Examination of autoantibodies to type I interferon in patients suffering from long COVID.

Long COVID (LC) is an emerging global health concern. The underlying mechanism and pathophysiology remain unclear. Presence of neutralizing autoantibodies against type 1 interferons (IFN) has been established as a predictor of critical COVID-19. We hypothesized that persistent autoimmune activity with autoantibodies against type 1 IFN may contribute to symptoms in patients with LC. Plasma samples and clinical information were obtained from a Danish LC cohort consisting of adult patients with confirmed severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. Information on symptoms and quality of life was derived from an LC-specific questionnaire and the EQ-5D-5L questionnaire. Detection of type 1 IFN autoantibodies in plasma were performed by ELISA. Samples collected between June, 2020, and September, 2021, from 279 patients were analyzed and compared to a control group of 94 individuals with prior mild SARS-CoV-2 infection who did not develop LC symptoms. In total, five LC patients (1.8%) and 3 (3.2%) of the controls had detectable circulating type 1 IFN autoantibodies. Collectively, prevalence of autoantibodies against type 1 IFN subtypes in our LC cohort were primarily driven by men and did not exceed the prevalence in controls. Thus, in our cohort, anti-type I IFN autoantibodies are unlikely to drive LC symptoms.

Varicella Zoster Virus Encephalitis in Denmark From 2015 to 2019-A Nationwide Prospective Cohort Study.

BACKGROUND: Knowledge of the epidemiology and clinical characteristics of varicella zoster virus (VZV) encephalitis remains limited. METHODS: Nationwide prospective cohort study of adults treated for microbiologically confirmed VZV encephalitis at Danish departments of infectious diseases from 2015 to 2019. Modified Poisson regression analysis was used to compute adjusted relative risks (RRs) of unfavorable outcome. RESULTS: We identified 92 adults (49% female) with VZV encephalitis, yielding an incidence of 5.3/1 000 000 per year (95% CI, 4.2-6.6). Median age was 75 years (IQR, 67-83) and immunocompromising conditions were frequent (39%). Predominant symptoms were confusion (76%), headache (56%), nausea (45%), gait disturbance (42%), and personality changes (41%). Cranial imaging showed cerebral vasculitis (including infarction and hemorrhage) in 14 (16%) patients and encephalitic abnormalities in 11 (13%) with predilection for the brainstem and deep brain structures. Intravenous acyclovir treatment was initiated a median (IQR) of 13.4 hours (5.2-46.3) since admission, while cranial imaging and lumbar puncture were performed after 6.3 hours (2.5-31.0) and 18.5 hours (4.9-42.0). In-hospital, 1-month, and 3-month mortalities were 4%, 9%, and 11%, respectively. Unfavorable outcome (Glasgow Outcome Score of 1-4) was found in 69% at discharge, with age (adjusted RR [aRR], 1.02; 95% CI, 1.01-1.03), vasculitis (aRR, 1.38; 95% CI, 1.02-1.86), and Glasgow Coma Scale (GCS) <15 (aRR, 1.32; 95% CI, 1.01-1.73) identified as independent risk factors. CONCLUSIONS: VZV encephalitis occurs primarily in elderly or immunocompromised patients with a higher incidence than previously estimated. The diagnosis is often delayed; risk factors for unfavorable outcome are age, cerebral vasculitis, and GCS <15.

Successful use of extracorporeal membrane oxygenation in respiratory failure due to influenza and acute myeloid leukemia.

We report the use of extracorporeal membrane oxygenation (ECMO) in a 28-year-old woman who had an influenza infection complicated with severe acute respiratory distress syndrome (ARDS) during treatment for acute myeloid leukemia. Despite ventilator management with positive end-expiratory pressure, nitrogen oxide inhalation, and prone positioning, there was severe hypoxemia. ECMO led to improvement in gas exchange and lung mechanics. This case shows that ECMO can be lifesaving in the treatment of immunocompromised patients who have hypoxemia that is refractory to conventional treatment.