Pos0110 Concordance of Initial Baseline Presentation Features, First Relapse Symptoms and Second Relapse Symptoms in Patients With Giant Cell Arteritis: An Analysis of Three Patient Cohorts

Background: Relapse is common in patients with giant cell arteritis (GCA). A clinically relevant question for both patients and providers is whether the initial symptoms at GCA diagnosis will be present at time of relapse or whether other clinical features may manifest. Given most cohorts describe both baseline and relapse symptoms in aggregate, evaluation of patient level concordance between initial symptoms and relapse symptoms has not been delineated. Objectives: To evaluate symptom concordance from initial presentation to first relapse and from first relapse to second relapse across a cohort of patients with GCA. Methods: A 510-patient aggregate of three previously described GCA cohorts was analyzed [1-3]. Clinical symptoms at diagnosis and relapse were grouped into five categories: constitutional, musculoskeletal (MSK), cranial (non-visual), visual, and large vessel (LV). Patients could have more than one category present at each time point. Odds ratios and conditional probabilities were calculated. Results: 303/510 (59%) patients had at least one relapse and 160/510 (31%) had at least two relapses. 20% of patients presented with a symptom category on first relapse that was not present at baseline. At first relapse, 68% of patients had symptoms in a single category, versus 10% at baseline. At second relapse, 64% of patients had symptoms in a single category. Odds ratios for presence of symptoms at first relapse associated with presence of given symptoms at baseline (1A) and presence of symptoms at second relapse associated with given symptoms at first relapse (1B) are shown in Table 1. In 1A, patients with cranial symptoms at baseline were near 6 times less likely to develop LV at first relapse. There was a 15-fold increased risk of visual symptoms at first relapse if visual symptoms were present at baseline and a 25-fold increased risk of LV symptoms at first relapse if LV symptoms were present at baseline. In 1B, visual symptoms at first relapse resulted in a 30-fold increased risk for visual symptoms on second relapse. LV symptoms on first relapse resulted in a 15.5-fold increased risk for LV symptoms on second relapse. Conditional probabilities of symptoms at first relapse according to presence or absence of baseline symptoms (2A) and conditional probabilities of given symptom category at second relapse according to presence or absence of first relapse symptom category (2B) are shown in Table 2. In 2A, no patient without cranial symptoms at baseline developed visual symptoms at first relapse. The probabilities of specific symptom categories repeating themselves on first relapse if present at baseline were: 27% for constitutional, 57% for MSK, 56% for cranial, 13% for visual, and 44% for LV. In 2B, the probabilities of specific symptom categories repeating themselves on second relapse if present at first relapse were: 64% for constitutional, 78% for MSK, 59% for cranial, 29% for visual, and 45% for LV. Conclusion: In our study, approximately 1 in 5 patients reported a new symptom domain at first relapse that was not present at baseline. Visual symptoms on first relapse were overall uncommon, but risk was higher if visual symptoms were present at baseline. Providers should educate patients on the spectrum of GCA symptoms to be aware of, even beyond those present at a patient's diagnosis. The significance of this study lies in its potential to aid clinicians in providing patient-level data regarding relapsing GCA that will ultimately translate into better patient education and overall better monitoring of the disease. REFERENCES: [1] Predictors of relapse and treatment outcomes in biopsy-proven giant cell arteritis: a retrospective cohort study. Rheumatology (Oxford). 2016;55(2):347-56. [2] Giant cell arteritis and its mimics: A comparison of three patient cohorts. Semin Arthritis Rheum. 2020;50(5):923-9. [3] Relapse Risk and Safety of Long-Term Tocilizumab Use Among Patients With Giant Cell Arteritis: A Single-Enterprise Cohort Study. J Rheumatol. 2023;50(10):1310-7. Acknowledgements: NIL. Disclosure of Interests: None declared.