The Impact of IFNλ4 on the Adaptive Immune Response to SARS-CoV-2 Infection.

Genetic polymorphisms at the IFNL4 loci are known to influence the clinical outcome of several different infectious diseases. Best described is the association between the IFNL4 genotype and hepatitis C virus clearance. However, an influence of the IFNL4 genotype on the adaptive immune system was suggested by several studies but never investigated in humans. In this cross-sectional study, we have genotyped 201 severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2)-positive participants for 3 IFNL4 polymorphisms (rs368234815, rs12979860, and rs117648444) and stratified them according to the IFNλ4 activity. Based on this stratification, we investigated the association between the IFNL4 genotype and the antibody as well as the CD8+ T cell response in the acute phase of the SARS-CoV-2 infection. We observed no differences in the genotype distribution compared with a Danish reference cohort or the 1,000 Genome Project, and we were not able to link the IFNL4 genotype to changes in either the antibody or CD8+ T cell responses of these patients.

Long-Term Symptoms among Hospitalized COVID-19 Patients 48 Weeks after Discharge-A Prospective Cohort Study.

Follow-up studies of COVID-19 survivors have been performed to characterize persistence of long-term symptoms, but data are scarce on one year of follow-up. This study provides data from 48 weeks of follow-up after discharge. All patients discharged from the Department of Infectious Diseases at Aarhus University Hospital, Denmark between 1 March and 1 July 2020 were followed for 48 weeks. In total, 45 of 66 eligible patients were interviewed after 48 weeks. The median age was 57 (IQR 51-70) years, the majority were female (53%) and Caucasian (87%). Median BMI was 28.1 (IQR 24.8-32.6) kg/m2. One or more comorbidities were registered among 62% of the patients. In total, 39 out of 45 (87%) interviewed patients reported persistence of at least one symptom 48 weeks after hospitalization with COVID-19. Most frequently reported symptoms were fatigue, dyspnea, and concentration difficulties. This study provides new long-term data following COVID-19, contributing to the accumulating data of COVID-19 sequelae. Many patients suffer long-term sequelae and further research is urgently needed to gain further knowledge of the duration and therapeutic options.

Effect of Age on Innate and Adaptive Immunity in Hospitalized COVID-19 Patients.

An effective but balanced cellular and inflammatory immune response may limit the severity of coronavirus disease (COVID-19), whereas uncontrolled inflammation leads to disease progression. Older age is associated with higher risk of COVID-19 and a worse outcome, but the underlying immunological mechanisms for this age-related difference are not clear. We investigated the impact of age on viral replication, inflammation, and innate and adaptive cellular immune responses in 205 hospitalized COVID-19 patients. During the early symptomatic phase of COVID-19, we found that patients above 65 years had significantly higher viral load, higher levels of proinflammatory markers, and inadequate mobilization and activation of monocytes, dendritic cells, natural killer cells, and CD8 T cells compared to those below 65 years. Our study points toward age-related deficiencies in the innate immune cellular response to SARS-CoV-2 as a potential cause of poorly controlled viral replication and inflammation during the early symptom phase and subsequent disease progression.

Persistent Symptoms in Patients Recovering From COVID-19 in Denmark.

BACKGROUND: Although persistent symptoms after coronavirus disease 2019 (COVID-19) are emerging as a major complication to the infection, data on the diversity and duration of symptoms are needed. METHODS: Patients aged ≥18 years with a positive polymerase chain reaction (PCR) test for severe acute respiratory syndrome coronavirus 2 who were hospitalized at the Department of Infectious Diseases, Aarhus University Hospital, Denmark, in the period from March 11 to May 15 were offered follow-up after hospitalization. On admission, a comprehensive symptom and medical history was collected, including demographic characteristics, duration of symptoms, comorbidities, and concomitant medications. At discharge, patients were offered follow-up consultations-either by telephone or at an in-person visit-at 6 and 12 weeks at our post-COVID-19 outpatient clinic to assess whether symptoms present at admission had resolved. RESULTS: During the inclusion period, 71 patients were admitted with COVID-19. Of these, 10 patients died, 3 were transferred to another region, 4 declined to participate, and 5 were lost to follow-up before the 12-week evaluation. Thus, 49 patients were included. Overall, 96% reported 1 or more persisting symptoms at 12-week follow-up. The main symptoms were fatigue, dyspnea, cough, chemosensory dysfunction, and headache. CONCLUSIONS: A wide range of persistent symptoms in patients recovering from COVID-19 were present 12 weeks after hospitalization, calling for larger descriptive studies and interdisciplinary research collaborations.

Camostat mesylate against SARS-CoV-2 and COVID-19-Rationale, dosing and safety.

The coronavirus responsible for COVID-19, SARS-CoV-2, utilizes a viral membrane spike protein for host cell entry. For the virus to engage in host membrane fusion, SARS-CoV-2 utilizes the human transmembrane surface protease, TMPRSS2, to cleave and activate the spike protein. Camostat mesylate, an orally available well-known serine protease inhibitor, is a potent inhibitor of TMPRSS2 and has been hypothesized as a potential antiviral drug against COVID-19. In vitro human cell and animal studies have shown that camostat mesylate inhibits virus-cell membrane fusion and hence viral replication. In mice, camostat mesylate treatment during acute infection with influenza, also dependent on TMPRSS2, leads to a reduced viral load. The decreased viral load may be associated with an improved patient outcome. Because camostat mesylate is administered as an oral drug, it may be used in outpatients as well as inpatients at all disease stages of SARS-CoV-2 infection if it is shown to be an effective antiviral agent. Clinical trials are currently ongoing to test whether this well-known drug could be repurposed and utilized to combat the current pandemic. In the following, we will review current knowledge on camostat mesylate mode of action, potential benefits as an antiviral agent and ongoing clinical trials.