IMMUNOGENIC MARKER AND HLA GENOTYPE
IN JAPANESE CHILDREN WITH TYPE 1 DIABETES MELLITUS
Sasaki
N
Department
of Pediatrics, Saitama Medical School
Objective:
To elucidate the effect of HLA-associated genetic factors on the clinical
heterogeneity of IDDM in Japanese people.
Methods.
HLA-DRB1, DQA1, and DQB1 genotypes in 88 childhood-onset Japanese IDDM
patients were examined.
Results: Of the 88 IDDM patients, 38
(43.2%) had DRB1*0901-DQA1*0302-DQB1*0303/X (DR9-DQ9/X), 26 (29.5%) had
DRB1*0405-DQA1*0302-DQB1*0401/X (DR4-DQ4/X), and 9 (10.2%) were DR4/9-DQ4/9
heterozygous. The frequency of DR9-DQ9 genotype was significantly higher in
the younger (0-10 years) than in the older (11-16 years) age-group of
onset, but the frequency of DR4-DQ4 was higher in the older (11-16 years)
age-group. Long-standing patients with DR9-DQ9 had significantly higher
levels of GADAb than those with DR4-DQ4. The residual pancreatic β-cell function was retained more in
patients with DR4-DQ4 than in those with DR9-DQ9 at diagnosis through 12-18
months after diagnosis.
Conclusion:
These results suggest that the DR9-DQ9 genotype may induce stronger
autoimmune destructive response against target β-cell
than the DR4-DQ4 genotype does. Our findings may warrant further studies on
the association of diabetogenic autoimmune response with HLA class II
molecules and contribute to a clarification of interracial differences in
HLA-encoded susceptibility to IDDM.