ABSTRACT
We aimed to compare the classic Light's criteria with different testing strategies in an effort to improve the accuracy of pleural fluid (PF) categorization. Thirty-two patients with transudates and 140 with exudates on the basis of their clinical diagnosis were entered into the study. We examined the discriminative properties of 10 analytes in the identification of PF, both singly and in combination with an 'or' rule, to see which was best in distinguishing a transudate from an exudate. A combination of PF lactate dehydrogenase (LD) > 307 U/L (two-thirds of the upper limit of the serum LD reference range) with either PF cholesterol > 1.55 mmol/L or PF to serum protein ratio > 0.5 had a diagnostic accuracy similar to that of Light's criteria. We suggest the use of PF LD and cholesterol in combination as an alternative method for distinguishing pleural transudates from exudates. This test combination avoids the need for venepuncture and the simultaneous collection of a blood sample.
Subject(s)
Exudates and Transudates/chemistry , Pleural Effusion/chemistry , Pleural Effusion/diagnosis , Adult , Aged , Aged, 80 and over , Cholesterol/analysis , Clinical Chemistry Tests , Diagnosis, Differential , Female , Humans , L-Lactate Dehydrogenase/analysis , Male , Middle Aged , Prospective Studies , Proteins/analysisABSTRACT
OBJECTIVE: To determine whether measurement of the complement activation products SC5b-9 and C3a-desArg in pleural fluid can reliably differentiate tuberculous from malignant pleural effusions. DESIGN: Twenty-four patients with tuberculous pleuritis, 29 with malignant pleural effusion, and 30 control subjects with transudates were enrolled in the study. SCSb-9 and C3a-desArg were measured in pleural fluid using commercial ELISA tests, and their performances were evaluated using receiver operating characteristic (ROC) analysis. RESULTS: Patients with tuberculous pleuritis had higher mean levels of pleural SC5b-9 (5052 microg/L) and C3a-desArg (7436 microg/L) than those with malignant effusions (1048 and 2835 microg/L, respectively), whereas only SC5b-9 concentrations in the latter were comparable with controls. The area under the ROC curve (AUC) was 0.84 for SC5b-9 and 0.81 for C3a-desArg. Pleural SC5b-9 showed an accuracy of 80.8%, compared with 78.8% for C3a-desArg, when cut-off points of 1500 and 4500 microg/L, respectively, were used. Using a stepwise logistic regression model, the combination of pleural SCSb-9 > or =1500 microg/L, age < or =35 years, and pleural monocyte percentage > or =90% provided the highest accuracy for tuberculous pleurisy (88.5%, AUC 0.95). CONCLUSION: This pilot study suggests that pleural SC5b-9 is clinically useful for differentiating tuberculous and malignant pleural effusions.
Subject(s)
Anaphylatoxins/analysis , Complement C3a/analogs & derivatives , Complement System Proteins/analysis , Glycoproteins/analysis , Pleural Effusion, Malignant/diagnosis , Tuberculosis, Pleural/diagnosis , Adult , Complement C3a/analysis , Complement Membrane Attack Complex , Diagnosis, Differential , Enzyme-Linked Immunosorbent Assay , Female , Humans , Logistic Models , Male , Multivariate Analysis , Pilot Projects , Pleural Effusion/chemistry , Pleural Effusion/cytology , Prospective Studies , ROC CurveABSTRACT
OBJECTIVES: To compare the accuracy of Light's criteria for categorizing a pleural effusion as an exudate with several alternative criteria. DESIGN: Prospective evaluation of patients who underwent a diagnostic thoracocentesis. SETTING: Community teaching hospital in Lleida, Spain. PATIENTS AND METHODS: Medical records and pleural fluid characteristics of 241 consecutive patients with pleural effusion admitted over a 29-month period were reviewed. Forty eight of these patients were excluded for different reasons. Light's criteria and a different cutoff level for the pleural fluid cholesterol level were applied and their accuracies were calculated. RESULTS: Of the 193 patients included, 38 (20%) had transudates and 155 (80%) exudates. The accuracy of Light's criteria for identifying exudates was 92% [confidence intervals (CI), 88-96%], with a sensitivity of 97% (CI, 94-100%) and specificity of 71% (CI, 57-85%). A cutoff level of 50 mg dl-1 was selected for pleural cholesterol, which yielded a sensitivity and specificity of 84% (CI, 79-90%), with an accuracy of 84% (CI, 72-96%). Overall, pleural cholesterol misclassified more exudates as transudates than Light's criteria (15 vs. 3.2%, P < 0.001). The combination of pleural cholesterol with lactate dehydroegnase (LDH) or pleural fluid/serum protein ratio revealed a comparable accuracy to that achieved with Light's criteria. CONCLUSIONS: Light's criteria are just as useful as the association of pleural cholesterol and LDH to detect exudates. In the present study, no parameter, including pleural cholesterol, was superior to Light's criteria.
