Giant-cell arteritis associated with myelodysplastic syndrome: French multicenter case control study and literature review

Introduction: Myelodysplastic syndromes (MDS) and MDS/myeloproliferative neoplasms (MDS/MPN) can be associated with giant cell arteritis (GCA). In this nationwide study by the ``French Network of dysimmune disorders associated with hemopathies'' (MINHEMON) the objective was to evaluate characteristics, treatment and outcome of GCA MDS-MDS/MPN. Patients and methods: Retrospective analysis of patients that presented a MDS or MDS/MPN associated with GCA. Treatment efficiency, relapse-free and overall survival of GCA MDS-MDS/MPN were compared to GCA alone. Results: Twenty-one patients with GCA MDS-MDS/MPN were included with median age 76 [42-92], M/F ratio 2.5, 8 MDS with multilineage dysplasia (38%), 4 chronic myelomonocytic leukemia (19%), at low or intermediate risk according to IPPS and IPSS-R. The prevalence of headaches, jaw claudication and anterior ischemic optic neuropathy was significantly lower in patients with GCA MDS-MDS/MPN compared to idiopathic GCA (14.3%, 0% and 0% versus 30%, 25%, and 25%, respectively; p < .05). Other clinical and histology findings were similar. All GCA patients received steroid therapy as first-line treatment. Complete or partial response was observed in 14 GCA MDS-MDS/MPN patients (66.7%), of whom 6 (28.6%) received combined immunosuppressive therapies (versus 10% of idiopathic GCA; p = .07). Relapse incidence was similar in the two groups. Steroid dependence was more frequent among GCA MDS-MDS/MPN patients (12 (57%) versus 18 (22.5%); p < .05). Relapse-free and steroid-free survivals were significantly decreased in GCA MDS-MDS/MPN patients (log rank 0.002 and 0.049 respectively), but not overall survival. Conclusion: Characteristics of GCA MDS-MDS/MPN seem different than idiopathic GCA, with a distinct clinical phenotype and poorer outcome with a higher risk of steroid dependence and relapse.