Pleural effusion: ANA antibodies made SLE more likely.

Clinical bottom line (level 4)

  1. Antinuclear antibodies found in pleural effusions made systemic lupus erythematosus more likely (LR+6.9) , but were not diagnostic (LR-0.28) .
  2. No antibodies made SLE much less likely.
Khare et al: Chest 1994; 106 (3): 866-871
Expires October 2003

The study

Setting: university hospital, USA

82 patients (aged range 19 to 93 years; mean 51, ?% male) having diagnostic or therapeutic thoracentesis for pleural effusions

Excluded if
  • charts unavailable
  • cause of pleural effusion could not be determined



    • Independent ?blinded reference standard, applied in all patients from a consecutive ?appropriate spectrum.
    Reference standard:
    • American Rheumatology Association criteria for systemic lupus erythematosus (SLE) based on information from medical records
    Diagnostic test: antinuclear antibodies (ANA) in pleural effusion: positive if reaction at 1:40 dilution or higher

    The evidence

    pre-test probability of systemic lupus erythematosus: 9.8%, (95% CI: 3.3% to 16%)

    diagnostic test SLE no SLE LR+
    (95% CI)    		 post-test probability LR-
    (95% CI)    		 post-test probability
    ANA positive 6 8 6.9
    (3.2 to 15)     		43% 0.28
    (0.084 to 0.93)     		3%
    total 8 74

    Comments

    1. SLE was a common finding amongst patients with pleural effusions - other studies have reported collagen vascular disease as ~1% of pleural effusions.

    Citation

    1. Khare V, Baethge B, Lang S, et al: antinuclear antibodies in pleural fluid. Chest 1994; 106 (3): 866-871
    Search Terms: reference from Pleural effusion chapter in 'Quick Consult Manual to Evidence-based Medicine': publ. Lippincott-Raven, 1997
    Contributor: Chris Ball and Clare Wotton, October 2000
    Reviewer:

    Clinical Question.
    Patient pleural effusion
    Intervention or Exposure antinuclear antibodies
    Outcome systemic lupus erythematosus