Hígado y SARS-CoV-2: aspectos claves de la literatura / Liver and SARS-CoV-2: Literature key aspects

Resumen El nuevo coronavirus del síndrome respiratorio agudo grave de tipo 2 (SARS-CoV-2), virus que se ha expandido por todo el mundo, produce una infección respiratoria aguda capaz de producir la muerte; sin embargo, el daño en otros órganos también es frecuente. Diversos estudios han evidenciado alteraciones en pruebas de lesión hepáticas, las cuales se han asociado con enfermedad grave y mayor estancia hospitalaria; así mismo, en la infección por el virus en pacientes con enfermedad hepática preexistente se observó una elevación significativa de las aminotransferasas durante el curso de la enfermedad y mayor riesgo de enfermedad grave. La explicación fisiopatológica de la afectación hepática en estos pacientes abarca el efecto citopático directo producido por la unión del virus a la enzima convertidora de la angiotensina II (ECA-II) a los hepatocitos y colangiocitos, una respuesta inmunitaria desproporcionada y, en algunos casos, la hepatotoxicidad por medicamentos.

Abstract The new severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), a virus that has spread around the world, causes an acute respiratory infection and it may also cause death. The damage that can cause in other organs is frequent. Many studies had also shown alterations in liver function tests, that are then related to serious illness and with hospitalization requirements. Moreover, in patients infected with the virus that had underlying liver disease, a significant increase in the level of aminotransferases was observed in the course of the disease. A greater risk of serious illness was also detected. The pathophysiological explanation of liver injury in those patients covers the direct cytopathic effect produced by binding the virus, the angiotensin-converting enzyme (ACE2) to the hepatocytes and the cholangiocytes, excessive immune response, and in some cases, drug-induced hepatotoxicity.

The Prion-like Properties of Amyloid-beta Peptide and Tau: Is there Any Risk of Transmitting Alzheimer's Disease During Neurosurgical Interventions?

Recent studies have recognized similarities between the peptides involved in the neuropathology of Alzheimer's disease and prions. The Tau protein and the Amyloid ß peptide represent the theoretical pillars of Alzheimer's disease development. It is probable that there is a shared mechanism for the transmission of these substances and the prion diseases development; this presumption is based on the presentation of several cases of individuals without risk factors who developed dementia decades after a neurosurgical procedure. This article aims to present the role of Aß and Tau, which underlie the pathophysiologic mechanisms involved in the AD and their similarities with the prion diseases infective mechanisms by means of the presentation of the available evidence at molecular (in-vitro), animal, and human levels that support the controversy on whether these diseases might be transmitted in neurosurgical interventions, which may constitute a wide public health issue.