文本框: AUTOANTIBODIES ASSESSMENT IN TYPE 1 DIABETES MELLITUS (DM 1) MEXICAN CHILDREN, THEIR PARENTS AND SIBLINGS Mendoza M-F, Bravo R-LE, León H-L, Cárdenas T-H, Montero G-P. General Hospital, “La Raza” National Medical Center, México DF, México Objective: The investigation of the presence of autoantibodies to Glutamic Acid Decarboxylase (GADab), endogenous Insulin (Iab), tyrosine phosphatase-like protein (IA2ab) and C-peptide, and insulin levels as a cross sectional survey in recently diagnosed DM 1 Mexican mestizo children, their parents and siblings. Methods: A 5.0 mL blood sample was drawn, immediately centrifuged, the serum was kept frozen to -20° C until Radio Binding Assay was performed with commercially available kits (CIS) to 38 DM 1, 55 parents and 52 siblings included. Results: Positiveness is referred as follows: for Iab values 3 S.D. above the binding percentage mean, for IA2ab over 1.0 U/mL, for GADab higher than 1.1 U/mL. Reference values for: C- peptide 0.85 to 3.98 in ng/mL and insulin 4.3 to 20 mIU/mL respectively. Iab IA2ab GADab C-peptide Insulin D.M.1 25/38 (65.8%) 15/38 (39.5%) 14/38 (36.8%) 35/38 * (92.1% ** Siblings 2/52 (3.8%) 5/52 (9.6%) 3/52 (5.8%) 2/50 ‡ (3.8%) 36/49 ‡‡ (69.2%) Parents 1/55 (1.8%) 1/55 (1.8%) 2/55 (3.6%) 1/55 ¢ (1.8%) 20/55 ‡‡ (36.4%) *median of 0.090, < 1.8 ng/mL . ** insulin values are not consigned because they were insulin treated. ‡ < 2.2 ng/mL. ‡‡ in fasting state > 20 mIU/mL. ¢one case was 4.1 ng/mL. Conclusions: The frequencies of IA2ab and GADab in DM 1 children were very similar, although under the frequencies obtained in Caucasian population. Thus confirming our previous results (Rev Invest Clin 2000; 52: 427), in the sense that there is significative difference between the frequency of positive DM 1 autoantibodies in different ethnic groups. The Iab were more frequent in the siblings than in the parents. 0934