**2. Materials and Methods**

Patients were at the "Hospital das Clínicas" of the Medical School of the University of São Paulo (HCFMUSP). SARS-CoV-2 RNA was detected by a reverse-transcriptase polymerase chain reaction in nasopharyngeal swab samples. In a cohort of 397 patients, 39 were solid organ transplant recipients: 25 kidney transplant recipients (KIDNEY), 7 heart transplant recipients (HEART), and 7 liver transplant recipients (LIVER). Two patients from the LIVER group received the transplant from a living donor. All patients underwent solid organ transplants more than 18 months prior to SARS-CoV-2 infection. The control group consisted of 25 non-transplant recipients without comorbidities diagnosed with COVID-19 during the same period (CONTROL).

Exclusion criteria for all groups were the presence of other comorbidities except for systemic arterial hypertension (SAH) and type 1 and 2 diabetes mellitus (DM). All patients with SAH underwent daily use of losartan (50 mg) for SAH control. Cyclosporine and tacrolimus levels on the serum were monitored and within the reference levels during COVID-19 (cyclosporine: 100–300 ng/mL and tacrolimus: 5–20 ng/mL). During hospitalization, COVID-19 patients received systemic and standard treatment. All patients received antibiotics (azithromycin) and anticoagulants. Part of the patients received antivirals (oseltamivir) and the other part received systemic corticosteroids (dexamethasone), as depicted in Supplementary Table S1. This study was approved by the Ethics Committee of HCFMUSP (No. 30800520.7.0000.0068-2020) and followed the 2013 revision of the Declaration of Helsinki and Istanbul. The Ethics Committee waived the need for written informed consent for its retrospective observational nature. EDTA blood samples were collected daily during hospitalization. Statistical analyses were performed using the Kruskal–Wallis test with Dunn's multiple comparisons and survival analyses were performed with the log-rank test for trend with GraphPad Prism-8 software (GraphPad Inc., San Diego, CA, USA).
