[An immunoradiometric assay of the serum TPA from patients with primary lung cancer and a comparison with the conventional double antibody method].

The serum level of tissue polypeptide antigen (TPA) has been measured by a new immunoradiometric assay (IRMA) method that has been recently developed using a specific antibody, and compared with the results obtained by the conventional double antibody method, using a polyclonal antibody. Both methods gave essentially the same results, i.e. the serum TPA level in patients with primary lung cancer was higher when compared with non-malignant pulmonary diseases and healthy individuals (p less than 0.01). However the positive rate and average values of TPA with patients of non-malignant diseases were found to be lower by the new IRMA method than by the conventional method. This may be due to the improvement in specificity and accuracy of this newer method of assay, as they also statistically decrease within the cut off level (110 U/L) estimated in non-malignant diseases and healthy individuals. Therefore, it has been concluded that the IRMA method is more suitable than the conventional method for diagnosis of primary lung cancer.