Evaluation of the specific structures of IgA1 hinge glycopeptide in 30 IgA nephropathy patients by mass spectrometry

Hiroko Odani, Koichiro Yamamoto, Sachiko Iwayama, Hitoo Iwase, Akihiko Takasaki, Kazuo Takahashi, Yoshiro Fujita, Satoshi Sugiyama, Yoshiyuki Hiki

Research output: Contribution to journalArticlepeer-review

16 Citations (Scopus)


Background: Although many reports have described the abnormal structures of O-glycan in the IgA1 hinge region in IgA nephropathy (IgAN), the specific glycopeptide that can be used as a diagnostic biomarker for IgAN has not yet been identified. To pursue this diagnostic approach, we used mass spectrometric analysis to search for specific structures in IgA1 hinge glycopeptides in 30 IgAN patients contrasted with 30 healthy controls. Method: IgA1 hinge glycopeptides were individually purified from the sera of 30 biopsy-proven IgAN patients and 30 healthy controls. The structure of each glycopeptide was analyzed by ion trap mass spectrometry. Sugar conformations in each glycopeptide were estimated by collision-induced dissociation tandem mass spectrometry. Furthermore, to search for specific O-glycans in IgAN patients with a statistical significance, the identified hinge glycopeptides were analyzed by Fisher exact test. Result: A total of 57 hinge glycopeptides were identified from each of the 2 sample groups. Among the structures of the hinge glycopeptides identified, statistical significance was found for 6 glycopeptides (O-glycan compositions were 33-mer hinge core peptides + xGalNAc + yGal + zNeu5Ac; x:y:z = 5:3:3, 5:3:0, 5:2:1, 4:2:2, 3:1:1, 3:1:0) by Fisher exact test (p<0.05). In these 6 O-glycan compositions, 3 compositions (x:y:z = 4:2:2, 3:1:1, 3:1:0) were only observed in IgAN patients and were absent in the 30 controls. Conclusion: Statistically specific O-glycans were identified in 30 IgAN patients compared with 30 controls. These results open the possibility for preparation of lectin and/ or antibodies binding to specific glycopeptides in IgAN.

Original languageEnglish
Pages (from-to)70-76
Number of pages7
JournalJournal of Nephrology
Issue number1
Publication statusPublished - 01-2010

All Science Journal Classification (ASJC) codes

  • Nephrology


Dive into the research topics of 'Evaluation of the specific structures of IgA1 hinge glycopeptide in 30 IgA nephropathy patients by mass spectrometry'. Together they form a unique fingerprint.

Cite this