Objectives:To compare the thin-slice CT features of two groups of age- and gender-matched TB patients with (DM-TB) or without type 2 diabetes (NDM-TB). Methods:CT scans of a total of 42 patients from the NDM-TB and of 38 patients from the DM-TB group were analyzed.All the CT scans were done at the first registration of the patients in SPH and before taking lung surgery.Results:Biopsies with larger necrosis areas were found in DM-TB (84.1%) than in NDM-TB (66.7%,P=0.023).Accompany with the increased necrosis,fewer multinucleated giant cells however severe fibrotic encapsulations were found around DM-TB granulomas.The biopsies with extensive (level 2-3) fibrotic encapsulation around granuloma consists 82.3% of total biopsies from DM-TB,compared with only 50.8% from NDM-TB (P=0.001); the extent of fibrotic encapsulation is correlated with increasing of serum glucose level.In line with this,computed tomography study demonstrated increased ratio of fibrotic thick walled cavities in DM-TB groups (P=0.011).In in vitro study,high glucose treatment increased expression of genes correlated with epithelial cell / fibroblast proliferation and fibrosis in monocyte-derived macrophages.Higher expression of basic fibroblast growth factor was detected both in mRNA and protein levels in peripheral blood of DM-TB patients.CT study demonstrated increased ratio of fibrotic thick walled cavities in DM-TB groups (P=0.011).Conclusions:the association of DM-TB with more severe lung injury and fibrosis,which may be helpful for better designing of the treatment strategy for DM-TB.