Lin Yang1, Zhiguang Zhou, Tao DU, Shaozhen Tan, Yi Zhnag, Ping Jin. 1. Department of Endocrinology, Institute of Metabolism and Endocrinology, Diabetes Center, Second Xiangya Hospital, Central South University, Changsha, China.
Abstract
OBJECTIVE: To explore the characteristics of T cell immunity in peripheral blood of patients with carboxypeptidase-H antibody (CPH-Ab). METHODS: Forty-two latent autoimmune diabetes in adults (LADA) patients with CPH-Ab(+) alone, 20 Type 2 diabetes mellitus patients (T2DM), and 22 healthy controls were selected and their peripheral blood mononuclear cells were isolated. Human recombinant carboxypeptidase (CPH) protein was expressed and further used as a stimulant in Enzyme-linked immunospot (ELISPOT) assay to detect IFN-gamma-Th1 and IL-4-Th2 cells in the 3 groups. Th1/Th2 ratios were also calculated. CPH-Ab and glutamic acid decarboxylase antibody (GAD-Ab) were determined by radioligand assay. RESULTS: Compared with healthy controls and T2DM, IFN-gamma-Th1 and IL-4-Th2 numbers did not increase significantly in CPH-Ab(+) group, nor did the Th1/Th2 ratios (P>0.05). We further divided the CPH-Ab(+) patients into a short duration group (n=22) and a long duration subgroup (n=20) according to the duration of 3 years. CPH-IL-4-T in the short duration subgroup was significantly higher than that in T2DM and healthy controls (1.8 vs. 0.2 and 0.3, both P<0.05) and we did not find any factor that was significantly correlated with the IL-4 spots number. There were not any significant differences in T cell responses to phaseolus vulgaris agglutinin (PHA) among all groups (P>0.05). CONCLUSION: CPH does not directly involve in the cellular pathological mechanism of LADA. Anti-CPH immunity may be associated with more slowly aggressive beta cell autoimmunity.
OBJECTIVE: To explore the characteristics of T cell immunity in peripheral blood of patients with carboxypeptidase-H antibody (CPH-Ab). METHODS: Forty-two latent autoimmune diabetes in adults (LADA) patients with CPH-Ab(+) alone, 20 Type 2 diabetes mellituspatients (T2DM), and 22 healthy controls were selected and their peripheral blood mononuclear cells were isolated. Human recombinant carboxypeptidase (CPH) protein was expressed and further used as a stimulant in Enzyme-linked immunospot (ELISPOT) assay to detect IFN-gamma-Th1 and IL-4-Th2 cells in the 3 groups. Th1/Th2 ratios were also calculated. CPH-Ab and glutamic acid decarboxylase antibody (GAD-Ab) were determined by radioligand assay. RESULTS: Compared with healthy controls and T2DM, IFN-gamma-Th1 and IL-4-Th2 numbers did not increase significantly in CPH-Ab(+) group, nor did the Th1/Th2 ratios (P>0.05). We further divided the CPH-Ab(+) patients into a short duration group (n=22) and a long duration subgroup (n=20) according to the duration of 3 years. CPH-IL-4-T in the short duration subgroup was significantly higher than that in T2DM and healthy controls (1.8 vs. 0.2 and 0.3, both P<0.05) and we did not find any factor that was significantly correlated with the IL-4 spots number. There were not any significant differences in T cell responses to phaseolus vulgaris agglutinin (PHA) among all groups (P>0.05). CONCLUSION: CPH does not directly involve in the cellular pathological mechanism of LADA. Anti-CPH immunity may be associated with more slowly aggressive beta cell autoimmunity.