FRI0278 Risk factors for mortality in patients with lupus nephritis: a long-term study at a single center in japan

Background Lupus nephritis (LN) is a major cause of morbidity and mortality in patients with systemic lupus erythematous (SLE). Previous reports showed age (>50 years), nonwhite race, and renal dysfunction at the time renal biopsy are life-threating factors 1,2). However, there are few studies focused on Asian patients with LN. Objectives We performed a retrospective analysis to investigate mortality and its risk factors in LN patients at our institution. Methods One hundred fifty-eight patients (21 male and 137 female; 154 Japanese, 2 Chinese, 1 Pilipino and 1 Thai) who received renal biopsy and diagnosed with LN at our institution from 1975 to 2012 were examined. Results The mean observation period after renal biopsy was 9.8±7.6 years. The mean patient age, estimated glomerular filtration rate (eGFR) and urinary protein at the time of renal biopsy were 36.2±13.4 years, 79.2±33.1 ml/min/1.73m2 and 3.97±4.08 g/gCr, respectively. Renal histology by ISN/RPS 2003 classification was as follows; II 12.7%, III 14.6%, IV 41.8%, V 14.5%, III/IV+V 14.5%. Steroids were used in all patients and immunosuppressants were added to 122 patients (77.2%). During the observation period, progression of renal dysfunction defined by doubling serum creatinin or end-stage kidney disease (ESRD) were observed in 14 patients (8.9%) and in 9 patients (5.7%), respectively. Eighteen patients were died; infection (n=4), cardiovascular diseases (n=4), malignancy (n=3), intestinal perforation (n=2), CNS lupus (n=1), gastrointestinal hemorrhage (n=1), pulmonary hemorrhage (n=1), traffic accident (n=1) and suicide (n=1). The average period between renal biopsy and death was 11.9±8.6 years. Early death within 1 year was observed only in 2 patients. Five, 10 and 20-year survival rates were 95.5, 93.1 and 76.1%. Statistical significant risk factors for increased mortality by univariate analysis were as following; age (>50 years), positive for anti-SSB antibody, complication of CNS lupus, overlap with other autoimmune diseases, complication with diabetes mellitus and progression of kidney dysfunction. Neither eGFR at the time of renal biopsy nor ISN/RPS class was associated with mortality. A multivariate stepwise Cox hazard model revealed the following 3 parameters as the independent risk factors for death; age (>50 years) [Hazard Ratio (HR) 9.0, 95%CI 2.6 to 31.5, p=0.001], complication with CNS lupus [HR 20.1, 95%CI 4.0 to 99.7, p