title: Differential diagnosis of pleural effusion by lactate dehydrogenase isoenzyme analysis.
abstract: OBJECTIVE
  To determine the diagnostic value of pleural fluid lactate dehydrogenase (LDH) isoenzyme analysis in the differential diagnosis of pleural fluid.
  
  
  METHODS
  Eighty-seven consecutive patients with pleural effusion caused by congestive heart failure (33), infection (33), and malignancy (21) comprised a derivation set of patients. Pleural fluid LDH activity and isoenzyme pattern were established in all patients and analyzed by the classification and regression trees (CART) method. An additional group of 20 consecutive patients comprised a validation set that was used for cross-validation of CART-derived decision tree.
  
  
  RESULTS
  A decision tree, with a positive predictive value of 83%, was constructed and validated by data from a validation set of patients.
  
  
  CONCLUSIONS
  Pleural fluid LDH isoenzyme pattern may be helpful for the differential diagnosis of the most common causes of pleural effusions: congestive heart failure, infections, and malignancy.
authors.affiliation: Institute of Pulmonology, Hadassah University Hospital, Jerusalem, Israel.
authors.forename: I S
authors.initials: IS
authors.lastname: Lossos
authors.forename: R
authors.initials: R
authors.lastname: Breuer
authors.forename: O
authors.initials: O
authors.lastname: Intrator
authors.forename: M
authors.initials: M
authors.lastname: Sonenblick
mesh_terms: D000465:Algorithms; D004796:Clinical Enzyme Tests; D003663:Decision Trees; D003937:Diagnosis, Differential; D006333:Heart Failure / Q000150:complications; D006801:Humans; D007527:Isoenzymes; D007770:L-Lactate Dehydrogenase / Q000032:analysis*; D010996:Pleural Effusion / Q000175:diagnosis* / Q000209:etiology; D016066:Pleural Effusion, Malignant / Q000175:diagnosis; D011014:Pneumonia / Q000150:complications; D011237:Predictive Value of Tests; D012680:Sensitivity and Specificity
chemical_list: D007527:Isoenzymes; D007770:L-Lactate Dehydrogenase