Overview: Fluorescent Treponemal Antibody Absorption TestIntroduction: The Fluorescent Treponemal Antibody Absorption Test detects antibodies to Treponema pallidum to diagnose syphilis, causing sores or rash. Following 2023 CDC guidelines, it uses an immunoassay for high specificity, aiding in infectious disease screening. This test is critical for guiding diagnosis, treatment, and improving outcomes in serology for patients with suspected syphilis.
Other Names: FTA-ABS Assay, Syphilis Antibody Test.
FDA Status: Laboratory-developed test (LDT), meeting serology standards for diagnostic accuracy.
Historical Milestone: FTA-ABS testing began in the 1960s with syphilis research. Immunoassays improved in the 1980s, and by the 2000s, standardized methods enhanced accuracy.
Purpose: Diagnoses syphilis, guides antibiotic treatment, and monitors treponemal antibodies in patients with sores or rash.
Test Parameters: 1. Fluorescent Treponemal Antibodies
Pretest Condition: No fasting required. Collect serum or saliva at any time. Report symptoms like sores or rash, and list sexual history or medications.
Specimen: 2-5 mL serum (SST) or 1-2 mL saliva (sterile container). Centrifuge serum 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 sores, rash, or history of syphilis. Include sexual history and 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 with fluorescence to detect treponemal antibodies. Results are available in 1-2 days, enabling rapid clinical decisions.
Factors Affecting Result Accuracy: Cross-reactivity with other spirochetes or improper storage can affect results. Early infection may yield false negatives.
Clinical Significance: Positive results confirm syphilis, prompting antibiotic treatment. Negative results may require non-treponemal testing.
Specialist Consultation: Consult an infectious disease specialist for result interpretation.
Additional Supporting Tests: RPR, VDRL, or treponemal PCR to confirm syphilis.
Test Limitations: False positives may occur with related infections. Results require clinical correlation.
References: CDC Syphilis Guidelines, 2023; Clinical Infectious Diseases, Workowski KA, 2022.
