Purpose: To verify the efficacy of a serum autoantibody against hypoxia-inducible factor prolyl hydroxylase-3 (PHD3) as a serological marker for RCC.
Methods: Serum samples and surgically resected tumor tissue specimens were obtained from 22 patients with primary RCC, 15 of whom underwent radical nephrectomy and 7 partial nephrectomy. Preoperative serum samples were obtained just before tumor resection. Postoperative serum samples were obtained from 17 patients at least 1 month after tumor removal. Serum samples were also obtained from 26 healthy volunteers. Titers of the anti-PHD3 antibody (Ab) were determined by enzyme-linked immunosorbent assay.
Results: Serum anti-PHD3 Ab titers were significantly higher in patients with RCC than in healthy volunteers (0.610 ± 0.023 vs. 0.591 ± 0.031, P = 0.0001). Using a cutoff point of 0.599, sensitivity, specificity, and positivity for prediction of RCC were 86.4, 57.7, and 63.3%, respectively. In all 17 patients, titers of serum anti-PHD3 were decreased after the surgical resection compared with those before operation (0.622 ± 0.023 vs. 0.580 ± 0.024, P = 0.0003).
Conclusions: The present study suggests that the anti-PHD3 Ab may be a novel serological marker for RCC and the titer may reflect the tumor burden in each individual.