Pathology tests database

Sample and container requirements

Li Heparinised blood

Minimum volume required

Adults and children (> 10 years): one 6 mL LiHep tube. • Children 2 - 9 years: one 4 mL LiHep tube. • Children < 2 years: one 2 mL LiHep paediatric tube

Special requirements

Adults and children (> 10 years): one 6 mL LiHep tube. • Children 2 - 9 years: one 4 mL LiHep tube. • Children < 2 years: one 2 mL LiHep paediatric tube. Blood should be stored at room temperature (no refrigeration) and assayed within eight hours.

Patient preparation

None

Sample viability

Turnaround time

7 days

Reference range

RESULTS - Positive, Negative, Borderline and Indeterminate results A negative result suggests no active immune response to Mycobacterium Tuberculosis. A positive results indicates a response to MTB infection, but does not distinguish between active and latent disease. The test cannot be used to exclude active infection, since false-negative results do occur. It should always be interpreted in the context of other clinial and laboratory features. Due to biological variations, re-testing of borderline (equivocal) results is recommended. Indeterminate results indicate failure of positive or negative controls which may be due to technical or patient-specific factors. Re-testing recommended.

Clinical guidance

T-Spot test can be used to detect exposure to Mycobacterium Tuberculosis. This assay is currently not available through Primary Care https://labtestsonline.org.uk/tests/interferon-gamma-release-assay

Notes

Assay run Monday through thursday.Please phone laboratory (42184) to arrange. To arrive in laboratory by 2.00 pm. No Friday service. T-SPOT assay requires cell culture overnight. Blood should be collected and ideally progressed within eight hours of collection. This time can be prolonged by using the T-cell Xtend reagent.