Objectives: There is an emerging role of autoimmune causes related to severe mental disorders (SMD). The clinical approach in patients with chronic SMD and novel anti-central nervous system antibodies is complex.
Methods: Two corresponding cumulative cases are presented. Cerebrospinal fluid (CSF) and serum were investigated using tissue-based assays.
Results: Both patients suffered from chronic SMD and were negative for well-characterized neuronal antibodies. Patient 1 suffered from a dysexecutive and neurocognitive syndrome with mild abnormalities in automated electroencephalography analysis, elevated CSF protein levels, several serum autoantibodies (including antibodies against endothelial cells), and novel antibodies with a "dotted/scalloped" binding against cytoplasmic structures in CSF. Patient 2 with obsessive-compulsive disorder had left temporal abnormalities on automated magnetic resonance imaging analysis, an elevated CSF/serum albumin quotient, and novel atypical cytoplasmic "spotted" antibody staining in the serum. Patient 1 improved with immunotherapy using high-dose steroids, but patient 2 did not improve under the same treatment.
Conclusions: The detection of autoantibodies in CSF of chronic SMD may be beneficial in selecting some patients for immunotherapy. The possible impact of novel anti-cytoplasmic antibodies in this context is critically discussed. Further research is needed to establish the underlying pathophysiological processes as well as their diagnostic and therapeutic implications.
Keywords: Autoimmune encephalitis; anti-cytoplasmic antibodies; autoimmune OCD; autoimmune psychosis; cerebrospinal fluid.