MVista® Blastomyces Antibody IgG EIA

• Test Code

  331

• CPT Code

  86612

• Clinical Significance

  This assay indirectly detects anti-Blastomyces IgG by recognizing the BAD-1 repeat surface protein. During validation testing, the sensitivity was found to be 94.29% and specificity 95.00% with an assay cutoff of 14.0 EU. It offers an improvement over the current method of detecting antibodies by FID, where sensitivity has been reported as only 32%. Complement fixation is even less sensitive than FID.

  The Blastomyces Antibody IgG EIA is useful for diagnosing blastomycosis in patients with negative antigen results. Secondly, when both Histoplasma and Blastomyces antigen assays are positive, comparing Histoplasma and Blastomyces antibody concentrations may assist in establishing the correct diagnosis. Additionally, following changes in antibody concentration via repeat testing may determine whether the infection has resolved or if relapse has occurred.

• Methodology

  Semi-Quantitative Indirect Enzyme Immunoassay (EIA)

• Limitations

  Specimens positive for Histoplasma capsulatum may cross-react with the Blastomyces Antibody EIA (IgG detection) and test positive (20% cross reactivity).

• Specimen Collection

  Serum: Collect serum specimens in serum separator or red top tube. Allow blood to clot for 30 minutes, then centrifuge. Pipette serum separated from clot into a plastic screw cap vial.
  Plasma: Plastic screw cap vial

• Minimum Specimen Requirements

  Serum/Plasma: 0.5 mL

• Specimen Stability
  • Room Temperature: 30 days
  • Refrigerated: 30 days
  • Frozen: 30 days
• Specimen Rejection

  Any specimen type other than serum

• Transport Temperature

  Ambient/Refrigerated/Frozen

• Shipping

  Ship to arrive Monday‐Friday using a next day delivery service. Samples may be shipped on dry ice, frozen ice packs, or ambient.

• Turnaround Time

  Testing is performed on Monday, Tuesday, Wednesday, Thursday, and Friday

  Reported next day

• Reference Range

  Negative

• Interpretative Information
  • Negative: < 10.0 EU
  • Intermediate: 10.0 EU – 13.9 EU
  • Positive: 14.0 EU to ≥ 80.0 EU

  Results should be correlated with clinical presentation and history.