The performance of T-cell Xtend reagent in increasing blood storage times for interferon gamma release assays.

Background: T-cell Xtend (TCX) was introduced to extend the blood storage time for T-SPOT.TB test, a widely used commercial interferon gamma release assay (IGRA) for rapid in vitro tuberculosis.

Methods: A total of 99 Uyghur suspected tuberculosis patients were recruited in this study.