Study of the HLA system and glyoxalase in 31 insulin-dependent diabetics free from micro and macro-angiopathies after more than a 20-year development

Insulin-dependent diabetics are not equal as concerns vascular complications. Many factors have been incriminated. The object of this study was to determine if a genetic factor protected the insulin-dependent diabetic from vascular complications. The population included 31 unrelated, white insulin-dependent diabetic subjects (18 females and 13 males), with diabetes of over 20 years' duration (21 to 43 years, m +/- SD 27.82 +/- 6.03 years; age at diagnosis: 2 to 57 years, m +/- SD 22.7 +/- 15.19 years). The absence of vascular lesions was checked for by the following investigations: visual acuity, fundoscopic examination, retinal fluorescein angiography (Canon F 60 Z), systolic pressure on the thigh and ankle, Doppler velocimetry, plethysmography of the lower limbs, serum creatinine level, urinary protein. The study of the HLA A, B, DR specificities was carried out using the Tersaki microlymphocytotoxicity assay, those of C4 by high voltage gel electrophoresis followed by hemolytic detection, those of B1 using Alper's method and those of glyoxalase by gel electrophoresis followed by a glutathione redox reaction in order to test for a marker for a possible protective genetic factor against complications. The antigen frequencies found were compared with: 1) Those in the general Caucasian reference population (9th Histocompatibility Workshop, 1984). The study group presented the HLA characteristics known to occur in insulin-dependent diabetes: increase in A30, B8, B18, D6, DR3, DR4, BfF1 and decrease in A3, B7, DR2. Furthermore an increase in the frequency of DRw53, DQw2 and DQw3 alleles was noted.(ABSTRACT TRUNCATED AT 250 WORDS)     

Insulin-dependent diabetes and HLA.

The study of a hundred and fifteen unrelated insulin-dependent diabetes and eight families with at least two insulin-dependent diabetes members made it possible to confirm the higher frequency of HLA-B8 and B18 (p less than 0.001) among patients, producing a RR of 2.24 and 2.47 respectively. The increased B15 frequency did not achieve statistical significance. B18 whose gametic association (delta = 0.0438) was significant only in diabetic patients was often related to Aw19-2 (Aw30 + Aw31). The B8/B18 genotype gave a relative risk (RR = 4.98) which was significantly higher than that of B8, B18 and B15 heterozygotes (1.50, 1.24 and 1.39 respectively). Pairs of diabetic siblings were more frequently HLA identical than would be expected by chance, and distribution of the pairs of affected sibs into the three categories, identical, semi-identical and different, was closer to the recessive model than to the dominant one. The fact that the B8/B18 individuals had a RR slightly higher than the B8 and B18 homozygotes and distinctly higher than the heterozygotes for only one of these genes, favours the hypothesis of two dominant genes, giving the appearance of recessivity. The gene associated with B18 in Southern Europe seems to play the same part as that of the gene associated with B15 in Northern Europe.