Prevalence Of IA-2βA In Type 1 Diabetes Patients And Its Relation With Clinical Features

Part 1 Prevalence of IA-2βA in type 1 diabetes patients and combined detection of GADA,IA-2A,IA-2βA in type 1 diabetesObjective: 1. To investigate the prevalence of IA-2βA in Chinese type 1 diabetes (T1DM) patients. 2. To explore the value of combined analysis of GADA, IA-2A, IA-213A in T1DM patients.Methods: According to the WHO criteria(1999), 401 subjects with T1DM and 200 healthy controls were recruited. 401 subjects with T1DM were screened for GADA, IA-2A, IA-2βA with radioligand assay. We observed the prevalence of IA-2βA and explored the value of combined analysis of GADA, IA-2A, IA-213A in T1DM patients.Results: 1. In T1DM 8.7% (35/401) of patients were positive for IA-213A, 23.4% (94/401) for IA-2A and 50.6%(203/401) for GADA. 2. Out of 35 IA-2BA positives 16 (45.7%) were positive for IA-2A, indicating a marked immunological overlap between IA-2A and IA-2βA. Among 401 patients with T1DM, levels of IA-2βA were not correlatedwith IA-2A (r=0.021,P=0.780). 3. Comparison of antibody frequencies in patients with T1DM showed an inverse correlation between the presence of IA-2BA and IA-2A compared with age and the prevalences of both IA-2βA and IA-2A were higher in the age group 0-9 years as compared with other age groups. In contrast, GADA were not significantly correlated with age. 4. Combined detection of GADA, IA-2A, IA-2βA identified 58.6% of patients with T1DM, whose positive frequency was higher than that of combined detection of GADA and IA-2A(57.6%).Conclusion: The prevalence of IA-βA in T1DM patients is lower than that of IA-2A. There is an inverse correlation between the presence of IA-2βA compared with age and the prevalence of IA-2βA is higher in children-onset T1DM. Combined detection of IA-2βA with GADA and IA-2A offers only marginal advantages for diagnosis. Part2 Relation of IA-2βA with clinical features in T1DMObjective: To explore the relation of IA-2βA with clinical features in T1DM.Methods: Sera of 401 T1DM patients have been determinated for GADA, IA-2A, IA-2βA. And then we explore the relation of IA-2βA with clinical features in T1DM.Results: 1. Compared with 366 IA-2βA-negative patients with T1DM, 35 IA-2βA-positive patients had a trend to have shorter duration of disease, lower BMI, but there were no significant differences between the two groups. Among all clinical features, only one feature HDL was significantly higher in IA-2βA-positive group, while the others, such as SBP, DBP, FBS, PBS, FCP, HbAlc, TG, TC, etc, were not found significant differences between the two groups. 2. 203 GADA-positive patients with T1DM were devided into four groups (both negative, LA-2βA positive alone, IA-2A positive alone and both positive). Compared with the group both negative, the other three groups had a trend to have younger onset age, shorter duration of disease, but there were no significant differences (P＞0.05). None of the clinical features had significant differences among the four groups. 3. Comparing four groups positive for GADA alone, IA-2A alone, IA-2βA alone and negative for all antibodies, we found that FBS and PBS in the group positive for IA-2βA alone were significantly higher than that in the group negative for all antibodies (P＜0.05). The study found no significant differences in other clinical features among the four groups.Conclusion: IA-2βA-positive T1DM patients have similar clinical features with IA-2A-positive patients, who have a trend to have shorter duration of disease, lower BMI and younger onset age. Other clinical features remain unknown until the sample size positive for IA-2βA alone are expanded.