Efficacy of Pre-exposure Treatment With Hydroxy-Chloroquine on the Risk and Severity of COVID-19 Infection

Inclusion Criteria: Group with hydroxychloroquine treatment (HC +): * LED/SG diagnosed * Treatment with Hydroxy-Chloroquine in the 3 months before and during the outbreak at COVID 19, at least in December 2019. Patients may have treatment with immunosuppressants in combination with Hydroxy-Chloroquine. * COVID19 diagnostic questionnaire and available serology result. Group without hydroxychloroquine treatment (HC-) : * No Hydroxy-Chloroquine intake for more than 12 months --\> HC- without an immunosuppressant * Viral hepatitis C cured for more than 12 months or primitive bile cholangitis (CBP) whose diagnosis is based on international criteria. * Non-significant liver fibrosis assessed either by historical histology or by fibroscan with non-significant liver fibrosis Metavir - F3 (at last available examination) * No Hydroxy-Chloroquine, or immunosuppressants have been taken for more than 12 months. * COVID19 diagnostic questionnaire and COVID19 serology result available. --\>HC- with an immunosuppressant * Diagnosis of LED/SG according to the CAB criteria revised in 1997 or autoimmune hepatitis according to the international criteria validated in 2008. * Patients treated with immunosuppressants for at least three months before the start of the pandemic at COVID 19, at least since December 2019. * COVID19 diagnostic questionnaire and available serology result. Exclusion Criteria: * Anti-CD20 or Cyclophosphamide taken during the six months prior to the completion of the COVID 19 serology. * Refusal of a blood test for antibodies to COVID-19. * Protected adults * Pregnant or breastfeeding women. * Lack of health insurance coverage