An observational study aiming to assess the serological profile of SARS-Cov2 patients with systemic diseases such as systemic lupus erythematosus, Sjogren syndrome, sarcoidosis, inflammatory myopathies, Behçet's disease, Rheumatoid arthritis and Spondyloarthritis

The study is a prospective, observational, multicenter clinical trial to be conducted in the internal medicine, rheumatology and virology departments of Military Hospital of Tunis. After obtaining informed consent from the patient, the investigator will perform an inclusion visit made of a patient interview and performing blood sample to search for IgG and anti-SARS IgM CoV2.

Patients with IgM-like antibodies will have an RT-PCR test for active infection. If the study participants will be diagnosed with COVID-19 positive during the study period, the attending physician is entitled to decide on their management based on the severity of the clinical status.

Inclusion Criteria:

• Age over 18 years old
• One of the following conditions: systemic lupus, Sjögren's syndrome, rheumatoid arthritis, inflammatory myopathies, spondyloarthritis, sarcoidosis and Behçet's disease.
• Informed consent obtained and signed

Exclusion Criteria:

• Refusal to repeat blood sampling if the first one was badly performed
• Informed consent not obained

Patients with one of the following conditions: systemic lupus, Sjögren's syndrome, rheumatoid arthritis, inflammatory myopathies, spondyloarthritis, sarcoidosis and Behçet's disease.