Association Of HLA-A0205,HLA-A30 And MICA Gene Exon 5 With Latent Autoimmune Diabetes In Adults (LADA)

Background Latent autoimmune diabetes in adults is an important subgroup of adult-onset diabetes mellitus. The major characteristic of LADA is autoimmune distraction of islet cells. According to the WHO diabetes classification 1999), LADA is a slowly progressive subtype of the autoimmune type 1 diabetes. The autoimmune type 1 diabetes has been shown to be a polygenic inherited disease, with polymorphism of the major histocompatibility complex (MHC) as the main contributor for the development of the disease. Genetical heterogeneity may account for the clinical difference between LADA and typical type 1diabetes.Objective To investigate the association of HLA-A0205 and HLA-A30 with LADA in Chengdu Hans.Methods 121 subjects (41 cases of LADA, 40 cases of T2DM and 40 controls) were enrolled in the study. The diagnosis and classification of diabetes were based on the 1999 WHO criteria. The diagnosis of LADA was as follows: 1) The onset of age was more than 25 years old, with overt diabetic symptoms. 2) No ketosis during the initial 6 months after onset without insulin treatment. 3) Positivity for autoantibodies against islet antigens. The frequency of HLA-A0205 and HLA-A30 was determined bynested PCR-SSP and direct sequencing. Allele frequency among patient groups and controls were compared by the chi-square test with SPSS 11.0 (of=0.05). Hardy-weinberg equilibrium was tested with HWE (cfO. 05)Results Among study subjects, HLA-A0205 was present in 1 case with LADA and 1 control (2.44%, 2.5%, respectively), HLA-A30 was present in 2 cases with LADA, 1 case with T2DM and 2 controls(4.87%, 5.0%, 2.5%, respectively). The frequency was not different among the three groups.Conclusion These results suggest that HLA-A0205, HLA-A30 may not be related to LADA in Chengdu Hans. But further studies with larger sample size are warranted to confirm this conclusion.