Biopsy-free diagnosis, monitoring and assessing severity of coeliac disease is not routinely feasible with current clinical tests such as histology, serology and genetics. Coeliac disease is caused and maintained by an acquired T cell-driven immune response targeting a limited number of conserved amino-acid motifs corresponding to epitopes for gluten-specific CD4+ T cells and B cells. These epitopes are well defined. Gluten-specific T cells can be isolated consistently from both the intestinal mucosa and blood in patients with coeliac disease. But in blood they are often so rare that measuring them is impossible without sophisticated reagents such as MHC-peptide multimers and antibodies to surface markers staining predetermined T cells populations. Recently, two new approaches have been developed to measure gluten-specific T-cell immunity in patients: ex vivo whole blood gluten-stimulated cytokine release ("Novoleukin-C(R)") and "in vivo" gluten challenge-stimulated cytokine release. Both approaches have optimal performance characteristics when interleukin-2 (IL-2) is measured by a validated ultra-sensntive assay. Serum IL-2 elevation 3 - 4 hours after one-off bolus gluten challenge correlates with severity of acute gluten-associated symptoms, ex vivo whole blood IL-2 release and frequency of gluten-specific CD4+ T cells assessed by MHC-peptide tetramers. Both assays of gluten-stimulated IL-2 release are effective in patients regularly ingesting or strictly avoiding dietary gluten. Under optimised conditions these IL-2 tests are sensitive and specific for coeliac disease. Both tests have been widely deployed in drug development programs and are expected to be available in clinical care in coming years. These new IL-2 tests promise to accelerate and simplify diagnosis, reverse misdiagnosis and stratify severity of coeliac disease.