Use of Anakinra in Hospitalized Patients with Crystal-associated Arthritis.

Objective: In this retrospective observational study, we assess the efficacy and safety of the interleukin 1 receptor antagonist anakinra in medically complex, hospitalized patients with acute gout and calcium pyrophosphate crystal arthritis.

Methods: Adult inpatients treated with anakinra from 2014 to 2017 were identified for inclusion. Charts were reviewed for demographics, comorbidities, laboratory data, pain scores, joint involvement, prior treatment, dosing and response to anakinra, concurrent infections, and surgical interventions. Response to anakinra treatment was determined from review of provider documentation, as well as recorded pain scores on a numeric scale.

Results: We identified 100 individuals accounting for 115 episodes of arthritis. This population was 82% male, with an average age of 60 years. Comorbidities included renal disease (45%) and history of organ transplantation (14%). Twenty-nine episodes of arthritis occurred in the perioperative setting. Concurrent infection was present in 34 episodes. Eighty-six episodes of arthritis had partial or complete response to anakinra within 4 days of treatment initiation; 66 episodes had partial or complete response within 1 day of anakinra administration. Anakinra was well tolerated.

Conclusion: To our knowledge, this is the largest observational study of anakinra use in the inpatient setting for the acute treatment of crystal-associated arthritis. We observed a rapid response to anakinra, with 75% of episodes significantly improving or completely resolving within 4 days of the first dose. Our data also support the use of this biologic agent in individuals with infections, as well as perioperative individuals and immunosuppressed transplant recipients.