Serum and pleural fluid levels of CA50 in malignant and tuberculous effusions

Abstract The measurement of CA50 in serum and pleural fluid by immunoradiometric assay was presented in 45 (27 malignancy and 18 tuberculosis) patients with pleural effusion. The mean CA50 level in malignant effusion (89·26 ± 122·32 U ml −1 ) was significantly higher than that in tuberculous effusion (5·18 ± 8·65 U ml −1 ) ( P −1 were found in 78% of malignant fluids and in 6% of tuberculous fluids. The serum CA50 value from 27 patients with malignant effusion (58·67 ± 85·85 U ml −1 ) was also higher than that from 18 patients with tuberculous effusion (6·18 ± 8·37 U ml −1 ) ( P