🩸 PLASMIC Score (TTP Probability)
Estimate the probability of thrombotic thrombocytopenic purpura (TTP) with the PLASMIC score.
Clinical takeaway
High scores predict severe ADAMTS13 deficiency (< 10%).
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When to use
Predict severe ADAMTS13 deficiency and prioritise plasma exchange.
How it works
Seven points (platelets, haemolysis, no cancer, no transplant, MCV, INR, creatinine). 0–4 low, 5 intermediate, 6–7 high probability.
Key points
- High scores predict severe ADAMTS13 deficiency (< 10%).
- Helps decide on empirical plasma exchange while ADAMTS13 is pending.
- Validated in adults with thrombotic microangiopathy.
References
Decision support for licensed clinicians only; not a substitute for clinical judgement, diagnosis or local protocols.
Worked calculation
The values below come from this tool's own example placeholders and are computed server-side with the formula shown on this page, so the arithmetic can be checked quickly. It demonstrates how to substitute values only — it is not clinical advice and not a real case.
| Platelet count < 30 ×10⁹/L | No |
|---|---|
| Haemolysis (retic > 2.5%, haptoglobin undetectable, or indirect bili > 2) | No |
| No active cancer | No |
| No solid-organ/stem-cell transplant | No |
| MCV < 90 fL | No |
| INR < 1.5 | No |
| Creatinine < 2.0 mg/dL | No |
→PLASMIC0/7
- Interpretation：Low (0–4%) probability of severe ADAMTS13 deficiency
- Action：Lower likelihood — pursue alternative TMA causes.
| Platelet count < 30 ×10⁹/L | Yes (+1) |
|---|---|
| Haemolysis (retic > 2.5%, haptoglobin undetectable, or indirect bili > 2) | Yes (+1) |
| No active cancer | Yes (+1) |
| No solid-organ/stem-cell transplant | Yes (+1) |
| MCV < 90 fL | Yes (+1) |
| INR < 1.5 | Yes (+1) |
| Creatinine < 2.0 mg/dL | Yes (+1) |
→PLASMIC7/7
- Interpretation：High (62–82%) — strongly consider TTP
- Action：Send ADAMTS13 and start plasma exchange empirically if TTP suspected.
Frequently asked questions
- What is PLASMIC Score (TTP Probability)?
- Estimate the probability of thrombotic thrombocytopenic purpura (TTP) with the PLASMIC score.
- How is PLASMIC Score (TTP Probability) calculated? What is the core formula?
- Seven points (platelets, haemolysis, no cancer, no transplant, MCV, INR, creatinine). 0–4 low, 5 intermediate, 6–7 high probability.
- When is PLASMIC Score (TTP Probability) used?
- Predict severe ADAMTS13 deficiency and prioritise plasma exchange.
- What are the key clinical points for PLASMIC Score (TTP Probability)?
- High scores predict severe ADAMTS13 deficiency (< 10%). Helps decide on empirical plasma exchange while ADAMTS13 is pending. Validated in adults with thrombotic microangiopathy.
- What are the limits and cautions when using PLASMIC Score (TTP Probability)?
- For licensed clinicians and clinical researchers. Interpret results with history, investigations and local protocols; not a diagnosis or prescription, and not a substitute for multidisciplinary decision-making or local guidelines.
- How is PLASMIC Score (TTP Probability) calculated in practice? Can you show a worked example?
- Inputs: Platelet count < 30 ×10⁹/L No, Haemolysis (retic > 2.5%, haptoglobin undetectable, or indirect bili > 2) No, No active cancer No, No solid-organ/stem-cell transplant No, MCV < 90 fL No, INR < 1.5 No, Creatinine < 2.0 mg/dL No → Result: PLASMIC 0 /7（Interpretation: Low (0–4%) probability of severe ADAMTS13 deficiency, Action: Lower likelihood — pursue alternative TMA causes.） Inputs: Platelet count < 30 ×10⁹/L Yes (+1), Haemolysis (retic > 2.5%, haptoglobin undetectable, or indirect bili > 2) Yes (+1), No active cancer Yes (+1), No solid-organ/stem-cell transplant Yes (+1), MCV < 90 fL Yes (+1), INR < 1.5 Yes (+1), Creatinine < 2.0 mg/dL Yes (+1) → Result: PLASMIC 7 /7（Interpretation: High (62–82%) — strongly consider TTP, Action: Send ADAMTS13 and start plasma exchange empirically if TTP suspected.）