Neuropsychiatric systemic lupus erythematosus: pathogenesis and biomarkers

Systemic lupus erythematosus (SLE) is a complex clinical syndrome, elements of which remain poorly understood. Although recognized over 140 years ago when Kaposi recorded the systemic nature and manifestations of the disease, CNS involvement represents one of the least understood aspects of SLE. This knowledge gap remains despite the fact that up to 75% of adults and children with SLE will, at some point over the course of the disease and to different extents, experience the various disabling effects of neuropsychiatric SLE (NPSLE). Indeed, after decades of research, our understanding of the underlying pathophysiology of NPSLE, in particular, remains limited. Numerous factors contribute to the immune dysfunction that occurs in SLE, including genetic, environmental and hormonal influences, and the contributory or predisposing components that lead to neurological tropism of disease in some patients have not been clearly demonstrated. Features of NPSLE pathogenesis that might be directly linked to clinical manifestations have been identified; however, the complexity and variety of NPSLE symptoms and the clinical overlap with other psychiatric disorders continue to make accurate diagnosis difficult and time-consuming. Thus, efforts to define biomarkers of NPSLE are needed to improve prediction of disease outcomes and guide treatment. In this article, we review the manifestation and pathogenesis of NPSLE, focusing on the features that might aid identification of potential biomarkers.