Is a D-dimer (D-dimer test) level of 291 considered elevated?

Is a D-dimer of 291 Considered High?

A D-dimer level of 291 ng/mL is not considered high as it falls within the normal reference range, which is typically below 500 ng/mL for most standard assays. 1

Understanding D-dimer Reference Ranges

D-dimer is a fibrin degradation product that serves as a biomarker for both clot formation and breakdown. The interpretation of D-dimer values depends on:

• Standard cutoff: Most laboratories use 500 ng/mL (or 0.5 μg/mL) as the upper limit of normal for D-dimer 1
• Assay type: Different D-dimer assays have varying sensitivities and specificities:
  • Highly sensitive assays (e.g., ELISA, Vidas) use the 500 ng/mL cutoff
  • Moderately sensitive assays (e.g., SimpliRED, Tinaquant) may use slightly different thresholds 1

Clinical Significance of Your D-dimer Value

A D-dimer value of 291 ng/mL:

• Is below the standard cutoff of 500 ng/mL
• Would be considered negative in the context of venous thromboembolism (VTE) evaluation
• Has a high negative predictive value for ruling out VTE in low to moderate risk patients 1

Special Considerations for D-dimer Interpretation

While your value is normal, it's important to understand that D-dimer interpretation can be affected by:

1. Age: D-dimer levels naturally increase with age, and some guidelines suggest age-adjusted cutoffs (age × 10 μg/L for patients >50 years) 2

2. Pregnancy: Normal D-dimer ranges increase during pregnancy:

   • First trimester: 0.11-0.40 μg/mL
   • Second trimester: 0.14-0.75 μg/mL
   • Third trimester: 0.16-1.3 μg/mL 2

3. Clinical context: D-dimer has reduced specificity in:

   • Hospitalized patients
   • Cancer patients
   • Post-surgical patients
   • Patients with infections or inflammatory conditions 1

When to Be Concerned About D-dimer Levels

• Mildly elevated (2× upper limit): Increased VTE risk and poorer prognosis
• Moderately elevated (3-4× upper limit): May indicate need for hospital admission
• Severely elevated (≥6× upper limit or >3000 ng/mL): Strong predictor of thrombotic events and mortality 2, 3

Bottom Line

Your D-dimer value of 291 ng/mL is within normal limits and would not trigger further investigation for venous thromboembolism in standard clinical algorithms. In the context of VTE evaluation, this normal D-dimer result, especially when combined with low clinical probability (such as a low Wells score), effectively rules out VTE with a 3-month thromboembolic risk below 1% 1.