Background Long-term health sequelae of COVID-19 may be multiple but have thus far not been systematically studied. Methods All patients discharged after COVID-19 from the Radboud university medical centre, Nijmegen, The Netherlands, were consecutively invited to a multidisciplinary outpatient facility. Also, non-admitted patients with mild disease but with symptoms persisting >6 weeks could be referred by general practitioners. Patients underwent a standardized assessment including measurements of lung function, chest CT/X-ray, 6-minute walking test, body composition, and questionnaires on mental, cognitive, health status and quality of life (QoL). Results 124 patients (age 59±14 years, 60% male) were included; 27 with mild, 51 with moderate, 26 with severe and 20 with critical disease. Lung diffusion capacity was below lower limit of normal in 42% of discharged patients. Ninety-nine percent of discharged patients had reduced ground-glass opacification on repeat CT imaging, and normal chest X-rays were found in 93% of patients with mild diseases. Residual pulmonary parenchymal abnormalities were present in 91% of discharged patients, and correlated with reduced lung diffusion capacity. Twenty-two percent had low exercise capacity, 19% low fat-free mass index, and problems in mental and/or cognitive function were found in 36% of the patients. Health status was generally poor, particularly in the domains functional impairment (64%), fatigue (69%) and QoL (72%). Conclusions This comprehensive health assessment revealed severe problems in several health domains in a substantial number of ex-COVID-19 patients. Longer follow-up studies are warranted to elucidate natural trajectories and to find predictors of complicated long-term trajectories of recovery.

Background The literature regarding COVID-19 associated pulmonary aspergillosis (CAPA) has shown conflicting observations, including survival of CAPA patients not receiving antifungal therapy and discrepancy between CAPA diagnosis and autopsy findings. To gain insight into the pathophysiology of CAPA we performed a case-control study, in which we compared Aspergillus test profiles in CAPA patients and controls in relation to ICU-mortality. Methods A multinational case-control study, in which Aspergillus test results, use of antifungal therapy and mortality were collected from critically-ill COVID-19 patients. Patients were classified using the 2020 ECMM/ISHAM consensus case definitions. Results 219 critically-ill COVID-19 cases were analyzed, including one proven, 38 probable, 19 possible CAPA cases, 21 Aspergillus colonized patients, seven patients only positive for serum (1, 3)-ß-D-glucan (BDG), and 133 cases with no evidence of CAPA. Mortality was 53.8% in CAPA patients compared to 24.1% in patients without CAPA (p=0.001). Positive serum galactomannan (GM) and BDG were associated with increased mortality compared to serum biomarker negative CAPA patients (87.5% versus 41.7%, p=0.046; 90.0% versus 42.1%, p=0.029, respectively). For each point increase in GM or ten-point BDG serum concentration, the odds of death increased (GM, OR 10.208, 95%CI 1.621-64.291, p=0.013; BDG, OR 1.247, 95%CI 1.029-1.511, p=0.024). Conclusions CAPA is a complex disease, probably involving a continuum of respiratory colonization, tissue-invasion and angioinvasion. Serum biomarkers are useful for staging CAPA disease progression and, if positive, indicate angioinvasion and a high probability of mortality. There is need for a biomarker that distinguishes between respiratory tract colonization and tissue invasive CAPA disease.

The clinical spectrum of COVID-19 varies and the differences in host response characterizing this variation have not been fully elucidated. COVID-19 disease severity correlates with an excessive pro-inflammatory immune response and profound lymphopenia. Inflammatory responses according to disease severity were explored by plasma cytokine measurements and proteomics analysis in 147 COVID-19 patients. Furthermore, peripheral blood mononuclear cell cytokine production assays and whole blood flow cytometry were performed. Results confirm a hyperinflammatory innate immune state, while highlighting hepatocyte growth factor and stem cell factor as potential biomarkers for disease severity. Clustering analysis reveals no specific inflammatory endotypes in COVID-19 patients. Functional assays reveal abrogated adaptive cytokine production (interferon-gamma, interleukin-17 and interleukin-22) and prominent T cell exhaustion in critically ill patients, whereas innate immune responses were intact or hyperresponsive. Collectively, this extensive analysis provides a comprehensive insight into the pathobiology of severe to critical COVID-19 and highlight potential biomarkers of disease severity.

Aspergillus conidia are unique in triggering Th2 responses in human PBMCs, through a CR3-dependent pathway. ABPA patients display a significantly increased Aspergillus-induced Th2/Th1 ratio that can be modulated by biologicals. These data provide a rationale to explore IFNγ therapy in ABPA as a corticosteroid-sparing treatment option, by dampening Th2 responses and supplementing the IFNγ deficiency at the same time.