[Immunologic and clinical study of paraneoplastic limbic encephalitis]

To probe into the pathogenic mechanisms of paraneoplastic limbic encephalitis (PLE) in patients with small cell lung carcinoma (SCLC).

The indirect immunoperoxidase method and Western blot analysis were used for detecting anti-Hu antibodies in 16 PLE patients associated with SCLC. Autopsy and pathological study were performed on two cases.

Eight patients (50%) had anti-Hu antibodies (anti-Hu+) whereas eight patients (50%) no detectable antineuronal antibodies (anti-Hu-). The clinical and laboratory features of PLE and time to diagnosis of SCLC were similar in the anti-Hu+ and anti-Hu- groups. Involvement of other areas of the nervous system in seven (87.5%) patients of the anti-Hu+ group but in only one (12.5)% of the anti-Hu- group (P = 0.012).

The presence of this characteristic neurological disorder strongly suggested that with an accompanying SCLC, existence of anti-Hu autoantibody was in favour of an autoimmune mechanism participating in PLE.