REVUE ALGERIENNE D’ALLERGOLOGIE
Volume 11, Numéro 1, Pages 25-31
2026-03-05

Immunological And Genetic Profile Of A Group Of Algerian Patients With Type 1 Diabetes

Authors : Boussaha Hadia . Allam Ines . Djidjik Reda .

Abstract

Introduction: The aim of this study is to investigate the prevalence of autoimmune markers and vitamin D dosage in patients with T1D, and to study the association between HLA class II genes and T1D. Methods : The study was carried out firstly on 54 patients who were tested for antibodies to insulin (IAA), glutamic acid decarboxylase 65 (GADA) and insulinoma-2 antigen (IA-2A). Patients with at least one positive autoantibody (Ab) then underwent further testing for autoantibodies to thyroid peroxidase (TPOAb), thyroglobulin (TGAb), tissue transglutaminase (tTG IgA/IgG), serum 25-hydroxy vitamin D [25(OH)D] and screening for the HLA-DR/DQ haplotypes. Results :We found that GADA was the most common islet Ab (90%), followed by IA2-A (36.7%) and then IAA (12.5%). 16.7% of the T1D patients were positive for tTG IgA/IgG Ab compared to no positive individuals in the control group (P=0.02). There was also a significant difference in 25(OH)D dose (ng/ml) between the T1D and control groups (25.96 ± 8.32; 17.47 ± 8.96, P =0.0003). No significant differences was observed between the T1D group and the control group in the positivity of TPOAb (23.3% vs 6.7%; P =0.071), TG Ab (6.7% vs 0%; P =0.150), and both (23.3% vs 6.7%; P=0.071). HLA DRB1*03 (DR3), DRB1*04 (DR4), DQB1*02:01 (DQ2) and DQB1*03:02 (DQ8) were highly expressed in the T1D group compared to healthy controls (83. 3% vs. 31.4%, P <10-6), (46.7% vs. 26.4%, P = 0.028), (66.7% vs. 39.3%, P = 0.006) and (63.3% vs. 19.3%, P <10-5) while HLA DR7 and HLA DQ6 were weakly expressed (3.3% vs.17.9%, P=0.045)and(6.7% vs. 32.9%, P=0.004). Conclusion: People with T1D are prone to other autoimmune diseases. Low vitamin D levels are associated with an increased risk of developing T1D. HLA DR3, DR4, DQ2 and DQ8 alleles are significantly associated with T1D, whereas HLA DR7 and DQ6 alleles are protective against T1D in Algerian T1D patients.

Keywords

Type 1 diabetes ; Islet autoantibodies ; Celiac disease ; Autoimmune thyroid disease ; Vitamin D ; HLA