Sequelae of Sars-CoV-2 Infections

Coronavirus disease 2019 (COVID-19) caused by SARS-CoV-2 requires hospitalization in a
significant amount of patients. The hospitalization rate and disease severity increases in
the elderly and patients with comorbidities such as diabetes, arterial hypertension, lung
pathologies and obesity (Garg et al.). Patients with severe infections have pneumonia,
requiring prolonged invasive ventilation. Sequelae of longer periods of mechanical
ventilation and reduction of quality of life after acute respiratory distress syndrome (ARDS)
are described (Herridge et al., 2 references). Besides, SARS-CoV-2 can induce - without
preexisting immunity - strong inflammatory reactions, which can affect various organs.
COVID-19 specific complications like thromboembolic events, neurologic events, myocardial
involvement, or liver damage are reported during the acute stage of the infection. The lung
is affected even during less severe infections, and ground glass opacities can result in
consolidations (Shi et al.). These changes were reported to persist after discharge (Mo et
al.). Acute kidney failure occurs in critically ill patients in 20-40% (Richardson et al.),
and 40% of patients admitted to the hospital had proteinuria (Cheng et al.). Myocardial
damage is reported, and some patients even presented initially with chest tightness and
palpitations before having fever or cough (Zheng et al.). Moreover, patients with COVID-19
have a higher risk of thromboembolic events (Klok et al., Llitjos et al). Typically these
patients have a prolonged activated partial thromboplastin time (aPTT), and often
antiphospholipid antibodies (Bowles et al.). The long-term consequences of the strong
inflammatory response affecting various organs are currently unknown. We hypothesize that
some patients will have transient or persistent sequelae requiring medical care. The study
group will therefore clinically examine patients that were hospitalized due to COVID-19, and
monitor pulmonary, and other organ functions for at least one year after symptom onset. The
study group will thereby perform lung and cardial examinations, monitor nephrologic
parameters and perform radiology. Pneumologic tests will include a lung function test, a
spiroergometry, a 6-minute walking test, and a grip-force test. Cardiac examination will
include an echocardiography, and an electrocardiogram. In case of of severe pneumonia, or
deterioration in lung function, computer tomography of the lungs will be performed. Blood
(and urine) tests will include kidney parameters, inflammatory markers, liver values, and
coagulation tests. Additional examinations will be done on an individual basis if clinically
indicated, e.g. lung biopsies in case of suspected interstitial fibrosis. Additionally
patient samples, which were taken for diagnostic purposes (serum, PBMCs, biopsies) will be
stored in the biobank of the German center for lung research (DZL). Clinical evaluation and
testing will start 2 months after symptom onset and the last visit is scheduled 10 months
later. Depending on the results and the needs of the individual patient additional testing
will be conducted.