BD Glucan vs. Fungitell: Understanding the Terminology
"BD glucan" and "Fungitell" are not the same thing—Fungitell is a specific brand name for one particular (1→3)-β-D-glucan assay manufactured by Associates of Cape Cod, Inc., while "BD glucan" or "BDG" refers to the fungal cell wall component being measured, which can be detected by multiple different commercial assays.
Key Distinctions
What is (1→3)-β-D-Glucan (BDG)?
- BDG is a cell wall component found in most pathogenic fungi
- It's the actual biomarker being measured in blood, not a test itself
- When fungi invade tissues, BDG is released into the bloodstream
Multiple Commercial Assays Exist
The evidence clearly demonstrates that several different commercial kits measure BDG, and they are not interchangeable 1:
Available BDG Assays:
- Fungitell® (Associates of Cape Cod) - colorimetric method
- Wako β-glucan test (Fujifilm Wako) - turbidimetric method
- Glucatell® - colorimetric method
- Fungitec-G®
- Dynamiker Fungus®
- GKT®
Critical Clinical Implications
Different Assays Have Different Characteristics
Fungitell Assay:
- Manufacturer's recommended cutoff: ≥80 pg/mL 1
- Requires duplicate testing
- Colorimetric methodology
- Most extensively studied in clinical literature 2
Wako Assay:
- Manufacturer's recommended cutoff: ≥11 pg/mL 3, 4
- Single-sample testing capability
- Turbidimetric methodology
- Lower inter- and intra-run variability 3
- Optimized cutoff of ≥3.6-4 pg/mL may provide better sensitivity matching Fungitell 5, 3
GKT Assay:
- Reported thresholds: 10-14 pg/mL 1
- Different performance characteristics than Fungitell
Why This Matters Clinically
You cannot directly compare results between different assays because:
- Different cutoff values: An 80 pg/mL result on Fungitell does not equal 80 pg/mL on Wako
- Different methodologies: Colorimetric vs. turbidimetric approaches yield different numerical ranges
- Studies excluded for using wrong assay: Meta-analyses specifically excluded studies using non-Fungitell assays because results cannot be pooled 1
Common Pitfalls to Avoid
- Don't assume "BD glucan" automatically means Fungitell—verify which specific assay your laboratory uses
- Don't apply Fungitell cutoffs to other assays—each has manufacturer-specific thresholds
- Don't interpret results without knowing the assay brand—the same numerical value has different clinical meanings across platforms 5, 3
- Recognize false positives: All BDG assays can show false positivity with hemodialysis membranes, surgical gauzes, albumin/IVIG administration, and certain antibiotics like piperacillin-tazobactam 1
Practical Recommendation
When ordering or interpreting a "beta-D-glucan test," always specify and document which commercial assay is being used (Fungitell, Wako, etc.), as this determines the appropriate cutoff values and interpretation. The term "BD glucan" alone is insufficient for clinical decision-making—you need to know the specific brand and methodology 1, 5, 2, 3.