[Intrathecal synthesis of the anti-Hu antibody in patients with paraneoplastic encephalomyelitis or sensory neuronopathy].

OBJECTIVE

To probe into the pathogenic mechanisms of paraneoplastic encephalomyelitis (PEM) or sensory neuronopathy(PSN).

METHODS

The serum and cerebral spinal fluid(CSF) anti-Hu antibodies and titers in 16 patients with PEM and 14 patients with PSN were detected with indirect immunohistochemistry (ABC) method. Intrathecal IgG synthesis and antibody specific activity (ASA) were calculated with Schuller's formulas according to the titers of the anti-Hu antibodies in the serum and CSF of the patients. Anti-Hu antibodies were identified by detecting the antigens of the nuclear extracts from the human cerebral cortex neurons with Western blot analysis. IgG in the serum and CSF and the albumin in the CSF were tested with electroimmunodiffusion method.

RESULTS

The serum and CSF anti-Hu antibody titers in patients with PEM were significantly higher than those in patients with PSN (P < 0.001). A ratio of intrathecal ASA/serum ASA of anti-Hu antibody > 2 in 14 (88%) of the 16 patients with PEM and one (7%) patient with PSN indicated that the patients with PEM had a positive intrathecal anti-Hu antibody synthesis (P < 0.001). The Rankin scores are 4.5 +/- 1.7 in patients with PEM and 3.0 +/- 1.4 in patients with PSN (P < 0.01). Patients with PEM were more disabled than those with PSN.

CONCLUSIONS

The detection of intrathecal ASA/serum ASA ratio for identifying the anti-Hu antibody intrathecal synthesis is valuable in judging the severity of disease and prognosis in patients with paraneoplastic syndromes of nervous system.