Long-term prognosis and factors associated with damage accrual in Japanese patients with systemic lupus erythematosus

Yoko Wada, Hisashi Hasegawa, Takako Saeki, Satoshi Ito, Takeshi Kuroda, Masaaki Nakano, Ichiei Narita

Using a single-center cohort of Japanese patients with SLE, we attempted to clarify the long-term outcome and factors associated with damage accrual using the Systemic Lupus International Collaborating Clinics/American College of Rheumatology Damage Index (SDI). We examined a cohort of 557 patients who had been referred to Niigata University Hospital and diagnosed as having SLE between 1961 and 2013. The patients' data at the latest visit were collected from their clinical records, and causes of death were defined on the basis of those data. Survival from the time of diagnosis was calculated by the Kaplan-Meier method. The SDI was calculated and analyzed using Spearman's correlation coefficient and stepwise multiple regression analysis to reveal the factors associated with any organ damage. Data from 458 of the patients were successfully obtained. The overall 5-year survival rate was 92.2%, and patients diagnosed after 2000 had a significantly high 5-year survival rate of 96.4%. Stepwise multiple regression analysis selected serum creatinine levels (B = 0.6051, p < 0.0001), age (standardized beta = 0.2762, p < 0.001), hypertension (standardized beta = 0.2267, p < 0.001), and antiphospholipid antibody syndrome (standardized beta = 0.1533, p = 0.005) as positive independent variables, whereas administration of bisphosphonate (standardized beta = - 0.1295, p = 0.016) was selected as a negative independent variable. These results suggest that Japanese patients with SLE have a favorable long-term prognosis, and also indicate that disease control as well as management of chronic complications such as hypertension and osteoporosis has possible effects for prevention of organ damage.