Inclusion Criteria:  Age>18 years; Patients with CKD stage 3-5, patients on dialysis or KTx patients with confirmed COVID-19, at minimum 2 weeks after the confirmed test; Age, sex and kidney disease (CKD stage 3-5, dialysis or KTx) matched patients without confirmed SARS-CoV-2 infection.  Exclusion Criteria:  Prior diagnosis of pulmonary fibrosis, pneumectomy or massive pleural effusion; Active malignancies. Pregnancy; Active systemic infections (due to difficulties in the interpretation of nonspecific inflammation biomarkers in this type of patients); Congenital heart disease.