An ELISA for antibodies to recombinant glutamic acid decarboxylase in IDDM.
To detect serum antibodies to GAD in subjects with IDDM, three recombinant mBGAD 67 peptides encompassing the full-length protein were used in an ELISA. In this study 7 of 9 (78%) preclinical IDDM subjects (ICA+ first-degree relatives of a person with IDDM) and 6 of 13 (46%) recent-onset IDDM subjects, but no subjects with Graves' disease (n = 10) or scleroderma (n = 10), nor healthy nondiabetic control subjects (n = 10) had antibodies that reacted with one or more of the recombinant mBGAD peptides. We found no preferential reactivity with any recombinant peptide. Although only 3 preclinical subjects and 1 recent-onset subject had antibodies to all three mBGAD peptides, the results indicate that mBGAD 67 contains at least three B-cell autoepitopes. Compared with an immunoprecipitation assay of native human brain GAD, the ELISA detected 5 of 6 (83%) preclinical and 6 of 6 (100%) recent-onset IDDM subjects. The ELISA should facilitate screening to evaluate the role of autoimmunity to GAD in the development of IDDM.
DeAizpurua
H J
HJ
Burnet Clinical Research Unit, Walter and Eliza Hall Institute of Medical Research, Parkville, Australia.
Harrison
L C
LC
Cram
D S
DS
D000293:Adolescent; D000328:Adult; D000595:Amino Acid Sequence; D000906:Antibodies / Q000032:analysis* / Q000276:immunology; D002648:Child; D003922:Diabetes Mellitus, Type 1 / Q000276:immunology*; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D005968:Glutamate Decarboxylase / Q000276:immunology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D008969:Molecular Sequence Data; D011233:Precipitin Tests; D011994:Recombinant Proteins / Q000276:immunology
D000906:Antibodies; D011994:Recombinant Proteins; D005968:Glutamate Decarboxylase