FTA-ABS IgG Fluorescence Absorbed IgG
Sample: Serum
Schedule: Daily (Immunofluorescence IFA)
Units: Titer Range Positive = Past infection
Remarks: FTA-ABS (Fluorescence Treponema Assay- Absorbed) is used to confirm syphilis infection. False-positive results may be associated with increased or abnormal globulins, antinuclear antibodies (ANA), pregnancy, Herpes infections, cold agglutinins, Mycoplasma antibodies, and others (see table below). It is estimated that about 2% of the population may be falsely FTA-ABS positive. Borderline FTA-ABS results are inconclusive results and cannot be interpreted.
False-Positive Results in Syphilis tests
| Test | Infection causes | Non Infectious causes |
|---|---|---|
| FTA-ABS or TPHA | Lime disease Leprosy Malaria I.M. Relapsing Fever Leptospira | S.L.E. |
| RPR or VDRL | Pneumococcus spp Scarlet Fever Relapsing Fever Bacterial endocarditis Malaria C. psittacii Leptospira Tuberculosis Chickenpox Measles Mumps I.M. HIV Viral hepatitis | Pregnancy Chronic liver disease Intravenous drugs Connective tissue disease Multiple blood transfusions Advanced cancer |
