[Immune response against modified low-density lipoproteins in patients with non-insulin-dependent diabetes mellitus].
BACKGROUND
Diabetes mellitus is a risk factor for atherosclerosis. Low density lipoproteins are considered a key factor in the formation of atheroma and the immune system has an important contribution to this process.


OBJECTIVE
To quantify the immune response against modified low density lipoproteins in patients with non insulin dependent diabetes mellitus.


METHODS
LDLs obtained from blood of healthy subjects, were glycated or altered with malondialdehyde and used as antigens. Serum autoantibodies against these LDLs were measured by ELISA in 22 patients with non insulin dependent diabetes mellitus aged 46 to 67 years old and 13 healthy controls aged 41 to 65 years old. Basal and LDL stimulated tumor necrosis factor a production in vitro, by peripheral leukocytes of diabetics and controls was also measured.


RESULTS
The ratio of glycated LDL/native LDL antibodies was higher in diabetics than in controls (9.37 +/- 2.72 and 0.41 +/- 0.11 respectively p < 0.05) and the ratio of MDA modified LDL/native LDL antibodies was not significantly different (8.64 +/- 3.83 and 2.14 +/- 1.26 respectively, NS). Tumor necrosis or production by leukocytes was higher in diabetics than in controls in basal conditions (53.3 +/- 15.3 and 26.9 +/- 14.7 arbitrary units (a.u.) respectively), when stimulated with native LDL (46.5 +/- 5 and 24.3 +/- 9.4 a.u. respectively), when stimulated with malondialdehyde modified LDL (50 +/- 16.2 and 24.4 +/- 7.7 a.u. respectively) or when stimulated with glycated LDL (38.3 +/- 8.8 and 14.4 +/- 7.5 a.u. respectively).


CONCLUSIONS
Diabetic patients have an enhanced immune response against low density lipoproteins, factor that could contribute to the accelerated atherogenesis of this disease.
González
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Departamento de Bioquímica Clínica e Inmunología, Facultad de Farmacia, Universidad de Concepción, Chile.
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D000328:Adult; D000368:Aged; D000917:Antibody Formation; D001161:Arteriosclerosis / Q000209:etiology; D001323:Autoantibodies / Q000276:immunology*; D003924:Diabetes Mellitus, Type 2 / Q000150:complications / Q000276:immunology*; D005260:Female; D006801:Humans; D007111:Immunity, Cellular; D008077:Lipoproteins, LDL / Q000276:immunology*; D008297:Male; D008875:Middle Aged; D012307:Risk Factors; D014409:Tumor Necrosis Factor-alpha / Q000276:immunology*
D001323:Autoantibodies; D008077:Lipoproteins, LDL; D014409:Tumor Necrosis Factor-alpha