Résumé
To detect the presence of antibodies against p53 protein in the sera and cytologically positive malignant effusions. Cross-sectional study. Department of Pathology, Postgraduate Medical Institute, Lahore from March 1997 to November 1999. Forty cancer patients were selected with different types of malignancies and having cytologically positive effusions. Both sera and respective effusion fluid were collected and stored at '20°C. Anti-p53 ELISA was then carried out by using commercially available ELISA kit. according to the manufacturer's instructions. A positive p53 antibody level corresponded to the presence of antibodies against mutant p53 protein produced as a result of a mutation of p53 gene in the said cancer. Positivity for anti-p53 antibodies was observed in 27 out of 40 sera [67.5%] and in 19 out of 40 effusions [47.5%] of patients with different types of cancers. The comparison revealed a significant difference with a p value of < 0.05. Out of these, 18 subjects had positive anti-p53 antibodies in both the sera and in respective effusion fluids, yielding an overall sensitivity of 66.6% and specificity of 92.3%. The present study demonstrates the usefulness of anti-p53 antibody estimation both in the serum and in effusions, as a marker of neoplasia and as an adjunct to conventional diagnostic cytopathological techniques especially in those tumours in which p53 gene mutations occur