SARS-CoV-2 infection associated with monoclonal gammopathy. A case report based on the study of minimally invasive ultrasound-guided autopsy.

Coronavirus disease-2019 (COVID-19) is a global public health emergency with numerous clinical facets, including acute kidney injury and acute cerebrovascular disease. Further knowledge of its various pathogenic mechanisms is essential, including coagulation disorders. Monoclonal gammopathy is characterized by the overproduction of a monoclonal immunoglobulin caused by clonal proliferation. Using a postmortem study of ultrasound-guided percutaneous core biopsies, the aim of this report is to present our observations on the severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) infection pathology associated with monoclonal gammopathy. The clinical presentation was acute renal failure. Pathological findings revealed kappa light chain cast nephropathy. SARS-CoV-2 immunohistochemistry was positive in some renal tubular cells. Another notable finding was the presence of a high density of alveolar megakaryocytes, which probably explained the final outcome (acute cerebrovascular disease). Immunohistochemical study for SARS-CoV-2 does not verify the pathogenic effect of the virus and thus its contribution to the acute kidney injury.

SARS-CoV-2 infection associated with monoclonal gammopathy. A case report based on the study of minimally invasive ultrasound-guided autopsy

Coronavirus disease-2019 (COVID-19) is a global public health emergency with numerous clinical facets, including acute kidney injury and acute cerebrovascular disease. Further knowledge of its various pathogenic mechanisms is essential, including coagulation disorders. Monoclonal gammopathy is characterized by the overproduction of a monoclonal immunoglobulin caused by clonal proliferation. Using a postmortem study of ultrasound-guided percutaneous core biopsies, the aim of this report is to present our observations on the severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) infection pathology associated with monoclonal gammopathy. The clinical presentation was acute renal failure. Pathological findings revealed kappa light chain cast nephropathy. SARS-CoV-2 immunohistochemistry was positive in some renal tubular cells. Another notable finding was the presence of a high density of alveolar megakaryocytes, which probably explained the final outcome (acute cerebrovascular disease). Immunohistochemical study for SARS-CoV-2 does not verify the pathogenic effect of the virus and thus its contribution to the acute kidney injury.(AU)

La enfermedad por coronavirus de 2019 (COVID-19) es una emergencia sanitaria pública global con numerosas facetas clínicas que incluyen enfermedad renal aguda y enfermedad cerebrovascular aguda. Es necesario un conocimiento adicional de su mecanismo patogénico. Los trastornos de coagulación están claramente incluidos en dichos mecanismos. La gammapatía monoclonal se caracteriza por la sobreproducción de inmunoglobulina monoclonal causada por proliferación clonal. Utilizando un estudio postmortem de biopsias percutáneas ecoguiadas, el objetivo de este informe es presentar nuestras observaciones sobre la patología del síndrome respiratorio agudo severo por infección de coronavirus 2 (SARS-CoV-2) con gammapatía monoclonal. La presentación clínica fue insuficiencia renal aguda. Los hallazgos patológicos revelaron nefropatía por cilindros de cadenas ligeras kappa. La inmunohistoquímica de SARS-CoV-2 fue positiva en ciertas células tubulares renales. La presencia de megacariocitos alveolares (alta densidad) fue un hallazgo notable, que explica probablemente el resultado final del paciente (enfermedad cerebrovascular aguda). El estudio inmunohistoquímico frente a SARS-CoV-2 no verifica el efecto patogénico del virus y, por tanto, su contribución a la nefropatía aguda.(AU)

El megacariocito: una célula muy original / The megakaryocyte: a very original cell

Resumen El megacariocito es la célula más grande de la médula ósea, por lo tanto es relativamente fácil reconocer su presencia al observar un aspirado o una biopsia de este tejido. Difiere de otras células por su tamaño, por ser poliploide y crecer por endomitosis. No hay otra célula humana que crezca así. Además, tiene funciones biológicas muy importantes. La más conocida es el dar origen a las plaquetas, que son indispensables para la hemostasia y la reparación de los vasos sanguíneos dañados, así como para la cicatrización de los tejidos que rodean a las heridas. Sin embargo, en los últimos años, a los megacariocitos también se les han atribuido algunas otras funciones que discutiremos en esta revisión.

Abstract The Megakaryocyte is the biggest cell in the bone marrow; therefore, it is easy to recognize in a bone marrow aspirate. In humans, this cell differs from others because of its size, its polyploidy and because it grows by endomitosis. It is the only human cell that grows this way. In addition, the megakaryocyte has very important biological functions. Its best-known function is being in charge of the production of platelets, which are essential for hemostasis, the repair of damaged blood vessels, and healing the tissues surrounding wounds. However, in recent years, other functions have been attributed to the megakaryocyte, which will be discussed in this review.