A screening antibody measure for syphilis, reported against a signal cutoff.
This is the syphilis screening test for Treponema pallidum IgG and IgM antibodies, reported as a Signal-to-Cutoff (S/Co) index instead of a simple positive or negative. The S/Co compares your sample's signal against the test's cutoff line.
A value below 1.0 is non-reactive, and a value at or above 1.0 is reactive. The number reflects how the assay read the sample, not the severity of any infection.
Reporting syphilis screening as an S/Co index gives a clear, objective threshold for whether antibodies are present. It supports consistent reading of results across samples.
A non-reactive S/Co is reassuring. A reactive S/Co points to possible syphilis exposure and needs confirmatory testing before any diagnosis or staging.
Aniva reads your result against research-backed ranges, not just the lab's wide normal. The reference shown below is specific to this biomarker.
This test is reported as a Signal-to-Cutoff (S/Co) index.
| S/Co value | Interpretation |
|---|---|
| Less than 1.0 | Non-reactive (negative) |
| 1.0 or above | Reactive, needs confirmation |
The cutoff is defined by the assay and may vary by laboratory. A reactive result is not a diagnosis on its own.
You see where your signal sits relative to the cutoff. An S/Co below 1.0 is non-reactive. An S/Co at or above 1.0 is reactive and leads to confirmatory testing. The value is not a diagnosis and does not indicate infection stage.
Antibodies take time to appear, so very early infection can be missed. Treponemal antibodies often persist for life after treatment, so a reactive S/Co does not by itself mean active disease. Rare false-reactive results are possible. Fasting does not affect the result.
Read with confirmatory non-treponemal tests such as RPR or VDRL, with TPPA, and with your clinical and exposure history.
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