Abnormal glycosylation of serum IgG in patients with IgA nephropathy.
BACKGROUND
We postulated that IgA nephropathy (IgAN) involved alterations of serum IgG. The present study was undertaken to elucidate changes in serum IgG oligosaccharide structure analysis and to assess the diagnostic usefulness of this analysis in IgAN.


METHODS
The subjects were 28 children who were definitively diagnosed as having IgAN on the basis of renal biopsy and who had not received treatment for this disease; 27 healthy children; 15 untreated adults definitely diagnosed as having IgAN; 5 patients with other nephropathies; and 61 healthy adults. Oligosaccharide analyses of IgG were performed by reverse-phase high-performance liquid chromatography (HPLC) developed by Takahashi and colleagues.


RESULTS
In both the children and the adults, the peak area ratio of isomers with two different galactosyl-N-acetylglucosamine (Gal-GlcNAc) binding sites was significantly lower in the presence of IgAN than in the healthy subjects (P<0.05 in children and P<0.001 in adults). The ratio of Gal-free oligosaccharides to Gal-positive oligosaccharides did not differ according to the presence or absence of IgAN in children or in adults.


CONCLUSIONS
The analysis of the oligosaccharide structure of serum IgG seems to be useful in diagnosing IgAN.
Homma
Hideki
H
Department of Nephro-urology, Nagoya City University Graduate School of Medical Sciences, 1 Kawasumi Mizuho-cho, Mizuho-ku, Nagoya, 467-8601, Japan. mie-mew@d8.dion.ne.jp
Tozawa
Keiichi
K
Yasui
Takahiro
T
Itoh
Yasunori
Y
Hayashi
Yutaro
Y
Kohri
Kenjiro
K
D000293:Adolescent; D000328:Adult; D001706:Biopsy; D002648:Child; D002675:Child, Preschool; D002851:Chromatography, High Pressure Liquid / Q000379:methods; D005260:Female; D005922:Glomerulonephritis, IGA / Q000097:blood* / Q000175:diagnosis*; D006031:Glycosylation; D006801:Humans; D007074:Immunoglobulin G / Q000097:blood* / Q000737:chemistry; D007668:Kidney / Q000473:pathology; D008297:Male; D008875:Middle Aged; D009844:Oligosaccharides / Q000032:analysis / Q000737:chemistry; D006023:Glycoproteins
D007074:Immunoglobulin G; D009844:Oligosaccharides; C046179:glycosylated IgG; D006023:Glycoproteins