The antibody was found in all Lambert-Eaton patients with small cell lung cancer, but in none of those without cancer.
In patients with Lambert-Eaton myasthenic syndrome (LEMS), researchers previously found that 43% of those with small cell lung cancer (SCLC) also had antiglial nuclear antibodies. The same researchers have now conducted further research to identify the antigen of these antibodies and to explore its association with paraneoplastic LEMS.
First, they used serum from patients with LEMS, SCLC, and antiglial nuclear antibodies to probe a brain cDNA library. They cloned SOX1, a protein that is involved in neural development and is also expressed in SCLC. Additional studies confirmed that SOX1 was the autoantigen of the antiglial nuclear antibody. The authors then looked for the SOX1 antigen in serum from 105 patients with LEMS (55 with SCLC, 50 idi…