[Diagnostic efficiency of serum lipid-bound sialic acid level in malignant pleural effusions]

In this study, pleural fluid and serum lipid-bound sialic acid (LBSA) levels of 68 cases with pleural effusion hospitalised at the department of Chest Diseases in the Medical School of Selçuk University, and serum LBSA levels of 30 healthy individuals as control group were studied. Pleural effusions of 32 cases were due to malignancy of which considerably lung cancer. In the other 36 cases the causes were nonmalignant in origin. Levels of mean serum LBSA in malignant and benign groups were significantly higher than control group (p< 0.001). However, difference of the mean serum LBSA levels of malignant and benign groups was not statistically significant. We found the mean pleural fluid LBSA level of 23.34 mg/dL in malignant group and it was significantly higher than benign group (17.97 mg/dL) (p< 0.05). It was observed that there was no significant statistical difference between the pleural fluid to serum LBSA ratios of malignant and benign groups. In differential diagnosis of malignant pleural effusions, sensitivity and specificity of pleural fluid LBSA were 91%, and 51%, respectively. In conclusion, for the differentiation of malignant pleural effusions LBSA is not believed to be a reliable tumor marker since it may also increase in various chronic and inflammatory diseases. Despite of that, in cases with a suspicion of malignancy, the increased level of pleural fluid LBSA may be useful as a supportive parameter.