SAT0396 The risk factors of serious infection in patients with rheumatoid arthritis
Authors: E. Hasegawa, D. Kobayashi, S. Ito, I. Narita, K. Nakazono
Journal: Annals of the Rheumatic Diseases (2018)

<h3>Background</h3> Although life expectancy has improved for many rheumatoid arthritis (RA) patients, serious infection is one of the major causes of mortality. Undernutrition is widely known to be a risk factor for infection; however, the association between undernutrition and infection in RA patients is not well known. <h3>Objectives</h3> The aim of this study was to identify the risk factors associated with infection requiring hospitalisation in RA patients. <h3>Methods</h3> We retrospectively analysed data obtained from 74 patients with RA (male, n=21; female, n=53; age 74.7±12.6), who were admitted to our hospital between 2016 and 2017 for infection (infection group). Among the patients who experienced multiple infections during this time, only the first infection was included in this study. We also recruited control RA patients (n=222) who were matched for age, gender and disease duration, with a match ratio of 1:3 (non-infection group). The details of the patients' infections, clinical characteristics (including nutritional conditions), and RA treatment were obtained from their clinical records. The nutritional condition was assessed based on the body mass index (BMI), serum albumin (Alb) level, total lymphocyte count (TLC), haemoglobin (Hb) level, controlling nutrition status (CONUT) score, and prognostic nutritional index (PNI). Differences between each group were compared using a nonparametric Wilcoxon's rank sum test for continuous variables and Fisher's exact test for categorical variables. Multiple regression analyses were performed to determine the factors associated with the development of serious infection. We selected seven candidate factors: Steinbrocker's classification (Stage)≥III, BMI≥18.5, CONUT score ≥5, DAS28-ESR≥3.2, use of methotrexate, use of prednisolone, use of biologics. <h3>Results</h3> The respiratory tract was the most frequent site of infection (n=33, 44.6%), followed by the urinary tract (n=14, 18.9%), skin (n=13, 17.6%), bones and joints (n=5, 6.8%), and gastrointestinal tract (n=3, 4.1%). Seven patients died during hospitalisation for infection, in spite of treatment. Relative to the non-infection group, the BMI (20.9±4.1 vs. 22.0±3.4, p=0.036), Alb (3.3±0.7 vs. 3.9±0.4 g/dL, p&lt;0.001), TLC (1190±574 vs. 1328±526/μL, p=0.008), Hb (11.1±1.9 vs. 12.3±1.5 g/dL, p&lt;0.001), and PNI (55.4±8.0 vs. 60.4±8.0, p&lt;0.001) values were significantly lower, and the CONUT score (4.1±2.7 vs. 1.9±1.5, p&lt;0.001) was significantly higher in the infection group. In addition, the DAS 28-ESR (3.5±1.2 vs. 2.9±1.1, p=0.001), dose of prednisolone (4.6±3.4 vs. 2.3±2.3, p&lt;0.001), and rate of biologics usage (33.8 vs. 21.2%, p=0.041) were higher, while the dose of methotrexate (1.6±3.2 vs. 3.2±4.0, p=0.002) was lower in the infection group. The multiple regression analysis revealed that the CONUT score (odds ratio [OR], 62.9; 95% credible interval [CrI], 7.9 to 500.0), use of prednisolone (OR, 6.7; CrI, 2.2 to 20.7), and use of biologics (OR, 3.9; CrI,1.7 to 9.3) were significant risk factors for serious infection. <h3>Conclusions</h3> Multiple factors were found to be associated with infection in RA patients. The improvement of nutrition may have a beneficial effect with regard to the prevention of infection during the care of RA patients. <h3>Disclosure of Interest</h3> None declared