RetourWANTAI TB-IGRA was developed and is produced by Beijing Wantai Biological Pharmacy Enterprise Co Ltd, Beijing, China, and is similar to QFT-Plus. Test kits are supplied as three tubes: the first contains phytohemagglutinin acting as a positive control; the second does not contain any antigen and acts as a nil or negative control, and the third contains TB-specific antigens. In WANTAI TB-IGRA, the TB-specific antigens are a recombinant fusion protein of CFP-10 and ESAT-6 (expressed in genetically engineered bacteria) to elicit cell-mediated immune responses from CD4+ T-lymphocytes, whereas QFT-Plus uses polypeptide antigens of CFP-10 and ESAT-6 (53).
Fig. 3.5. WANTAI TB-IGRA kits and components
Source: Reproduced with permission of Beijing Wantai Biological Pharmacy Enterprise Co., Ltd, ©2021. All rights reserved.