Ab0107 Anakinra Treatment of Acute CPPD Crystal Arthritis With Cervical Spine Involvement (Crowned Dens Syndrom) - Is It Worth? R.LUNZER1, E.WIPFLER-FREISSMUTH1; P.SKRABL1, K.NADLER1, G.REICHT1, 1 St. John’s Hospital, Rheumatology, Graz, Austria

Background: Calcium pyrophosphate crystal-induced arthritis (CPPD) is an acute crystal arthritis, involving the wrist or the knee. In individual cases, the cervical spine region can also be affected. This manifestation is also known as "crowned dens" syndrome. Monosodium urate in gout or CPPD in pseudogout have been shown to trigger the release of IL-1β, a strong pro-inflammatory cytokine, through a complex intracellular molecular cascade. IL-1 blockade showed efficacy in treating acute gouty arthritis in phase 3 controlled studies, and there are published retrospectives series and case reports showing a good clinical response in CPPD arthritis in blocking IL-1 with anakinra, an IL-1 receptor antagonist. Treatment of acute CPP arthritis mainly relies on expert opinion, as there are no trials that assessed the efficacy of anti-inflammatory drugs, despite the high frequency of the disease. In most cases, these patients with acute CPPD-Arthritis are older and often have relevant comorbidities that can limit the use of glucocorticoids. Case presentation Single center, Case-series. This is a collection of 5 cases with radiologically (computer-tomography) confirmed CPPD manifestation in the cervical spine region, so called "crowned-dens". Patients presenting between 2019 and 2023. In 3 cases a spinal puncture was performed beforehand to rule out a CNS-infection. Acute CPPD arthritis was defined as presence of clinical symptoms and CPPD crystals confirmed in computer-tomography of the cervical Region (atlas-dens). Primary outcome was the pain evaluation at 72 hours post dose on a 0-100 mm VAS scale. Secondary outcomes were assessments by the patient and physician of pain intensity and global response over a 28 days period and the changes or deteriorations in relevant comorbidities. All 5 patients suffer from diabetes mellitus, heart failure, had heart attacks, kidney failure, 2 had triple coronary stents. Baseline (Table 1) Learning points for clinical practice Due to the pronounced cervical spine pain with confirmed CPPD arthritis of the cervical spine, Anakinra was administered s.c. with 100mg for 5 days. After 72 hours, the VAS improved from an average of 89.2 mm to 32 mm. No side effects were documented, as well as no exacerbation of blood sugar levels, cardiac or renal insufficiency. All patients were able to leave the hospital after 6.7 days. Within the following 28 days, only one patient showed a relapse. Conclusion: There is no question that therapy with anakinra for CPPD is extremely effective, as these 5 patient cases show. Whether this would have been possible with significantly cheaper therapy options, such as glucocorticoids or colchicine, can only be assumed. The existing comorbidities in advanced age (>75) limit these alternatives. The significantly lower side effect potential of Anakinra must be weighed against the side effects of a higher dose of glucocorticoid therapy. What should perhaps also not be ignored is the shorter stay in hospital. It would be possible to administer the drug therapy on an outpatient basis, but Anakinra is not approved and therefore not reimbursed. REFERENCES: NIL. Acknowledgements: NIL. Disclosure of Interests: None declared.