Overview: Endotoxin TestIntroduction: The Endotoxin Test measures endotoxin levels to detect bacterial infections, causing fever or sepsis. Following 2023 IDSA guidelines, it uses an immunoassay for high sensitivity, aiding in infectious disease screening. This test is critical for guiding diagnosis, treatment, and improving outcomes in immunology for patients with suspected bacterial infections.
Other Names: Endotoxin Assay, Bacterial Lipopolysaccharide Test.
FDA Status: Laboratory-developed test (LDT), meeting immunology standards for diagnostic accuracy.
Historical Milestone: Endotoxin testing began in the 1970s with sepsis research. Limulus amebocyte lysate (LAL) assays emerged in the 1980s, and by the 2000s, high-sensitivity immunoassays improved accuracy.
Purpose: Detects bacterial endotoxins, guides antibiotic therapy, and monitors infection in patients with fever or sepsis.
Test Parameters: 1. Endotoxin
Pretest Condition: No fasting required. Collect serum or plasma at any time. Report symptoms like fever or sepsis, and list recent infections or antibiotic use.
Specimen: 2-5 mL serum (SST) or 2-4 mL plasma (EDTA). Centrifuge within 1 hour. Transport in a biohazard bag within 8 hours.
Sample Stability at Room Temperature: 8 hours
Sample Stability at Refrigeration: 7 days
Sample Stability at Frozen: 6 months
Medical History: Document fever, sepsis, or history of bacterial infections. Include current medications, especially antibiotics.
Consent: Written consent required, detailing the tests purpose, diagnostic implications, and potential need for antibiotic therapy.
Procedural Considerations: Uses an immunoassay (e.g., LAL-based) to measure endotoxin levels. Results are available in 1-2 days, enabling rapid clinical decisions.
Factors Affecting Result Accuracy: Contamination or hemolysis can affect results. Non-bacterial inflammation may elevate levels.
Clinical Significance: Elevated endotoxin levels suggest bacterial infection, prompting antibiotic therapy. Normal levels may require further testing.
Specialist Consultation: Consult an infectious disease specialist or critical care specialist for result interpretation.
Additional Supporting Tests: Blood culture, procalcitonin, or CRP to confirm bacterial infection.
Test Limitations: Non-specific elevations may occur in non-bacterial conditions. Results require clinical correlation.
References: IDSA Sepsis Guidelines, 2023; Clinical Infectious Diseases, Opal SM, 2022.
