People living with HIV co-infected with the Kaposi Sarcoma-associated Herpes Virus have a distinct HIV Tat profile and higher rates of antiretroviral virologic failure, more evident among those with Kaposi's sarcoma.

Kaposi sarcoma (KS) is a neoplasm of vascular origin that promotes angiogenesis and the growth of endothelial cells triggered by the Kaposi Sarcoma-associated Herpes Virus (KSHV). When associated with HIV, KSHV becomes more aggressive and rapidly evolves. The HIV-1 TAT protein can be essential in developing AIDS-associated KS by promoting angiogenesis and increasing KSHV replication. Therefore, we evaluated the genetic profile of the first exon of tat gene among groups of people living with HIV (PLHIV) with (case group, n = 36) or without KS, this later with (positive control group, n = 46) and without KSHV infection (negative control group, n = 24); all individuals under antiretroviral therapy. The genetic diversity, the DN/DS ratio, and the genetic entropy of the first exon of tat were higher in the case group, followed by the positive control group, which was higher than the negative control group. The number of tat codons under positive selection was seven in the case group, six in the positive control group, and one in the negative control group. The prevalence of HIV viral loads below the detection limit was equal in the case and positive control groups, which were lower than in the negative control group. The mean CD4+ T cell counts were higher in the negative control group, followed by the positive control group, and followed by the case group. These results emphasize the negative influence of KSHV in antiretroviral treatment, as well as the HIV-specific TAT profile among PLHIV who developed KS.

Unveiling the role of KSHV-infected human mesenchymal stem cells in Kaposi's sarcoma initiation.

Kaposi's sarcoma (KS) may derive from Kaposi's sarcoma herpesvirus (KSHV)-infected human mesenchymal stem cells (hMSCs) that migrate to sites characterized by inflammation and angiogenesis, promoting the initiation of KS. By analyzing the RNA sequences of KSHV-infected primary hMSCs, we have identified specific cell subpopulations, mechanisms, and conditions involved in the initial stages of KSHV-induced transformation and reprogramming of hMSCs into KS progenitor cells. Under proangiogenic environmental conditions, KSHV can reprogram hMSCs to exhibit gene expression profiles more similar to KS tumors, activating cell cycle progression, cytokine signaling pathways, endothelial differentiation, and upregulating KSHV oncogenes indicating the involvement of KSHV infection in inducing the mesenchymal-to-endothelial (MEndT) transition of hMSCs. This finding underscores the significance of this condition in facilitating KSHV-induced proliferation and reprogramming of hMSCs towards MEndT and closer to KS gene expression profiles, providing further evidence of these cell subpopulations as precursors of KS cells that thrive in a proangiogenic environment.

Impact of valganciclovir therapy on severe IRIS-Kaposi Sarcoma mortality: An open-label, parallel, randomized controlled trial.

INTRODUCTION: High HHV-8 viral load (VL) in Kaposi Sarcoma (KS) has been associated with Severe Immune Reconstitution Inflammatory Syndrome (Severe-IRIS-KS), which can occur after initiating cART, and leads to high mortality, particularly in patients with pulmonary involvement. We investigate if valganciclovir (as an anti-HHV-8 agent) initiated before cART reduces the mortality associated with Severe-IRIS-KS and the incidence of Severe-IRIS-KS. METHODS: Open-label parallel-group randomized clinical trial in AIDS cART naïve patients with disseminated KS (DKS) as defined by at least two of the following: pulmonary, lymph-node, or gastrointestinal involvement, lymphedema, or ≥30 skin lesions. In the experimental group (EG), patients received valganciclovir 900 mg BID four weeks before cART and continued until week 48; in the control group (CG), cART was initiated on week 0. Non-severe-IRIS-KS was defined as: an increase in the number of lesions plus a decrease of ≥one log10 HIV-VL, or an increase of ≥50cells/mm3 or ≥2-fold in baseline CD4+cells. Severe-IRIS-KS was defined as abrupt clinical worsening of KS lesions and/or fever after ruling out another infection following cART initiation, and at least three of the following: thrombocytopenia, anemia, hyponatremia, or hypoalbuminemia. RESULTS: 40 patients were randomized and 37 completed the study. In the ITT analysis, at 48 weeks, total mortality was the same in both groups (3/20), severe-IRIS-KS attributable mortality was 0/20 in the EG, compared with 3/20 in the CG (p = 0.09), similar to the per-protocol analysis: 0/18 in the EG, and 3/19 in the control group (p = 0.09). The crude incidence rate of severe-IRIS-KS was four patients developed a total of 12 episodes of Severe-IRIS-KS in the CG and two patients developed one episode each in the EG. Mortality in patients with pulmonary KS was nil in the EG (0/5) compared with 3/4 in the CG (P = 0.048). No difference was found between groups in the number of non-S-IRIS-KS events. Among survivors at week 48, 82% achieved >80% remission. CONCLUSIONS: Although mortality attributable to KS was lower in the EG the difference was not statistically significant.

1α,25(OH)2D3 regulates pro-angiogenic factors in endothelial cells transformed by Kaposi's sarcoma-associated herpesvirus G protein coupled receptor.

When tumoral cell expansion exceeds the vascular supply, regions of hypoxia or low oxygen concentration are generated promoting the formation of new vessels through cell proliferation and migration. Viral G protein-coupled receptor (vGPCR) is associated to Kaposi's sarcoma pathology and induces a paracrine transformation when is stably expressed in murine endothelial cells activating hypoxia-induced transcription factors. Previously, we reported the antiproliferative actions of 1α,25-dihydroxyvitamin D3 (1α,25(OH)2D3) in endothelial cells transformed by the vGPCR (SVEC-vGPCR). Herein, we further investigated if pro-angiogenic factors as AP-1, HIF-1α and VEGF are modulated by 1α,25(OH)2D3. We found by qRT-PCR analysis that the mRNA level of JunB, a negative regulator of cell proliferation, was similarly increased at all-time points tested after 1α,25(OH)2D3 treatment in SVEC-vGPCR cells. Also, mRNA levels of the pro-angiogenic factor c-Fos, which induces tumor invasion, were only decreased during one short period treatment. In addition, Hif-1α mRNA and protein levels were significantly reduced after 1α,25(OH)2D3 treatment in a VDR dependent fashion. However, mRNA levels of the angiogenic activator Vegf, promoted in turn by Hif-1α expression, were surprisingly high depending on VDR expression as well. Moreover, Egr-1, which has been reported to induce VEGF expression independently of HIF-1α, diminished its expression with 1α,25(OH)2D3 treatment, fact that was related to the decline of p-ERK1/2. Altogether, these results suggest a negative modulation of some pro-angiogenic factors like AP-1 and HIF-1α, as part of the antiproliferative mechanism of 1α,25(OH)2D3 in SVEC-vGPCR endothelial cells.

Clinical and histopathology characteristics of Castleman disease: a multicenter study of 51 Brazilian patients.

Castleman's disease (CD) is a rare and heterogeneous lymphoproliferative disorder, with limited available clinical information in Brazil. A retrospective study was carried out through information contained in the medical records of 51 patients, between July 1999 and June 2020. Seven patients were excluded, and 44 were analyzed in total. The average age of unicentric CD (UCD) patients was 35 years old and of multicentric CD (MCD) patients was 49 years old (p = 0.013). Regarding gender, there was a predominance of females among patients with UCD (68.4%) and males in patients with MCD (57.9%) (p = 0.103). The most common site of involvement in UCD was the cervical region (36.8%). A total of 73.7% of patients with UCD and 68.4% of patients with MCD presented the histological form hialyne-vascular (HV) (p = 0.499). Most patients with laboratory abnormalities had MCD. A total of 78% of the patients were asymptomatic, with the majority of symptomatic patients with MCD (p = 0.042). Only two of the 27 patients evaluated for the presence of human immunodeficiency virus (HIV) had positive serology. HHV-8 was evaluated in 14 cases, being positive in two. Of the patients with UCD, 94.7% underwent excisional biopsy, against only 41.2% of patients with MCD (p = 0.01). The mean follow-up was 61 months. We observed similarities in the clinical profile between patients in our study and patients described in the literature, such as gender, mean age, B symptoms, visceromegaly, fluid accumulation, and treatment. Unlike the literature, the cervical region was the most affected site, besides the greater association of the HV histological subtype among patients with MCD.

Human Gammaherpesvirus 8 Oncogenes Associated with Kaposi's Sarcoma.

Kaposi's sarcoma-associated herpesvirus (KSHV), also known as human gammaherpesvirus 8 (HHV-8), contains oncogenes and proteins that modulate various cellular functions, including proliferation, differentiation, survival, and apoptosis, and is integral to KSHV infection and oncogenicity. In this review, we describe the most important KSHV genes [ORF 73 (LANA), ORF 72 (vCyclin), ORF 71 or ORFK13 (vFLIP), ORF 74 (vGPCR), ORF 16 (vBcl-2), ORF K2 (vIL-6), ORF K9 (vIRF 1)/ORF K10.5, ORF K10.6 (vIRF 3), ORF K1 (K1), ORF K15 (K15), and ORF 36 (vPK)] that have the potential to induce malignant phenotypic characteristics of Kaposi's sarcoma. These oncogenes can be explored in prospective studies as future therapeutic targets of Kaposi's sarcoma.

Enfermedad de Castleman multicéntrica en pacientes HIV positivos. Reporte de dos casos y revisión de la literatura / Multicentric Astleman disease in HIV positive patients. Two cases. Report and literature review

La enfermedad de Castleman (EC) es un proceso linfoproliferativo poco frecuente que se caracteriza por hiperplasia de los ganglios linfáticos. Existen dos variedades histológicas bien diferenciadas la hialino-vascular y la plasmocelular, que a su vez pueden ser localizadas o multicéntricas. La forma hialino-vascular suele ser asintomática y localizada en mediastino mientras que la plasmocelular se presenta frecuentemente con signo-sintomatología sistémica y suele ser difusa o multicéntrica. En el contexto de la enfermedad debida al virus de la inmunodeficiencia humana (VIH), la EC se asocia en su patogenia a la infección por el herpes virus humano tipo-8 (HHV-8). La mayoría de los casos corresponden a la variante hialino-vascular (80/90%) en tanto un pequeño porcentaje (10/20%) son de la variante plasmocelular. En algunos pacientes, el patrón histopatológico puede ser mixto. Se describen dos casos de enfermedad de Castleman multicéntrica HHV8- positiva en pacientes con enfermedad HIV/SIDA.

Castleman's disease (CD), is a rare hematological condition of uncertain etiology, involves a massive proliferation of lymphoid tissues and typically presents as mediastinal masses. This is considered as a distinct type of lymphoproliferative disorder associated with inflammatory symptoms. In the context of human immunodeficiency virus (HIV) infection, CD is associated with human herpesvirus-8 (HHV8) infection. Most cases of CD represent either the hyaline vascular variant (80­90% of cases) or the plasma cell variant (10­20%); a small percentage present with a mixed histologic appearance. Two cases of Castleman's disease associated with HHV-8 and HIV/AIDS infection are described

Molecular and immune interactions between ß- and γ-herpesviruses in the immunocompromised host.

ß- and γ-herpesviruses persistently infect most of the world population, largely without clinical manifestations. However, in immunosuppressive settings like transplantation, these viruses are often jointly reactivated, associating with graft dysfunction/rejection, HCMV disease, and lymphoproliferation. In HIV/AIDS, direct interaction mechanisms have been described for EBV and KSHV in primary effusion lymphoma, demonstrating that the cooperation between both viruses enhances lymphomagenesis. Here, we discuss the clinical evidence supporting that the simultaneous reactivation of these viruses increases the probability of mutual interactions, also providing a conceptual framework explaining how one virus can influence another. Specifically, we propose mechanisms of indirect communication through immune soluble mediators, mainly cytokines, chemokines, and IFN regulatory molecules, based on common features of their infectious cycles and the convergent need on immunomodulatory mechanisms. This latter point should be experimentally addressed in feature research.

[Primary effusion lymphoma with multisystemic extracavitary involvement in HIV negative diagnosed by autopsy] / Linfoma primario de las efusiones con afectación extracavitaria multisistémica en HIV negativo diagnosticado mediante autopsia.

Introduction: Primary effusion lymphoma is a low-frequency and high-grade non-Hodgkin lymphoma caused by the Human Herpes virus 8. It mainly affects individuals infected with the human immunodeficiency virus (HIV), although it has also been described in HIV-negative cases. It is characterized by the presence of a malignant lymphomatous effusion in the different serous cavities, the pleural cavity being the most affected. Involvement outside the serosae is very rare. Diagnosis is made by analysis of the fluid accumulated in the serosae or by biopsy of the same, demonstrating the presence of characteristic neoplastic lymphocytes. Treatment consists of different chemotherapy regimens associated with antiretroviral therapy in HIV-positive patients. The prognosis of this disease is poor, with a survival of a few months after diagnosis. Methodology: We present the case of an 83-year-old man, HIV negative, with left pleural effusion and ascites, observing a fluid with a predominance of mononuclear cells without the presence of malignant cells on cytological examination. Results: The patient died and the autopsy made the diagnosis of Primary effusion lymphoma, also observing multisystemic extracavitary involvement. Conclusion: Although Primary effusion lymphoma preferentially affects HIV-positive individuals, the absence of HIV infection should not rule out the disease. Extracavitary involvement should be sought even in asymptomatic patients.

Introducción: El Linfoma primario de las efusiones es un Linfoma no Hodgkin de alto grado y escasa frecuencia producido por el virus Herpes Humano 8. Afecta principalmente a individuos infectados por el virus de la inmunodeficiencia humana (HIV), aunque también se ha descripto en HIV negativos. Se caracteriza por la presencia de derrame linfomatoso maligno en las distintas cavidades serosas siendo la cavidad pleural la más afectada. La afectación fuera de las serosas es muy poco frecuente. El diagnóstico se realiza por análisis del líquido acumulado en las serosas o mediante biopsia de las mismas demostrando la presencia de linfocitos neoplásicos característicos. El tratamiento consiste en distintos regímenes de quimioterapia asociados a terapia antirretroviral en pacientes HIV positivos. El pronóstico de esta enfermedad es pobre, con una supervivencia de escasos meses posteriores al diagnóstico. Metodología: Presentamos el caso de un varón de 83 años, HIV negativo, con derrame pleural izquierdo y ascitis, observándose un líquido con predominio de mononucleares sin presencia de células malignas al examen citológico. Resultados: El paciente falleció y mediante la autopsia se llegó al diagnóstico de Linfoma primario de las efusiones, observándose además afectación extracavitaria multisistémica. Conclusión: Si bien el Linfoma primario de las efusiones afecta preferentemente a individuos HIV positivos, la ausencia de infección por HIV no debe descartar la enfermedad. El compromiso extracavitario debe ser buscado aún en pacientes asintomáticos.

Discovery and validation of a novel subgroup and therapeutic target in idiopathic multicentric Castleman disease.

Idiopathic multicentric Castleman disease (iMCD) is a poorly understood hematologic disorder involving cytokine-induced polyclonal lymphoproliferation, systemic inflammation, and potentially fatal multiorgan failure. Although the etiology of iMCD is unknown, interleukin-6 (IL-6) is an established disease driver in approximately one-third of patients. Anti-IL-6 therapy, siltuximab, is the only US Food and Drug Administration-approved treatment. Few options exist for siltuximab nonresponders, and no validated tests are available to predict likelihood of response. We procured and analyzed the largest-to-date cohort of iMCD samples, which enabled classification of iMCD into disease categories, discovery of siltuximab response biomarkers, and identification of therapeutic targets for siltuximab nonresponders. Proteomic quantification of 1178 analytes was performed on serum of 88 iMCD patients, 60 patients with clinico-pathologically overlapping diseases (human herpesvirus-8-associated MCD, N = 20; Hodgkin lymphoma, N = 20; rheumatoid arthritis, N = 20), and 42 healthy controls. Unsupervised clustering revealed iMCD patients have heterogeneous serum proteomes that did not cluster with clinico-pathologically overlapping diseases. Clustering of iMCD patients identified a novel subgroup with superior response to siltuximab, which was validated using a 7-analyte panel (apolipoprotein E, amphiregulin, serum amyloid P-component, inactivated complement C3b, immunoglobulin E, IL-6, erythropoietin) in an independent cohort. Enrichment analyses and immunohistochemistry identified Janus kinase (JAK)/signal transducer and activator of transcription 3 signaling as a candidate therapeutic target that could potentially be targeted with JAK inhibitors in siltuximab nonresponders. Our discoveries demonstrate the potential for accelerating discoveries for rare diseases through multistakeholder collaboration.

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.

Update of the global distribution of human gammaherpesvirus 8 genotypes.

Human gammaherpesvirus 8 (HHV-8) consists of six major clades (A-F) based on the genetic sequence of the open reading frame (ORF)-K1. There are a few conflicting reports regarding the global distribution of the different HHV-8 genotypes. This study aimed to determine the global distribution of the different HHV-8 genotypes based on phylogenetic analysis of the ORF-K1 coding region using sequences published in the GenBank during 1997-2020 and construct a phylogenetic tree using the maximum likelihood algorithm with the GTR + I + G nucleotide substitution model. A total of 550 sequences from 38 countries/origins were analysed in this study. Genotypes A and C had similar global distributions and were prevalent in Africa and Europe. Genotype B was prevalent in Africa. Of the rare genotypes, genotype D was reported in East Asia and Oceania and genotype E in South America, while genotype F was prevalent in Africa. The highest genotypic diversity was reported in the American continent, with Brazil housing five HHV-8 genotypes (A, B, C, E, and F). In this study, we present update of the global distribution of HHV-8 genotypes, providing a basis for future epidemiological and evolutionary studies of HHV-8.

Sarcoma de Kaposi en pacientes que viven con el VIH en Guinea Ecuatorial / Kaposi sarcoma in patients living with HIV in Equatorial Guinea

Introducción: El sarcoma de Kaposi es una neoplasia oportunista asociada a la inmunodepresión causada por VIH, que se relaciona con la infección por VHH tipo 8. Objetivo: Describir la presentación del sarcoma de Kaposi en personas que viven con VIH en Guinea Ecuatorial. Métodos: Se realizó un estudio descriptivo de carácter retrospectivo para identificar la prevalencia y las características epidemiológicas y clínicas del sarcoma de Kaposi en las personas que viven con VIH que acuden a las unidades de referencia para el manejo de casos en Guinea Ecuatorial. Se revisaron las historias clínicas de una muestra aleatoria y representativa de 338 pacientes del grupo que ha recibido tratamiento en las unidades de referencia para enfermedades infecciosas de Bata, desde enero de 2007 a febrero de 2012. Resultados: Se identificaron 40 pacientes diagnosticados de sarcoma de Kaposi (prevalencia del 11, 83 por ciento). La mediana de la edad al diagnóstico de sarcoma de Kaposi fue de 43 años, siendo la ratio del sexo de 1/1. La media de linfocitos CD4 al diagnóstico fue de 166 (rango 21-375) y la frecuencia de afectación oral fue de 45 por ciento. En la mayoría de los pacientes (94,6 por ciento) la observación del sarcoma de Kaposi fue anterior al inicio del tratamiento antirretroviral. Las cifras de linfocitos T CD4/mm3 inferiores a 100 aparecían sobre todo en pacientes menores de 30 años, y esto era especialmente frecuente en el grupo de mujeres (OR 11, p <0,04, Ic 95 por ciento 0,8-148). Conclusiones: El sarcoma de Kaposi es una neoplasia prevalente en personas que viven con VIH seguidas en las unidades de referencia en Guinea Ecuatorial. En mujeres menores de 30 años podría existir un diagnóstico tardío(AU)

Introduction: Kaposi sarcoma is an opportunistic neoplasm associated to the immunosuppression caused by HIV and related to infection by HHV-8. Objective: Describe the presentation of Kaposi sarcoma in people living with HIV in Equatorial Guinea. Methods: A retrospective descriptive study was conducted to identify the prevalence and the clinical and epidemiological characteristics of Kaposi sarcoma in people living with HIV attending reference units for the management of cases in Equatorial Guinea. A review was carried out of the medical records of a random sample representative of 338 patients from the group receiving treatment at Bata reference unit for infectious diseases from January 2007 to February 2012. Results: A total 40 patients diagnosed with Kaposi sarcoma were identified (prevalence of 11,83 percent). Mean age at Kaposi sarcoma diagnosis was 43 years, with a 1/1 sex ratio. The mean CD4 lymphocyte count at diagnosis was 166 (range 21-375), whereas the frequency of oral damage was 45 percent. In most patients (94.6 percent) detection of Kaposi sarcoma was prior to the start of antiretroviral therapy. CD4 T lymphocyte levels / mm3 below 100 were mainly found in patients aged under 30 years, a fact particularly frequent among women (OR 11, p< 0.04, CI 95% 0.8-148). Conclusions: Kaposi sarcoma is a neoplasm prevailing in people living with HIV who attend reference units in Equatorial Guinea. Late diagnosis could exist among women aged under 30 years(AU)

Low prevalence of human gammaherpesvirus 8 (HHV-8) infection among HIV-infected pregnant women in Rio De Janeiro, Brazil.

Pregnant women coinfected with the human immunodeficiency virus (HIV) and human gammaherpesvirus 8 (HHV-8) are at higher risk of Kaposi's sarcoma development, increased viral load, and vertical transmission of these viruses. A total of 131 pregnant women infected with HIV were examined for antibodies against HHV-8 latency-associated nuclear antigen (LANA) and lytic antigens using immunofluorescence assays. The presence of HHV-8 DNA was confirmed using real-time polymerase chain reaction (qPCR) and nested PCR. Overall, 0.8% (1/131) of the patients contained antibodies to HHV-8 LANA and lytic antigens, and no HHV-8 DNA was detected. This study, including a small population of HIV-infected pregnant women in Brazil, indicates a low prevalence of HHV-8 seropositivity and absence of active infection in this group. However, a potential role of HHV-8 in the increased transmission and pathogenic activity of HIV in pregnant women is suggested. Attention should be given to the emergence of HHV-8 infection in this population group in order to avoid comorbidities and transmission of HIV.

Evaluation of IL-2, IL-4, IL-6, IL-10, TNF-α, and IFN-γ cytokines in HIV/HHV-8 coinfection.

Imbalance in the immune response is one of the main pathogenic mechanisms of diseases related with human immunodeficiency virus (HIV)/human gammaherpesvirus 8 (HHV-8) coinfection, such as Kaposi's sarcoma (KS), primary effusion lymphoma (PEL), multicentric Castleman disease (MCD) and the Kaposi's sarcoma-associated herpesvirus inflammatory cytokine syndrome (KICS). However, significant changes in pro- and anti-inflammatory cytokine levels may be observed in HIV/HHV-8 individuals who are negative for KS, PEL, MCD, and/or KICS. In this study, serum levels of interleukin-2 (IL-2), IL-4, IL-6, IL-10, tumor nucrosis factor α (TNF-α) and interferon γ (IFN-γ) were assessed in 69 HIV and 48 HIV/HHV-8 individuals, all negatives for HHV-8-related diseases. The cytokines were measured by flow cytometry and analyzed by the Mann-Whitney test. The p < .05 and 95% confidence interval were considered in all analyzes. IL-4 (p = .0155), IL-6 (p = .0036), and IL-10 (p = .0036) levels were significantly higher in HIV/HHV-8 patients than in the HIV group. On the other hand, IL-2 (p = .2295), TNF-α (p = .1216) and IFN-γ (p = .1178) did not differ between the groups analyzed. To our knowledge, to date, this is the first report on significant differences in the levels of IL-4 and IL-6 in HIV versus HIV/HHV-8 individuals. Finally, these early findings are important as a prognostic tool and contribute to clarifying the HHV-8-host interaction.

Sarcoma de Kaposi ganglionar postrasplante renal: reporte de dos casos en un centro de trasplante colombiano Kaposi sarcoma in lymph nodes after kidney transplantation: report of two cases in a Colombian transplant center / Sarcoma de Kaposi ganglionar postrasplante renal: reporte de dos casos en un centro de trasplante colombiano Kaposi sarcoma in lymph nodes after kidney transplantation: report of two cases in a Colombian transplant center

El cáncer es una causa importante de morbilidad y mortalidad en los receptores de trasplante. La combinación de infecciones virales, terapia de inmunosupresión y la alteración en el sistema inmune en los pacientes trasplantados, contribuyen al desarrollo de cáncer. El sarcoma de Kaposi es causado por el virus herpes humano 8 (VHH-8), y aunque es raro en la población general, puede ser hasta 300 veces más frecuente en los pacientes con trasplante renal. El diagnóstico de la enfermedad se realiza a menudo con base en las características de las lesiones, pero debe ser confirmado por histología. En años recientes, los inhibidores de mTOR han mostrado ser efectivos para el control del sarcoma de Kaposi en los pacientes trasplantados, ya que se interrumpe el efecto antiapoptótico y la angiogénesis dependientes de la proteína mTOR, los cuales son esenciales para el desarrollo y la propagación de células malignas. Se presentan dos casos de pacientes con sarcoma de Kaposi ganglionar, sin lesiones en piel, en nuestro centro de trasplante, quienes respondieron de manera positiva al cambio del esquema inmunosupresor con inhibidores de mTOR

Cancer is a major cause of morbidity and mortality in transplant recipients. The combination of viral infections, immunosuppression therapy and immune system dysfunction in transplant patients contribute to the development of cancer. Kaposi sarcoma is caused by human herpes virus 8 (HHV-8) and although rare in the general population, it is reported to be up to 300 times more common in kidney transplant patients. Diagnosis of the disease is often made on the basis of the characteristic appearance of lesions, but must be confirmed by histology. In recent years, mTOR inhibitors have been shown to be effective in controlling Kaposi sarcoma in transplant patients, due to disruption of the antiapoptotic effect and angiogenesis dependent on the mTOR protein, which are essential for development and propagation of malignant cells. We present two case reports of patients with Kaposi sarcoma in lymph nodes and no skin lesions, who responded well to the immunosuppressive therapy switch with mTOR inhibitors

International evidence-based consensus diagnostic and treatment guidelines for unicentric Castleman disease.

Castleman disease (CD) includes a group of rare and heterogeneous disorders with characteristic lymph node histopathological abnormalities. CD can occur in a single lymph node station, which is referred to as unicentric CD (UCD). CD can also involve multicentric lymphadenopathy and inflammatory symptoms (multicentric CD [MCD]). MCD includes human herpesvirus-8 (HHV-8)-associated MCD, POEMS-associated MCD, and HHV-8-/idiopathic MCD (iMCD). The first-ever diagnostic and treatment guidelines were recently developed for iMCD by an international expert consortium convened by the Castleman Disease Collaborative Network (CDCN). The focus of this report is to establish similar guidelines for the management of UCD. To this purpose, an international working group of 42 experts from 10 countries was convened to establish consensus recommendations based on review of treatment in published cases of UCD, the CDCN ACCELERATE registry, and expert opinion. Complete surgical resection is often curative and is therefore the preferred first-line therapy, if possible. The management of unresectable UCD is more challenging. Existing evidence supports that asymptomatic unresectable UCD may be observed. The anti-interleukin-6 monoclonal antibody siltuximab should be considered for unresectable UCD patients with an inflammatory syndrome. Unresectable UCD that is symptomatic as a result of compression of vital neighboring structures may be rendered amenable to resection by medical therapy (eg, rituximab, steroids), radiotherapy, or embolization. Further research is needed in UCD patients with persisting constitutional symptoms despite complete excision and normal laboratory markers. We hope that these guidelines will improve outcomes in UCD and help treating physicians decide the best therapeutic approach for their patients.

KSHV G-protein coupled receptor vGPCR oncogenic signaling upregulation of Cyclooxygenase-2 expression mediates angiogenesis and tumorigenesis in Kaposi's sarcoma.

Kaposi's sarcoma-associated herpesvirus (KSHV) vGPCR is a constitutively active G protein-coupled receptor that subverts proliferative and inflammatory signaling pathways to induce cell transformation in Kaposi's sarcoma. Cyclooxygenase-2 (COX-2) is an inflammatory mediator that plays a key regulatory role in the activation of tumor angiogenesis. Using two different transformed mouse models and tumorigenic full KSHV genome-bearing cells, including KSHV-Bac16 based mutant system with a vGPCR deletion, we demostrate that vGPCR upregulates COX-2 expression and activity, signaling through selective MAPK cascades. We show that vGPCR expression triggers signaling pathways that upregulate COX-2 levels due to a dual effect upon both its gene promoter region and, in mature mRNA, the 3'UTR region that control mRNA stability. Both events are mediated by signaling through ERK1/2 MAPK pathway. Inhibition of COX-2 in vGPCR-transformed cells impairs vGPCR-driven angiogenesis and treatment with the COX-2-selective inhibitory drug Celecoxib produces a significant decrease in tumor growth, pointing to COX-2 activity as critical for vGPCR oncogenicity in vivo and indicating that COX-2-mediated angiogenesis could play a role in KS tumorigenesis. These results, along with the overexpression of COX-2 in KS lesions, define COX-2 as a potential target for the prevention and treatment of KSHV-oncogenesis.

Case for diagnosis. Penile lesion in HIV-negative patient

Abstract We present the case of an HIV-negative man with asymptomatic penile erythematoviolaceous papules associated with similar slightly verrucous papules in the interdigital space of the right foot. A biopsy of the penile lesion confirmed Kaposi's sarcoma. No other causes of immunosuppression were observed. Penile lesions of KS are rare in HIV-negative individuals but it should also be considered in the differential diagnosis. Careful follow-up is recommended.

Genetic diversity and phylogeographic analysis of human herpesvirus type 8 (HHV-8) in two distant regions of Argentina: Association with the genetic ancestry of the population.

BACKGROUND: The genetic diversity of persistent infectious agents, such as HHV-8, correlates closely with the migration of modern humans out of East Africa which makes them useful to trace human migrations. However, there is scarce data about the evolutionary history of HHV-8 particularly in multiethnic Latin American populations. OBJECTIVES: The aims of this study were to characterize the genetic diversity and the phylogeography of HHV-8 in two distant geographic regions of Argentina, and to establish potential associations with pathogenic conditions and the genetic ancestry of the population. STUDY DESIGN: A total of 101 HIV-1 infected subjects, 93 Kaposi's Sarcoma (KS) patients and 411 blood donors were recruited in the metropolitan (MET) and north-western regions of Argentina (NWA). HHV-8 DNA was detected by ORF-26 PCR in whole blood, saliva and FFPE tissues. Then, ORF-26 and ORF-K1 were analyzed for subtype assignment. Mitochondrial DNA and Y chromosome haplogroups, as well as autosomal ancestry markers were evaluated in samples in which subtypes could be assigned. Phylogeographic analysis was performed in the ORF-K1 sequences from this study combined with 388 GenBank sequences. RESULTS: HHV-8 was detected in 50.7%, 59.2% and 8% of samples from HIV-1 infected subjects, KS patients and blood donors, respectively. ORF-K1 phylogenetic analyses showed that subtypes A (A1-A5), B1, C (C1-C3) and F were present in 46.9%, 6.25%, 43.75% and 3.1% of cases, respectively. Analyses of ORF-26 fragment revealed that 81.95% of strains were subtypes A/C followed by J, B2, R, and K. The prevalence of subtype J was more commonly observed among KS patients when compared to the other groups. Among KS patients, subtype A/C was more commonly detected in MET whereas subtype J was the most frequent in NWA. Subtypes A/C was significantly associated with Native American maternal haplogroups (p = 0.004), whereas subtype J was related to non-Native American haplogroups (p < 0.0001). Sub-Saharan Africa, Europe and Latin America were the most probable locations from where HHV-8 was introduced to Argentina. CONCLUSIONS: These results give evidence of the geographic circulation of HHV-8 in Argentina, suggest the association of ORF-26 subtype J with KS development and provide new insights about its relationship with ancient and modern human migrations and identify the possible origins of this virus in Argentina.