SERA FROM SOME PATIENTS WITH ANTIBODY-ASSOCIATED PARANEOPLASTIC ENCEPHALOMYELITIS SENSORY NEURONOPATHY RECOGNIZE THE RO-52K ANTIGEN

Screening a small cell lung cancer cDNA library with serum from a pati ent with antibody-associated paraneoplastic sensory neuronopathy (Anti -Hu syndrome) resulted in the isolation of a cDNA clone encoding the R o-52 kD antigen. The Ro-52 kD antigen is one of the major antigens rec ognized by the sera of patients with Sjogren's syndrome and systemic l upus erythematosus. Further investigation revealed that the sera of on ly a small percentage (4%) of patients with the Hu syndrome reacted wi th Ro-52 kD antigen. The cross-reactivity may result from a domain of high homology between Ro-52 kD and the HuD antigen. These results emph asize the necessity of using recombinant antigens whenever possible wh en assaying for specific antibodies.