Here, we assess the performance of the new EUROLINE Neurologic Syndrome 15 Ag (IgG) which expands the EUROLINE Paraneoplastic Neurologic Syndrome 12 Ag by adding CDR2L (together with CDR2 targeted by anti-Yo^1,2), AK5³, and Neurochondrin (NCDN)^4,5.

Many paraneoplastic as well as non-paraneoplastic autoantibodies (AAbs) have been described in neurological disorders in the last decade. By integrating the associated antigens into existing assays, the diagnostic work-up of patients is being improved and diagnostic gaps reduced.

Sensitivity of each AAb was analyzed using a total of 194 clinically and diagnostically pre-characterized samples (table 1). Specificity of each AAb was investigated using a minimum of 100 sera from healthy blood donors.

Using the EUROLINE Neurologic Syndrome 15 Ag, autoantibody positivity was confirmed in 89-100% of samples. In particular, all samples for which clinical and tissue-based indirect immunofluorescence assay pre-characterization indicated anti-Yo positivity were anti-CDR2 and -CDR2L double positive. Anti-AK5 was determined in serum and cerebrospinal fluid (CSF) with a sensitivity of 90 and 100%, respectively, and anti-NCDN with a sensitivity of 100%. The individual specificities were ≥99%.

This kit is a tool for the qualitative in vitro determination of AAbs against a large panel of 15 different neuronal autoantigens to support the diagnosis of neurologic syndromes. The parallel detection of anti-CDR2 and anti-CDR2L (both anti-Yo) increases the diagnostic significance, as double positivity is strongly related to paraneoplastic cerebellar degeneration.

Table 1: Performance of EUROLINE Neurologic Syndrome 15 Ag (IgG)