Clearance and persistence of SARS-CoV-2 RNA in patients with COVID-19.

Patients with coronavirus disease-2019 may be discharged based on clinical resolution of symptoms, and evidence for viral RNA clearance from the upper respiratory tract. Understanding the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) viral clearance profile is crucial to establish a re-testing plan on discharge and ending isolation of patients. We aimed to evaluate the number of days that a patient needed to achieve undetectable levels of SARS-CoV-2 in upper respiratory tract specimens (nasopharyngeal swab and/or an oropharyngeal swab). The clearance and persistence of viral RNA was evaluated in two groups of positive patients: those who achieved two negative reverse transcription-polymerase chain reaction (RT-PCR) tests and those who kept testing positive. Patients were organized thereafter in two subgroups, mild illness patients discharged home and inpatients who had moderate to severe illness. Results from RT-PCR tests were then correlated with results from the evaluation of the immune response. The study evidenced that most patients tested positive for more than 2 weeks and that persistence of viral RNA is not necessarily associated with severe disease but may result from a weaker immune response instead.

Atypical hemolytic-uremic syndrome: recurrent phenotypic expression of a patient with MCP gene mutation combined with risk haplotypes.

: We bring the case of a 38-year-old man who was presented to the emergency department with nausea, fever, and choluria, 4 days after the ingestion of raw oysters. Analytical study revealed thrombocytopenia and acute kidney injury that were associated to a possible thrombotic microangiopathy. Therapeutic plasma exchange was started and resolution of the manifestations was obtained. To identify the cause of the thrombotic microangiopathy a molecular study was performed and a pathogenic variant in the MCP gene, c.287-2A>G (splice acceptor) in heterozygous state with a concomitant presence of both risk haplotypes, MCPggaac and Complement factor H (CFH)-H3 were identified. These findings make the diagnosis of atypical hemolytic-uremic syndrome (aHUS), and despite a relatively benign course with a positive response to plasma exchange without an evolution to renal failure was evident a recurrent profile of aHUS when associated with an infectious trigger.

New combined CFH/MCP mutations and a rare clinical course in atypical haemolytic uraemic syndrome.

Atypical haemolytic uraemic syndrome (aHUS) is a rare, life-threatening, chronic, genetic disease due to uncontrolled alternative pathway complement activation. In this report, we discuss the case of a heterozygous carrier of a mutation on both factor H and membrane cofactor protein, who persistently presents haemolytic anaemia without need for blood transfusions, normal platelet count, normal renal function and no signs or symptoms of organ injury due to thrombotic microangiopathy 4 years after the diagnosis of aHUS.