POS1428 VALIDATION OF ANCA-ASSOCIATED VASCULITIS AS THE CAUSE OF END-STAGE RENAL DISEASE IN THE UNITED STATES RENAL DATA SYSTEM

Background: Glomerulonephritis and other renal manifestations are common in ANCA-associated vasculitis (AAV). Renal involvement AAV is associated with adverse outcomes, including end-stage disease (ESRD) up to 25% of patients (1). The United States Data System (USRDS), a national registry ESRD patients, represents unique nationwide data source for studying ESRD. Prior research has assessed how often attributed have biopsy-proven glomerulonephritis USRDS (2), but the validity diagnosis as cause remains unknown. Objectives: We aim validate primary listed USRDS. Methods: identified all Mass General Brigham (MGB) healthcare system billing code advanced chronic kidney or procedure dialysis transplantation. MGB fulfilling these criteria records by name, sex, date birth, social security number. From this cohort we those related diagnoses causing (ICD9: 446.0, 446.4 ICD10: M31.3X, M31.7). Two authors reviewed medical collect information on whether not physician had diagnosed AAV, details history, non-renal biopsies, antineutrophil cytoplasmic antibody (ANCA) tests. Discrepancies were resolved through consensus. Details regarding initial onset obtained from To calculate positive predictive value (PPV) definite (a confirmed two physicians based available data) record was used gold standard. sensitivity, linked Partners Cohort using same methods. A considered true types nephritis false negative. Results: 89 which AAV. Of these, 85 be cases after review (PPV=96%) (Table 1). Among classified 84 (99%) ANCA test, predominantly MPO/P-ANCA (47, 55%); 36 (42%) biopsy, supportive diagnosis. majority ICD9 10 codes Wegener’s granulomatosis (446.4 M313.1). Within records, 33 (55%) 60 ESRD; remainder, non-specific codes. Table 1. non-AAV due (N=89) Physician-Diagnosed (N=85) type n (%) (98.8) MPO/P-ANCA+ 47 (55.3) PR3/C-ANCA+ (38.8) biopsy (42.4) Pauci-Immune 16 (44%) Non-renal Yes (11.8) No 74 (87.1) Years median [IQR] 1 [0, 6] Principal (ICD9/ICD10) (446.4, 446.4B, M313.1) 81 (95.3) Conclusion: found that USRD high PPV, suggesting accurate classification USRDS, sensitivity moderate. These findings support past future use References: [1]Moiseev S, Novikov P, Jayne D, Mukhin N. End-stage vasculitis. Nephrol Dial Transplant. 2017;32(2):248-53. [2]Layton JB, Hogan SL, Jennette CE, Kenderes B, Krisher J, JC, et al. Discrepancy between Medical Evidence Form 2728 glomerular diseases. Clin J Am Soc Nephrol. 2010;5(11):2046-52. Disclosure Interests: None declared