With an urgent need for bedside imaging of coronavirus disease 2019 (COVID-19), this study’s main goal was to assess inter- and intraobserver agreement in lung ultrasound (LUS) of COVID-19 patients. In this single-center study we prospectively acquired and evaluated 100 recorded ten-second cine-loops in confirmed COVID-19 intensive care unit (ICU) patients. All loops were rated by ten observers with different subspeciality backgrounds for four times by each observer (400 loops overall) in a random sequence using a web-based rating tool. We analyzed inter- and intraobserver variability for specific pathologies and a semiquantitative LUS score. Interobserver agreement for both, identification of specific pathologies and assignment of LUS scores was fair to moderate (e.g., LUS score 1 Fleiss’ κ = 0.27; subpleural consolidations Fleiss’ κ = 0.59). Intraobserver agreement was mostly moderate to substantial with generally higher agreement for more distinct findings (e.g., lowest LUS score 0 vs. highest LUS score 3 (median Fleiss’ κ = 0.71 vs. 0.79) or air bronchograms (median Fleiss’ κ = 0.72)). Intraobserver consistency was relatively low for intermediate LUS scores (e.g. LUS Score 1 median Fleiss’ κ = 0.52). We therefore conclude that more distinct LUS findings (e.g., air bronchograms, subpleural consolidations) may be more suitable for disease monitoring, especially with more than one investigator and that training material used for LUS in point-of-care ultrasound (POCUS) should pay refined attention to areas such as B-line quantification and differentiation of intermediate LUS scores.

Cardiovascular magnetic resonance offers both diagnostic and prognostic information in myocarditis. Using an established animal model of myocarditis, the aim of this study was to measure myocardial T1 before the onset, in the acute and in the chronic phases of the disease and to compare its course with histological and immunohistochemistry findings. Male young Lewis rats were immunized with 0.25 mg porcine myocardial myosin into the rear footpads on day 0. Native and contrast-enhanced ECG-triggered cardiac MRI examinations were performed before immunization on day 0 and on days 14, 21 and 35. Left ventricular function, pre- and post- contrast T1 parameters and LGE images were assessed using Small animal look-locker inversion recovery (SALLI). For each of the indicated time points a minimum of 4 rats were randomly sacrificed for pathological investigations including conventional histology (HE and Sirius-Red staining) and immunohistochemistry (CD 68) investigations. All immunized rats developed myocarditis (morbidity 100 %). Histologically we observed increased wall thickness with biventricular macrophage-rich mixed inflammatory infiltrates. All rats with a histologically severe myocarditis showed increased native T1 and decreased post-contrast T1 of the myocardium. The assessment of native T1 and post-contrast T1 allows accurate differentiation between healthy myocardium and myocardium with inflammation and also between the acute and chronic phases of the disease.

Background: Adult-onset Still’s disease (AOSD) is an autoinflammatory multi-systemic syndrome. Macrophage activation syndrome (MAS) is a potentially life-threatening complication of AOSD with a mortality rate of 10–20%. Especially viral infection is thought to be a common trigger for development of MAS. On the other hand, the occurrence of MAS following vaccinations is extremely rare and has been described in a few cases after measles or influenza vaccinations and more recently after ChAdOx1 nCoV-19 (COVID-19 viral vector vaccine, Oxford-AZ). Case presentation: We report the case of a twenty-year-old female with adult-onset Still’s disease (AOSD), who developed a MAS six days after receiving her first COVID-19 vaccine dose of BNT162b2 (mRNA vaccine, BioNTech/Pfizer) with ferritin levels of 136,680 µg/l (ref.: 13–150 µg/l). Conclusions: To the best of our knowledge, this is the first case report of development of MAS in a patient with preexisting AOSD after vaccination in general, and SARS-CoV-2 vaccination in particular. The new mRNA vaccines have generally shown a reassuring safety profile, but it has been shown that nucleic acids in general, including mRNA can act as pathogen-associated molecular patterns that activate toll-like receptors with extensive production of pro-inflammatory cytokines and further activation of immune cells. Proving an interferon 1 response in our patient directly after vaccination, we think that in this particular case the vaccination might have acted as trigger for the development of MAS. Even if it remains difficult to establish causality in the case of rare adverse events, especially in patients with autoimmune or autoinflammatory conditions, these complications are important to monitor and register, but do not at all diminish the overwhelming positive benefit-risk ratio of licensed COVID-19 vaccines.