AB0435 RISK OF SERIOUS INFECTION IN LUPUS NEPHRITIS AND RHEUMATOID ARTHRITIS MEASURED USING THE JAPANESE REAL WORLD HOSPITAL CLAIMS DATABASE

Abstract

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 5thSeptember 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.