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.