Th1/Th2 Cytokine Ratio Assay

This test measures certain cytokines, which are signalling molecules produced by immune cells, and looks at the balance between two groups of them, known as Th1 and Th2. These two groups are associated with different types of immune response, and the balance between them is sometimes described as the Th1/Th2 ratio. The test assesses this balance in a blood sample. It is requested by some clinicians as part of a wider immune or fertility investigation.

What is measured

• Th1 and Th2 cytokines: signalling molecules linked to two different types of immune response
• Th1/Th2 ratio: the balance between these two groups, assessed in a blood sample

Interpreting your result

This is a specialist test, and the result is provided to the clinician who referred you. Cytokine levels can be affected by infections, inflammation, stress, and other temporary factors, so the result is interpreted in context rather than on its own. Your referring clinician will explain what your result means alongside your history and any other investigations, and advise on any next steps.

Why it matters

This test provides a specialist measure of immune signalling that a clinician may request as part of a wider investigation. Because it requires expert interpretation in the context of your individual situation, it is carried out on referral so that your result is understood and applied appropriately within your care.