Clinical Research Directory

Inclusion Criteria: * Patient over 18 years of age with the capacity to give express free and informed consent. * Patient followed in one of the services participating in the study and meeting the 2 following conditions 1. have myelodysplastic syndrome, or multiple myeloma, or monoclonal gammopathy of undetermined significance, or Schnitzler's syndrome. 2. have a fever of undetermined etiology associated with one of the following symptoms: rash, arthralgia or arthritis, serositis, abdominal pain. Exclusion Criteria: * Patient incapable of giving express free and informed consent. * Subject under guardianship, curatorship or safeguarding of justice. * Subject does not speak French. * Subject incapable of answering questions or expressing himself/herself. * Presence of a differential diagnosis that may explain the patient's symptoms.