MALDI MS profiling of serum extracts to identify Galactomannan Enzyme Immunoassay False Positivity via Immunoglobulin Products
- The clinical application of MALDI MS is growing as a result of it’s ease of use, low cost per test and ability to identify biomarkers from body fluids which correlate with disease. We report a clinical scenario where MALDI MS profiling is used to investigate the origin of false positive Galactomannan enzyme immunoassay (EIA) results in a clinical laboratory.
- Therapeutic immunoglobulins (IVIG) are used as replacement or immunomodulatory therapy, but can transmit clinically important molecules (Ramsey et al., 2016). Indications for their use include replacement therapy in antibody-deficiency syndromes.
- Patients in these groups are at increased risk of invasive fungal disease (IFD) with Aspergillus fumigatus.
- Galactomannan antigen (GM) is a component of the cell wall of Aspergillus fumigatus and several other clinically important fungi. The Galactomannan enzyme immunoassay (GM-EIA) is used largely as a screening test for early detection of invasive aspergillosis in at-risk patients. Several immunodominant glycoproteins in Aspergillus fumigatus have been identified previously via immunoblot, but with the use of Aspergillus fumigatus anti-cell wall antibody (Haynes et al., 1990). These glycoprotein masses are described.
- Some patients were found to become positive for the GM-EIA screening test following IVIG administration, although aspergillus culture, pan-fungal and aspergillus specific PCR were negative. The testing of the IVIG vials produced a similar pattern.
- A false-positive GM-EIA result can be interpreted as an early biomarker of invasive aspergillosis or other invasive fungal infection leading to further investigation or treatment.
- Here, the development of a MALDI-based assay to confirm a false-positive GM-EIA result was investigated.
*Not available in the U.S.
- Content Type:
- Paper
- Document Number:
- PO-CON1762E
- Product Type:
- Mass Spectrometry, Life Science Lab Instruments, MALDI-TOF Mass Spectrometry
- Keywords:
- Clinical research, Forensics, Healthcare, Clinical research, MALDI-8020
- Language:
- English
- File Name:
- ego317098.pdf
- File Size:
- 479kb