Screening for DPPX autoantibodies is used in suspected autoimmune encephalitis, encephalomyelopathy of unknown etiology, and progressive encephalomyelitis with rigidity and myoclonus (PERM).
Testing for anti-neuronal antibodies against the DPPX protein (Dipeptidyl Aminopeptidase-like Protein 6) in serum or cerebrospinal fluid (CSF) is particularly important in the differential diagnosis of encephalitis. DPPX protein is mainly produced in brain tissue and interacts with the KV4 potassium channel. The DPPX protein is an essential regulator of membrane viability in hippocampal CA1 pyramidal cells. Antibodies against DPPX can lead to autoimmune encephalitis.
DPPX belongs to the group of extracellular antigens.