Estudio de mutaciones en neoplasias mieloproliferativas Philadelphia negativas en un hospital público chileno / Search for mutations in patients with Philadelphia negative myeloproliferative neoplasms in a public hospital in Chile

BACKGROUND: Philadelphia negative myeloproliferative neoplasms (Ph-MPN) are clonal disorders whose pathogenesis has been elucidated in recent years, creating diagnostic and prognostic algorithms. AIM: To study JAK2, CALR y MPL gene mutations in patients with Ph-MPN. MATERIALS AND METHODS: Descriptive cross-sectional observational study of patients with MPN (2015-2019), reviewing clinical, demographic and laboratory data. JAK2, CALR and MPL gene mutations were analyzed by RT-PCR. Results: We studied 72 patients. Fifty percent had essential thrombocythemia (ET), 26.4% had polycythemia vera (PV) and 23.6% had primary myelofibrosis (PM). Bone marrow biopsy was available in 76.5%. At diagnosis, the mean age was 65.5 years and 61% were symptomatic. A thrombotic event was the most frequent problem in 20% and 25% had splenomegaly. There were statistically significant differences in hematological parameters between the different MPNs. JAK2 V617F mutation was detected in 61.1%. Only 19 JAK2 V617F negative patients were available for CALR and MPL mutation studies, identifying 10 triple negative cases. Kaplan Meier curves showed a median survival of 88 months, being similar in the three MPNs. Causes of death in 20 patients were thrombotic complications in 30%, disease progression in 25%, infection in 20%, other neoplasms in 15% and other causes in 10%. CONCLUSIONS: The presentation and frequency of JAK2 V617F, CALR and MPL mutations in our cohort was similar to those reported in other studies for ET and PM. JAK2 V617F mutation was lower for PV. No significant differences between the three MPNs were observed for overall survival. We could not assess the prognostic value of the mutations.

[Search for mutations in patients with Philadelphia negative myeloproliferative neoplasms in a public hospital in Chile]. / Estudio de mutaciones en neoplasias mieloproliferativas Philadelphia negativas en un hospital público chileno.

BACKGROUND: Philadelphia negative myeloproliferative neoplasms (Ph-MPN) are clonal disorders whose pathogenesis has been elucidated in recent years, creating diagnostic and prognostic algorithms. AIM: To study JAK2, CALR y MPL gene mutations in patients with Ph-MPN. MATERIALS AND METHODS: Descriptive cross-sectional observational study of patients with MPN (2015-2019), reviewing clinical, demographic and laboratory data. JAK2, CALR and MPL gene mutations were analyzed by RT-PCR. RESULTS: We studied 72 patients. Fifty percent had essential thrombocythemia (ET), 26.4% had polycythemia vera (PV) and 23.6% had primary myelofibrosis (PM). Bone marrow biopsy was available in 76.5%. At diagnosis, the mean age was 65.5 years and 61% were symptomatic. A thrombotic event was the most frequent problem in 20% and 25% had splenomegaly. There were statistically significant differences in hematological parameters between the different MPNs. JAK2 V617F mutation was detected in 61.1%. Only 19 JAK2 V617F negative patients were available for CALR and MPL mutation studies, identifying 10 triple negative cases. Kaplan Meier curves showed a median survival of 88 months, being similar in the three MPNs. Causes of death in 20 patients were thrombotic complications in 30%, disease progression in 25%, infection in 20%, other neoplasms in 15% and other causes in 10%. CONCLUSIONS: The presentation and frequency of JAK2 V617F, CALR and MPL mutations in our cohort was similar to those reported in other studies for ET and PM. JAK2 V617F mutation was lower for PV. No significant differences between the three MPNs were observed for overall survival. We could not assess the prognostic value of the mutations.

[Management and follow-up of acute myeloblastic leukemia with translocation (8; 21). Report of one case]. / Tratamiento de la leucemia mieloblástica aguda con translocación (8;21) en Hospital Base Valdivia: ejemplificado en un caso clínico.

We describe the management and follow-up of a 20-year-old male with acute myeloblastic leukemia with translocation (8; 21) [t (8; 21)]. A quantitative polymerase chain reaction for t(8; 21) in bone marrow was performed at diagnosis and after three consolidations with high doses of cytarabine. Currently, the management of this type of leukemias has been oriented towards the early detection of relapse. The concept of minimal or measurable residual disease, as the burden of leukemia cells that persist undetected, is an important tool in the therapeutic decision and follow-up of these patients.

Tratamiento de la leucemia mieloblástica aguda con translocación (8; 21) en Hospital Base Valdivia: ejemplificado en un caso clínico / Management and follow-up of acute myeloblastic leukemia with translocation (8; 21): report of one case

We describe the management and follow-up of a 20-year-old male with acute myeloblastic leukemia with translocation (8; 21) [t (8; 21)]. A quantitative polymerase chain reaction for t(8; 21) in bone marrow was performed at diagnosis and after three consolidations with high doses of cytarabine. Currently, the management of this type of leukemias has been oriented towards the early detection of relapse. The concept of minimal or measurable residual disease, as the burden of leukemia cells that persist undetected, is an important tool in the therapeutic decision and follow-up of these patients.

Herpes Simplex Virus Type 1 Enhances Expression of the Synaptic Protein Arc for Its Own Benefit.

Herpes simplex virus type 1 (HSV-1) is a neurotropic virus able to reach the central nervous system (CNS) after primary infection in oronasal mucosa. HSV-1 establishes latency inside neurons due the repression of its gene expression process, which is related to periodic reactivations in response to cellular stress conditions, constituting a risk factor for neurodegenerative diseases such as Alzheimer's disease (AD). The immediate-early gene Arc plays an essential role in neuronal morphology, synaptic plasticity and memory formation. Arc acts as a hub protein, interacting with components of the endocytic machinery required for AMPA receptor (AMPAR) recycling as well as with proteins of the post-synaptic density and actin cytoskeleton. However, to date, no studies have evaluated whether persistent neurotropic HSV-1 infection modulates the expression or function of Arc protein in brain tissue. Here, we report that neuronal in vivo and in vitro infection of HSV-1 significantly increases Arc protein levels, showing a robust perinuclear distribution in neuronal cell lines, a process that is dependent on an active HSV-1 replication cycle. Finally, we found that silencing Arc protein caused a decrease in HSV-1 proteins and viral progeny, suggesting that Arc is involved in the lifecycle of HSV-1. Our studies strongly suggest that pathogenicity of HSV-1 neuronal reactivations in humans could be mediated in part by Arc neuronal upregulation and its potential role in endocytic trafficking and AMPA-neuronal function impairment. Further studies are necessary to define whether this phenomenon could have repercussions in cognition and learning processes in infected individuals.

Herpes Simplex Virus Type 1 Neuronal Infection Perturbs Golgi Apparatus Integrity through Activation of Src Tyrosine Kinase and Dyn-2 GTPase.

Herpes simplex virus type 1 (HSV-1) is a ubiquitous pathogen that establishes a latent persistent neuronal infection in humans. The pathogenic effects of repeated viral reactivation in infected neurons are still unknown. Several studies have reported that during HSV-1 epithelial infection, the virus could modulate diverse cell signaling pathways remodeling the Golgi apparatus (GA) membranes, but the molecular mechanisms implicated, and the functional consequences to neurons is currently unknown. Here we report that infection of primary neuronal cultures with HSV-1 triggers Src tyrosine kinase activation and subsequent phosphorylation of Dynamin 2 GTPase, two players with a role in GA integrity maintenance. Immunofluorescence analyses showed that HSV-1 productive neuronal infection caused a scattered and fragmented distribution of the GA through the cytoplasm, contrasting with the uniform perinuclear distribution pattern observed in control cells. In addition, transmission electron microscopy revealed swollen cisternae and disorganized stacks in HSV-1 infected neurons compared to control cells. Interestingly, PP2, a selective inhibitor for Src-family kinases markedly reduced these morphological alterations of the GA induced by HSV-1 infection strongly supporting the possible involvement of Src tyrosine kinase. Finally, we showed that HSV-1 tegument protein VP11/12 is necessary but not sufficient to induce Dyn2 phosphorylation. Altogether, these results show that HSV-1 neuronal infection triggers activation of Src tyrosine kinase, phosphorylation of Dynamin 2 GTPase, and perturbation of GA integrity. These findings suggest a possible neuropathogenic mechanism triggered by HSV-1 infection, which could involve dysfunction of the secretory system in neurons and central nervous system.

[Correlation between clinical and laboratory criteria of suspected Hantavirus cases and the results of the reference diagnostic technique]. / Correlación entre criterios clínicos y de laboratorio de casos notificados por sospecha de hantavirosis y el resultado de la técnica de referencia.

BACKGROUND: Currently in Chile, due to the frequent clinical suspicion of Hantavirus disease and the high public health impact that this causes, it is necessary to strengthen the criteria for clinical and epidemiological suspicion in the health team. OBJECTIVE: To analyze the information contained in the reports of suspected Hantavirus infection versus the confirmatory diagnosis with the reference technique, IgM capture ELISA anti-hantavirus. Material andMethods: Correlation between the information provided in notifications versus the result of confirmation was analyzed by calculating diagnostic accuracy. RESULTS: 3.4% of 1,566 patients studied (53 cases) was confirmed as SCPH. 58.6% of the analyzed notifications was incomplete. The percentage of positivity of the reference technique associated with fever, myalgia and headache was 80-85%. The presence of immunoblasts (> 10%) showed 25% sensitivity, 98% specificity, 37% PPV, 97% NPV. Thrombocytopenia exhibited 98% sensitivity, 74% specificity, 16% PPV, 100% NPV. CONCLUSION: It is necessary to reinforce the importance of comprehensive data reporting at the health system level. The presence of thrombocytopenia and immunoblasts (> 10%) is highly sensitive and specific, respectively, for detecting patients with SCPH. There is a need to develop training programs in order to optimize the suspicion of Hantavirus infection and appropriate use of health resources.

Correlación entre criterios clínicos y de laboratorio de casos notificados por sospecha de hantavirosis y el resultado de la técnica de referencia / Correlation between clinical and laboratory criteria of suspected Hantavirus cases and the results of the reference diagnostic technique

Antecedentes: Actualmente en Chile, debido a la elevada sospecha clínica de enfermedad por hantavirus y el alto impacto en salud pública que esto provoca, se hace necesario reforzar al equipo de salud, los criterios de sospecha clínica y epidemiológica de hantavirosis. Objetivo: Analizar la información contenida en las notificaciones de sospecha de infección por hantavirus versus la técnica de referencia para el diagnóstico confirmatorio de casos sospechosos, ELISA IgM de captura anti-hantavirus. Material y Método: Mediante cálculo de precisión diagnóstica se analizó la correlación que existe entre la información entregada en las notificaciones versus el resultado de la confirmación mediante la técnica de referencia. Resultados: De 1.566 pacientes estudiados 3,4% (53 casos) fue confirmado para SCPH. De las notificaciones analizadas 58,6% estaban con datos incompletos. Los porcentajes de positividad de la técnica de referencia asociada a fiebre, mialgia y cefalea, fueron de 80-85%. Destaca que la presencia de inmunoblastos (> 10%), presenta: S: 25%, E: 98%, VPP: 37%, VPN: 97%. Paratrombocitopenia se obtuvo: S: 98%, E: 74%, VPP: 16%, VPN: 100%. Conclusión: Se hace necesario reiterar a nivel del sistema sanitario chileno la importancia de contar con datos completos en los formularios de notificación. La presencia de trombocitopenia e inmunoblastos (> 10%) fue altamente sensible y especifica, respectivamente, en la detección de pacientes con SCPH. Con el fin de optimizar la sospecha de infección por hantavirus, según la definición de caso sospechoso, se plantea la necesidad de desarrollar programas de capacitación para la sospecha clínica y lectura de parámetros de laboratorio, tales como presencia de inmunoblastos en el hemograma, así como incluir un algoritmo con el fin de optimizar la sospecha y el uso adecuado de los recursos sanitarios.

Background: Currently in Chile, due to the frequent clinical suspicion of Hantavirus disease and the high public health impact that this causes, it is necessary to strengthen the criteria for clinical and epidemiological suspicion in the health team. Objective: To analyze the information contained in the reports of suspected Hantavirus infection versus the confirmatory diagnosis with the reference technique, IgM capture ELISA anti-hantavirus. Material andMethods: Correlation between the information provided in notifications versus the result of confirmation was analyzed by calculating diagnostic accuracy. Results: 3.4% of 1,566 patients studied (53 cases) was confirmed as SCPH. 58.6% of the analyzed notifications was incomplete. The percentage of positivity of the reference technique associated with fever, myalgia and headache was 80-85%. The presence of immunoblasts (> 10%) showed 25% sensitivity, 98% specificity, 37% PPV, 97% NPV. Thrombocytopenia exhibited 98% sensitivity, 74% specificity, 16% PPV, 100% NPV. Conclusion: It is necessary to reinforce the importance of comprehensive data reporting at the health system level. The presence of thrombocytopenia and immunoblasts (> 10%) is highly sensitive and specific, respectively, for detecting patients with SCPH. There is a need to develop training programs in order to optimize the suspicion of Hantavirus infection and appropriate use of health resources.

Nutraceutical activators of AMPK/Sirt1 axis inhibit viral production and protect neurons from neurodegenerative events triggered during HSV-1 infection.

Herpes simplex virus type-1 (HSV-1) is ubiquitous and is able to establish a lifelong persistent latent infection in neurons of infected individuals. It has been estimated that in approximately 70% of the population over 50 years old, the virus enters the brain and infects neurons, and possibly undergoes recurrent reactivation episodes during lifetime, especially in immunodepressed individuals. We previously showed that the sensors AMP-dependent kinase (AMPK) and Sirtuin 1 (Sirt1), involved in survival pathways and neuroprotection, were affected during the course of HSV-1 infection. To evaluate if natural activators of the AMPK/Sirt1 axis, such as Resveratrol and Quercetin could reduce viral propagation and/or counteract the effects of neuronal infection, we analyzed progeny virion production, neuronal viability and neurodegenerative events during HSV-1 infection. We found that the activators of AMPK/Sirt1 axis, increased the viability of infected neurons, significantly reduced the viral titer in the supernatant and the expression of viral genes. More importantly, pretreatment of neurons with Resveratrol or Quercetin significantly reduced the levels of caspase-3 cleaved- and hyperphosphorylated tau associated with HSV-1 infection. These results suggest that activators of the AMPK/Sirt1 axis could be potentially useful in reducing the risk of HSV-1 productive infection in neurons and the cellular damage associated with reactivation episodes.

Modulation of the AMPK/Sirt1 axis during neuronal infection by herpes simplex virus type 1.

Currently, it is unclear whether a neuron that undergoes viral reactivation and produces infectious particles survives and resumes latency or is killed, which is intriguing even if still unanswered. Previous reports have shown that herpes simplex virus type 1 (HSV-1) inhibits apoptosis during early infection, but is pro-apoptotic during productive infection. Taking in consideration that the stress sensors AMPK and Sirt1 are involved in neuronal survival and neuroprotection, we hypothesized that HSV-1 could activate the AMPK/Sirt1 axis as a strategy to establish latency through inhibition of apoptosis and restoration of the energy status. These effects could be accomplished through deacetylation of pro-apoptotic protein p53 and regulation of the master regulator of mitochondrial biogenesis and function PGC-1α and its target gene TFAM. Accordingly, we evaluated the AMPK/Sirt1 axis and its targets p53, PGC-1α, and acetyl CoA carboxylase in mice neuronal cultures infected with HSV-1 by western blot, RT-qPCR, and immunofluorescence analyses. Herein, we show that HSV-1 differentially modulates the AMPK/Sirt1 axis during the course of infection. In fact, during early infection (2 hpi) activated AMPK (p-AMPK) was down-regulated, but thereafter recovered gradually. In contrast, the levels of acetylated-p53 increased during the first hours post infection, but afterwards were reduced in parallel with the activation of Sirt1. However, acetylated-p53 peaked again at 18 hpi during productive infection, suggesting an activation of apoptosis. Strikingly, acetylated-p53, Sirt1, and p-AMPK apparently translocate from the nucleus to the cytoplasm after 4 hpi, where they accumulate in discrete foci in the perinuclear region. These results suggest that HSV-1 modulates the AMPK/Sirt1 axis differentially during the course of infection interfering with pro-apoptotic signaling and regulating mitochondrial biogenesis.