Tumor progression and serum anti-HuD antibody concentration in patients with paraneoplastic neurological syndromes.

The aim of this study was to investigate whether there are clues for a correlation between tumor progression and serum anti-Hu antibody concentration in patients with anti-Hu-associated paraneoplastic neurological syndromes (PNS). 19 patients with anti-Hu-associated PNS were assigned to three groups according to the course of tumor progression. Group 1 corresponds to patients with rapid tumor progression [n = 5; mean survival in months/standard deviation (SD); 24/10]; in group 2 patients with a favorable tumor prognosis were included (n = 7; mean/SD 79/25, 6 patients still alive); group 3 consisted of patients in whom tumor progression could not be assessed (n = 7; mean/SD 23/20). The anti-Hu antibody concentrations in sera were measured in a recombinant HuD-ELISA. In sera from patients of group 1 the anti-Hu antibody concentration was modest (mean OD 0.56, SD 0.08) whereas a significantly higher anti-Hu antibody concentration was detected in sera from patients with a favorable tumor prognosis (group 2, mean OD 1.86, SD 0.34). These results hint at a negative correlation between tumor progression and the anti-Hu antibody concentration in sera from patients with PNS. These findings confirm and extend previous reports of more indolent tumor growth in patients with an anti-Hu immune response.