The diagnostic value of pleural effusion ferritin and the ratio of it to serum ferritin in differentiating exudates from transudates

To explore the diagnostic value of measuring the level of ferritin in pleural and peritoneal effusion for differentiating exudates from transudates, 128 effusion samples were initially detected for differentiating exudates from transudates by traditional method and Light's criteria. Ferritin in the effusions and serum ferritin were detected simultaneously, and the ratio of effusion ferritin (PFt) to serum ferritin (SFt) was counted. Based on the clinical data, the samples were divided into four groups and PFt and PFt/SFt were compared. At the same time, the sensitivity and specificity of PFt and PFt/SFt in differentiating exudates from transudates were compared with traditional method and Light's criteria. The results showed that in the groups of tuberculous pleurisy, non-tuberculous, benign pleurisy, and malignant tumor, the concentration of Ft in the effusions was significantly higher than that in the group of congestive heart failure and cirrhosis; and the Ft in exudates was significantly higher than that in transudates (P<0.01), but it had no difference in serum (P>0.05). If the cut-off value was set up for Ft in the effusion as 100 μg/L and PFt/SFt ratio as 0.5, respectively, the differentiating sensitivity and specificity were 94.2% and 87.0%, respectively. Conclusion was that the concentration of PFt and PFt/SFt in exudates are higher than 100 μg/L and 0.5, respectively. On the contrary, they are lower than the cut-off level in transudates. PFt and PFt/SFt have high sensitivity and high specificity in differentiating exudates from transudates, and have great diagnostic value