SAR-COVID is a national, multicenter, prospective, observational longitudinal registry of consecutive patients with diagnosis of rheumatic diseases treated or not with immunomodulatory and/or immunosuppressive drugs and SARS-CoV-2 infection (asymptomatic or COVID-19).

Hypothesis: Patients with rheumatic diseases who are under chronic treatment with immunomodulatory and/or immunosuppressive drugs more frequently have an asymptomatic infection, a milder COVID-19 and lower mortality than patients with rheumatic diseases without immunomodulatory and/or immunosuppressive treatments.

SAR-COVID is a national, multicenter, prospective, observational longitudinal registry of consecutive patients with diagnosis of rheumatic diseases treated or not with immunomodulatory and/or immunosuppressive drugs and SARS-CoV-2 infection (asymptomatic or COVID-19).

HYPOTESIS: Patients with rheumatic diseases who are under chronic treatment with immunomodulatory and/or immunosuppressive drugs more frequently have an asymptomatic infection, a milder COVID-19 and lower mortality than patients with rheumatic diseases without immunomodulatory and/or immunosuppressive treatments.

TARGET POPULATION: Patients > 18 years of age with any rheumatic disease. ELIGIBILITY CRITERIA Inclusion Criteria

• Age > 18 years.
• Patients with diagnosis of rheumatic diseases (treated or not with immunomodulatory and/or immunosuppressive drugs).
• Patients with diagnosis of SARS-CoV-2 infection (past or present) with positive test for the virus SARS-CoV-2 from analysis of nasopharyngeal or oropharyngeal swab specimens (reverse transcriptase-polymerase- chain-reaction assay) or by serology, independently of symptoms.

Exclusion Criteria

• Patients who do not wish to participate or are unable to give informed consent.

RECRUITMENT: All rheumatologists, members of the Argentine Society of Rheumatology will be invited to participate in the registry. It is expected that 3,000 patients with COVID-19 and some rheumatic disease, who are cared for by rheumatologists in any of the 23 provinces of Argentina, will be enrolled in the SAR-COVID registry during the period from July 1 to December 31, 2020. Twelve-month extension of the recruitment period will be applied if the expected number of patients is not achieved by the end of the inclusion date. Two cohorts will be included: the first will enroll 1,500 patients treated with immunomodulatory and/or immunosuppressive drugs, and the second will enroll 1,500 patients without immunomodulatory and/or immunosuppressive drugs.

DATA COLLECTION: All variables will be collected by self-report, clinical and laboratory examination and/or medical records review, performed by the rheumatologist during patient hospitalization due to COVID-19, or at the patient control visit performed after SARS-CoV-2 infection. The data will be entered into the ARTHROS eCRF (online application designed ad hoc), which in turn will facilitate generating queries and perform the statistical analysis.

PERIODIC REPORTS: Patients will be followed up for 12 months, in order to evaluate their evolution and identify the effect of the SARS-CoV-2 infection on their rheumatological disease. For this reason, in this registry the data will be collected in two phases:

• PHASE I: Corresponds to the baseline visit (T0). Sociodemographic data, diagnosis, symptoms, treatment, hospitalization, complications, characteristics of the rheumatic disease and its treatment before and during the infectious process will be recorded.
• PHASE II: This second visit (T1) will be carried out 12 months after patients registration. Its objective is to identify long-term complications after SARS-CoV-2 infection and to assess the impact of infection on rheumatic disease.

Inclusion Criteria:

• Age equal or older than 18 years.
• Patients with diagnosis of rheumatic diseases (treated or not with immunomodulatory and/or immunosuppressive drugs).
• Patients with diagnosis of SARS-CoV-2 infection (past or present) with positive test for the virus SARS-CoV-2 from analysis of nasopharyngeal or oropharyngeal swab specimens (reverse transcriptase-polymerase- chain-reaction assay) or by serology, independently of symptoms.

Exclusion Criteria:

• Patients who do not wish to participate or are unable to give informed consent.

Patients with COVID-19 and some rheumatic disease, who are cared for by rheumatologists in any of the 23 provinces of Argentina