HHV8 a subtype is associated with rapidly evolving classic Kaposi's sarcoma

Malignancy and viral infections in Sub-Saharan Africa: A review

The burden of malignancy related to viral infection is increasing in Sub-Saharan Africa (SSA). In 2018, approximately 2 million new cancer cases worldwide were attributable to infection. Prevention or treatment of these infections could reduce cancer cases by 23% in less developed regions and about 7% in developed regions. Contemporaneous increases in longevity and changes in lifestyle have contributed to the cancer burden in SSA. African hospitals are reporting more cases of cancer related to infection (e.g., cervical cancer in women and stomach and liver cancer in men). SSA populations also have elevated underlying prevalence of viral infections compared to other regions. Of 10 infectious agents identified as carcinogenic by the International Agency for Research on Cancer, six are viruses: hepatitis B and C viruses (HBV and HCV, respectively), Epstein-Barr virus (EBV), high-risk types of human papillomavirus (HPV), Human T-cell lymphotropic virus type 1 (HTLV-1), and Kaposi's sarcoma herpesvirus (KSHV, also known as human herpesvirus type 8, HHV-8). Human immunodeficiency virus type 1 (HIV) also facilitates oncogenesis. EBV is associated with lymphomas and nasopharyngeal carcinoma; HBV and HCV are associated with hepatocellular carcinoma; KSHV causes Kaposi's sarcoma; HTLV-1 causes T-cell leukemia and lymphoma; HPV causes carcinoma of the oropharynx and anogenital squamous cell cancer. HIV-1, for which SSA has the greatest global burden, has been linked to increasing risk of malignancy through immunologic dysregulation and clonal hematopoiesis. Public health approaches to prevent infection, such as vaccination, safer injection techniques, screening of blood products, antimicrobial treatments and safer sexual practices could reduce the burden of cancer in Africa. In SSA, inequalities in access to cancer screening and treatment are exacerbated by the perception of cancer as taboo. National level cancer registries, new screening strategies for detection of viral infection and public health messaging should be prioritized in SSA's battle against malignancy. In this review, we discuss the impact of carcinogenic viruses in SSA with a focus on regional epidemiology.

Molecular epidemiology of Kaposi sarcoma virus in Spain

BACKGROUND

Since human herpesvirus 8 (HHV-8) infection may be underestimated and HHV-8 subtype circulation in Spain remains unknown, a molecular epidemiologic study is highly desirable.

OBJECTIVES

This study aimed to analyse HHV-8 subtype diversity and their distribution in Spain.

STUDY DESIGN

The study included 142 HHV-8 infected patients. A nested PCR was developed in order to permit Sanger sequencing of HHV-8 K1 ORF directly from clinical samples received at the CNM from 2013 to 2021. Phylogenetic characterization was performed.

RESULTS

Genotypes A and C comprised 55.6% and 42.3% of strains. Regarding subtypes, 25.4% of strains were C3, 19.7% were A3, 14.1% were A5, and C2, A1, A4, C1, A2, C7 were 11.3%, 11.3%, 8.5%, 4.2%, 2.1% and 1.4%, respectively. Subtype E1, E2 and B1 were found in only one patient each (0.7%). The Madrid region accounted for 52.1% of patients and showed a significantly different subtype distribution compared to the others (P = 0.018). Subtypes B1, E1, and E2 were observed to appear sporadically, although overall genotypes A and subtype C3 remained the most frequent and unwavering. Subtype A3 presented the highest diversity as displayed by the highest number of clusters in phylogenetic analysis. Non-significant differences in viral loads between genotypes were found, but significantly higher viral loads in subtype C2 compared to subtype C3 was found, while no significant subtype differences were observed between subtypes within genotype A. Infections with HHV-8 were detected in 94 (66.2%) patients without KS and compared to patients with KS non-significant differences in subtype distribution were found.

CONCLUSIONS

Subtype prevalence and regional distribution followed a similar pattern compared to other western European countries. Our study is the first to report HHV-8 subtypes E1 and E2 circulating in Europe that might be reflective of migration of population from Caribbean countries. Our study suggests that infection by HHV-8 is underestimated, and wider screening should be recommended for risk groups.

Systematic analysis of Kaposi's sarcoma (KS)-associated herpesvirus genomes from a KS case-control study in Cameroon: Evidence of dual infections but no association between viral sequence variation and KS risk

In sub-Saharan Africa, Kaposi's sarcoma-associated herpesvirus (KSHV) is endemic, and Kaposi's sarcoma (KS) is a significant public health problem. Until recently, KSHV genotype analysis was performed using variable gene regions, representing a small fraction of the genome, and thus the contribution of sequence variation to viral transmission or pathogenesis are understudied. We performed near full-length KSHV genome sequence analysis on samples from 43 individuals selected from a large Cameroonian KS case-control study. KSHV genomes were obtained from 21 KS patients and 22 control participants. Phylogenetic analysis of the K1 region indicated the majority of sequences were A5 or B1 subtypes and all three K15 alleles were represented. Unique polymorphisms in the KSHV genome were observed including large gene deletions. We found evidence of multiple distinct KSHV genotypes in three individuals. Additionally, our analyses indicate that recombination is prevalent suggesting that multiple KSHV infections may not be uncommon overall. Most importantly, a detailed analysis of KSHV genomes from KS patients and control participants did not find a correlation between viral sequence variations and disease. Our study is the first to systematically compare near full-length KSHV genome sequences between KS cases and controls in the same endemic region to identify possible sequence variations associated with disease risk.

Kaposi's Sarcoma-Associated Herpesvirus, the Etiological Agent of All Epidemiological Forms of Kaposi's Sarcoma

Simple Summary

Kaposi’s sarcoma-associated herpesvirus (KSHV) is one of the seven oncogenic viruses currently recognized by the International Agency for Research on Cancer. Its presence for Kaposi’s sarcoma development is essential and knowledge on the oncogenic process has increased since its discovery in 1994. However, some uncertainties remain to be clarified, in particular on the exact routes of transmission and disparities in KSHV seroprevalence and the prevalence of Kaposi’s sarcoma worldwide. Here, we summarized the current data on the KSHV viral particle’s structure, its genome, the replication, its seroprevalence, the viral diversity and the lytic and latent oncogenesis proteins involved in Kaposi’s sarcoma. Lastly, we reported the environmental, immunological and viral factors possibly associated with KSHV transmission that could also play a role in the development of Kaposi’s sarcoma.

Abstract

Kaposi’s sarcoma-associated herpesvirus (KSHV), also called human herpesvirus 8 (HHV-8), is an oncogenic virus belonging to the Herpesviridae family. The viral particle is composed of a double-stranded DNA harboring 90 open reading frames, incorporated in an icosahedral capsid and enveloped. The viral cycle is divided in the following two states: a short lytic phase, and a latency phase that leads to a persistent infection in target cells and the expression of a small number of genes, including LANA-1, v-FLIP and v-cyclin. The seroprevalence and risk factors of infection differ around the world, and saliva seems to play a major role in viral transmission. KSHV is found in all epidemiological forms of Kaposi’s sarcoma including classic, endemic, iatrogenic, epidemic and non-epidemic forms. In a Kaposi’s sarcoma lesion, KSHV is mainly in a latent state; however, a small proportion of viral particles (<5%) are in a replicative state and are reported to be potentially involved in the proliferation of neighboring cells, suggesting they have crucial roles in the process of tumorigenesis. KSHV encodes oncogenic proteins (LANA-1, v-FLIP, v-cyclin, v-GPCR, v-IL6, v-CCL, v-MIP, v-IRF, etc.) that can modulate cellular pathways in order to induce the characteristics found in all cancer, including the inhibition of apoptosis, cells’ proliferation stimulation, angiogenesis, inflammation and immune escape, and, therefore, are involved in the development of Kaposi’s sarcoma.

A simple and rapid approach for human herpesvirus type 8 subtype characterization using single base extension

Sequence analysis of the ORFK1 of human herpesvirus type 8 (HHV-8) allows the identification of six major subtypes (A-F), which are related to human migrations and the clinical progression of Kaposi's sarcoma. Sequencing and subsequent phylogenetic analysis of ORFK1 is considered to be the most reliable method for HHV-8 genotyping. However, it exhibits challenges and limitations. Herein, we designed and validated a single base extension (SBE) protocol for characterization of HHV-8 ORFK1 subtypes. A nested polymerase chain reaction (PCR) protocol was carried out to amplify a small 294-bp PCR product encompassing four single nucleotide polymorphisms at positions 360, 406, 465 and 527 of the HHV-8 genome. Finally, a multiplex SBE technique was developed and validated in 20 samples previously genotyped by phylogenetic analysis. The patterns obtained in this reaction could successfully discriminate between ORFK1 subtypes. The typing results obtained completely matched with those of the 'gold standard' method in all analysed samples. This method can reliably identify HHV-8 subtypes A, B and C, which are the most prevalent ones worldwide, and the remaining subtypes (D, E and F). SBE can be useful as an efficient, rapid and low-cost screening method for viral genotyping in a single tube, particularly samples with low-quality DNA, and with easy data interpretation.

New Kaposi's sarcoma-associated herpesvirus variant in men who have sex with men associated with severe pathologies

BACKGROUND

Kaposi sarcoma (KS)-associated herpesvirus (KSHV) subtype depends mostly on patient origin. The current study aimed to assess KSHV diversity in a population of men who have sex with men (MSM) living in France.

METHODS

The study included 264 patients. In 65 MSM, including 57 human immunodeficiency virus (HIV)-infected men with KS, multicentric Castleman disease, or primary effusion lymphoma and 8 HIV-uninfected men receiving HIV preexposure prophylaxis (PrEP), we performed KSHV typing with K1 open reading frame Sanger and KSHV whole-genome sequencing. In 199 other patients, we performed real-time polymerase chain reaction screening for the new variant.

RESULTS

We found that 51% of KSHV-strains were subtype C (85% C3), and 33% were subtype A. Four patients with severe KSHV disease (2 with visceral KS, 1 with multicentric Castleman disease, and 1 with primary effusion lymphoma) and 1 asymptomatic PrEP user had a new variant resembling the Ugandan subtype F, but with different K1 open reading frame and KSHV whole-genome sequences and a different epidemiological context (MSM vs African population). Its prevalence was 4.5% in Caucasian MSM, and it was absent in other epidemiological groups.

CONCLUSIONS

Subtype C predominated among MSM living in France. The new F variant was identified in Caucasian MSM and associated with severe KSHV disease, suggesting that subtype F could be split into F1 and F2 variants. Careful screening for this variant may be required in MSM, given the severe clinical presentation of associated diseases.

Intra-host changes in Kaposi sarcoma-associated herpesvirus genomes in Ugandan adults with Kaposi sarcoma

Intra-host tumor virus variants may influence the pathogenesis and treatment responses of some virally-associated cancers. However, the intra-host variability of Kaposi sarcoma-associated herpesvirus (KSHV), the etiologic agent of Kaposi sarcoma (KS), has to date been explored with sequencing technologies that possibly introduce more errors than that which occurs in the viral population, and these studies have only studied variable regions. Here, full-length KSHV genomes in tumors and/or oral swabs from 9 Ugandan adults with HIV-associated KS were characterized. Furthermore, we used deep, short-read sequencing using duplex unique molecular identifiers (dUMI)–random double-stranded oligonucleotides that barcode individual DNA molecules before library amplification. This allowed suppression of PCR and sequencing errors to ~10⁻⁹/base as well as afforded accurate determination of KSHV genome numbers sequenced in each sample. KSHV genomes were assembled de novo, and rearrangements observed were confirmed by PCR and Sanger sequencing. 131-kb KSHV genome sequences, excluding major repeat regions, were successfully obtained from 23 clinical specimens, averaging 2.3x10⁴ reads/base. Strikingly, KSHV genomes were virtually identical within individuals at the point mutational level. The intra-host heterogeneity that was observed was confined to tumor-associated KSHV mutations and genome rearrangements, all impacting protein-coding sequences. Although it is unclear whether these changes were important to tumorigenesis or occurred as a result of genomic instability in tumors, similar changes were observed across individuals. These included inactivation of the K8.1 gene in tumors of 3 individuals and retention of a region around the first major internal repeat (IR1) in all instances of genomic deletions and rearrangements. Notably, the same breakpoint junctions were found in distinct tumors within single individuals, suggesting metastatic spread of rearranged KSHV genomes. These findings define KSHV intra-host heterogeneity in vivo with greater precision than has been possible in the past and suggest the possibility that aberrant KSHV genomes may contribute to aspects of KS tumorigenesis. Furthermore, study of KSHV with use of dUMI provides a proof of concept for utilizing this technique for detailed study of other virus populations in vivo.

Kaposi sarcoma (KS) is a leading cancer in sub-Saharan Africa and in persons with HIV co-infection. Kaposi sarcoma-associated herpesvirus (KSHV, also referred to as human herpesvirus-8, or HHV-8) is the etiologic agent of KS, but the factors that contribute to the development of KS, which occurs in only a small subset of infected individuals, remain largely unknown. While strain differences or mutations in other tumor viruses are known to affect the risk and progression of their associated cancers, whether genetic variation in KSHV is important to the natural history of KS is unclear. Most studies of KSHV diversity have only characterized ~4% of its 165-kb genome, and the observed variation in some studies is likely to have been impacted by PCR or cloning artifacts. To precisely define genomic diversity of KSHV in vivo, we evaluated full-length viral genomes (except the internal repeat regions) using a technique that greatly lowers sequencing error rates and thus measures genomic diversity much more accurately than previous studies. In addition, we extended our analyses to look for potential tumor-specific changes in the KSHV genomes by examining viruses in both tumor and non-tumor tissues. To these ends, we performed highly sensitive, single-molecule sequencing of whole KSHV genomes in paired KS tumors and oral swabs from 9 individuals with KS. We found that KSHV genomes were virtually identical within the 9 individuals, with no evidence of quasispecies formation or multi-strain infection. However, KSHV genome aberrations and gene-inactivating mutations were found to be common in KS tumors, often impacting the same genes and genomic regions across individuals. Whether theses mutations influence KS tumorigenesis or result from genomic instability commonly found in tumors warrants further study. Lastly, aberrant KSHV genomes were found to be shared by distinct tumors within individuals, suggesting the capacity of KS tumor cells to metastasize and seed new lesions.

HIV-positive patients with oral Kaposi's sarcoma: An overall survival analysis of 31 patients

OBJECTIVE

The aim of this study was to evaluate the influence of viral load and lymphocyte count on survival of patients who presented with human immunodeficiency virus (HIV)-associated oral Kaposi's sarcoma.

STUDY DESIGN

Thirty-one cases (from January 2010 to December 2019) of oral Kaposi's sarcoma in patients with HIV from 2 oral pathology centers in Brazil were reviewed, considering clinical data and correlation of viral load and lymphocyte count with overall survival. Overall survival rates were estimated by a Kaplan-Meier analysis and compared using a log-rank test. The factors introduced stepwise into a Cox proportional hazard model to identify the independent predictors of survival. A P value <.05 was considered significant.

RESULTS

Most of the patients were males (90.3%) with a mean age of 32.4 years (range, 19-58). Hard palate, soft palate, and tongue were the most affected sites. Treatment, viral load >999 copies/mL, CD4⁺ level ≤200 cells/mm³, CD4⁺/CD8⁺ level ≤0.39 cells/mm³, and CD4⁺ nadir level <50 cells/mm³ were related to overall survival.

CONCLUSIONS

Survival of patients affected by oral HIV-associated Kaposi's sarcoma is influenced by treatment, viral load, CD4⁺, CD4⁺/CD8⁺, and CD4⁺ nadir count.

Dual infection and recombination of Kaposi sarcoma herpesvirus revealed by whole-genome sequence analysis of effusion samples

Kaposi sarcoma herpesvirus (KSHV) is the etiological agent of three malignancies, Kaposi sarcoma (KS), primary effusion lymphoma (PEL) and KSHV-associated multicentric Castelman disease. KSHV infected patients may also have an interleukin six-related KSHV-associated inflammatory cytokine syndrome. KSHV-associated diseases occur in only a minority of chronically KSHV-infected individuals and often in the setting of immunosuppression. Mechanisms by which KSHV genomic variations and systemic co-infections may affect the pathogenic pathways potentially leading to these diseases have not been well characterized in vivo. To date, the majority of comparative genetic analyses of KSHV have been focused on a few regions scattered across the viral genome. We used next-generation sequencing techniques to investigate the taxonomic groupings of viruses from malignant effusion samples from fourteen participants with advanced KSHV-related malignancies, including twelve with PEL and two with KS and elevated KSHV viral load in effusions. The genomic diversity and evolutionary characteristics of nine isolated, near full-length KSHV genomes revealed extensive evidence of mosaic patterns across all these genomes. Further, our comprehensive NGS analysis allowed the identification of two distinct KSHV genome sequences in one individual, consistent with a dual infection. Overall, our results provide significant evidence for the contribution of KSHV phylogenomics to the origin of KSHV subtypes. This report points to a wider scope of studies to establish genome-wide patterns of sequence diversity and define the possible pathogenic role of sequence variations in KSHV-infected individuals.

Introduction of human gammaherpesvirus 8 genotypes A, B, and C into Brazil from multiple geographic regions

Variations in the open reading frame (ORF) K1 gene sequence of human gammaherpesvirus 8 (HHV-8) has led to the identification of 6 major genotypic clades (A, B, C, D, E, and F) in specimens isolated from around the world. These clades exhibit clear clustering among individuals in different ethnic groups and from different geographic regions. The human population of Brazil varies greatly in ethnicity because of multiple immigration events from Africa, Europe, Asia, and indigenous communities. However, there is scant information about the HHV-8 genotypes currently circulating in Brazil. Here, we describe HHV-8 genotypic diversity in isolates from Brazilian HIV-infected patients living with Kaposi's sarcoma (KS) by analysis of the complete ORF-K1 region. We also identified the most likely geographic origins of these different Brazilian genotypes. We extracted HHV-8 DNA (24 positive samples) from individuals with HIV/KS from the states of São Paulo and Rio de Janeiro, amplified the ORF-K1 gene using nested PCR (about 870 base pairs), performed sequencing and phylogenetic analysis, and then calculated the mean genetic distances of Brazilian sequences from sequences in other regions of the world (523 sequences analyzed). Phylogenetic analysis showed that genotypes C, A, and B were present in 45.8 %, 29.2 % and 25 % of the isolates from Brazil, respectively. These isolates grouped into separate clades, rather than a single monophyletic cluster. Mean genetic distance analyses suggested that these genotypes were introduced into the Brazil multiple times from different geographical regions. HHV-8/A isolates appear to be from Ukraine, Russia, and the Tartar ethnic group; HHV-8/B isolates appear to be from Congo and Democratic Republic of the Congo; and HHV-8/C isolates appear to be from Australia, Algeria, England, and French Guiana. These results contribute to a better understanding of the genetic diversity and origins of HHV-8 strains circulating in Brazil, and will provide a foundation for further epidemiological and evolutionary studies of HHV-8.

K1 gene transformation activities in AIDS-related and classic type Kaposi's sarcoma: Correlation with clinical presentation

Kaposi's sarcoma-associated herpesvirus (KSHV) causes both AIDS-related Kaposi's sarcoma (KS) and classic KS, but their clinical presentations are different, and respective mechanisms remain to be elucidated. The KSHV K1 gene is reportedly involved in tumorigenesis through the immunoreceptor tyrosine-based activation motif (ITAM). Since we found the sequence variations in the K1 gene of KSHV isolated from AIDS-related KS and classic KS, we hypothesized that the transformation activity of the K1 gene contributes to the different clinical presentations. To evaluate our hypothesis, we compared the transformation activities of the K1 gene between AIDS-related KS and classic KS. We also analyzed ITAM activities and the downstream AKT and NF-κB. We found that the transformation activity of AIDS-related K1 was greater than that of classic K1, and that AIDS-related K1 induced higher ITAM activity than classic K1, causing more potent Akt and NF-κB activities. K1 downregulation by siRNA in AIDS-related K1 expressing cells induced a loss of transformation properties and decreased both Akt and NF-κB activities, suggesting a correlation between the transformation activity of K1 and ITAM signaling. Our study indicates that the increased transformation activity of AIDS-related K1 is associated with its clinical aggressiveness, whereas the weak transformation activity of classic type K1 is associated with a mild clinical presentation and spontaneous regression. The mechanism of spontaneous regression of classic KS may provide new therapeutic strategy to cancer.

Human herpesvirus 8 DNA detection and variant analysis in patients with multiple sclerosis

Several studies reported a complex interplay between viral infections and neural cells leading to multiple sclerosis. A role for some viral infections has been proposed in MS. In this study, DNA sequences of human herpesvirus 8 (HHV-8) were searched in the peripheral blood of 54 patients with multiple sclerosis and 130 healthy subjects using nested-PCR assay to amplify ORF26 locus. Furthermore, HHV-8 positive samples were subjected to a nested-PCR to amplify K1 gene of HHV-8 followed by direct nucleotide sequencing. HHV-8 genome was detected in 18.5% (10/54) and 3% (4/130) of MS patients and controls, respectively, and the difference reached statistically significant level (P = 0.0017). Genotyping analysis revealed that genotype C was common (88.9%) in all study subjects, followed by genotype A. Our results showed higher detection of HHV-8 DNA in MS patients than control group.

Anaplastic Kaposi's sarcoma: 5 cases of a rare and aggressive type of Kaposi's sarcoma

BACKGROUND

Anaplastic Kaposi's sarcoma (KS) is a rare form of KS characterized clinically by the development of a tumour mass with unusual local aggressiveness and histologically by a specific architecture and cytological morphology. A very small number of limited series in endemic countries have established characteristics common to these anaplastic forms of KS. We present five patients with an anaplastic form in a context of KS ongoing for several years in a non-endemic country.

MATERIALS AND METHODS

We collected 5 cases of anaplastic KS followed in our department over a period of 20years. We describe the main developmental, clinical, virological and histological features.

RESULTS

The cases involved 4 men and 1 woman whose mean age at diagnosis of anaplastic KD was 70years, with an average time of 25years between initial diagnosis of KD and anaplastic transformation. Our patients were all treated with chemotherapy and/or radiotherapy (RT) prior to diagnosis of anaplastic transformation. All patients had a tumour mass of the lower limbs developing in classically indolent KS with associated chronic lymphoedema. Progression was very aggressive locally with deep invasion of the soft tissues as well as osteoarticular involvement, without visceral dissemination. At present, three patients are dead, one patient is showing partial response, and one patient is in locoregional progression. Diagnosis of the disease was based on histopathological findings. The tumour cells were undifferentiated, pseudo-cohesive, and chiefly organized in sheets. The mitotic count was high (27 mitoses per 10 fields at high magnification). Necrosis was constant.

DISCUSSION

To our knowledge, this is the first series describing anaplastic Kaposi's sarcoma in a non-endemic country. The severity of the prognosis, despite the absence of visceral dissemination, is related to the local aggressiveness of anaplastic KS and to its resistance to radiotherapy and chemotherapy, with amputation being required in certain cases.

Was Kaposi's sarcoma-associated herpesvirus introduced into China via the ancient Silk Road? An evolutionary perspective

Kaposi's sarcoma-associated herpesvirus (KSHV) has become widely dispersed worldwide since it was first reported in 1994, but the seroprevalence of KSHV varies geographically. KSHV is relatively ubiquitous in Mediterranean areas and the Xinjiang Uygur Autonomous Region, China. The origin of KSHV has long been puzzling. In the present study, we collected and analysed 154 KSHV ORF-K1 sequences obtained from samples originating from Xinjiang, Italy, Greece, Iran and southern Siberia using Bayesian evolutionary analysis in BEAST to test the hypothesis that KSHV was introduced into Xinjiang via the ancient Silk Road. According to the phylogenetic analysis, 72 sequences were subtype A and 82 subtype C, with C2 (n = 56) being the predominant subtype. The times to the most recent common ancestors (tMRCAs) of KSHV were 29,872 years (95% highest probability density [HPD], 26,851-32,760 years) for all analysed sequences and 2037 years (95% HPD, 1843-2229 years) for Xinjiang sequences in particular. The tMRCA of Xinjiang KSHV was exactly matched with the time period of the ancient Silk Road approximately two thousand years ago. This route began in Chang'an, the capital of the Han dynasty of China, and crossed Central Asia, ending in the Roman Empire. The evolution rate of KSHV was slow, with 3.44 × 10-6 substitutions per site per year (95% HPD, 2.26 × 10-6 to 4.71 × 10-6), although 11 codons were discovered to be under positive selection pressure. The geographic distances from Italy to Iran and Xinjiang are more than 4000 and 7000 kilometres, respectively, but no explicit relationship between genetic distance and geographic distance was detected.

Diversity of human herpesvirus 8 genotypes in patients with AIDS and non-AIDS associated Kaposi's sarcoma, Castleman's disease and primary effusion lymphoma in Argentina

HHV-8 genotypes are distributed heterogeneously worldwide. The variable K1 gene and the conserved ORF26E region serve to genotype. The aim of the study was to characterize HHV-8 isolates from patients with AIDS, classical, and iatrogenic KS, primary effusion lymphoma and Castleman's disease and one organ donor from Argentina by analysis of ORFK1 and ORF26E regions. DNA was extracted from fresh or paraffin embedded biopsies, blood, and saliva samples and submitted to HHV-8 PCR. Phylogenetic analyses of ORFK1 showed that subtypes C (C1, C2, and C3), B1 and A (A1, A2, and A3) were present in 70.8%, 16.7%, and 12.5% of cases, respectively. Analyses of ORF26E fragment revealed that most strains (45.8%) were subtype A/C while the remaining fall into K, J, B2, R, and D subtypes. Linkage between ORFK1-ORF26E subtypes corresponded to reported relationships, except for one strain that clustered with B1 (K1 African) and D (ORF26E Asian-Pacific) subtypes. This research reveals predominance of subtype C, a broad spectrum of HHV-8 genotypes and reports the first isolation of the African B genotype in Argentina.

Effect of electrochemotherapy on human herpesvirus 8 kinetics in classic Kaposi sarcoma

BACKGROUND

Electrochemotherapy (ECT) has shown to be an effective treatment for cutaneous and subcutaneous Kaposi sarcoma (KS) lesions. However, no study has investigated the impact of ECT treatment on the kinetics of human herpesvirus type 8 (HHV8), which is considered the necessary causal agent of KS. We aimed to evaluate HHV8 viral load and expression levels in patients affected by classic KS who received one or more ECT treatments and have been followed semi annually for up to four years.

METHODS

A total of 27 classic KS patients were enrolled in this study. Tumour biopsies and blood samples were obtained before ECT treatment. Additional blood samples were collected at six month intervals for 12-48 months. HHV8 viral load and expression profiles of latent (ORF72 and ORF73) and lytic (K2, K8, K8.1, K10/K10.1, K10.5/K10.6 and ORF16) genes were assessed in all samples by real-time PCR. HHV8 ORF26 and K1 regions were amplified and subjected to direct nucleotide sequencing followed by phylogenetic analysis for variant identification.

RESULTS

All KS biopsies and 46.4% of peripheral blood mononuclear cells (PBMCs) collected before ECT treatment were positive for HHV8 DNA. Viral load ranged from 0.02 to 2.3 copies per cell in KS lesions and 3.0 × 10^-7 to 6.9 × 10^-4 copies per cell in PBMCs. Overall, latent ORF72 and ORF73 as well as lytic K2, K8 and K10/K10.1 were expressed in all KS biopsies. ORF16 mRNA was detected in 71.4% and both K8.1 and K10.5/K10.6 mRNAs in 57.1% of KS samples. The ORF72, ORF73 and K2 transcripts were amplified in 37.5%, 25% and 25% of PBMCs collected before ECT, respectively. After the first ECT session, complete response was achieved in 20 out of 27 (74.1%) patients and HHV8 DNA was detected in four out of 27 (14.8%) PBMC samples at six month follow up. Phylogenetic analysis of ORF26 amplimers showed that most viral variants belonged to A/C (82.3%), and few to C2 (5.9%) or C3 (11.8%) subtype. The K1/VR1 variants fell into A (33.3%) and C (66.7%) HHV8 clade. No correlation was found between HHV8 subtypes and ECT complete response.

CONCLUSIONS

ECT therapy has a significant effect on HHV8 kinetics in patients with classic KS. The complete remission of patients was accompanied by clearance of circulating virus.

Molecular typing of human herpesvirus 8 among HIV positive in comparison to HIV-negative individuals in Iran

It is still unclear whether different HHV-8 genotypes may have different pathogenic and tumorigenic properties associated with a diverse rate of disease progression. In some areas where genotype C was found to be prominent among classic KS patients, genotype A was shown to be more frequent among AIDS-associated KS patients. Genotype C was previously reported to be widespread in Iran, with genotype A being less frequent among patients with classic KS although no data are available with regards to the HHV-8 genotyping among Iranian HIV-infected patients. In order to analyze HHV-8 genotypes (ORF K1), six HIV-infected patients (with or without KS), and 22 HIV-negative subjects (classic/iatrogenic KS patients and IVDUs) were investigated using nested PCR. Genotype A was detected more frequently among HIV-infected patients with or without KS (three out of six) whereas genotype C was found more common among HIV-negative subjects including classic/iatrogenic KS patients and IVDSs (21 out of 22), and this difference was statistically significant (P = 0.044). In conclusion, our data further support the dominancy of HHV-8 genotype C in Iranian general population. Moreover, genotype A was more common among HIV-infected patients with or without KS. J. Med. Virol. 89:703-709, 2017. © 2016 Wiley Periodicals, Inc.

Genotypic distribution of HHV-8 in AIDS individuals without and with Kaposi sarcoma: Is genotype B associated with better prognosis of AIDS-KS?

AIDS-associated Kaposi's sarcoma (AIDS-KS) caused by human herpes virus 8 (HHV-8) is the most severe and resistant form of KS tumor. Our aim was to verify whether there is an association between HHV-8 variability and development of AIDS-KS in Brazil by comparing the HHV-8 variability between individuals without and with KS. Saliva samples and blood, when available, were analyzed by polymerase chain reaction (PCR) techniques for detection of the fragments of ORF K1 of HHV-8, which were then genotyped and analyzed regarding the genetic variability. Our study described 106 positive cases for HHV-8 in the saliva from 751 AIDS patients without previous KS. In addition, we performed a phylogenetic analysis of HHV-8 in 34 of the 106 AIDS patients without KS and in 33 of the 37 patients with active KS. The distribution of HHV-8 genotypes A, B, C, and F in AIDS individuals was indistinguishable by comparing non-KS and KS groups, as well as regarding ethnicity. Considering the KS group, genotype B was associated with better prognosis of KS tumor. Interestingly, we found a particular profile of diversity within clade C and 2 recombinant patterns of HHV-8 in the saliva of AIDS individuals without KS. We emphasize the need to achieve standard genotyping protocol for ORF K1 amplification, thus allowing for substantial detection of HHV-8 variants. Our findings can shed light on the role of HHV-8 variability in the pathogenesis of AIDS-KS.

High Prevalence of Human Herpesvirus 8 Infection in Diabetes Type 2 Patients and Detection of a New Virus Subtype

The prevalence of Human Herpesvirus 8 (HHV8) DNA and antiviral antibodies in Diabetes type 2 (DM2) and control subjects was studied, in order to confirm a possible link between DM2 and HHV8 infection. The HHV8-DNA from diabetic patients was typed for detecting possible genomic differences with known HHV8 reference viruses.DM2 patients and healthy controls were examined for the presence of HHV8 DNA into the peripheral blood lymphocytes. Both anti-lytic and latent phase antibodies were detected in HHV8 positive and negative diabetic patients, as well in a number of controls. The HHV8 ORF K1 and ORF 26 genes from DM2 patients were typed and matched to reference strains.A significant prevalence of HHV8 DNA in DM2 subjects versus healthy controls was detected (about 58 % against 27 %). Anti-lytic phase, but not anti-latent phase antibodies, were significantly increased in DM2 patients versus controls. In addition, about 30 % of HHV8 strains isolated from DM2 lymphocytes showed consistent differences in the ORF 26 gene sequence, so that a new HHV8 subtype was proposed. These findings give additional support to the hypothesis that HHV8 could be considered an additional risk factor for DM2 onset.

Genetic diversity of HHV8 subtypes in South Africa: A5 subtype is associated with extensive disease in AIDS-KS

Human herpes virus 8 (HHV8) is the etiological agent of all forms of Kaposi's sarcoma (KS). Six major subtypes (A-F), based on genetic variability of open reading frame (ORF)-K1, have been identified. Numerous studies point to differing tumorigenic and pathogenic properties of the HHV8 subtypes. The study objectives were to determine the HHV8 subtypes and their prevalence in a cohort of clinical and histologically confirmed KS in Cape Town, South Africa, and analyze associations between the different subtypes and clinical presentation of KS. Clinical records were prospectively reviewed to extract clinical presentation; demographic data were retrospectively collected and tissue biopsies were taken for ORF-K1 subtyping. Eighty six patients were subtyped; 81 AIDS (acquired immune deficiency syndrome)-KS and 5 African endemic-KS. Subtype A5 (42/86) and B2 (16/86) predominated. B1, B3, A1 and A4 subtypes were identified in 10/86, 9/86, 4/86 and 1/86 patients, respectively. A5 and B subtypes were found in African blacks and individuals of mixed ancestry, while subtypes A1 and A4 were found only in whites and individuals of mixed ancestry. Subtype A5 was associated with >10 KS lesions at presentation in the AIDS cohort (adjusted OR: 3.13; CI: 1.02-9.58). Subtypes A1 and A4 combined were less likely to be associated with poor risk tumor extension (P = 0.031) and A1 was associated with lower likelihood of lower limb involvement (P = 0.019). In conclusion, these results indicate that subtype A5 and B predominate in South Africa and A5 may be associated with more extensive disease.

Analysis of the ORFK1 hypervariable regions reveal distinct HHV-8 clustering in Kaposi's sarcoma and non-Kaposi's cases

Background

Classical Kaposi’s Sarcoma (cKS) is a rare vascular tumor, which develops in subjects infected with Human Herpesvirus-8 (HHV-8). Beside the host predisposing factors, viral genetic variants might possibly be related to disease development. The aim of this study was to identify HHV-8 variants in patients with cKS or in HHV-8 infected subjects either asymptomatic or with cKS-unrelated cutaneous lymphoproliferative disorders.

Methods

The VR1 and VR2 regions of the ORF K1 sequence were analyzed in samples (peripheral blood and/or lesional tissue) collected between 2000 and 2010 from 27 subjects with HHV-8 infection, established by the presence of anti-HHV-8 antibodies. On the basis of viral genotyping, a phylogenetic analysis and a time-scaled evaluation were performed.

Results

Two main clades of HHV-8, corresponding to A and C subtypes, were identified. Moreover, for each subtype, two main clusters were found distinctively associated to cKS or non-cKS subjects. Selective pressure analysis showed twelve sites of the K1 coding gene (VR1 and VR2 regions) under positive selective pressure and one site under negative pressure.

Conclusion

Thus, present data suggest that HHV-8 genetic variants may influence the susceptibility to cKS in individuals with HHV-8 infection.

Vascular endothelial growth factor A polymorphism and risk of Kaposi's sarcoma herpesvirus viremia in kidney allograft recipients

BACKGROUND

Kaposi's sarcoma herpesvirus (KSHV) causes Kaposi's sarcoma (KS), primary effusion lymphoma, and multicentric Castleman's disease in immunocompromised patients including allograft recipients. Detection of KSHV DNA in blood, as well as host genetic polymorphisms has been found to be associated with an increased risk for KS. We investigated an association between single nucleotide polymorphisms (SNPs) in vascular endothelial growth factor A (VEGFA) gene region and KSHV viremia in kidney transplant recipients (KTR) in Saudi Arabia.

METHODS

In total, 152 KTR who have survived kidney transplantation for at least 6 months were included in the study. KSHV viremia was determined by real-time polymerase chain reaction (PCR). Genotyping of SNPs in the VEGFA region was performed by PCR and direct sequencing, as well as by restriction fragment length polymorphism.

RESULTS

KSHV DNA was detected in 28.9% (n = 44) of the study population. The A-allele at position C172A VEGFA gene promoter region was found to be associated with KSHV viremia (odd ratio [OR] = 4.8, P = 0.005). In addition, the G-allele at position C+405G in the 5'-untranslated region was associated with KSHV viremia in women, but not in men (OR = 3.98, P = 0.004).

CONCLUSIONS

Our results suggest an association of VEGFA polymorphisms with KSHV viremia among KTR in this study population. A limitation of our study is that the results can only be predicated for patients 6 months after kidney transplantation and should be validated in another cohort with larger sample size.

Kaposi's sarcoma: etiology and pathogenesis, inducing factors, causal associations, and treatments: facts and controversies

Kaposi's sarcoma (KS), an angioproliferative disorder, has a viral etiology and a multifactorial pathogenesis hinged on an immune dysfunction. The disease is multifocal, with a course ranging from indolent, with only skin manifestations to fulminant, with extensive visceral involvement. In the current view, all forms of KS have a common etiology in human herpesvirus (HHV)-8 infection, and the differences among them are due to the involvement of various cofactors. In fact, HHV-8 infection can be considered a necessary but not sufficient condition for the development of KS, because further factors (genetic, immunologic, and environmental) are required. The role of cofactors can be attributed to their ability to interact with HHV-8, to affect the immune system, or to act as vasoactive agents. In this contribution, a survey of the current state of knowledge on many and various factors involved in KS pathogenesis is carried out, in particular by highlighting the facts and controversies about the role of some drugs (quinine analogues and angiotensin-converting enzyme inhibitors) in the onset of the disease. Based on these assessments, it is possible to hypothesize that the role of cofactors in KS pathogenesis can move toward an effect either favoring or inhibiting the onset of the disease, depending on the presence of other agents modulating the pathogenesis itself, such as genetic predisposition, environmental factors, drug intake, or lymph flow disorders. It is possible that the same agents may act as either stimulating or inhibiting cofactors according to the patient’s genetic background and variable interactions.

Treatment guidelines for each form of KS are outlined, because a unique standard therapy for all of them cannot be considered due to KS heterogeneity. In most cases, therapeutic options, both local and systemic, should be tailored to the patient’s peculiar clinical conditions.

Non-AIDS-related Kaposi's sarcoma: A single-institution experience

AIM: To evaluate the outcomes and potential prognostic factors in patients with non-acquired immunodeficiency syndrome (AIDS)-related Kaposi’s sarcoma (KS).

METHODS: Patients with histologically proven non-AIDS-related KS treated with systemic chemotherapy were included in this retrospective analysis. In some cases, the human herpes virus 8 status was assessed by immunohistochemistry. The patients were staged according to the Mediterranean KS staging system. A multivariable model was constructed using a forward stepwise selection procedure. A P value < 0.05 was considered statistically significant, and all tests were two-sided.

RESULTS: Thirty-two cases were included in this analysis. The average age at diagnosis was 70 years, with a male/female ratio of approximately 2:1. Eighty-four percent of the cases had classic KS. All patients received systemic chemotherapy containing one of the following agents: vinca alkaloid, taxane, and pegylated liposomal doxorubicin. Ten patients (31.5%) experienced a partial response, and a complete response was achieved in four patients (12.4%) and stable disease in sixteen cases (50%). Two patients (6.2%) were refractory to the systemic treatment. The median progression-free survival (PFS) was 11.7 mo, whereas the median overall survival was 28.5 mo. At multivariate analysis, the presence of nodular lesions (vs macular lesions only) was significantly related to a lower PFS (hazard ratio: 3.09; 95%CI: 1.18-8.13, P = 0.0133).

CONCLUSION: Non-AIDS-related KS appears mostly limited to the skin and is well-responsive to systemic therapies. Our data show that nodular lesions may be associated with a shorter PFS in patients receiving chemotherapy.

Molecular diagnosis of infection-related cancers in dermatopathology

The association between viruses and skin cancer is increasingly recognized in a number of neoplasms, that is, cutaneous squamous cell carcinoma, Kaposi sarcoma, nasopharyngeal carcinoma, and Merkel cell carcinoma, as well as hematolymphoid malignancies such as adult T-cell leukemia/lymphoma and NK/T-cell lymphoma (nasal type) and post-transplant lymphoproliferative disorders. Molecular assays are increasingly used to diagnose and manage these diseases. In this review, molecular features of tumor viruses and related host responses are explored. The tests used to identify such features are summarized. Evaluation of the utility of these assays for diagnosis and/or management of specific tumor types is presented.

In vivo and in vitro evidence for an association between the route-specific transmission of HHV-8 and the virus genotype

The study was performed to determine if there is an association between the genotype and transmission of HHV-8 types A and C. These HHV-8 subtypes are prevalent in the area of North of Sardinia, which is an island off west Italy's mainland that has a high HHV-8 seroprevalence (35%). Blood and saliva samples from 30 patients with classic Kaposi's sarcoma who were lifetime residents of North Sardinia were analyzed to identify the HHV-8 genotype and quantitate the viral load. Genotype A, especially A1 subtype, was found more frequently (9/30 patients) and had a significantly higher viral load in saliva compared to blood (P = 0.029), where type C was found more frequently but with a viral load lower than 10(3)  copies/ml. To determine if there is a correlation between the viral genotype and cellular tropism, type A1 and C3 HHV-8 viral particles were obtained from cell lines BCBL1 and BC3 infected chronically with HHV-8 A1 and C3 genotypes respectively and used to infect HEK293 epithelial origin cells and PBMCs in vitro. The data indicate that the A1 HHV-8 genotype is tropic and replicates at higher levels in the epithelial cell lines.

African ancestry and innate immunity contribute to the incidence of multicentric Castleman’s disease in HIV-1/Kaposi’s sarcoma herpesvirus-coinfected individuals

Aims: Kaposi’s sarcoma herpesvirus (KSHV) is the etiological agent of Kaposi’s sarcoma and multicentric Castleman’s disease (MCD), a lymphoproliferative disorder associated with high KSHV load. Here, we analyze the frequency of A299G, a TLR4 single nucleotide polymorphism associated with increased MCD incidence, in a cohort of HIV-1+ individuals, exploring the link between genotype, KSHV disease and ethnicity. Materials & methods: One hundred and seven HIV-1+ patients presenting with KSHV-related (n = 41) and KSHV-unrelated (n = 66) malignancies were analyzed according to ethnicity, and genotyped for A299G. DNA was extracted from peripheral blood, and the presence of A299G determined by pyrosequencing. Results: Of 41 patients presenting with KSHV-related malignancies, 12 were of African ancestry and 29 of European ancestry. MCD was diagnosed in 18 individuals, 50% of whom had African ancestry. HIV-1+ individuals with KSHV-related malignancies of African ancestry had a 2.4-fold increased occurrence of MCD compared with European counterparts (relative risk: 2.42; 95% CI: 1.28–4.55; p = 0.025). A299G was found to be present in 33% of black African and 10% of white European patients with KSHV-related malignancies. In the cohort of patients diagnosed with MCD (n = 18), A299G was present at a frequency of 0.33, regardless of ethnicity. Conclusion: The 2.4-fold higher incidence of MCD in patients of African ancestry presenting with KSHV-related malignancies may be due to the more than three-times higher frequency of A299G compared with that observed in European counterparts. This data highlights a clinically relevant consideration for those caring for KSHV+HIV-1+ patients of African ancestry, linking genetic variation to disease.

Original submitted 25 April 2012; Revised submitted 10 May 2012

Activating KIR/HLA complexes in classic Kaposi's Sarcoma

BACKGROUND

Classic Kaposi's Sarcoma (cKS) is a rare vascular tumor associated with Human Herpesvirus 8 (KSHV) infection, nevertheless not all KSHV-infected individuals have cKS.

OBJECTIVE

We investigated whether particular KIR/HLA receptor/ligand genotypes would be preferentially present in KSHV-infected and uninfected individuals who have or have not developed cKS.

METHODS

KIR/HLA genotypes were analyzed by molecular genotyping in 50 KSHV-infected individuals who did or did not have cKS and in 33 age-and sex-matched KSHV seronegative individuals.

RESULTS

There was no association of individual KIR, HLA or receptor ligand combinations with KSHV infection. However, activating KIR and KIR/HLA genotypes were significantly more frequent in cKS cases, specifically KIR3DS1, KIR2DS1, and KIR2DS1 with its HLA-C2 ligand.

CONCLUSION

A nonspecific inflammatory response triggered by activation of NK cells upon KIR-HLA interaction could be associated with the pathogenesis of KS.

Molecular epidemiology of human herpesvirus 8 variants in Kaposi's sarcoma from Iranian patients

Kaposi's sarcoma (KS) is a rare cancer in Iran and there is no epidemiological and molecular information about HHV-8 variants circulating among the Iranian population. In this study HHV-8 sequences have been analyzed in 43 cutaneous KS biopsies from Iranian patients mainly affected by classic KS. DNA samples were subjected to PCR amplification of HHV-8 ORF26, T0.7 and K1 followed by direct nucleotide sequencing and phylogenetic analysis. The analysis of ORF26 showed that 30 (69.8%) and 13 (30.2%) samples belonged to subtypes A/C and K, respectively. In general, the clustering of HHV-8 T0.7 variants paralleled that of ORF26. Genotyping of K1 sequences showed that the majority of samples (39 out of 41) fall into the large C clade with only 2 belonging to the A clade. In conclusion, HHV-8 variants identified among classic Iranian KS are largely related to Eurasian genotypes previously identified in KS from Mediterranean, Middle East, and East Asian regions.

Saliva as a diagnostic fluid

Salivary diagnostics is a dynamic and emerging field utilizing nanotechnology and molecular diagnostics to aid in the diagnosis of oral and systemic diseases. In this article the author critically reviews the latest advances using oral biomarkers for disease detection. The use of oral fluids is broadening perspectives in clinical diagnosis, disease monitoring, and decision making for patient care. Important elements determining the future possibilities and challenges in this field are also discussed.

Intrafamiliar transmission of Kaposi's sarcoma-associated herpesvirus and seronegative infection in family members of classic Kaposi's sarcoma patients

The link between Kaposi's sarcoma-associated herpesvirus (KSHV or human herpesvirus 8) and Kaposi's sarcoma has been proven, but the transmission routes, especially in the heterosexual population, are not yet completely understood. To assess the intrafamilial patterns of transmission among first-degree relatives of Italian classic Kaposi's sarcoma (cKS) patients, KSHV seroprevalence and the presence of viral DNA in blood and saliva were evaluated in 18 families (32 cKS patients and 35 family members), comparing the results with those obtained in 200 elderly healthy controls without known exposure to KSHV. The KSHV genotype of variable region VR1 of the hypervariable ORF K1 gene was subsequently analysed in all KSHV-positive samples. The results showed that KSHV infection was significantly higher in relatives of cKS patients (11/35 cases) than in healthy controls (17/200 cases; P=0.001). The 11 infected relatives included spouses (n=3), siblings (n=2) and offspring (n=6) of the cKS patients; the same KSHV genotype was shared within the same family in the majority of cases (85%), indicating the presence of person-to-person transmission within families. Viral DNA was mostly observed in the saliva of infected relatives (45.4%); detection of DNA in blood was less frequent (27.3%). Notably, KSHV DNA was present in saliva and/or blood of three KSHV-infected relatives with indeterminate or negative serostatus. Thus, the risk of KSHV infection is greatly enhanced within families of cKS patients, where close contacts (horizontal and/or sexual) can contribute to the spread of KSHV.

Prevalence of antibodies against Kaposi's sarcoma associated herpes virus (KSHV) complement inhibitory protein (KCP) in KSHV-related diseases and their correlation with clinical parameters

Kaposi's sarcoma-associated herpes virus (KSHV) encodes its own inhibitor of the complement system, designated KSHV complement control protein (KCP). Previously, we detected anti-KCP antibodies in a small group of 22 patients suffering from Kaposi's sarcoma (KS) and KSHV-related lymphoproliferative diseases (Vaccine, 25:8102-9). Anti-KCP antibodies were more prevalent in individuals suffering from KSHV-related lymphomas than KS and also in those with high titer of antibodies against lytic KSHV antigens. Herein we analyze anti-KCP antibodies in 175 individuals originating from three different groups from northern Sweden or Italy, which included patients suffering from classical or HIV-associated KS, Multicentric Castleman's Disease, KSHV-associated solid lymphoma, pleural effusion lymphoma and healthy individuals with detectable KSHV immune response. Our current study confirmed previous observations concerning antibody prevalence but we also analyzed correlations between anti-KCP antibodies and classical KS evolution, clinical stage and viral load in body fluids. Furthermore, we show that patient's anti-KCP antibodies are able to decrease the ability of KCP to inhibit complement. This fact combined with results of statistical analysis suggests that KCP inactivation by specific antibodies may influence progression of classical KS.

Kaposi sarcoma (KS)-associated herpesvirus microRNA sequence analysis and KS risk in a European AIDS-KS case control study

BACKGROUND

We recently identified polymorphisms in Kaposi sarcoma-associated herpesvirus (KSHV)-encoded microRNA (miRNA) sequences from clinical subjects. Here, we examine whether any of these may contribute to KS risk in a European AIDS-KS case-control study.

METHODS

KSHV load in peripheral blood was determined by real-time quantitative polymerase chain reaction. Samples that had detectable viral loads were used to amplify the 2.8-kb miRNA encoding region plus a 646-bp fragment of the K12/T0.7 gene. Additionally, we characterized an 840-bp fragment of the K1 gene to determine KSHV subtypes.

RESULTS

KSHV DNA was detected in peripheral blood mononuclear cells of 49.6% of case patients and 6.8% of controls, and viral loads tended to be higher in case patients. Sequences from the miRNA-encoding regions were conserved overall, but distinct polymorphisms were detected, some of which occurred in primary miRNAs, pre-miRNAs, or mature miRNAs.

CONCLUSIONS

Patients with KS were more likely to have detectable viral loads than were controls without disease. Despite high conservation in KSHV miRNA-encoded sequences, polymorphisms were observed, including some that have been reported elsewhere. Some polymorphisms could affect mature miRNA processing and appear to be associated with KS risk.

View and review on viral oncology research

To date, almost one and a half million cases of cancer are diagnosed every year in the US and nearly 560,000 Americans are expected to die of cancer in the current year, more than 1,500 people a day (data from the American Cancer Society at http://www.cancer.org/). According to the World Health Organization (WHO), roughly 20% of all cancers worldwide results from chronic infections; in particular, up to 15% of human cancers is characterized by a viral aetiology with higher incidence in Developing Countries. The link between viruses and cancer was one of the pivotal discoveries in cancer research during the past Century. Indeed, the infectious nature of specific tumors has important implications in terms of their prevention, diagnosis, and therapy. In the 21st Century, the research on viral oncology field continues to be vigorous, with new significant and original studies on viral oncogenesis and translational research from basic virology to treatment of cancer. This review will cover different viral oncology aspects, starting from the history of viral oncology and moving to the peculiar features of oncogenic RNA and DNA viruses, with a special focus on human pathogens.

Update on HHV-8-Associated Malignancies

The human herpesvirus 8 (HHV-8) is the oncogenic virus associated with Kaposi's sarcoma (KS) and lymphoproliferative disorders, namely, primary effusion lymphoma and multicentric Castleman's disease. KS is among the most common malignancies seen in HIV-infected patients despite the decreased incidence of KS in the era of highly active antiretroviral therapy. Advances in molecular pathology reveal HHV-8 tumorigenesis is mediated through molecular mimicry wherein viral-encoded proteins can activate several cellular signaling cascades while evading immune surveillance. This knowledge has led to the evolution of multiple therapeutic strategies against specific molecular targets. Many such therapeutic modalities have shown activity, but none have proven to be curative. Identifying possible prognostic factors is another active area of research. This review summarizes the recent developments in the fields of virus transmission, molecular biology, and treatment of HHV-8-related neoplasms.

Human herpesvirus type 8 variants circulating in Europe, Africa and North America in classic, endemic and epidemic Kaposi's sarcoma lesions during pre-AIDS and AIDS era

Human herpesvirus-8 (HHV-8) variants have been found heterogeneously distributed among human populations living in diverse geographic regions, but their differential pathogenicity in Kaposi's sarcoma development remains controversial. In the present study, HHV-8 variant distribution has been analyzed in classic, iatrogenic, endemic as well as epidemic Kaposi's sarcoma (KS) during pre-AIDS and AIDS period (1971-2008) in countries with different KS incidence rate. DNA samples from cutaneous KS lesions of 68 patients living in Africa (n=23, Cameroon, Kenya and Uganda), Europe (n=34, Greece and Italy) and North America (n=11) have been subjected to PCR amplification of HHV-8 ORF 26, T0.7, K1 and K14.1/15, followed by direct nucleotide sequencing and phylogenetic analysis. Among the 23 African samples, the majority of HHV-8 ORF 26 variants clustered with the subtype R (n=12) and B (n=5). Conversely, the viral sequences obtained from 45 European and North European tumors belonged mainly to subtype A/C (n=36). In general, HHV-8 and K1 variant clustering paralleled that of ORF 26 and T0.7. Genotyping of the K14.1/15 loci revealed a large predominance of P subtype in all tumors. In conclusion, comparison of the HHV-8 sequences from classic or endemic versus AIDS-associated KS showed a strong linkage of the HHV-8 variants with specific populations, which has not changed during AIDS epidemic.

Mother-to-child HIV and HHV-8 transmission in neonates at Saint Camille Medical Centre in Burkina Faso

In Sub-Saharan Africa, many HIV infected people are co-infected with Human Herpes Virus 8 (HHV-8). Therefore, the present study aimed to: (1) identify the pregnant women co-infected by HIV and HHV-8 at Saint Camille Medical Centre; (2) use three molecules (Zidovudine, Nevirapine and Lamivudine) to interrupt the vertical transmission of HIV and (3) use the PCR technique to diagnose children, who were infected by these viruses, in order to offer them an early medical assistance. A total of 107 pregnant women, aged from 19 to 42 years were diagnosed to be HIV positive at Saint Camille Centre; among them 13 were co-infected with HHV-8. All included women received the HAART. Two to six months after childbirth their babies underwent PCR diagnosis for HIV and HHV-8. The results revealed that, among these mothers, 68.2% were housewives, 34.6% were illiterates and 60.7% did not have university degree. The prevalence of HHV-8 among these pregnant women was 12.15% and the rate of vertical transmission of both HIV and HHV-8, was 0.0%. The issue of this study revealed that the antiretroviral therapy increased the mother CD4 T-cells, prevented the transcription of the mRNA of HHV-8 and blocked HIV vertical transmission.