Manejo de arteritis de células gigantes en Argentina

Introducción: hasta ahora el diagnóstico de la Arteritis de Células Gigantes (ACG) se ha basado fundamentalmente en la clínica y la biopsia de arteria temporal y el tratamiento en corticoides. En los últimos años, han aparecido nuevos métodos que ayudan en el diagnóstico, y recientemente nuevos tratamientos

Detection of Merkel Cell Polyomavirus (MCPyV) DNA and Transcripts in Merkel Cell Carcinoma (MCC)

Merkel cell polyomavirus (MCPyV) is the etiological agent of the majority of Merkel cell carcinoma (MCC): a rare skin tumor. To improve our understanding of the role of MCPyV in MCCs, the detection and analysis of MCPyV DNA and transcripts were performed on primary tumors and regional lymph nodes from two MCC patients: one metastatic and one non-metastatic. MCPyV-DNA was searched by a quantitative polymerase chain reaction (qPCR), followed by the amplification of a Large T Antigen (LTAg), Viral Protein 1 (VP1) and Non-Coding Control Region (NCCR). LTAg and VP1 transcripts were investigated by reverse-transcription PCR (RT-PCR). Viral integration was also studied, and full-length LTAg sequencing was performed. qPCR revealed that the primary tumor of both patients and the lymph node of one patient was positive for the small t-antigen, with an average value of 7.0 × 102 copies/µg. The same samples harbored LTAg, NCCR and VP1 DNA. Sequencing results showed truncated LTAg with the conserved retinoblastoma (Rb) protein binding motif and VP1 and NCCR sequences identical to the MCC350 strain. RT-PCR detected LTAg but not VP1 transcripts. The MCPyV genome was integrated into the primary tumor of both patients. The results confirmed the connection between MCPyV and MCC, assuming integration, LTAg truncation and Rb sequestration as key players in MCPyV-mediated oncogenesis

Detection of human neurotropic JCPyV DNA sequence in pediatric anaplastic xanthoastrocytoma

Due to its peculiar histopathological findings, pleomorphic xanthoastrocytoma (PXA), a rare cerebral tumor of young adults with a slow growth and a good prognosis, resembles to the lytic phase of progressive multifocal leukoencephalopathy, a fatal neurodegenerative disease caused by JC polyomavirus (JCPyV). Therefore, the presence of JCPyV DNA was examined in an 11-year-old child with xanthoastrocytoma, WHO grade 3, by quantitative PCR (qPCR) and nested PCR (nPCR) using primers amplifying sequences encoding the N- and C-terminal region of large T antigen (LTAg), the non-coding control region (NCCR), and viral protein 1 (VP1) DNA. The expression of transcripts from LTAg and VP1 genes was also evaluated. In addition, viral microRNAs’ (miRNAs) expression was investigated. Cellular p53 was also searched at both DNA and RNA level. qPCR revealed the presence of JCPyV DNA with a mean value of 6.0× 104 gEq/mL. nPCR gave a positive result for the 5ʹ region of the LTAg gene and the NCCR, whereas 3ʹ end LTAg and VP1 DNA sequences were not amplifiable. Only LTAg transcripts of 5ʹ end were found whereas VP1 gene transcript was undetectable. Although in most cases, either Mad-1 or Mad-4 NCCRs have been identified in association with JCPyV-positive human brain neoplasms, the archetype NCCR structure was observed in the patient’s sample. Neither viral miRNA miR-J1-5p nor p53 DNA and RNA were detected. Although the expression of LTAg supports the possible role of JCPyV in PXA, further studies are warranted to better understand whether the genesis of xanthoastrocytoma could depend on the transformation capacity of LTAg by Rb sequestration

Detection Analysis and Study of Genomic Region Variability of JCPyV, BKPyV, MCPyV, HPyV6, HPyV7 and QPyV in the Urine and Plasma of HIV-1-Infected Patients

Since it was clearly established that HIV/AIDS predisposes to the infection, persistence or reactivation of latent viruses, the prevalence of human polyomaviruses (HPyVs) among HIV-1-infected patients and a possible correlation between HPyVs and HIV sero-status were investigated. PCR was performed to detect and quantify JCPyV, BKPyV, MCPyV, HPyV6, HPyV7 and QPyV DNA in the urine and plasma samples of 103 HIV-1-infected patients. Subsequently, NCCR, VP1 and MCPyV LT sequences were examined. In addition, for MCPyV, the expression of transcripts for the LT gene was investigated. JCPyV, BKPyV and MCPyV’s presence was reported, whereas HPyV6, HPyV7 and QPyV were not detected in any sample. Co-infection patterns of JCPyV, BKPyV and MCPyV were found. Archetype-like NCCRs were observed with some point mutations in plasma samples positive for JCPyV and BKPyV. The VP1 region was found to be highly conserved among these subjects. LT did not show mutations causing stop codons, and LT transcripts were expressed in MCPyV positive samples. A significant correlation between HPyVs’ detection and a low level of CD4+ was reported. In conclusion, HPyV6, HPyV7 and QPyV seem to not have a clinical relevance in HIV-1 patients, whereas further studies are warranted to define the clinical importance of JCPyV, BKPyV and MCPyV DNA detection in these subjects

Recomendaciones de la Sociedad Argentina de Reumatología en el manejo de la arteritis de células gigantes

La arteritis de células gigantes (ACG) es una vasculitis sistémica que afecta a personas adultas; compromete vasos arteriales de mediano y gran calibre, con potenciales complicaciones de gravedad, como la ceguera, y es considerada una emergencia médica. El objetivo de estas guías fue desarrollar las primeras recomendaciones argentinas para su tratamiento, basadas en la revisión de la literatura mediante metodología GRADE. Un panel de expertos en vasculitis elaboró las preguntas en formato PICO (población, intervención, comparador y outcomes), y luego un panel de expertos en metodología efectuó la revisión de la bibliografía con la extracción de la evidencia para cada una de las preguntas. Se realizó un focus group de pacientes para conocer sus preferencias y experiencias. Finalmente, con la información recabada, el panel de expertos en vasculitis procedió a la votación de las recomendaciones que a continuación se presentan

Guías Argentinas de Vasculitis

La arteritis de células gigantes (ACG) es una vasculitis sistémica que afecta a personas adultas; compromete vasos arteriales de mediano y gran calibre, con potenciales complicaciones de gravedad, como la ceguera, y es considerada una emergencia médica. El objetivo de estas guías fue desarrollar las primeras recomendaciones argentinas para su tratamiento, basadas en la revisión de la literatura mediante metodología GRADE. Un panel de expertos en vasculitis elaboró las preguntas en formato PICO (población, intervención, comparador y outcomes), y luego un panel de expertos en metodología efectuó la revisión de la bibliografía con la extracción de la evidencia para cada una de las preguntas. Se realizó un focus group de pacientes para conocer sus preferencias y experiencias. Finalmente, con la información recabada, el panel de expertos en vasculitis procedió a la votación de las recomendaciones que a continuación se presentan