Detection of serum P53-IgG antibody and its preliminary clinical studies

Objective To establish an enzyme linked immunosorbent assay (Elisa) method for detecting P53 IgG antibody in serum and to evaluate its preliminary clinical significance. Methods P53 MoAb was used as coating antibody, and the immunopurified P53 antigen through affinity chromatograph acted as an immunosorbent for the serm P53 antibody. We developed an enzyme immunoassay for the detection of P53 IgG antibody.Results P53 IgG antibody was positive in 32.62%(27/78) of the sera from patients with digestive cancer, but in none of 32 healthy donors and 30 non cancer patients ( P 0.01). The positive rate of serum P53 IgG antibody in the positively immunostained cases was 56.26% (27/48), and it was significantly higher than in the negatively immunostained cases (0/30) ( P 0.01). The diagnostic specificity of P53 IgG antibody for the cancer was 100%, the sensitivity was 34. 62%, and the predictive value of positive and negative test was 100% and 58.82% respectively. The specificity of our method was 100%, intraassay coefficient of variation was 3.8%, and the interassay coefficient of variation was 16.2%.Conclusions Serum P53 IgG antibody was correlated to the overexpression of P53 protien in the primary tumor. It was one of auxiliary indicators for investigating the status of the P53 gene in tumor.