CTLA-4 CT-60 A/G and CTLA-4 1822 C/T Gene Polymorphisms in Indonesians with Type 1 Diabetes Mellitus

Abstract

Introduction: CTLA-4 gene polymorphism plays an important role in children with type 1 diabetes mellitus (T1DM). However, data on this subject vary among different races and ethnics. Purpose: To analyze CTLA-4 CT-60 A/G and CTLA-4 1822 C/T gene polymorphism among children with T1DM compared to control. Patients and Methods: The CTLA-4 CT-60 A/G and CTLA-4 1822 C/T gene polymorphism in children with T1DM using polymerase chain reaction-restriction fragment length polymorphism in 25 T1DM and 25 controls. The inclusion criteria were patients regularly controlled at the Pediatric Endocrine Outpatient Clinic of Dr. Soetomo Hospital, aged 4–18 years and willing to join this study and the exclusion criteria were T1DM patients hospitalized in the pediatric intensive care unit. In the control group, the inclusion criteria were healthy children, aged 4–18 years and willing to join this study. The exclusion criteria included children with ongoing infection, history of other autoimmune diseases, allergies, or malignancy. Results: The mean age was 12.48 years old, and the mean of T1DM onset was 9.28 years old. The CTLA-4 1822 T allele observed in 62% T1DM and 56% in control (p = 0.388, OR = 0.78, 95% CI = 0.44–1.37) and CTLA-4 CT-60 G allele observed in 52% T1DM and 58% in control (p = 0.393, OR = 1.27, 95% CI = 0.73–2.22). The C/T genotypes was significantly higher in control group (p = 0.045, OR = 3.27, 95% CI = 1.00–10.62). The A/G genotypes was commonly found in control group (p = 0.765, OR = 1.20, 95% CI = 0.37– 3.86). The Javanese was the dominant ethnic group in our study. Conclusion: The frequency of CTLA-4 CT-60 A/G polymorphism almost equivalent in T1DM and control group. However, CTLA-4 1822 C/T polymorphism was more prevalent in the control group; thus, this genotype may have a protective effect against T1DM.