Ab1291 Comparison of Symptoms Between Diagnosis and Relapse in Giant Cell Arteritis: A Retrospective Cohort Study

Background: About half of patients with giant cell arteritis (GCA) experience disease relapse. However, the relationship between symptoms at diagnosis and at time of relapse remains unknown. Objectives: To compare the symptoms at diagnosis with those at time of first relapse in GCA patients. Methods: Patients with a diagnosis of GCA between 2000 and 2020 who were followed for ≥12 months at the University Hospitals Leuven, were included retrospectively. Relapse was defined as recurrence of clinical symptoms compatible with polymyalgia rheumatica (PMR) or GCA and/or increase of inflammatory markers requiring escalation of treatment. Symptoms were categorized as constitutional, PMR, cranial, or limb claudication. As patients could present or relapse with symptoms in >1 category, cumulative percentages add up to >100%. Results: We included 398 GCA patients (mean age 72 years, 64% females). Median duration of follow-up was 42 months (IQR 24-83). Relapse occurred in 224 patients (56%). The median time since diagnosis until first relapse was 13 months (IQR 9-17) with a median daily dose of methylprednisolone of 1 mg (IQR 0-4). Figure 1 shows the distribution of symptoms at diagnosis and at time of first relapse. At diagnosis, 302 (76%) patients had constitutional symptoms, 296 (74%) cranial symptoms, 181 (45%) PMR symptoms and 8 (2%) limb claudication. At first relapse, 79 (35%) patients reported constitutional symptoms, 77 (34%) cranial symptoms, 136 (61%) PMR symptoms and 3 (1%) limb claudication. The symptoms at first relapse divided according to symptoms at diagnosis are presented in Table 1. Despite having no cranial or PMR symptoms at diagnosis, 21/33 (64%) patients with isolated constitutional symptoms and/or raised inflammatory markers had PMR symptoms and 6/33 (18%) had cranial symptoms at time of first relapse. Of the 73 patients with isolated cranial symptoms at diagnosis with at least one relapse, only 43 (59%) had cranial symptoms at time of first relapse, while 26 (36%) had PMR symptoms for the first time. Conclusion: PMR was the most frequent symptom at time of first relapse in GCA patients, whereas cranial and constitutional symptoms were more frequently reported at diagnosis. Even in patients without PMR symptoms at diagnosis, PMR is a common symptom at time of first relapse. Our hypothesis is that cranial and constitutional symptoms more frequently occur in case of high disease activity, whereas PMR is an early, less severe phenotype of the GCA-PMR spectrum, which first reappears in case of increased disease activity. REFERENCES: NIL. Acknowledgements: NIL. Disclosure of Interests: Lien Moreel Roche, Albrecht Betrains: None declared, Steven Vanderschueren: None declared, Daniel Blockmans Roche, GSK, Eli Lily, Roche.