resembled angiosarcoma. Skin biopsies showed a dermal proliferation of atypical spindle cells associated with slit-like vascular spaces, abundant hemorrhage and nuclear atypia suggestive of Kaposi’s sarcoma, but lacking fully-transformed nuclear features of malignancy, mitoses, and plasma cells. The atypical cells expressed the endothelial markers CD31 and CD34. Both lesions evaluated by reverse transcriptase in situ polymerase chain reaction for human herpes virus 8 (HHV8) were negative. One of the two patients was receiving low-dose prednisone for idiopathic pulmonary fibrosis. Based upon the kaposiform histomorphology in the absence of unequivocal features of malignant degeneration, the absence of typical risk factors for Kaposi’s sarcoma, relative unresponsiveness to radiation, and the lack of HHV8 expression, we postulate that both lesions represent benign kaposiform angoendotheliomata with overlap features between Kaposi’s sarcoma and a benign angioma. These cases compliment that described by Kuntsfeld and Petzelbauer (J Am Acad Dermatol 2001;45:601) and represent, to the authors’ knowledge, the second and third reported cases of this distinctive entity.

Development of real-time NASBA assays with molecular beacon detection to quantify mRNA coding for HHV-8 lytic and latent genes.

BackgroundHuman herpesvirus-8 (HHV-8) is linked to the pathogenesis of Kaposi's sarcoma (KS), and the HHV-8 DNA load in peripheral blood mononuclear cells (PBMC) is associated with the clinical stage of KS. To examine the expression of HHV-8 in PBMC, four HHV-8 mRNA specific NASBA assays were developedMethodsWe have developed four quantitative nucleic acid sequence-based amplification assays (NASBA-QT) specifically to detect mRNA coding for ORF 73 (latency-associated nuclear antigen, LANA), vGCR (a membrane receptor), vBcl-2 (a viral inhibitor of apoptosis) and vIL-6 (a viral growth factor). The NASBA technique amplifies nucleic acids without thermocycling and mRNA can be amplified in a dsDNA background. A molecular beacon is used during amplification to enable real-time detection of the product. The assays were tested on PBMC samples of two AIDS-KS patients from the Amsterdam Cohort.ResultsFor all four assays, the limit of detection (LOD) of 50 molecules and the limit of quantification (LOQ) of 100 molecules were determined using in vitro transcribed RNA. The linear dynamic range was 50 to 107 molecules of HHV-8 mRNA. We found HHV-8 mRNA expression in 9 out of the 10 tested samples.ConclusionThese real-time NASBA assays with beacon detection provide tools for further study of HHV-8 expression in patient material.

Expression of human herpesvirus-8 (HHV-8) encoded pathogenic genes in Kaposi's sarcoma (KS) primary lesions.

Transcription of six different HHV-8 specific mRNAs was examined in early- and late-stage KS primary lesions. Expression of the latency-associated T0.7 mRNA and of VP23 mRNA which is a specific marker of lytic/productive infection suggested that HHV-8 is secondarily recruited into the KS lesions by productively infected monocytes, macrophages. From these cells HHV-8 is transmitted to the KS spindle cells, which are latently infected. v-BCL-2, v-MCP-1 and v-IL-6 were not expressed in latently infected KS spindle cells, therefore the impact of these factors in KS pathogenesis appears to be low. By contrast, v-Cyclin D was highly expressed in almost all latently infected spindle cells and may therefore be an important factor triggering progression of late-stage KS lesions.