Abstract: A method of diagnosing coeliac disease, or susceptibility to coeliac disease, in an individual comprising: (a) contacting a sample from the host with an agent selected from (i) the epitope comprising sequence which is: SEQ ID NO:1 or 2, or an equivalent sequence from a naturally occurring homologue of the gliadin represented by SEQ ID NO:3, (ii) an epitope comprising sequence comprising: SEQ ID NO:1, or an equivalent sequence from a naturally occurring homologue of the gliadin represented by SEQ ID NO:3, which epitope is an isolated oligopeptide derived from a gliadin protein, (iii) an analogue of (i) or (ii) which is capable of being recognised by a T cell receptor that recognises (i) or (ii), which in the case of a peptide analogue is not more than 50 amino acids in length, or (iv) a product comprising two or more agents as defined in (i), (ii) or (iii), and (b) determining in vitro whether T cells in the sample recognise the agent; recognition by the T cells indicating that the individual has, or is susce

Abstract: A method of diagnosing coeliac disease, or susceptibility to coeliac disease, in an individual comprising: (a) contacting a sample from the host with an agent selected from (i) the epitope comprising sequence which is: SEQ ID NO: 1 or 2, or an equivalent sequence from a naturally occurring homologue of the gliadin represented by SEQ ID NO: 3, (ii) an epitope comprising sequence comprising: SEQ ID NO: 1, or an equivalent sequence from a naturally occurring homologue of the gliadin represented by SEQ ID NO: 3, which epitope is an isolated oligopeptide derived from a gliadin protein, (iii) an analogue of (i) or (ii) which is capable of being recognised by a T cell receptor that recognises (i) or (ii), which in the case of a peptide analogue is not more than 50 amino acids in length, or (iv) a product comprising two or more agents as defined in (i), (ii) or (iii), and (b) determining in vitro whether T cells in the sample recognise the agent; recognition by the T cells indicating that the individual has, or is su

Abstract: A peptide analogue which is not more than 50 amino acids in length, and which is capable of being recognized by a T cell receptor that recognizes an epitope comprising sequence 62PQPELPY68 (SEQ ID NO:1), and fusion proteins, pharmaceutical compositions, and kits comprising the same, are provided herewith. Also provided are methods of diagnosing coeliac disease, or susceptibility to coeliac disease, in an individual comprising contacting a sample from the individual with a peptide analogue and determining in vitro whether T cells in the sample recognize the peptide analogue.