Humoral response to SARS-CoV-2 and seasonal coronaviruses in COVID-19 patients.

We used enzyme-linked immunoassay methods to measure the prevalence and the levels of antibody responses to the nucleocapsid (N) protein of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and four seasonal human coronaviruses (HCoV-OC43, HCoV-HKU1, HCoV 229E, and HCoV-NL63) in a cohort of 115 convalescent plasma donors infected with SARS-CoV-2 (1-61 days after symptom onset) compared to antibody levels in 114 individuals with no evidence of a recent infection with SARS-CoV-2. In the humoral response to the four seasonal coronaviruses, only HCoV-HKU1- and HCoV-229E-assays showed slightly elevated antibody levels in the COVID group compared to the control group. While in the COVID-group the levels of SARS-CoV-2 antibodies correlated significantly with disease severity, no association was found in the levels of antibodies against the seasonal coronaviruses. The most striking result in both groups was that the levels of antibodies against all tested coronaviruses, including the new SARS-CoV-2 showed a highly significant correlation with each other. There seems to be an individual predisposition to a weaker or stronger humoral immune response against all known seasonal human coronaviruses including the new SARS-CoV-2, which could lead to a definition of low and high responders against human coronaviruses with potential impact on the assessment of postinfection antibody levels and protection.

Fibrinolysis and the Influence of Tranexamic Acid Dosing in Cardiac Surgery.

OBJECTIVE: The present study aimed to determine whether underlying disease, performed surgery, and dose of tranexamic acid influence fibrinolysis measured with D-dimer levels. DESIGN: Retrospective analysis. SETTING: Single institution (Department of Cardiac Surgery and Section of Clinical Hemostaseology at the Düsseldorf University Hospital). PARTICIPANTS: The study comprised 3,152 adult patients undergoing elective cardiac surgery between February 2013 and October 2016. INTERVENTIONS: Two doses of tranexamic acid during surgery were administered. MEASUREMENTS AND MAIN RESULTS: D-dimer levels were analyzed at the start of surgery and before protamine administration. D-dimer levels at the start of surgery were compared according to disease. Intraoperative D-dimer development was analyzed according to the type of surgery and within 2 cohorts with different tranexamic acid doses. Interindividual variability was pronounced for D-dimer levels at the start of surgery, with significant differences among patients with coronary artery disease, valve disease, and aortic disease and patients undergoing heart transplantation compared with patients receiving a left ventricular assist device (p < 0.01). Aortic dissection, endocarditis, and extracorporeal life support were associated with higher D-dimer levels (p ≤ 0.01). With tranexamic acid at a fixed dose, intraoperative D-dimer levels decreased in on-pump and off-pump coronary bypass surgery, valve surgery, and left ventricular assist device surgery (p ≤ 0.02), but levels increased in aortic surgery and heart transplantations (p < 0.01). A decrease or increase in D-dimer levels during surgery was influenced significantly by a higher or lower tranexamic acid dose (p ≤ 0.01). CONCLUSIONS: D-dimer testing allows for the assessment of individual fibrinolytic activity in cardiac surgery, which is influenced by disease type, surgery type, and dose of tranexamic acid. The assessment of the fibrinolytic status may have the potential to facilitate dose-adjusted antifibrinolytic therapy in the future.

[66-year old female patient with vitreous and mucosal bleeding]. / 66-jährige Patientin mit Glaskörperblutung und Schleimhautblutungen.

HISTORY AND CLINICAL FINDINGS: We report on a 66-year-old female patient, who presented with a new occurrence of mucosal bleeding and also developed a vitreous hemorrhage. INVESTIGATIONS AND DIAGNOSIS: The bleeding symptoms were caused by an acquired von Willebrand disease (VWD) associated with Waldenström macroglobulinemia. In this context, acquired VWD disease results from a dysfunction of the von Willebrand factor (VWF) caused by monoclonal immunoglobulin of type IgM. TREATMENT AND COURSE: Chemotherapy led to normalization of VWF levels and activity, and a complete remission of the bleeding symptoms. CONCLUSIONS: Acquired VWD should be considered in patients with acquired bleeding tendency. Vitreous hemorrhage as observed in our patient is an unusual bleeding symptom induced by hemorrhagic disorders and has to our knowledge not yet been reported in association with this entity.