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.