Tocilizumab in Chronic Inflammatory CPPD Disease

Inclusion Criteria: * Adults \> 18 years * Diagnosis of CPPD according to ACR/EULAR 2023 classification criteria * Persistent inflammatory pain (\> 3 months) or ≥ 2 arthritics/month * Number of painful joints (NAD) \> 3 * Overall pain VAS (0\_100) \> 40 mm * Failure, intolerance or impossibility of repeated use of usual treatments: colchicine, NSAIDs, corticosteroids and anakinra * Use of an effective method of contraception in women of childbearing age until 3 months after the end of the study. * Informed consent Exclusion Criteria: * Presence of anti-CPP antibodies \> 50 IU/ml * Recurrent or chronic infections * History of severe infection (= requiring hospitalization) * Active infection * Vaccination with live or attenuated vaccine within 4 weeks prior to inclusion * History of intestinal ulceration or diverticulitis Untreated latent tuberculosis * History of viral hepatitis B ou C * Symptoms suggestive of demyelinating disease of the central nervous system * History of cancer, active cancer, or suspected cancer * Neutropenia \< 2000 elements/mm3, thrombocytopenia \< 100 000/mm3 * Elevated transaminases \> 3 x ULN * Known hypersensitivity to the active substance or one of the excipients; * Known severe immune deficiency * Patients not meeting classification criteria * Concomitant treatment with biological or targeted therapies, or immunosuppressive therapy (including methotrexate, leflunomide, azathioprine), systemic corticosteroids, anakinra, IL-6 inhibitors in subcuta…