Lepine Criteria (Pleural Exudate, No Serum Sample)
The Lepine criteria classify a pleural effusion as exudative without a paired serum sample.
Open the calculator → Runs in your browser. Data leaves only if you deliberately send a problem report from the interactive tool.
Example
- Pleural fluid LDH
- 100 U/L
- THE LABORATORY'S upper limit of normal for SERUM LDH
- 250 U/L
- Pleural fluid cholesterol
- 42 mg/dL
Result: Exudate
The tool opens with these values already filled in. Replace them with your own.
What the result means
- vs Heffner
- SAME two tests, thresholds moving in OPPOSITE directions: LDH bar HIGHER (0.6 vs 0.45), cholesterol bar LOWER (40 vs 45).
- Neither dominates
- Each calls some effusions exudative that the other calls transudative, in BOTH directions.
- Trade
- Lepine 0.91 sensitive / 0.73 specific vs Heffner 0.93 / 0.58. "Comparable to Light’s" is a claim about SPECIFICITY.
- Not serum-free
- The LDH test needs the LAB reference value. No patient blood is drawn, but a cutoff must never be hard-coded.
- Diuretics
- Diuresis concentrates a transudate and can push any of these rules to a false exudate.
- Scope
- Classifies only. Does NOT give the cause, does not indicate or contraindicate drainage.
What you enter
- Pleural fluid LDH.
- THE LABORATORY'S upper limit of normal for SERUM LDH - a reference value, not the patient's blood.
- Pleural fluid cholesterol.
Full field descriptions
- THE LABORATORY'S upper limit of normal for SERUM LDH - a reference value, not the patient's blood. REQUIRED AND NOT DEFAULTED: Lepine's cutoff is 0.6 times this and Heffner's is 0.45 times it, and both differ between laboratories.
- Pleural fluid cholesterol. Exudate above 40 mg/dL - LOWER than Heffner's 45, so easier to trigger on this axis.
How this is calculated
- Rule
- AN OR RULE: pleural LDH above 0.6 x the lab serum LDH upper limit, OR pleural cholesterol above 40 mg/dL (1.04 mmol/L). One positive is enough.
Lepine criteria as reproduced and evaluated in a comparison of seven cholesterol- and lactate-dehydrogenase-based criteria for differentiating exudative from transudative pleural effusions. Sci Rep. 2025. Read the source ↗
A reference and educational tool. Not medical, legal, or financial advice, and not a substitute for clinician judgment.