title: A proton nuclear magnetic resonance-based metabonomics study of metabolic profiling in immunoglobulin a nephropathy.
abstract: OBJECTIVE
  Immunoglobulin A nephropathy is the most common cause of chronic renal failure among primary glomerulonephritis patients. The ability to diagnose immunoglobulin A nephropathy remains poor. However, renal biopsy is an inconvenient, invasive, and painful examination, and no reliable biomarkers have been developed for use in routine patient evaluations. The aims of the present study were to identify immunoglobulin A nephropathy patients, to identify useful biomarkers of immunoglobulin A nephropathy and to establish a human immunoglobulin A nephropathy metabolic profile.
  
  
  METHODS
  Serum samples were collected from immunoglobulin A nephropathy patients who were not using immunosuppressants. A pilot study was undertaken to determine disease-specific metabolite biomarker profiles in three groups: healthy controls (N = 23), low-risk patients in whom immunoglobulin A nephropathy was confirmed as grades I-II by renal biopsy (N = 23), and high-risk patients with nephropathies of grades IV-V (N = 12). Serum samples were analyzed using proton nuclear magnetic resonance spectroscopy and by applying multivariate pattern recognition analysis for disease classification.
  
  
  RESULTS
  Compared with the healthy controls, both the low-risk and high-risk patients had higher levels of phenylalanine, myo-Inositol, lactate, L6 lipids ( = CH-CH2-CH = O), L5 lipids (-CH2-C = O), and L3 lipids (-CH2-CH2-C = O) as well as lower levels of β -glucose, α-glucose, valine, tyrosine, phosphocholine, lysine, isoleucine, glycerolphosphocholine, glycine, glutamine, glutamate, alanine, acetate, 3-hydroxybutyrate, and 1-methylhistidine.
  
  
  CONCLUSIONS
  These metabolites investigated in this study may serve as potential biomarkers of immunoglobulin A nephropathy. Point scoring of pattern recognition analysis was able to distinguish immunoglobulin A nephropathy patients from healthy controls. However, there were no obvious differences between the low-risk and high-risk groups in our research. These results offer new, sensitive and specific, noninvasive approaches that may be of great benefit to immunoglobulin A nephropathy patients by enabling earlier diagnosis.
authors.affiliation: Laboratory of Metabolic Diseases Research, Central Laboratory, 181st Hospital Guangxi, Guangxi Province, China. suiwg@163.com
authors.forename: Weiguo
authors.initials: W
authors.lastname: Sui
authors.forename: Liping
authors.initials: L
authors.lastname: Li
authors.forename: Wenti
authors.initials: W
authors.lastname: Che
authors.forename: Zuo
authors.initials: Z
authors.lastname: Guimai
authors.forename: Jiejing
authors.initials: J
authors.lastname: Chen
authors.forename: Wuxian
authors.initials: W
authors.lastname: Li
authors.forename: Yong
authors.initials: Y
authors.lastname: Dai
mesh_terms: D000293:Adolescent; D000328:Adult; D015415:Biomarkers / Q000032:analysis; D001706:Biopsy; D016022:Case-Control Studies; D016002:Discriminant Analysis; D005260:Female; D005922:Glomerulonephritis, IGA / Q000175:diagnosis* / Q000378:metabolism / Q000473:pathology; D006801:Humans; D007668:Kidney / Q000473:pathology; D016018:Least-Squares Analysis; D009682:Magnetic Resonance Spectroscopy / Q000379:methods*; D008297:Male; D055432:Metabolomics / Q000379:methods*; D011522:Protons; D012680:Sensitivity and Specificity; D055815:Young Adult
chemical_list: D015415:Biomarkers; D011522:Protons