sTNFR-I blood test in Chiswick

What the test measures

Tumour necrosis factor (TNF) is a signalling protein that drives inflammation. Despite its name, it is a normal part of the immune response to infection and injury rather than a cancer test. Cells carry two types of receptor for TNF. Receptor I is present on almost every cell in the body, and when the TNF pathway is active, part of the receptor is shed into the blood. This shed part is soluble TNF receptor I, or sTNFR-I.

Because sTNFR-I is more stable in the blood than TNF itself, it has been studied as a steadier reflection of TNF activity, particularly in research on kidney function in diabetes and on long-term inflammation. For now it remains an emerging marker, best used alongside other tests and a clinical assessment rather than as a stand-alone screen.

Your price includes the sample taken at our Chiswick clinic, analysis at the Randox accredited laboratory, a practitioner review of your result and a GP feedback report on request. No GP referral is needed.

Who it is for

• You are having a detailed inflammation assessment and your practitioner wants a specialist marker.
• You have diabetes and are interested in research markers linked with kidney health.
• You have a long-term inflammatory or autoimmune condition and want to explore additional markers.
• You have had sTNFR-I measured before and would like to look at a trend.

Understanding your result

sTNFR-I is cleared by the kidneys, so levels tend to rise as kidney function falls, and this is one of the main reasons it is read with eGFR. Levels can also rise with infection, autoimmune and inflammatory conditions, obesity and diabetes. A raised result does not point to one condition, and a normal one does not rule out inflammation. Changes over time are often more useful than a single value.

Your report shows the laboratory reference range. A result outside the range is a prompt for discussion with your practitioner, not a diagnosis.

Preparing for your test

Fasting is not required. Try to test when you are free of colds or other infections, and avoid hard exercise the day before. Tell us about medicines that act on the immune system, including steroids and biologic treatments such as TNF blockers, as these may affect the result. We will confirm any further preparation when you book.

sTNFR-I is one of the immune signalling markers included in Omnia Signature, where it is read with kidney, metabolic and inflammation results. For standard kidney measures, see the Kidney Health Check, or view every blood test and price in Chiswick.

Questions

How much is an sTNFR-I blood test in Chiswick?

The sTNFR-I test costs £109. That includes your sample at our clinic, analysis at an accredited laboratory, a practitioner review and a GP feedback report on request.

Is this a cancer test?

No. The name comes from the history of how TNF was discovered. sTNFR-I reflects inflammation signalling and is not used to detect or rule out cancer.

Why does kidney function matter for this result?

The kidneys clear sTNFR-I from the blood, so reduced kidney function can raise the level even without extra inflammation.

How is sTNFR-I different from CRP?

CRP is a widely used general marker made by the liver. sTNFR-I reflects one specific signalling pathway and is mainly used in specialist and research settings.