Objective: To describe clinical phenotypes in neuropsychiatric systemic lupus erythematosus (NPSLE).
Methods: Data were prospectively collected in the Leiden NPSLE referral clinic, where patients suspected of having NPSLE are assessed in a standardized multidisciplinary manner. In consensus meetings, all medical specialists agreed on therapeutic strategy based on the suspected pathogenetic mechanism of NPSLE in the individual patient. An algorithm illustrates the process of decision-making during the consensus meeting. Clinical phenotypes are described, classified by pathogenetic mechanism.
Results: One hundred consecutive patients were evaluated, of whom 71 had SLE (29 patients did not fulfill ≥ 4 American College of Rheumatology criteria) and 46 had NPSLE. Primary NPSLE was diagnosed in 38 patients (53%) and could be differentiated in 21 patients (55%) with inflammatory NPSLE who were advised on immunosuppressive therapy, 12 patients (32%) with ischemic NPSLE who were advised on anticoagulant therapy, and 5 patients (13%) with undefined NPSLE who were advised symptomatic treatment only. Cognitive dysfunction and higher level of disease activity were associated with inflammatory NPSLE. Although presence of immunoglobulin G anticardiolipin antibodies and abnormalities on magnetic resonance imaging (MRI) were associated with ischemic NPSLE, abnormalities on MRI lacked specificity to distinguish phenotypes. A history of renal disease and use of corticosteroids were associated with secondary NPSLE.
Conclusion: We describe multidisciplinary consensus as a standard for diagnosing and defining phenotypes in NPSLE. These phenotypes show specific characteristics, which can be used to support diagnosis and guide therapeutic decisions. Clinical phenotyping and selection of patients becomes increasingly important when advances in experimental science lead to new targets for therapy in NPSLE.