THU0322 CLINICAL CHARACTERISTICS OF BIOPSY-PROVEN IGA VASCULITIS IN CHILDREN AND ADULTS: A RETROSPECTIVE COHORT STUDY
Authors: Michel Villatoro Villar, Cynthia S. Crowson, Ashima Makol, Kenneth J Warrington, Steven R. Ytterberg, Matthew Koster
Journal: Annals of the Rheumatic Diseases (2019)

<h3>Background</h3> Differences in both presentation and outcome based on age of diagnosis have been described in patients with IgA vasculitis (IgAV) but data are limited due to cohort size and follow-up duration. <h3>Objectives</h3> To describe the differences in clinical characteristics and outcome between adult- and child-onset biopsy-proven IgA vasculitis (IgAV) in North America. <h3>Methods</h3> Patients with IgAV from January 1, 1997, through December 31, 2016 were retrospectively identified. Clinical characteristics, laboratory parameters and outcomes were abstracted from direct medical chart review. Proteinuria was classified as non-nephrotic (≥0.2 g/d, ≤3.5 g/d) or nephrotic (&gt;3.5 g/d). Microscopic hematuria was defined as ≥5 RBCs/hpf or ≥2+ on dipstick. Disease activity at each follow-up visit was categorized as complete response (normalization of all baseline abnormalities due to IgAV), partial response, non-response (lack of improvement of any abnormalities) or relapse (development of clinical signs of IgAV after a symptom-free period of at least one month). Prevalence of disease activity and competing risks were estimated using multi-state models. <h3>Results</h3> A total of 243 IgAV patients were identified (97% Caucasian, 58% male). 174 patients were adults (&gt;21 years) and 69 were &lt;21 years. Compared to patients &lt;21 years, adults at baseline had more frequent ulcerative skin lesions (11% vs. 1%; p=0.02) and nephrotic-range proteinuria (22% vs. 3%; p=0.007) but less commonly had abdominal pain (34% vs. 61%; p&lt;0.001), ischemic gastrointestinal involvement (10% vs. 20%; p=0.04) and arthralgias (38% vs. 61%; p&lt;0.001). Frequency of microscopic hematuria was similar between groups (47%). Oral corticosteroids were the most common initial treatment used (80%). Dialysis was required in 13 patients (8 adults) and renal transplant was performed in 4 cases (1 adult). Of 137 patients with hematuria during the study, 72% had complete resolution by 1 year after onset, compared to 50% of 179 patients with proteinuria. The prevalence of disease activity state at each follow-up time point is shown in figure 1. During 389 person-years of follow-up, 29 deaths were observed. The main causes of death were cancer, cardiovascular disease, infection and vasculitis. Five year survival rates (95% CI) for patients aged &lt;21, 21-50, and 51+ years were 100%, 94% (87, 100) and 40% (26, 63), respectively (p&lt;0.001). Standardized mortality ratio for patients aged 21-50 years at diagnosis was 5.62 (0.68, 20.3) and 7.60 (5.0, 11.1) for those 51 or older. <h3>Conclusion</h3> IgAV in adults is associated with more severe skin/kidney involvement and poorer renal outcome. Among adults with IgAV, patients aged 51 years or older at diagnosis have significantly higher mortality. <h3>References</h3> [1] Audemard-Verger A, Terrier B, Dechartres A, et al. Characteristics and Management of IgA Vasculitis (Henoch-Schonlein) in Adults: Data From 260 Patients Included in a French Multicenter Retrospective Survey. Arthritis &amp; rheumatology (Hoboken, N.J.). 2017;69:1862-1870. [2] Pillebout E, Thervet E, Hill G, Alberti C, Vanhille P, Nochy D. Henoch-Schonlein Purpura in adults: outcome and prognostic factors. Journal of the American Society of Nephrology : JASN. 2002;13:1271-1278. [3] Westman K, Flossmann O, Gregorini G. The long-term outcomes of systemic vasculitis. Nephrology, dialysis, transplantation : official publication of the European Dialysis and Transplant Association - European Renal Association. 2015;30 Suppl 1:i60-66. [4] Shrestha S, Sumingan N, Tan J, Alhous H, McWilliam L, Ballardie F. Henoch Schonlein purpura with nephritis in adults: adverse prognostic indicators in a UK population. QJM : monthly journal of the Association of Physicians. 2006;99:253-265. <h3>Disclosure of Interests</h3> None declared