This observational study will collect data from patients treated with siltuximab program for treatment of SARS-CoV-2 infection complicated with serious respiratory complications.

This observational study will group the patients into two cohorts receiving siltuximab..

Outcome of patients will be compared to a cohort of patients receiving standard treatment without siltuximab.

The patients will be divided into 2 cohorts. Those contained in Cohort A were treated after the use of continuous positive airways pressure (CPAP) or non-invasive ventilation (NIV). Patients in Cohort B were treated after intubation

This is a single-center observational cohort study that follows the use of treatment with siltuximab in patients with COVID-19 who have developed serious respiratory complications, defined by the need of ventilation (either invasive or non-invasive). Retrospective data collection will be carried out on those patients who have received siltuximab as a treatment for their Covid-19 and patients enrolled in ReCOVID19-2020, a retrospective study enrolling consecutive patients with a confirmed diagnosis of COVID-19 (interstitial pneumonia and positive test for SARS-COV-2) and who received standard treatment and who were hospitalized from 23 February up to 13 March 2020 at Papa Giovanni XXIII hospital.

The control cohort of the cohort study will include all the patients with pneumonia/ARDS in need of non-invasive ventilation (CPAP or NIV) or intubation and not receiving experimental treatments in the ReCOVID-19-2020.Patients that will be included will be divided into 2 cohorts, and per current estimation split in a 3:1 ratio: 75% will be in Cohort A as treated with CPAP/NIV, while 25% will form Cohort B and consists of patients in an ICU setting who are receiving mechanical ventilation.

Procedures outlined in this protocol are based on how the patients were managed as per clinicians' best judgement and best practice. No clinical procedures are required by this observational protocol. Data on the procedures already performed during the routine diagnosis and treatment of COVID-19 patients will be collected. The list of clinical and laboratory parameters is provided to direct data collection for this observational study (as available in the medical records).

During their hospitalization, patients will be monitored as per standard hospital practice or as per national (emergency) guidelines in accordance with extraordinary circumstances relating to the COVID-19 outbreak. After discharge, patients will be asked to provide (from their primary health care providers) relevant laboratory results and safety information for approximately 30 days following the start of COVID-19 treatment via ventilation (either mechanical or non-invasive).

Inclusion Criteria:

1. Clinical and radiological diagnosis of pulmonary infection by COVID-19
2. Positive microbiological evidence of SARS-CoV-2 infection
3. Diagnosis of acute respiratory distress syndrome clinical panel in accordance with Berlin 2012 criteria
4. Need of non-invasive ventilation (NIV or CPAP) or invasive ventilation (intubation)

Exclusion Criteria:

1. Active infection of bacterial or viral (non-Covid-19) origin
2. Treatment with other anti-interleukin therapy

The control cohort of the cohort study will include all the patients with pneumonia/ARDS in need of non-invasive ventilation (CPAP or NIV) or intubation and not receiving experimental treatments in the ReCOVID-19-2020.Patients that will be included into this observational study will be divided into 2 cohorts, and per current estimation split in a 3:1 ratio: 75% will be in Cohort A as treated with CPAP/NIV, while 25% will form Cohort B and consists of patients in an ICU setting who are receiving mechanical ventilation.