Humoral and cellular responses against KLH in patients vaccinated with KLH-pulsed DCs. (A) Patient serum was obtained both before the first, and after the first, second, and third vaccination cycles. Total IgG antibodies specific for KLH were detected by ELISA. Data represent optical density (OD) 450 values of serially diluted serum samples for a representative patient. (B) Patient PBMCs were isolated one week prior to the third vaccination cycle and cultured in the absence (control) or presence of 10 μg/mL KLH (KLH). Cellular responses were assessed in a tritiated thymidine incorporation assay. Data represent mean ± SD of experiments performed in 6-fold for a representative patient. Significant difference from control according to Student t test: *P < .001.