Seroprevalence of Kaposi's sarcoma-associated herpesvirus and risk factors in Xinjiang, China

Is human herpesvirus 8 infection more common in men than in women? an updated meta-analysis

BACKGROUND

Clinically, most patients with Kaposi's sarcoma (KS) are male, and several direct and indirect mechanisms may underlie this increased susceptibility in men, Kaposi's sarcoma-associated herpesvirus (KSHV), also known as human herpesvirus 8 (HHV-8), is considered to be the primary etiological agent responsible for KS. Thus, we propose the hypothesis that men are more susceptible to HHV-8 infection, leading to a higher incidence of Kaposi's sarcoma among males. A meta-analysis was conducted to evaluate the association between gender and HHV-8 seropositivity in the general population.

METHODS

A comprehensive literature search was performed using 6 online databases: PubMed, EMBASE, Cochrane library, Web of Science, CNKI, and Wanfang. Studies published before March 15, 2023, were included.

RESULTS

In all, 33 articles including 41 studies were included in the meta-analysis. In the included adult population. men had a higher risk of HHV-8 infection than did women in adult populations from all over the world (odds ratio [OR]: 1.08, 95% confidence interval [CI]: 1.01-1.15), but no differences were found in child population from all over the world (OR: 0.90, 95% CI: 0.79-1.01). There was a significant difference in HHV-8 seroprevalence between men and women in sub-Saharan Africa (SSA) adult population (OR: 1.15, 95% CI: 1.05-1.26). However, no significant differences were observed in sub-Saharan Africa (SSA) child population (OR: 0.90, 95%CI 0.78-1.03). As for other continents, the results showed no significant difference, such as the Asian population (OR: 1.03, 95%CI: 0.92-1.16). or the European and American populations (OR 1.01, 95%CI 0.87-1.17).

CONCLUSION

There was a slight gender disparity for HHV-8 infection in the adult population. Among the adult populations from SSA and globally, men were more likely to be infected with HHV-8 than were women. However, no statistical significance was observed in the child populations from SSA and globally. In the future, the inclusion of more standardized studies may strengthen the results of this study.

Kaposi's sarcoma: epidemiologic aspects, the immune reconstitution inflammatory syndrome, and more along the Silk Road of cognition

Kaposi's sarcoma remains enignmatic with many clinical and epidemiological patterns. We review them and describe the groove sign, an important association worthy of recognition. We also stress Kaposi's sarcoma (KS) without coexistent human immunodefiency virus infection, with recent data from China describing an extraordinarily high classical KS prevalence rate among Uygurs and Kazaks in the Xinjiang Uygur Autonomous Region in northwestern China, presumably derived from elderly men residing there. The possible travel of HHV-8 along the ancient silk road from Italy to the Xinjiang Uyghur region remains intriguing. If only one in 10,000 HHV-8-infected patients develops classical KS worldwide, then triggers for its overrepresentation in this population within China are of particular concern. The KS-related immune reconstitution inflammatory syndrome is also emphasized.

Role of the Killer Immunoglobulin-like Receptor and Human Leukocyte Antigen I Complex Polymorphisms in Kaposi Sarcoma-Associated Herpesvirus Infection

Background

Kaposi sarcoma, caused by the pathogen Kaposi sarcoma-associated herpesvirus (KSHV), is the most common neoplasm for patients with AIDS. Susceptibility to KSHV has been associated with several different genetic risk variants. The purpose of this study was to test whether variants of killer cell immunoglobulin-like receptors (KIRs) and their human leukocyte antigen (HLA-I) ligands influence the risk of KSHV infection.

Methods

A case-control study was performed in Xinjiang, a KSHV-endemic region of China. We recruited 299 individuals with HIV, including 123 KSHV-seropositive persons and 176 KSHV-seronegative controls. We used logistic regression and the MiDAS package to evaluate the association between KIR/HLA-I polymorphisms and KSHV infection.

Results

HLA-A*31:01, HLA-C*03:04, and HLA-C*12:03 were found to be associated with KSHV infection, with A*31:01 showing a protective effect under 3 different models (dominant: 0.30 [95% confidence interval {CI}, .08-.82], P = .031; additive: 0.30 [95% CI, .09-.80], P = .030; overdominant: 0.31 [95% CI, .09-.88], P = .042). The effect of A*31:01 might cause the variants of amino acid at HLA-A position 56, with individuals carrying an arginine having a lower KSHV infection risk. The increased homozygous KIR2DL3 was associated with a relatively high KSHV viral load (16.30% vs 41.94%, P = .010).

Conclusions

This study provides further insight into the link between HLA-I alleles and KIR genes and KSHV infection, highlighting KSHV-susceptible variants of HLA-I and KSHV replication caused by specific KIR genotype, and revealing a potential role of KIR-mediated natural killer cell activation in anti-KSHV infection.

Seroprevalence of Kaposi's sarcoma-associated herpesvirus and risk factors in Jiuquan area, China

The seroprevalence of Kaposi's sarcoma-associated herpesvirus (KSHV) is high in Xinjiang, China. But the seroprevalence of KSHV and risk factors are still unknown in Gansu which is adjacent to Xinjiang. Six hundred and seventy-eight serum samples of the general population and 87 serum samples of syphilis patients from Jiuquan, Gansu were tested for antibodies against KSHV, including one latent protein (ORF73) and two lytic proteins (ORF65 and K8.1) using the ELISA. The total KSHV-seropositive rate was 15.9% in 678 serum samples in the Jiuquan area, and the KSHV-seropositive rate of males was higher than females (18.0% vs. 14.6%, p > 0.05). The Uygur, Kazakh, Hui, Manchu, and Mongolian populations had a higher seroprevalence of KSHV than the Han population (43.8%, 40.0%, 34.5%, 30.3%, 35.0% vs. 11.0%, respectively) among the ethnic groups in Jiuquan. Compared to the Han, Uygur, Kazak, Hui, Manchu, and Mongolian people had an increase in the risk of KSHV of 528.9%, 439.1%, 325.6%, 251.6%, and 335.4% (p < 0.001, p < 0.001, p < 0.001, p = 0.002, p = 0.003, respectively). The serum prevalence of KSHV in subjects aged < 20 years, 20-50 years, and >50 years was 13.8%, 14.7%, and 20.1%, respectively. Compared to the subjects aged < 20 years, 20-50 years and >50 years had an increase in the risk of KSHV of 7.4% and 56.9% (p = 0.829 and p = 0.204, respectively). Compared to the positive rate of KSHV in the general population of Anhui, the positive rate of KSHV was significantly higher in the general population of the Jiuquan area (15.9% vs. 9%, p < 0.01). There was no significant difference in the positive rate of KSHV between the Han population of Jiuquan and the Han population of Anhui (p > 0.05). In the population of syphilis patients in the Jiuquan area, the positive rate of KSHV was 30.7%, which was higher than that of the general population in the Gansu area (p < 0.05). This study indicates that Gansu has a high seroprevalence of KSHV. Ethnicity and syphilis are risk factors for KSHV infection.

Human Herpesvirus 8 in Australia: DNAemia and Cumulative Exposure in Blood Donors

Human herpesvirus 8 (HHV-8), the causative agent of Kaposi’s sarcoma, multicentric Castleman’s disease and primary effusion lymphoma, predominantly manifests in immunocompromised individuals. However, infection in immunocompetent individuals does occur. The prevalence of HHV-8 exposure in blood donors from non-endemic countries ranges between 1.2% and 7.3%. Nothing was known about the prevalence in Australian blood donors. Therefore, this study investigated the active and cumulative exposure of HHV-8 in this cohort. Plasma samples (n = 480) were collected from eastern Australian blood donors and were tested for HHV-8 DNA by qPCR, and for HHV-8 antibodies by two different ELISAs. Samples initially positive on either ELISA were retested in duplicate on both, and on a mock-coated ELISA. Any samples positive two or three out of the three times tested on at least one ELISA, and repeat negative on the mock-coated ELISA, were assigned as repeat positive. None of the 480 samples tested contained HHV-8 DNA. Serological testing revealed 28 samples (5.83%; 95% CI: 3.74−7.93%) had antibodies to HHV-8. There was no difference (p > 0.05) in seropositivity between sex or with increasing age. This is the first study to show serological evidence of cumulative HHV-8 exposure and no HHV-8 DNAemia within a select blood donor population in Australia. Our molecular and serological data is consistent with published results for blood donors residing in HHV-8 non-endemic countries, which shows the prevalence to be very low.

KSHV (HHV8) vaccine: promises and potential pitfalls for a new anti-cancer vaccine

Seven viruses cause at least 15% of the total cancer burden. Viral cancers have been described as the "low-hanging fruit" that can be potentially prevented or treated by new vaccines that would alter the course of global human cancer. Kaposi sarcoma herpesvirus (KSHV or HHV8) is the sole cause of Kaposi sarcoma, which primarily afflicts resource-poor and socially marginalized populations. This review summarizes a recent NIH-sponsored workshop's findings on the epidemiology and biology of KSHV as an overlooked but potentially vaccine-preventable infection. The unique epidemiology of this virus provides opportunities to prevent its cancers if an effective, inexpensive, and well-tolerated vaccine can be developed and delivered.

Isolated Kaposi sarcoma of the upper aerodigestive tract in immunocompetent individuals, an underrecognized entity with favorable prognosis

Kaposi sarcoma (KS) is a rare vascular neoplasm that most commonly arises in the setting of immunosuppression, in areas with high prevalence of Human Herpesvirus-8 infection, and when both situations coexist. Most cases affect the skin, isolated involvement of the upper respiratory tract without skin involvement is extremely rare with only a few cases reported in the literature. We present a case of isolated nasopharyngeal KS in an immunocompetent patient who achieved remission after multimodality therapy. Recent advances in KS-therapy are discussed.

Prevalence and correlates of Kaposi's sarcoma-associated herpesvirus and herpes simplex virus type 2 infections among adults: evidence from the NHANES III data

BACKGROUND

Kaposi's sarcoma-associated herpes virus (KSHV) prevalence and risk factors exhibit considerable variations across populations in different geographic regions. Determinants and the transmission routes of KSHV infection are uncertain. We seek to identify the possible risk factors and the transmission routes of KSHV infection in non-endemic areas.

METHODS

We collected annual cases and seroprevalence of KSHV and herpes simplex virus type 2 (HSV-2) from the NHANES III sampled individuals from the US general population (1988-1994). We included 13,179 and 10,720 individuals with available remaining serum samples of KSHV and HSV-2. Logistic regression was employed to explore potential risk factors for the seropositivity.

RESULTS

The seroprevalence was 2.05% for KSHV infection and 31.03% for HSV2 infection among this population. All risk factors of sexual behaviors included were strongly associated with HSV-2 positive, however, only MSM had an approximately fivefold increased risk of KSHV infection (OR = 4.71; 95%CI 1.61 11.30). Mexican Americans (2.51%) and older (chi-squaretrend =  - 6.71, P < 0.001) individuals had a higher risk of KSHV infection. After adjustment, individuals with higher level of education and economic status had lower KSHV infection.

CONCLUSIONS

In non-endemic areas, KSHV transmission may be related to sexual activity in men, especially in male homosexuals. Higher education level and economic status are protective factors for KSHV infection.

Prevalence and Risk Factors of Kaposi’s Sarcoma-Associated Herpesvirus Infection among Han and Uygur Populations in Xinjiang, China

Kaposi's sarcoma-associated herpesvirus (KSHV) is the causative agent of Kaposi's sarcoma (KS), which is endangering human health worldwide, especially in Africa, Europe, the United States, and parts of Asia. The aim of this study was to investigate the prevalence of KSHV in Xinjiang. Three KSHV recombinant proteins (ORF65, ORF73, and K8.1) were used to detect KSHV infection. The serum samples to be tested were detected by an indirect ELISA method. The overall infection rate of KSHV in Xinjiang was 25.60%, with a higher infection rate in the Uygur population of 29.79%. After adjusting for possible confounders, Uygur (OR = 3.95, 95% CI 2.64–6.12, P < 0.001), agriculture and livestock (OR = 1.60, 95% CI 1.20–2.17, P = 0.002), age ≤ 50 years (OR = 1.50, 95% CI 1.13–2.00, P = 0.006), and predominantly meat-based diet (OR = 1.72, 95% CI 1.11–2.78, P = 0.018) were significantly associated with the odds of KSHV seropositivity correlation. Three unique sequences of KSHV were obtained in this study; genotypic analysis showed that the three unique sequences were all subtype A2.

Towards Better Understanding of KSHV Life Cycle: from Transcription and Posttranscriptional Regulations to Pathogenesis

Kaposi’s sarcoma-associated herpesvirus (KSHV), also known as human herpesvirus-8 (HHV-8), is etiologically linked to the development of Kaposi’s sarcoma, primary effusion lymphoma, and multicentric Castleman’s disease. These malignancies often occur in immunosuppressed individuals, making KSHV infection-associated diseases an increasing global health concern with persistence of the AIDS epidemic. KSHV exhibits biphasic life cycles between latent and lytic infection and extensive transcriptional and posttranscriptional regulation of gene expression. As a member of the herpesvirus family, KSHV has evolved many strategies to evade the host immune response, which help the virus establish a successful lifelong infection. In this review, we summarize the current research status on the biology of latent and lytic viral infection, the regulation of viral life cycles and the related pathogenesis.

Kaposi's sarcoma-associated herpesvirus seropositivity is associated with type 2 diabetes mellitus: A case-control study in Xinjiang, China

OBJECTIVE

To assess the potential relationship between Kaposi's sarcoma-associated herpesvirus (KSHV) infection and type 2 diabetes mellitus (DM-2) in Xinjiang, China.

METHODS

A case-control study of consecutively included DM-2 patients and normal controls was conducted among the Uygur and Han populations in Xinjiang Uygur Autonomous Region, China. Blood samples were collected and KSHV seroprevalence, antibody titers, and viral load were investigated. Logistic regression analysis and multiple linear regression analysis were applied to explore determinants of the main outcome measures.

RESULTS

A total of 324 patients with DM-2 and 376 normal controls were included. The seroprevalence of KSHV was 49.1% (95% confidence interval (CI) 43.6-54.5%) for diabetic patients and 23.7% (95% CI 19.4-28.0%) for the control group. After adjusting for variables of ethnicity, sex, body mass index, occupation, educational level, marital status, age, and smoking and alcohol consumption habits, the association between DM-2 and KSHV infection still existed (odds ratio (OR) 2.94, 95% CI 2.05-4.22), and the risk of KSHV infection increased with glucose concentration (OR 1.35, 95% CI 1.21-1.51). KSHV was more likely to express both the latent and lytic antigens in diabetic patients (latent: OR 3.27, 95% CI 2.25-4.75; lytic: OR 3.99, 95% CI 2.68-5.93). Antibody titers and viral load increased in patients with higher blood glucose levels (p<0.001).

CONCLUSIONS

Patients with DM-2 have an elevated risk of KSHV infection. Both antibody titers and viral load increased with blood glucose levels.

Kaposi sarcoma herpesvirus pathogenesis

Kaposi sarcoma herpesvirus (KSHV), taxonomical name human gammaherpesvirus 8, is a phylogenetically old human virus that co-evolved with human populations, but is now only common (seroprevalence greater than 10%) in sub-Saharan Africa, around the Mediterranean Sea, parts of South America and in a few ethnic communities. KSHV causes three human malignancies, Kaposi sarcoma, primary effusion lymphoma, and many cases of the plasmablastic form of multicentric Castleman's disease (MCD) as well as occasional cases of plasmablastic lymphoma arising from MCD; it has also been linked to rare cases of bone marrow failure and hepatitis. As it has colonized humans physiologically for many thousand years, cofactors are needed to allow it to unfold its pathogenic potential. In most cases, these include immune defects of genetic, iatrogenic or infectious origin, and inflammation appears to play an important role in disease development. Our much improved understanding of its life cycle and its role in pathogenesis should now allow us to develop new therapeutic strategies directed against key viral proteins or intracellular pathways that are crucial for virus replication or persistence. Likewise, its limited (for a herpesvirus) distribution and transmission should offer an opportunity for the development and use of a vaccine to prevent transmission.

This article is part of the themed issue ‘Human oncogenic viruses’.

Prevalence of Kaposi's sarcoma-associated herpesvirus in Uygur and Han populations from the Urumqi and Kashgar regions of Xinjiang, China

Kaposi’s sarcoma-associated herpesvirus (KSHV) is the infectious etiologic agent associated with Kaposi’s sarcoma (KS), primary effusion lymphoma, and multicentric Castleman disease. It has been shown that high KSHV prevalence and high incidence of both classic KS and AIDSassociated KS are found mostly among people of Uygur ethnicity in Xinjiang, while people of Han ethnicity in Xinjiang have a higher KSHV seroprevalence than those of other Han populations in mainland China. However, it is still unclear why there is such geographical and population variation in KSHV distribution in China. In this work, we focused on the populations in the Kashgar region and Urumqi area, where a total of 1294 research subjects were randomly selected to investigate the potential correlation between KSHV prevalence and different ethnicities in endemic areas of Xinjiang, and to determine risk factors that may affect KSHV infection rates or KS incidence. We identified a high seroprevalence of KSHV and high peripheral blood DNA infection in the general Uygur and Han populations in both Urumqi and Kashgar regions of Xinjiang, and determined that advancing age, low education level, and stationary population status affect KSHV infection rates. Further, KSHV-positive Uygur participants were shown to have higher prevalence of neutralizing antibodies and neutralizing antibody titers than KSHV-positive Han participants.

Human oncogenic viruses: nature and discovery

Seven kinds of virus collectively comprise an important cause of cancer, particularly in less developed countries and for people with damaged immune systems. Discovered over the past 54 years, most of these viruses are common infections of humankind for which malignancy is a rare consequence. Various cofactors affect the complex interaction between virus and host and the likelihood of cancer emerging. Although individual human tumour viruses exert their malignant effects in different ways, there are common features that illuminate mechanisms of oncogenesis more generally, whether or not there is a viral aetiology.This article is part of the themed issue 'Human oncogenic viruses'.

HIV-associated Kaposi sarcoma and related diseases

: The search for the etiologic agent for Kaposi sarcoma led to the discovery of Kaposi sarcoma-associated herpesvirus (KSHV) in 1994. KSHV, also called human herpesvirus-8, has since been shown to be the etiologic agent for several other tumors and diseases, including primary effusion lymphoma (PEL), an extracavitary variant of PEL, KSHV-associated diffuse large B-cell lymphoma, a form of multicentric Castleman disease, and KSHV inflammatory cytokine syndrome. KSHV encodes several genes that interfere with innate and specific immunity, thwart apoptosis, enhance cell proliferation and cytokine production, and promote angiogenesis, and these play important roles in disease pathogenesis. HIV is an important cofactor in Kaposi sarcoma pathogenesis, and widespread use of antiretroviral therapy has reduced Kaposi sarcoma incidence. However, Kaposi sarcoma remains the second most frequent tumor arising in HIV-infected patients in the United States and is particularly common in sub-Saharan Africa. KSHV prevalence varies substantially in different populations. KSHV is secreted in saliva, and public health measures to reduce its spread may help reduce the incidence of KSHV-associated diseases. Although there have been advances in the treatment of Kaposi sarcoma, KSHV-multicentric Castleman disease, and PEL, improved therapies are needed, especially those that are appropriate for Kaposi sarcoma in resource-poor regions.

Seroprevalence of Kaposi's sarcoma-associated herpesvirus among HIV-infected Uygurs in Xinjiang, China

Kaposi's sarcoma-associated herpesvirus (KSHV) is the etiological agent of Kaposi's sarcoma (KS), which primarily affects human immunodeficiency virus (HIV)-infected adults with advanced immunodeficiency. Xinjiang province in China is an endemic area for Kaposi's sarcoma (KS), however, currently, only limited data for KSHV infection among HIV-infected individuals living in this endemic area is available. A cross-sectional study of 86 HIV positive participants was conducted in Xinjiang, China from 2014 through 2015. Plasma samples were collected and screened for KSHV and HIV infection. HIV pol gene and KSHV ORF-K1 gene were amplified and sequenced, genotypes were determined by phylogenetic analysis. Over all, prevalence was 48.9% (42/86; 95%CI 38.4-59.3%) for KSHV. Only CRF07_BC subtype has been identified among all these HIV positive individuals, while the subtype A and C of KSHV were detected in the participants. Meanwhile, we found that those with high CD4 counts (>500) showed a lower anti-KSHV titer, compared with other groups. Our study indicated a high prevalence of KSHV among HIV positive individuals in Xinjiang, China. Thus, management of HIV/AIDS patients should include KSHV screen and should consider the risk of KSHV-associated malignancies.

Is human herpesvirus 8 infection more common in men than in women? Systematic review and meta-analysis

All forms of Kaposi sarcoma (KS) are more common in men than in women. It is unknown if this is due to a higher prevalence of human herpesvirus 8 (HHV-8), the underlying cause of KS, in men compared to women. We did a systematic review and meta-analysis to examine the association between HHV-8 seropositivity and gender in the general population. Studies in selected populations like for example, blood donors, hospital patients and men who have sex with men were excluded. We searched Medline and Embase from January 1994 to February 2015. We included observational studies that recruited participants from the general population and reported HHV-8 seroprevalence for men and women or boys and girls. We used random-effects meta-analysis to pool odds ratios (OR) of the association between HHV-8 and gender. We used meta-regression to identify effect modifiers, including age, geographical region and type of HHV-8 antibody test. We included 22 studies, with 36,175 participants. Men from sub-Saharan Africa (SSA) [OR 1.21, 95% confidence interval (CI) 1.09-1.34], but not men from elsewhere (OR 0.94, 95% CI 0.83-1.06), were more likely to be HHV-8 seropositive than women (p value for interaction = 0.010). There was no difference in HHV-8 seroprevalence between boys and girls from SSA (OR 0.90, 95% CI 0.72-1.13). The type of HHV-8 assay did not affect the overall results. A higher HHV-8 seroprevalence in men than women in SSA may partially explain why men have a higher KS risk in this region.

Prevalence of Kaposi's sarcoma associated herpesvirus among men attending sexually transmitted infections clinics in Anhui, China

Kaposi's sarcoma-associated herpesvirus (KSHV) may be transmitted via sexual contacts, but limited information is available on KSHV infection status among sexually transmitted infection (STI) patients in China. The main objective of the present study was to determine the KSHV seroprevalence and its risk factors among male STI patients. A cross-sectional survey was conducted in three prefectures of Anhui province, China, between June and September 2013. A total of 1,600 male patients who visited an STI clinic were invited, and 1,372 participated in the study. Data were abstracted from the medical records for all the patients. Blood samples were collected and tested for antibodies to KSHV, HIV, HCV, and syphilis. Factors associated with KSHV seropositivity were examined using multivariable logistic regression analysis. The overall prevalence of KSHV, HIV, HCV, and syphilis was 13.3%, 0.7%, 0.6%, and 12.5%, respectively. After adjusting for potential confounders, KSHV infection was significantly associated with ever having anal sex with men (19 out of 30 males, OR: 8.64, 95%CI: 1.92-38.79) and HIV infection (six out of nine HIV-positive individuals, OR: 8.39, 95%CI: 1.80-39.04). There were no significant associations of KSHV infection with drug use, heterosexual sex behaviors, syphilis, and HCV. Our finding has shown that a relatively moderate prevalence of KSHV was found among male STI patients. While an increased risk for KSHV infection was observed among participants with homosexual contacts. Routine KSHV testing is recommended for male individuals attending STI clinics.

Seroprevalence and determinants of Kaposi sarcoma-associated human herpesvirus 8 in Indian HIV-infected males

In India Kaposi's sarcoma is rarely seen in AIDS patients. Hence the current belief is that the incidence of human herpesvirus-8 (HHV-8) is very low in this subcontinent, most probably due to the heterosexual route of HIV transmission. However, there is a scarcity of data on the prevalence of HHV-8 in India. In India the primary mode of HIV transmission is the heterosexual route. Therefore we aimed to determine the prevalence of antibodies against HHV-8 in North Indian HIV-infected men naive of antiretroviral therapy (ART). In a prospective study, 165 Indian adult males were recruited from an ART clinic. Blood samples were collected before administering any antiretroviral drug. The sera were tested for antibodies against HHV-8 using a commercial enzyme-linked immunosorbent assay (ELISA) kit, which detects IgG antibodies to lytic antigens of HHV-8. All positive samples were confirmed for the presence of anti-HHV-8 antibodies using an indirect immunofluorescence assay (IFA). The IFA kit is intended to detect primary, latent, persistent, or reactivated infection of HHV-8. Of the 165 males, 43 (26.06%) were positive by ELISA while 26 (15.8%) were also positive by IFA. Seroprevalence decreased with increasing age (p<0.05). Factors independently associated with HHV-8 infection were younger age group and alcohol consumption. These findings suggest that even in a heterosexual population, HHV-8 can be transmitted frequently.

Genotypic analysis of Kaposi's sarcoma-associated herpesvirus from patients with Kaposi's sarcoma in Xinjiang, China

Kaposi's sarcoma-associated herpesvirus (KSHV) is the causal agent of all forms of Kaposi's sarcoma (KS), including AIDS-KS, endemic KS, classic KS and iatrogenic KS. Based on Open reading frame (ORF) K1 sequence analysis, KSHV has been classified into seven major molecular subtypes (A, B, C, D, E, F and Z). The distribution of KSHV strains varies according to geography and ethnicity. Xinjiang is a unique region where the seroprevalence of KSHV is significantly higher than other parts of China. The genotyping of KSHV strains in this region has not been thoroughly studied. The present study aimed to evaluate the frequency of KSHV genotypes isolated from KS tissues in Classical KS and AIDS KS patients from Xinjiang, China. ORF-K1 of KSHV from tissue samples of 28 KS patients was amplified and sequenced. Two subtypes of KSHV were identified according to K1 genotyping. Twenty-three of them belonged to subtype A, while five of them were subtype C. More genotype A than genotype C strains were found in both Classical KS and AIDS KS. No significant difference was found in the prevalence of different genotype between Classical KS and AIDS KS.

Epidemiology and transmission of Kaposi's sarcoma-associated herpesvirus

This review summarizes the current knowledge pertaining to Kaposi sarcoma-associated herpesvirus (KSHV) epidemiology and transmission. Since the identification of KSHV twenty years ago, it is now known to be associated with Kaposi's sarcoma (KS), primary effusion lymphoma, and multicentric Castleman's disease. Many studies have been conducted to understand its epidemiology and pathogenesis and their results clearly show that the worldwide distribution of KSHV is uneven. Some geographical areas, such as sub-Saharan Africa, the Mediterranean region and the Xinjiang region of China, are endemic areas, but Western Europe and United States have a low prevalence in the general population. This makes it imperative to understand the risk factors associated with acquisition of infection. KSHV can be transmitted via sexual contact and non-sexual routes, such as transfusion of contaminated blood and tissues transplants, or via saliva contact. There is now a general consensus that salivary transmission is the main route of transmission, especially in children residing in endemic areas. Therefore, there is a need to better understand the sources of transmission to young children. Additionally, lack of animal models to study transmission, gold standard serological assay and the lack of emphasis on endemic KS research has hampered the efforts to further delineate KSHV transmission in order to design effective prevention strategies.

The conundrum of causality in tumor virology: the cases of KSHV and MCV

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. MCV and Merkel cell carcinoma (MCC), in contrast, is an example in which mutations to our normal viral flora contribute to cancer. Given the near-ubiquity of human MCV infection, establishing cancer causality relies on molecular evidence that does not fit comfortably within traditional infectious disease epidemiological models. These two viruses reveal some of the challenges and opportunities for inferring viral cancer causation in the age of molecular biology.

One hundred and five Kaposi sarcoma patients: a clinical study in Xinjiang, Northwest of China

BACKGROUND

Kaposi's sarcoma (KS) is an unusual illness that may be associated with human herpes virus 8 (HHV-8) infections, and appears mainly in Jews, Italians and Greeks. There is a lack of patient data in Xinjiang regarding the clinical characteristics of KS.

OBJECTIVES

To review the clinical characteristics of a series of patients with KS in Xinjiang, Northwest China, over 16-year period.

METHODS

A retrospective analysis of patients referred to a Xinjiang hospital in Northwest China with classic KS (CKS) and AIDS-associated KS (AIDS-KS) between January 1997 and April 2013 was performed. Reviewed information included demographics, clinical features, histopathological traits, treatment and presence of HHV-8 infection.

RESULTS

During the study period, 105 patients with a diagnosis of KS, including 77 CKS and 28 AIDS-KS, were referred to our hospital. Mean age at diagnosis was 55.8 ± 16.8 years (range: 25-85 years). There were 70 (90.9%) males and 7 (9.1%) females (male-to-female ratio: 10 : 1) having CKS and 21 (75.0%) males and 7 (25.0%) females (male-to-female ratio: 3 : 1) with AIDS-KS. Most of the patients were Uyghur, including 67 CKS and 24 AIDS-KS. The rate of multifocal lesions at diagnosis was 98.1% (103/105). The most common area of lesions was between 1% and 5% of CKS and AIDS-KS. The main types of lesions were nodules, patches and plaques. The lower extremity and foot were the most common locations for CKS and AIDS-KS. In addition to skin damage, the penis, mouth, lymph nodes and interstitial lung tissues were involved in some cases. No second primary malignancy was diagnosed. Systemic chemotherapy and radiotherapy were effective treatments for CKS. The HHV-8 positivity rate was 98.98% in 98 KS cases.

CONCLUSIONS

In Xinjiang, most CKS and AIDS-KS patients were older Uyghur men. AIDS-KS was found predominantly among 30-year-old Uyghur patients, compared with 60 years for those having CKS. The latter exhibited certain characteristics such as disseminated skin disease; in some patients, the condition was accompanied by lymphedema, visceral or lymph node involvement, but no secondary malignancies. In addition, the HHV-8 positivity rate associated with KS was very high.

High prevalence of early childhood infection by Kaposi's sarcoma-associated herpesvirus in a minority population in China

In China, KSHV seroprevalence varies considerably among different regions and ethnicities. But in Xinjiang province, located in the northwestern China, there is a very high seroprevalence of KSHV in adults of Kazak and Ughur ethnicities. However, KSHV prevalence in children and the risk factors associated with the acquisition of infection are currently not known. The aim of this study was to investigate the prevalence of KSHV infection and identify associated socioeconomic or behavioural risk factors and the humoral immune response among children in this population. This is a cross-sectional study (N = 178) to screen children and their caregivers from Xinjiang for total KSHV antibodies, KSHV neutralizing antibodies and HIV infection. Structured questionnaires were utilized to investigate risk factors associated with KSHV prevalence. KSHV seroprevalence in children and caregivers in Xinjiang was 48.3% and 64.7%, respectively. Neutralizing antibody was detected in most seropositive caregivers (93.8%) but was detected in only 5.8% of the infected children. A significant association was observed between child KSHV seroprevalence and sharing of food among family members. These results suggest that similar to other endemic areas in Africa, KSHV infection in the minority populations of Xinjiang is likely to be occurring during early childhood, probably via horizontal transmission through saliva, and results in high seroprevalence in the adult population.

Kaposi sarcoma associated herpesvirus pathogenesis (KSHV)--an update

Kaposi sarcoma-associated herpesvirus (KSHV) is the etiological agent of several human malignancies. The virus is able to modulate pro-proliferative pathways to its advantage, while simultaneously inhibiting pro-apoptotic signaling pathways. These functions are carried out by multiple viral proteins acting in concert. The overall outcome is the survival and proliferation of the infected cell. Additionally, the virus also modulates innate immune pathways to allow for prolonged survival of the infected cell following primary infection, and during viral latency. Here we review the latest advances in our knowledge of KSHV pathogenesis.

Gender differences in Kaposi's sarcoma-associated herpesvirus infection in a population with schistosomiasis in rural China

Kaposi's sarcoma-associated herpesvirus (KSHV) is the causal agent of Kaposi's sarcoma (KS), a common cancer in patients with acquired immunodeficiency syndrome. The risk factors for KSHV infection have been extensively studied for Western countries but remain largely undefined for other parts of the world. Schistosomiasis, caused by Schistosoma japonicum infection, was recently identified as a cofactor for KSHV infection in rural Egypt. In this study, we examined the seroprevalence of KSHV in a population along the Yangtze River in China that has a high incidence of schistosomiasis. KSHV seroprevalence in subjects with schistosomiasis was slightly higher than that in subjects without schistosomiasis, but the difference was not statistically significant (8.4% versus 6.6%; P = 0.204). However, after adjusting for gender, KSHV seroprevalence in men with schistosomiasis was found to be significantly higher than that in men without schistosomiasis (8.4% versus 2.8%; odds ratio [OR], 3.170; 95% confidence interval [CI], 1.501-6.694; P = 0.002). Compared to men, women showed significantly higher seroprevalence of KSHV (5.9% versus 9.3%; OR, 1.621; 95% CI, 1.084-2.425; P = 0.019).

Prevalence and correlates of Kaposi's sarcoma-associated herpesvirus infection in a sample of men who have sex with men in eastern China

This study aimed to determine the seroprevalence of Kaposi's sarcoma-associated herpesvirus (KSHV) and related factors in men who have sex with men (MSM) in China. A total of 208 subjects were recruited from eastern China from 2008 to 2009. Plasma samples were collected and screened for KSHV, HIV and syphilis. Overall, KSHV seroprevalence was 32·7% in the subjects. About 92·7% of subjects reported having ever had anal sex with a man, of whom 67·8% had receptive anal sex and 77·9% had insertive anal sex. About 93·1% of the study participants reported having had oral sex with a man, of whom 76·0% had receptive oral sex and 56·7% had insertive oral sex. KSHV seropositivity was independently associated with receptive anal sex [odds ratio (OR) 2·68, 95% confidence interval (CI) 1·15–6·23], syphilis (OR 3·25, 95% CI 1·56–6·76) and HSV-2 infection (OR 2·40, 95% CI 1·09–5·26). KSHV infection is highly prevalent and is probably sexually transmitted among MSM in eastern China.

Seroprevalence and risk factors of Kaposi's sarcoma-associated herpesvirus infection among the general Uygur population from south and north region of Xinjiang, China

Background

Kaposi sarcoma (KS) is a complex multifocal neoplasm and is the major cause of death for about 50% of acquired immunodeficiency syndrome (AIDS) patients. Kaposi's sarcoma-associated herpesvirus (KSHV) is an oncogenic virus with a causal role in the development of all types of KS. KS is prevalent among the Uygur people in Xinjiang, especially in south area. Here we carried out a cross-sectional study among 1534 general Uygur individuals from south and north region of Xinjiang to assess the seroprevalence of KSHV and to identify the potential correlation between KSHV seroprevalence and KS incidence.

Results

Seroprevalence of KSHV in South and North Xinjiang was 23.1% and 25.9%, respectively. Older age was independently associated with higher KSHV seroprevalence. In subjects from South Xinjiang, lower educational level and reported drinking were each independently associated with higher KSHV seroprevalence. Furthermore, the antibody titer was significantly lower in both south and north KSHV seropositive individuals compared with KS patients, as analyzed by gradient dilution (P < 0.001).

Conclusion

KSHV is highly prevalent in the general Uygur population in both South and North Xinjiang. Interestingly, the infection rate of KSHV in these two geographical areas did not correlate well with KS incidence. Perhaps unknown factors exist that promote the progression of KSHV infection to KS development in the local minority groups.

Prevalence of human herpesvirus 8 and hepatitis C virus in a rural community with a high risk for blood-borne infections in central China

Illegal blood donation in the past decade has caused human immunodeficiency virus (HIV) outbreaks in some rural areas in China. Other HIV-associated virus infections, such as those caused by human herpesvirus 8 (HHV8), in such areas are still not well defined. In order to explore HHV8 and hepatitis C virus (HCV) seroprevalence and potential risk factors in such areas, a cross-sectional study with 305 HIV-positive and 315 HIV-negative subjects recruited from a rural county in Shanxi province was conducted, in which illegal blood collection was reported. Interview questionnaires and serum testing were carried out with these participants. HCV and HHV8 seroprevalence were found to be higher in the HIV-positive than in the HIV-negative group (76.4% vs. 2.5% and 15.4% vs. 4.8%, respectively), whereas the difference in HBV seroprevalence was not significant. Co-infection with HCV and HHV8 was also more prevalent in the HIV-positive group. HIV status (OR 2.71; 95% CI 1.16-6.30) and HBV status (OR 2.56; 95% CI 1.14-5.75) were independently associated with HHV8 infection. HIV status (OR 23.03; 95% CI 9.95-53.27) and blood/plasma selling history (OR 14.57; 95% CI 7.49-28.23) were strongly associated with HCV infection. These findings demonstrate that both HHV8 and HCV infections are prevalent in this community. HIV infection is an important risk factor for both HHV8 and HCV infection. HBV infection is associated with HHV8 infection but not with HCV infection. It is possible that HHV8 and hepatitis B virus, but not HCV, have similar modes of transmission in this population.

Herpes viruses in transplant recipients: HSV, VZV, human herpes viruses, and EBV

The herpes viruses are responsible for a wide range of diseases in patients following transplant, resulting from direct viral effects and indirect effects, including tumor promotion. Effective treatments and prophylaxis exist for the neurotropic herpes viruses HSV-1, HSV-2, varicella zoster virus, and possibly HHV-6. Antivirals seem to be less effective at prevention of the tumor-promoting effects of Epstein-Barr virus and HHV-8. Reduction in immunosuppression is the cornerstone to treatment of many diseases associated with herpes virus infections.

Risk factors influencing antibody responses to Kaposi's sarcoma-associated herpesvirus latent and lytic antigens in patients under antiretroviral therapy

BACKGROUND

Kaposi's sarcoma-associated herpesvirus (KSHV) seropositivity and lytic antibody titer are predictors for Kaposi's sarcoma.

METHODS

We examined demographic, viral, and immunologic factors that influence KSHV latent and lytic antibodies in HIV-infected patients.

RESULTS

Detection rate of KSHV latent but not lytic antibodies was lower in patients with CD4 cells/mm3 less than 200 than greater than 200 (odds ratio [OR], 0.26; 95% confidence interval [CI], 0.11-0.61) and CD8 cells/mm3 less than 400 than greater than 400 (OR, 0.26; 95% CI, 0.07-0.67). Overall seropositivity rate was higher in patients with CD4 cells/mm3 less than 200 than greater than 200 (OR, 2.34; 95% CI, 1.37-4.02) and HIV copies/mL greater than 400 than less than 400 (OR, 1.70; 95% CI, 1.09-2.65). Lytic antibody level was inversely correlated with CD4 count (P < 0.001). Lytic seropositivity (OR, 2.47; 95% CI, 1.35-4.50) and antibody level (adjusted difference mean optical density, 0.324; 95% CI, 0.16-0.46) were higher in patients with HIV infection greater than 15 than less than 15 years. Hispanics had higher lytic seropositivity rate (OR, 1.71; 95% CI, 1.07-2.73) and antibody level (adjusted difference mean optical density, 0.111; 95% CI, 0.03-0.18) than non-Hispanics.

CONCLUSIONS

Lower CD4 and CD8 counts impair antibody response to KSHV latent antigens. Immune deterioration, long-term HIV infection, and Hispanic status are risk factors for Kaposi's sarcoma predictors.

Classic Kaposi's sarcoma in Han Chinese and useful tools for differential diagnosis

Kaposi's sarcoma (KS) is a common AIDS-related malignant neoplasm in the head and neck region, especially in the oral cavity, but is rarely described in the HIV-negative and non-immunosuppressed individual. Our case is of interest, because it is the first case in which manifestation of the KS occurred in the face and head areas in a patient with a Han ethnic background who had an adequate immune system. The lesions were diagnosed as angiosarcomas twice. The clinical presentation, therapeutic options, and tools for differentiating Kaposi sarcoma from other vascular and nonvascular spindle cell lesions are presented, and the relevant literature is reviewed.

Establishment of an ELISA to detect Kaposi's sarcoma-associated herpesvirus using recombinant ORF73

Kaposi's sarcoma-associated herpesvirus (KSHV) is causally related to Kaposi's sarcoma (KS), primary effusion lymphoma (PEL) and a proportion of cases of multicentric Castleman's disease (MCD). The ORF73 protein was cloned into pQE80L-orf73 and expressed in E.coli and purified. The expressed recombinant ORF73 was identified by sodium dodecyl sulfatepolyacrylamide gel electrophoresis (SDS-PAGE). A protein of about 27 kDa was expressed as expected. Western Blotting showed that the purified recombinant ORF73 reacted with KSHV positive serum. The immunogenicity of the recombinant ORF73 was further analysed by ELISA and the optimal conditions were determined. The ORF73 ELISA was used to compare the KSHV seroprevalence between Hubei and Xinjiang Han people. The Han people in Xinjiang have significantly higher KSHV seroprevalence than their counterparts in Hubei (6.7% vs 2.9%, P = 0.005).

Human herpesvirus-8 in northwestern China: epidemiology and characterization among blood donors

Background

Human herpes virus 8 (HHV-8) is the etiologic agent associated with development of classical, AIDS-related, iatrogenic, and endemic Kaposi's sarcoma (KS). Several studies provide strong evidence that HHV-8 can be transmitted by blood transfusion. We evaluated the seroprevalence and potential risk factors of HHV-8 infection in blood donors in one region. We surveyed HHV-8 infection among 4461 blood donors in Xinjiang, China, a unique endemic area for HHV-8 and KS.

Results

The HHV-8 seroprevalence was higher in local minority groups which comprise most KS cases in China, than in Han people. HHV-8 prevalence was 18.6% in the Han ethnic group, 25.9% in Uygur subjects, 29.2% in Kazak subjects, 36.8% in Mongolian subjects, and 21.9% in other ethnic groups. In several subgroups, the time of donation of whole blood seemed to be a risk factor. In HHV-8-seropositive subjects, a larger fraction of local minorities (23.9%) had high HHV-8 titers than that of Han subjects (9.2%). HHV-8 infection was associated with ethnicity and residence.

Conclusion

HHV-8 seroprevalence was significantly high among blood donors in Xinjiang, where the prevalence of KS correlates with HHV-8 prevalence and titers in Uygur and Kazak ethnic groups. Blood exposure represented by the frequency of blood donation indicated a possible blood-borne transmission route of HHV-8 in Xinjiang. Detecting anti-HHV-8 antibodies before donation in this region is therefore important.