Prevalence, risk factors, and impact on mortality of neuropsychiatric lupus: a prospective, single-center study

Objective The objective of this paper is to identify the prevalence, risk factors, and impact on mortality of neuropsychiatric systemic lupus erythematosus (NPSLE). Methods Patients from the Hanyang BAE lupus cohort were registered and followed from 1998 to 2015. NPSLE was defined using American College of Rheumatology (ACR) case definitions and Ainiala criteria. Demographics, autoantibodies, Systemic Lupus Erythematosus Disease Activity Index (SLEDAI), and Systemic Lupus International Collaborating Clinic (SLICC)/ACR Damage Index were collected at baseline and then annually. Mortality data were derived by linking data from the Korean National Statistics Office. Multivariable logistic regression and Cox regression analysis were conducted in the inception cohort to assess the risk factors and mortality impact of NPSLE. Results Of 1121 registered patients, 429 (38.3%) had NPSLE manifestations according to ACR criteria and 216 (19.3%) by Ainiala criteria. In multivariable logistic regression analysis, higher SLEDAI (OR 1.08, CI 1.01-1.16, p = 0.02) and antiphospholipid antibody positivity (OR 1.72, CI 1.03-2.87, p = 0.04) at SLE diagnosis increased NPSLE risk, while elevated anti-dsDNA antibodies (OR 0.43, CI 0.24-0.78, p < 0.01) and greater education duration (OR 0.92, CI 0.85-1.00, p = 0.04) showed reduced risk of NPSLE. Cox proportional hazard models demonstrated that presence of NPSLE had a three-fold increased risk of mortality (HR 3.09, CI 1.03-9.21, p = 0.04), especially in patients with focal CNS NPSLE (HR = 7.83, CI 2.12-28.96, p < 0.01). Conclusion Higher SLEDAI, antiphospholipid antibody positivity, absence of anti-dsDNA antibody at SLE diagnosis, and fewer years of education are risk factors for development of NPSLE. Presence of NPSLE, especially focal CNS NPSLE, increased the risk of mortality in SLE patients.