Sequencing of Kaposi's Sarcoma Herpesvirus (KSHV) genomes from persons of diverse ethnicities and provenances with KSHV-associated diseases demonstrate multiple infections, novel polymorphisms, and low intra-host variance.

Recently published near full-length KSHV genomes from a Cameroon Kaposi sarcoma case-control study showed strong evidence of viral recombination and mixed infections, but no sequence variations associated with disease. Using the same methodology, an additional 102 KSHV genomes from 76 individuals with KSHV-associated diseases have been sequenced. Diagnoses comprise all KSHV-associated diseases (KAD): Kaposi sarcoma (KS), primary effusion lymphoma (PEL), KSHV-associated large cell lymphoma (KSHV-LCL), a type of multicentric Castleman disease (KSHV-MCD), and KSHV inflammatory cytokine syndrome (KICS). Participants originated from 22 different countries, providing the opportunity to obtain new near full-length sequences of a wide diversity of KSHV genomes. These include near full-length sequence of genomes with KSHV K1 subtypes A, B, C, and F as well as subtype E, for which no full sequence was previously available. High levels of recombination were observed. Fourteen individuals (18%) showed evidence of infection with multiple KSHV variants (from two to four unique genomes). Twenty-six comparisons of sequences, obtained from various sampling sites including PBMC, tissue biopsies, oral fluids, and effusions in the same participants, identified near complete genome conservation between different biological compartments. Polymorphisms were identified in coding and non-coding regions, including indels in the K3 and K15 genes and sequence inversions here reported for the first time. One such polymorphism in KSHV ORF46, specific to the KSHV K1 subtype E2, encoded a mutation in the leucine loop extension of the uracil DNA glycosylase that results in alteration of biochemical functions of this protein. This confirms that KSHV sequence variations can have functional consequences warranting further investigation. This study represents the largest and most diverse analysis of KSHV genome sequences to date among individuals with KAD and provides important new information on global KSHV genomics.

KSHV infection of B cells primes protective T cell responses in humanized mice.

Kaposi sarcoma associated herpesvirus (KSHV) is associated with around 1% of all human tumors, including the B cell malignancy primary effusion lymphoma (PEL), in which co-infection with the Epstein Barr virus (EBV) can almost always be found in malignant cells. Here, we demonstrate that KSHV/EBV co-infection of mice with reconstituted human immune systems (humanized mice) leads to IgM responses against both latent and lytic KSHV antigens, and expansion of central and effector memory CD4+ and CD8+ T cells. Among these, KSHV/EBV dual-infection allows for the priming of CD8+ T cells that are specific for the lytic KSHV antigen K6 and able to kill KSHV/EBV infected B cells. This suggests that K6 may represent a vaccine antigen for the control of KSHV and its associated pathologies in high seroprevalence regions, such as Sub-Saharan Africa.

Inflammasome activation in patients with Kaposi sarcoma herpesvirus (KSHV)-associated disorders.

Kaposi sarcoma herpesvirus (KSHV)-associated disorders include Kaposi sarcoma (KS), primary effusion lymphoma (PEL), KSHV-associated multicentric Castleman disease (MCD) and KSHV-inflammatory cytokine syndrome (KICS). PEL, MCD, and KICS are associated with elevated circulating inflammatory cytokines. However, activation of the inflammasome, which generates IL-1 and IL-18 via active caspase-1/4/5, has not been evaluated in patients with KAD. Here we report that patients with HIV and one or more KAD present with higher plasma levels of IL-18 and increased caspase-1/4/5 activity in circulating monocytes as compared to HIV-negative healthy volunteers (HV) or people with HIV without KAD (PWH). Within KAD subtypes, KICS and MCD shared enhanced caspase-1/4/5 activity and IL-18 production when compared to HV and PWH, while patients with PEL showed remarkably high levels of inflammasome complex formation (known as apoptosis-associated speck-like protein containing a caspase recruitment domain (CARD) (ASC)-speck). Moreover, caspase-1/4/5 activity and IL-18 plasma levels correlated with KSHV viral load, indicating KSHV-driven inflammasome activation in KAD. Accordingly, factors released by KSHV-latently infected cells triggered inflammasome activation and cytokine production in bystander monocytes, in vitro. Finally, both supervised and unsupervised analyses with inflammasome measurements and other inflammatory biomarkers demonstrate a unique inflammatory profile in patients with PEL, MCD, and KICS as compared to KS. Our data indicate that detrimental inflammation in patients with KAD is at least partially driven by KSHV-induced inflammasome activation in monocytes, thus offering novel approaches to diagnose and treat these complex disorders.

HIV-associated cancers and lymphoproliferative disorders caused by Kaposi sarcoma herpesvirus and Epstein-Barr virus.

SUMMARYWithin weeks of the first report of acquired immunodeficiency syndrome (AIDS) in 1981, it was observed that these patients often had Kaposi sarcoma (KS), a hitherto rarely seen skin tumor in the USA. It soon became apparent that AIDS was also associated with an increased incidence of high-grade lymphomas caused by Epstein-Barr virus (EBV). The association of AIDS with KS remained a mystery for more than a decade until Kaposi sarcoma-associated herpesvirus (KSHV) was discovered and found to be the cause of KS. KSHV was subsequently found to cause several other diseases associated with AIDS and human immunodeficiency virus (HIV) infection. People living with HIV/AIDS continue to have an increased incidence of certain cancers, and many of these cancers are caused by EBV and/or KSHV. In this review, we discuss the epidemiology, virology, pathogenesis, clinical manifestations, and treatment of cancers caused by EBV and KSHV in persons living with HIV.

Immune cell phenotype and function patterns across the life course in individuals from rural Uganda.

Background: To determine the pattern of immune cell subsets across the life span in rural sub-Saharan Africa (SSA), and to set a reference standard for cell subsets amongst Africans, we characterised the major immune cell subsets in peripheral blood including T cells, B cells, monocytes, NK cells, neutrophils and eosinophils, in individuals aged 3 to 89 years from Uganda. Methods: Immune phenotypes were measured using both conventional flow cytometry in 72 individuals, and full spectrum flow cytometry in 80 individuals. Epstein-Barr virus (EBV) IFN-γ T cell responses were quantified in 332 individuals using an ELISpot assay. Full blood counts of all study participants were also obtained. Results: The percentages of central memory (TCM) and senescent CD4+ and CD8+ T cell subsets, effector memory (TEM) CD8+ T cells and neutrophils increased with increasing age. On the other hand, the percentages of naïve T (TN) and B (BN) cells, atypical B cells (BA), total lymphocytes, eosinophils and basophils decreased with increasing age. There was no change in CD4+ or CD8+ T effector memory RA (TEMRA) cells, exhausted T cells, NK cells and monocytes with age. Higher eosinophil and basophil percentages were observed in males compared to females. T cell function as measured by IFN-γ responses to EBV increased with increasing age, peaking at 31-55 years. Conclusion: The percentages of cell subsets differ between individuals from SSA compared to those elsewhere, perhaps reflecting a different antigenic milieu. These results serve as a reference for normal values in this population.

Kaposi sarcoma herpesvirus viral load in bronchoalveolar lavage as a diagnostic marker for pulmonary Kaposi sarcoma.

OBJECTIVE: Kaposi sarcoma is a vascular tumor that affects the pulmonary system. However, the diagnosis of airway lesions suggestive of pulmonary Kaposi sarcoma (pKS) is reliant on bronchoscopic visualization. We evaluated the role of Kaposi sarcoma herpesvirus (KSHV) viral load in bronchoalveolar lavage (BAL) as a diagnostic biomarker in patients with bronchoscopic evidence of pKS and evaluated inflammatory cytokine profiles in BAL and blood samples. DESIGN: In this retrospective study, we evaluated KSHV viral load and cytokine profiles within BAL and blood samples in patients who underwent bronchoscopy for suspected pKS between 2016 and 2021. METHODS: KSHV viral load and cytokine profiles were obtained from both the circulation and BAL samples collected at the time of bronchoscopy to evaluate compartment-specific characteristics. BAL was centrifuged and stored as cell pellets and KSHV viral load was measured using primers for the KSHV K6 gene regions. RESULTS: We evaluated 38 BAL samples from 32 patients (30 with HIV co-infection) of whom 23 had pKS. In patients with airway lesions suggestive of pKS, there was higher KSHV viral load (median 3188 vs. 0 copies/10 6 cell equivalent; P  = 0.0047). A BAL KSHV viral load cutoff of 526 copies/10 6 cells had a sensitivity of 72% and specificity of 89% in determining lesions consistent with pKS. Those with pKS also had higher IL-1ß and IL-8 levels in BAL. The 3-year survival rate for pKS patients was 55%. CONCLUSION: KSHV viral load in BAL shows potential for aiding in pKS diagnosis. Patients with pKS also have evidence of cytokine dysregulation in BAL.

Human papillomavirus false positive cytological diagnosis in low grade squamous intraepithelial lesion

The purpose of this study was to investigate the number of Human Papillomavirus false positive cytological diagnosis in low grade squamous intraepithelial lesions (LSIL). Three hundred and two women who assisted to an Out-Patient Gynecologic Clinic in Maracaibo, Venezuela, were recruited for this study. Each patient had the Pap smear and a cervical swab for Hybrid Capture 2 (HC2). Three cytotechnologists reviewed the Pap smears and two pathologists rescreened all of them. The cytotechnologists reported 161 (53.3 percent) Pap smears negatives for intraepithelial lesion (IL) or malignancy, and 141 cases (46.7 percent) with epithelial abnormalities. They reported 46 percent of 302 patients with HPV infection in Pap smear slides. The pathologists found that 241 (79.8 percent) Pap smears were negatives for IL or malignancy and 61 (20.2 percent), with abnormal Pap smears. They found 14.6 percent HPV infection in all Pap smears (p<0.0001; 46 percent vs 14.6 percent). The HC2 study showed that 47 samples (15.6 percent) were positive for HPV. The study found that 114 Pap smears (False Positive: 85 percent) of 134 reported by the cytotechnologists and 24 (False Positive: 43 percent) of 56 cytologies reported by the pathologists as LSIL, were negative for HPV infection determined by HC2 (p<0.00003). The present study suggests that the cytotechnologists overdiagnosed cellular changes associated with HPV infection in the Pap smear, increasing the FP cytological diagnosis of LSIL.

El presente trabajo tuvo por objeto el investigar el número de falsos positivos reportados en la citología cervicovaginal (CCV) de la presencia del Virus del Papiloma Humano (VPH) con diagnóstico de Lesión Intraepitelial Escamosa de bajo grado (LIE-BG). Se estudiaron 302 mujeres que asistieron a la Consulta de Patología de Cuello Uterino del Hospital Manuel Noriega Trigo, en Maracaibo, Venezuela. A cada paciente se le practicaron una CCV y muestra para la captura de híbridos 2 (CH2). Tres citotecnólogos y 2 patólogos estudiaron las CCV. Los citotecnólogos reportaron 161(53,3 por ciento) de CCV negativas para lesión intraepitelial o malignidad y 141 casos (46,7 por ciento) con anomalías epiteliales. Éstos encontraron 46 por ciento de presencia de VPH en las 302 CCV. Los patólogos reportaron 241 CCV (79,8 por ciento) negativas y 61 CCV (20,2 por ciento) anormales. Estos encontraron en 14,6 por ciento de las CCV, la presencia de VPH (p < 0, 0001; 46 por ciento vs 14,6 por ciento). La CH2 mostró que 47 muestras (15, 6 por ciento) fueron positivas a VPH. Esta investigación mostró que 112 CCV de 134 (Falso Positivo: 85 por ciento) reportados por los citotecnólogos y 24 de 56 CCV (Falso Positivo: 43 por ciento) reportados por los patólogos como LIE-BG, fueron negativos a la infección del VPH determinados por la CH2 (p < 0,00003). La investigación sugiere un sobrediagnóstico de la presencia de cambios celulares debidos al VPH en la CCV, por parte de los citotecnólogos, incrementando los falsos positivos de la presencia del VPH en CCV con diagnóstico de LIE-BG.

Prevalence and risk factors of human papillomavirus infection in asymptomatic women in a Venezuelan urban area

The purpose of this study was to investigate the prevalence and risk factors of genital human papillomavirus (HPV) infection in asymptomatic women, using the HPV DNA Hybrid Capture 2 (HC2) test. Three hundred and two women who attended the Out-Patient Gynecological Clinic of a tertiary level hospital, in a Venezuelan urban area, were selected for the study. A pap smear, a cervical swab for HC2 and gynecological exam were performed to each patient. The HC2 testing showed that 47 samples (15.6%) were positive to HPV. Forty patients (13.2%) were positive to high risk-HPV (HR-HPV) and 11 (3.6%) were positive to low-risk-HPV (LR-HPV). The prevalence of HPV infections was higher for women under 35 years (51.1%; p < 0.02), and decreased to 6.4% for women 65 years old. Women who had not finished high school had a higher prevalence of HPV infection (p < 0.035). Twenty six (42.6%) of 61 pathological Pap smears were positives to HPV infection. A statistically significant difference was found when HPV infection was compared in normal and abnormal Pap smear (HSIL+LSIL; p<0.0001). Twenty four of 56 (43%) women with diagnosis of LSIL, and 2(40%) of 5 with diagnosis of HSIL were positive for HPV infection. A statistically significant difference was found when we compared HPV infection in negative Pap smears and those with LSIL (p<0.001). The present study found that the prevalence of HPV infection in asymptomatic Venezuelan women who attended a tertiary level hospital was 15.6%. HPV infection was more frequent in young adult, and in women with low educational level.

El propósito de este estudio fue investigar la prevalencia y factores de riesgo que influencia la presencia de la infección por el virus del papiloma humano (VPH) en pacientes asintomáticas que asistieron a un hospital nivel 3 en un área urbana venezolana. Se estudiaron las pacientes que acudieron a la Consulta de Patología del Cuello Uterino del Hospital Manuel Noriega Trigo. A cada paciente se le realizó una historia clínica, toma de citología cervico-vaginal y una muestra del cérvix para captura de híbridos 2(CH2). Se incluyeron 302 pacientes. La CH2 mostró 47 muestras (15,6%) positivas al VPH. Cuarenta mujeres (13,2%) fueron positivas a VPH de alto riesgo (VPH-AR) y 11 (3,6%) a VPH de bajo riesgo (VPH-BR). La prevalencia de la infección por VPH fue más alta en mujeres 35 años (51,1%; p < 0,02) y disminuyó a un 6,4% en mujeres 65 años. Las pacientes que no habían terminado los estudios de bachillerato presentaron un prevalencia más elevada del VPH (p < 0,035). Veinte y seis (42,6%) de 61 CCV patológicas fueron positivas a la infección del VPH. Una diferencia estadísticamente significativa fue encontrada cuando se comparó la presencia del VPH en las CCV normales con las CCV anormales (Lesión Intraepitelial Escamosa de Alto y Bajo Grado-LIE-AG y LIE-BG; p < 0,0001). Veinte y cuatro de 56 (43%) mujeres con diagnostico de LIE-BG, y 2(40%) de 5 con diagnóstico de LIE-AG fueron positivos a la presencia del VPH. Se encontró una diferencia estadísticamente significativa cuando se comparó la presencia de infección por el VPH en CCV normales y CCV con LIE-BG (p < 0,001). El presente estudio encontró una prevalencia de la infección por el VPH en mujeres asintomáticas que asisten a un hospital nivel 3 de 15,6% en área urbana venezolana. Fue más frecuente en mujeres jóvenes y de bajo nivel educacional.