Which of the following is not a feature of tuberculous pleural effusion?: (A) LDH > 60% serum LDH, (B) Adenosine deaminase, (C) WBC count 5000 - 10000, (D) Increased mesothelial cells
Answer is D. The effusion caused by post primary tuberculosis (TB) represents a delayed hypersensitivity reaction to spillage of organisms into the pleural space. The pleural fluid has the qualities of an exudates. The glucose concentration may be low (<60 mg/dL). pH of tuberculous effusion is below 7.2. Lymphocytes predominate and will be >50%. Mesothelial cells are scarce (<2%). The white cell count averages 5,000 to 2,000/mL. Adenosin deaminase levels are higher ( > 45 IU/L) for tuberculosis. Pleural fluid gamma-interferon (> 140 pg/mL) is also elevated. Positive polymerase chain reaction (PCR) is seen.