AB0435 RISK OF SERIOUS INFECTION IN LUPUS NEPHRITIS AND RHEUMATOID ARTHRITIS MEASURED USING THE JAPANESE REAL WORLD HOSPITAL CLAIMS DATABASE
Authors: M. Nio, K. Tajima, N. Sugaya, T. Ishiwata, T. Iwase, H. Kato, M. Hashizume
Journal: Annals of the Rheumatic Diseases (2020)

Background: Patients with lupus nephritis (LN) and rheumatoid arthritis (RA) are at risk of serious infections (SIs) due to the impact of the disease itself and treatments that modulate immune system. Though the epidemiology of RA has been well-established by developing many targeted DMARDs (tDMARDs) including biologics and targeted synthesized DMARDs, LN is a very rare disease. Therefore, a large sample size with a significant number of cases is required to determine the exact risk of SIs in LN. Objectives: To compare the incidence rates of SIs resulting in an inpatient claim in adult patients with LN compared with RA with or without tDMARDs using hospital claims data in Japan. Methods: LN and RA were identified using claims data provided by Medical Data Vision Co., Ltd (Tokyo, Japan) between April 2008 and June 2019 which was extracted 5 th September 2019. Data between January 2010 and December 2018 was used for analysis. Patients with LN and RA were identified using modifications to algorithms developed before [1, 2]. LN patients were required to have continuous insurance claim for both systemic lupus erythematosus (SLE) and LN for ≥ 6 months after index date and then RA patients had continuous insurance claim for RA for ≥ 6 months after index date. First incident SIs were defined as those that resulted in an inpatient claim for a pre-specified set of ICD-10 code. Incidence rates (IRs) were calculated along with 95% confidence intervals (CI). Results: The LN, RA, RA treated with tDMARDs and RA treated without tDMARDs cohorts included 6,403, 108,317, 16,450, and 91,867 patients, respectively. As anticipated, the LN and RA cohorts were predominantly female and the RA cohort was generally older than the LN cohorts. IRs per 1,000 person-year(PY) [95% CI] for pneumocystis carini pneumonia were 28.2 [26.0-30.4] in LN, 8.5 [8.2-8.8] in RA, 12.6 [11.7-13.5] in RA with tDMARDs and 7.7 [7.4-8.0] in RA without tDMARDs. IRs per 1,000 PY for septicaemia infection were 23.3 [21.3-25.3] in LN, 12.1 [11.7-12.4] in RA, 13.3 [12.3-14.2] in RA with tDMARDs and 11.8 [11.5-12.2] in RA without tDMARDs. IRs per 1,000 PY for cytomegalovirus infection were 13.4 [11.9-14.9] in LN, 4.4 [4.2-4.6] in RA, 6.2 [5.6-6.8] in RA with tDMARDs and 4.1 [3.8-4.3] in RA without tDMARDs. IRs per 1,000 PY for tuberculosis were 7.2 [6.0-8.3] in LN, 6.7 [6.5-7.0] in RA, 18.2 [17.1-19.3] in RA with tDMARDs and 4.4 [4.2-4.7] in RA without tDMARDs. Conclusion: In this population-based analysis of claims data from Japan, the IRs of SI such as pneumocystis carini pneumonia, septicemia infection and cytomegalovirus infection were higher in LN than in RA. And also, the incidence of tuberculosis in RA treated with tDMARDs was highest among these cohorts. These findings demonstrate the relative contribution of age, immunosuppressive therapies and disease-related factors in LN and RA. References: [1]Pawar A, et al. Ann Rheum Dis. 2019 Apr;78(4):456-464. [2] ChibnikLB et al. Lupus, 2010. May;19(6):741-3. Table 1. Description of study population LN RA tDMARDs Non tDMARDs N % N % N % N % Age (years) 18-34 1700 26.6 9015 8.3 1828 11.1 7187 7.8 35-44 1743 27.2 16662 15.4 2816 17.1 13846 15.1 45-54 1563 24.4 29955 27.7 4452 27.1 25503 27.8 55-64 1397 21.8 52685 48.6 7354 44.7 45331 49.3 Gender Female 5385 84.1 78419 72.4 12653 76.9 65766 71.6 Male 1018 15.9 29898 27.6 3797 23.1 26101 28.4 Table 2. IRs per 1,000 PY [95% CI] of SI for LN and RA patients LN total PY = 22065 RA total PY = 365033 tDMARDs Non tDMARDs total PY = 60999 total PY = 304034 Pneumocystis carini pneumonia 28.2 [26.0-30.4] 8.5 [8.2-8.8] 12.6 [11.7-13.5] 7.7 [7.4-8.0] Septicaemia 23.3 [21.3-25.3] 12.1 [11.7-12.4] 13.3 [12.3-14.2] 11.8 [11.5-12.2] Cytomegalovirus infection 13.4 [11.9-14.9] 4.4 [4.2-4.6] 6.2 [5.6-6.8] 4.1 [3.8-4.3] Tuberculosis 7.2 [6.0-8.3] 6.7 [6.5-7.0] 18.2 [17.1-19.3] 4.4 [4.2-4.7] Mycosis 5.1 [4.1-6.0] 2.7 [2.6-2.9] 4.6 [4.1-5.1] 2.4 [2.2-2.5] Aspergillosis 4.7 [3.8-5.6] 2.7 [2.5-2.9] 2.1 [1.7-2.5] 2.8 [2.6-3.0] Herpes 3.3 [2.5-4.0] 2.4 [2.2-2.6] 2.9 [2.5-3.3] 2.3 [2.1-2.5] Disclosure of Interests: Mariko Nio Employee of: Chugai Pharmaceutical Co., Ltd., Kosei Tajima Employee of: Chugai Pharmaceutical Co., Ltd., Naofumi Sugaya Employee of: Chugai Pharmaceutical Co., Ltd., Tomoyuki Ishiwata Employee of: Chugai Pharmaceutical Co., Ltd., Tatsuhiko Iwase Employee of: Chugai Pharmaceutical Co., Ltd., hiroyuki kato Employee of: Chugai Pharmaceutical Co., Ltd., Misato Hashizume Employee of: Chugai Pharmaceutical Co., Ltd.