【Abstract】Objective To explore the differential diagnostic value of major fibrinolytic parameters in pleural fluid. Methods Tissue-type plasminogen activator( t-PA) and plasminogen activator inhibitor-1( PAI-1) in pleural fluid at the first thoracentesis were measured with ELISA and D-dimer was measured with immunoturbidimetry. Results Eighty-four patients with pleural effusion were enrolled, among which 40 with malignant effusion, 33 with infectious effusion and 11 with transudative effusion. t-PA level was higher in malignant and transudative pleural fluid than that in infectious pleural fluid[ ( 52. 49 ±31. 46) ng /mL and ( 58. 12 ±23. 14) ng /mL vs ( 37. 39 ±22. 44) ng /mL, P lt; 0. 05] , but was not statistically different between malignant pleural fluid and transudative ( P gt; 0. 05) . PAI-1 level was higher in malignant and infectious pleural fluid than that in transudative [ ( 164. 86 ±150. 22) ng/mL and ( 232. 42 ±175. 77) ng/mL vs ( 46. 38 ±16. 13) ng/mL, P lt; 0. 01] , but was not statistically different between malignant and infectious pleural fluid( P gt;0. 05) . D-dimer levels in the three types of pleural fluid were significantly different, which was ( 23. 66 ±25. 18) mg/L, ( 6. 36 ±10. 87) mg/L and ( 66. 90 ±42. 17) mg/L in malignant, transudative and infectious pleural fluid, respectively. As single-item detection for malignant pleural fluid, the cutoff of t-PA was gt; 38. 7 ng/mL( area under ROC curve was 64. 0 ) , with sensitivity of 60. 0% , specificity of 63. 6%, positive predictive value of 66. 7%, negative predictive value of 56. 8% and accuracy of 61. 6% .The cutoff of D-dimer was lt; 27. 0 mg/L( area under ROC curve was 85. 5) , with sensitivity of 84. 8% ,specificity of 72. 5% , positive predictive value of 85. 3% , negative predictive value of 71. 8% and accuracy of78.1%. The sensitivity, specificity, positive predictive value, negative predictive value and accuracy of combined examination( t-PA + D-dimer) were 92. 5% , 60. 6% , 74. 0% , 87. 0% , 78. 1% , respectively.Conclusions The t-PA, PAI-1 and D-dimer levels are significantly different in the three types of pleural fluid. The detection of fibrinolytic parameters in pleural fluid, especially the value of D-dimer,may be helpful in the differential diagnosis of pleural effusion.
ObjectiveTo investigate the therapeutic effect of kinetin on bleomycin A5 (BLM-A5)-induced pulmonary fibrosis in rats. MethodsSixty female Wistar rats were randomly divided into three groups. Group A (n=20) was intratracheally injected with saline as control. Group B (n=20) were intratracheally injected with BLM-A5 to establish pulmonary fibrosis model. Group C (n=20) was intratracheally injected with BLM-A5 and received intraperitoneal injection of kinetin at 0.5 mL/100 g once daily. The rats were sacrificed on the 3rd,7th,14th and 28th day respectively. HE and Masson staining were performed to observe lung pathological changes. The contents of hydroxyproline (HYP),urokinase-type plasminogen activator (u-PA),tissue-type plasminogen activator (t-PA),and PAI-1 in lung and plasma were measured by ELISA. ResultsAlveolitis was most obvious on the 7th day and pulmonary fibrosis was most severe on the 28th day in group B compared with other two groups (P<0.05). Alveolitis and pulmonary fibrosis in group C were significantly alleviated compared with group B (P<0.05),but still more severe than group A (P<0.05). The HYP contents in group B,coincided with fibrosis,began to increase on the 7th day and reached the peak on the 28th day,significantly higher than those in other two groups (P<0.05). The u-PA contents of lung tissue in group B began to decline on the 3rd day,reached the minimum on the 7th day,and was still significantly lower than those in other two groups (P<0.05).On the 14th day, the u-PA contents had no significant difference among three groups. The u-PA plasma contents in group B began to decline on the 3rd day,reached the minimum and had significant difference compared with other two groups on the 7th day (P<0.05),and there was no significantly difference among three groups after the 14th day. The t-PA contents change of lung tissue and plasma in three groups were generally consistent with u-PA,but the t-PA plasma contents in group B were still significantly lower than those in group A on the 14th day (P<0.05). The PAI-1 contents of lung tissue in group B began to increase on the 3rd day,reached the maximum on the 7th day,was still significantly higher than those in other two groups (P<0.05),and there was no significant difference among three groups on the 14th day. The PAI-1 contents in group C decreased compared with those in group B (P<0.05),but still higher than those in group A (P<0.05),and there was no difference among them on the 14th day. The PAI-1 plasma contents in group B began to increase on the 3rd day,reached the maximum and was significantly higher than other two groups on the 7th day (P<0.05),and there was no significant difference among three groups on the 14th day. ConclusionThe contents of u-PA and t-PA are increased by inhibiting PAI-1 generation in lung tissue through kinetin treatment,so that,kinetin can suppress pulmonary fibrosis induced by BLM-A5.