Daniel Engelbert Blockmans, L. Henckaerts, Christoph Berger, D. S. Gozzoli, A. Hemmig, Dario Camellino, Mihaela Stegert, S. Imfeld, R. Buchanan, Elisabeth Brouwer, P. Moya, Alessandro Tomelleri, Corrado Campochiaro, H. Ymashita, Y. Van Sleen, H. Corominas, Hannah Ewald, L. Werlen, Marco A. Cimmino, Thomas Daikeler, Lars G. Hemkens, Diego Kyburz, C. Owen, and Markus Aschwanden
Background:GCA is characterized by cranial symptoms but imaging techniques show that patients with non-specific symptoms such as systemic inflammation or PMR may have undiagnosed large vessel (LV) GCA1. Although silent GCA in patients with clinically isolated PMR may have consequences for patients’ outcome, little is known about its prevalence and characteristics of affected patients.Objectives:To review data on the prevalence of silent GCA in newly diagnosed PMR patients without cranial GCA symptoms and to analyze which characteristics are associated with vascular involvement among PMR patients.Methods:We systematically screened PubMed, Embase and Web of Science databases and included studies screening for GCA in steroid naïve PMR patients without cranial symptoms consistent with GCA. Authors of the publications that used PET for vasculitis screening were invited to share their individual patient data (IPD) for a meta-analysis. We sought to define patient characteristics that were associated with vasculitis using univariable mixed effects logistic regression models with vascular involvement as the outcome, missing values were imputed using multilevel joint modeling multiple imputation. To fit a multivariable model with the candidate predictors we excluded variables that were hypothesized to have less medical relevance for the outcome and highly correlated inflammation markers (ESR, Lc).Results:Out of the 3047 studies screened independently by 2 authors (DG and TD), 13 fulfilled the inclusion criteria. These studies (published 1963-2019) reported on 543 PMR patients examined by temporal artery biopsy (n=175), ultrasound (n=110), PET or PET-CT (n=258). 115 PMR patients were diagnosed with GCA (21.2%), with prevalence ranging from 0-92%.We collected IPD for 243 patients from 4 cohorts using PET and 3 using PET/CT for GCA diagnosis. The overall median age of patients was 72.3 years (IQR 66.4-78.0) and vasculitis was found in 65 patients (26.7%) (table 1).Table 1.OverallPMRPMR+GCAn (%)243178 (73.3)65 (26.7)Female sex (%)146 (60.1)98 (55.1)48 (73.8)Shoulder girdle pain (%)236 (97.1)174 (97.8)62 (95.4)Pelvic girdle pain (%)174 (71.6)127 (71.3)47 (72.3)Inflammatory back pain (%)No107 (44.0)83 (46.6)24 (36.9)Yes106 (43.6)70 (39.3)36 (55.4)Lower limb pain (%)No87 (35.8)61 (34.3)26 (40.0)Yes81 (33.3)68 (38.2)13 (20.0)Weight loss (%)112 (46.1)78 (43.8)34 (52.3)CRP (mg/l) (median [IQR])46.0 [19.0, 77.7]44.0 [16.9, 74.2]52.0 [27.9, 85.0]ESR (mm/h) (mean (SD))65.2 (30.3)62.7 (30.2)72.3 (29.7)Hemoglobin (g/dl) (mean (SD))12.1 (1.5)12.2 (1.5)11.7 (1.6)Thrombocytes (1e+09/ml) (mean (SD))341.9 (106.3)323.9 (103.2)375.8 (104.6)In the univariable analyses the following factors were most strongly associated with vasculitic PET findings: female sex (OR 2.31, CI 1.17-4.58), inflammatory back pain (OR 2.73, CI 1.32-5.64), temperature >37° (OR 1.83, CI 0.90-3.7), weight loss (OR 1.83, CI 0.96-3.51), thrombocytosis (i.e., patients with a thrombocyte count 1 SD above mean have an OR of 1.51, CI 1.05-2.18), anemia (i.e., 1 g/dl decrease in Hb below mean corresponds to an OR of 1.25, CI 1.00-1.56). Patients with lower limb pain were less likely to have vasculitis (OR 0.43, CI 0.19–0.95). The estimated ORs were very similar in the multivariable model although the 95%CIs became wider.Conclusion:Although the prevalence across published studies showed substantial variation, 6 out of 13 studies reported a prevalence of silent GCA in 18-40% of all PMR patients. The exploratory analysis of the collected IPD identified female sex, inflammatory back pain, fever, weight loss, absence of lower leg pain, thrombocytosis and anemia as factors associated with LV-GCA. These findings should be validated in future prospective cohort studies. The presence or absence of these factors may further aid in diagnosing LV-GCA in PMR patients.References:[1]Buttgereit F, Dejaco C, Matteson EL, Dasgupta B. Polymyalgia Rheumatica and Giant Cell Arteritis: A Systematic Review. JAMA. 2016 Jun 14;315(22):2442–58.Acknowledgements:The study is funded by the “Schweizerische Stiftung für die Erforschung der Muskelkrankheiten (SSEM)”.Disclosure of Interests:Daniele Silvio Gozzoli: None declared, Andrea Hemmig: None declared, Lars Hemkens: None declared, Laura Werlen: None declared, Hannah Ewald: None declared, Christoph Berger: None declared, Diego Kyburz Grant/research support from: DK reports personal fees from Abbvie, Gilead, Lilly, Novartis and Pfizer, outside of the submitted work, Stephan Imfeld: None declared, Markus Aschwanden: None declared, Mihaela Stegert: None declared, Dario Camellino: None declared, Marco Amedeo Cimmino: None declared, Corrado Campochiaro Grant/research support from: personal fees from Roche, Alessandro Tomelleri: None declared, Liesbet Henckaerts: None declared, Daniel Blockmans Speakers bureau: Paid speaker for Roche, Consultant of: Paid consultant for Roche, Patricia Moya: None declared, Hector Corominas: None declared, Russell Buchanan: None declared, Claire Owen Speakers bureau: CO has received speaking honoraria from Roche, Janssen, Novartis and Pfizer, and meeting sponsorship from Roche, UCB and Janssen, Yannick van Sleen: None declared, Elisabeth Brouwer Speakers bureau: E. Brouwer as an employee of the UMCG received speaker fees and consulting fees from Roche in 2017, 2018 which were paid to the UMCG, Consultant of: E. Brouwer as an employee of the UMCG received speaker fees and consulting fees from Roche in 2017, 2018 which were paid to the UMCG, Hiroyuki Ymashita: None declared, Thomas Daikeler: None declared