 The determinants of infections occurring during the course of immune and inflammatory diseases treated with corticoids and immunosuppressive drugs or biotherapy are probably multiples. We hypothesized that the following variables may have an impact on the risk of infections in those patients: Epidemiological: gender, social situation, Clinical: causal disease, comorbidities, vaccination status, Therapeutic: type and doses of corticosteroids and immunosuppressive drugsbiotherapy, prevention treatment Biological : neutrophils, total lymphocytes, CD4-T lymphocytes, CD8-T lymphocytes, B lymphocytes, immune activation HLA-DR lymphocytes, CD5 and CD19 lymphocytes, CD27IgD lymphocytes, immunoglobulins IgA, IgM, IgG. 