Pleural effusion: adenosine deaminase and interferon gamma helped diagnose tuberculosis.

Clinical bottom line (level 4)

  1. Adenosine deaminase and interferon gamma made tuberculosis much more likely if it was present in a pleural effusion.
  2. If adenosine deaminase and interferon gamma were not found, tuberculosis was virtually ruled out.
Valdes et al: Chest 1993; 103 (2): 458-465
Expires October 2003

The study

Setting: three acute hospitals, Spain

405 patients (aged mean 55 years, 59% male) admitted with pleural effusions

Excluded if
  • no specific diagnosis made



    • Independent unblinded reference standard, applied in some patients from a consecutive appropriate spectrum.
    Reference standard:
    • pleural biopsy
    Diagnostic test:
    • adenosine deaminase > 47 U/l
    • adenosine deaminase effusion: serum ratio > 1.5
    • lysozyme > 15 g/ml
    • lysozyme effusion: serum ratio > 1.1
    • interferon gamma > 140 pg/ml

    The evidence

    pre-test probability of tuberculosis: 23%, (95% CI: 18% to 27%)

    diagnostic test tuberculosis no tuberculosis LR+
    (95% CI)    		 post-test probability LR-
    (95% CI)    		 post-test probability
    adenosine deaminase positive (> 47 U/l) 91 16 20
    (12 to 32)     		85% 0.0
    (0.0 to 0.034)     		0%
    total 91 314


    diagnostic test tuberculosis no tuberculosis LR+
    (95% CI)    		 post-test probability LR-
    (95% CI)    		 post-test probability
    adenosine deaminase effusion: serum ratio positive (> 1.5) 42 25 7.8
    (5.3 to 11)     		63% 0.16
    (0.08 to 0.32)     		3%
    lysozyme positive (> 15 g/ml) 42 87 2.2
    (1.8 to 2.7)     		33% 0.23
    (0.12 to 0.46)     		5%
    lysozyme effusion: serum ratio positive (> 1.1) 33 22 7.0
    (4.5 to 11)     		60% 0.36
    (0.24 to 0.54)     		7%
    total 49 227


    diagnostic test tuberculosis no tuberculosis LR+
    (95% CI)    		 post-test probability LR-
    (95% CI)    		 post-test probability
    interferon gamma positive (> 140 pg/ml) 33 9 12
    (6.1 to 22)     		79% 0.062
    (0.016 to 0.24)     		2%
    total 35 110

    Comments

    1. Note the high prevalence of tuberculosis in this study.

    Citation

    1. Valdes L, San Jose E, Alvarez D, et al: diagnosis of tuberculous pleurisy using the biologic parameters adenosine deaminase, lysozyme and interferon gamma. Chest 1993; 103 (2): 458-465
    Search Terms: reference from pleural effusion chapter in 'Quick Consult Manual to Evidence-based Medicine': publd Lippincott-Raven, 1997
    Contributor: Chris Ball and Clare Wotton, October 2000
    Reviewer:

    Clinical Question.
    Patient pleural effusion
    Intervention or Exposure adenosine deaminase, interferon gamma
    Outcome diagnosis of tuberculosis