Neuropsychiatric systemic lupus erythematosus

Abstract

  Of the various neuropsychiatric manifestations in systemic lupus erythematosus（NPSLE）, acute confusional state（ACS）in diffuse psychiatric/neuropsychological syndromes（diffuse NPSLE）is the most serious. Recent studies have demonstrated that the elevation of neuron-reactive autoantibodies in cerebrospinal fluid（CSF）, especially anti-NMDA receptor NR2（anti-NR2）and anti-Sm antibodies, is associated with diffuse NP-SLE, most notably with ACS.

  Overall, there are 2 mechanisms for the elevation of CSF IgG, including transudation through the damaged blood-brain barrier and intrathecal synthesis. We have recently revealed that CSF anti-NR2 and anti-Sm levels and Q albumin were significantly higher in an acute confusional state（ACS）than in non-ACS diffuse NPSLE（anxiety disorder, cognitive dysfunction, mood disorder and psychosis）or focal NPSLE. However, there was no significant difference in CSF anti-NR2 or anti-Sm index and serum anti-NR2 and anti-Sm levels among the 3 groups. Both CSF anti-NR2 and anti-Sm levels were significantly correlated with Q albumin. These results demonstrate that the severity of blood-brain barrier damage plays a crucial role in the development of ACS, the most recalcitrant form of diffuse NPSLE.

  On the other hand, CSF IL-6 was elevated more markedly in diffuse NPSLE than in focal NPSLE. Moreover, CSF IL-6 was much higher in ACS than in non-ACS diffuse NPSLE. Therefore, it is suggested that CSF IL-6 as well as CSF anti-NR2 might be surrogate markers for severity of diffuse NPSLE.