A diagnostic composition comprising a mixture of substantially pure polypeptides comprised of a) amino acid sequences of Rv3874 (SEQ ID NO 1), Rv3615 (SEQ ID NO 2) and Rv2348 (SEQ ID NO 4); or b) fragments of 6-50 amino acids in length from amino acid sequence of Rv3874 (SEQ ID NO1), fragments of 6-50 amino acids in length from amino acid sequence of Rv3615 (SEQ ID NO 2) and fragments of 6-50 amino acids in length from amino acid sequence of Rv2348 (SEQ ID NO 4) and wherein each of the fragments comprises immunogenic epitopes from said amino acid sequences; or c) (i) amino acid sequences having at least 80% sequence identity to amino acid sequences of Rv3874 (SEQ ID NO1) and at the same time being immunogenic, amino acid sequences having at least 80% sequence identity to amino acid sequences of Rv3615 (SEQ ID NO 2) and at the same time being immunogenic and amino acid sequences having at least 80% sequence identity to amino acid sequence of Rv2348 (SEQ ID NO 4) and at the same time being immunogenic or (ii) amino acid sequences having 80% sequence identity to fragments of 6-50 amino acids in length from amino acid sequence of Rv3874 (SEQ ID NO1) and at the same time being immunogenic, fragments of 6-50 amino acids in length from amino acid sequence of Rv3615 (SEQ ID NO 2) and at the same time being immunogenic and fragments of 6-50 amino acids in length from amino acid sequence of Rv2348 (SEQ ID NO 4) and at the same time being immunogenic. a) amino acid sequences of Rv3874 (SEQ ID NO 1), Rv3615 (SEQ ID NO 2) and Rv2348 (SEQ ID NO 4); or b) fragments of 6-50 amino acids in length from amino acid sequence of Rv3874 (SEQ ID NO1), fragments of 6-50 amino acids in length from amino acid sequence of Rv3615 (SEQ ID NO 2) and fragments of 6-50 amino acids in length from amino acid sequence of Rv2348 (SEQ ID NO 4) and wherein each of the fragments comprises immunogenic epitopes from said amino acid sequences; or c) (i) amino acid sequences having at least 80% sequence identity to amino acid sequences of Rv3874 (SEQ ID NO1) and at the same time being immunogenic, amino acid sequences having at least 80% sequence identity to amino acid sequences of Rv3615 (SEQ ID NO 2) and at the same time being immunogenic and amino acid sequences having at least 80% sequence identity to amino acid sequence of Rv2348 (SEQ ID NO 4) and at the same time being immunogenic or (ii) amino acid sequences having 80% sequence identity to fragments of 6-50 amino acids in length from amino acid sequence of Rv3874 (SEQ ID NO1) and at the same time being immunogenic, fragments of 6-50 amino acids in length from amino acid sequence of Rv3615 (SEQ ID NO 2) and at the same time being immunogenic and fragments of 6-50 amino acids in length from amino acid sequence of Rv2348 (SEQ ID NO 4) and at the same time being immunogenic. (i) amino acid sequences having at least 80% sequence identity to amino acid sequences of Rv3874 (SEQ ID NO1) and at the same time being immunogenic, amino acid sequences having at least 80% sequence identity to amino acid sequences of Rv3615 (SEQ ID NO 2) and at the same time being immunogenic and amino acid sequences having at least 80% sequence identity to amino acid sequence of Rv2348 (SEQ ID NO 4) and at the same time being immunogenic or (ii) amino acid sequences having 80% sequence identity to fragments of 6-50 amino acids in length from amino acid sequence of Rv3874 (SEQ ID NO1) and at the same time being immunogenic, fragments of 6-50 amino acids in length from amino acid sequence of Rv3615 (SEQ ID NO 2) and at the same time being immunogenic and fragments of 6-50 amino acids in length from amino acid sequence of Rv2348 (SEQ ID NO 4) and at the same time being immunogenic.