Urinary Peptide patterns in native kidneys and kidney allografts.
BACKGROUND
The use of biopsies to determine kidney health after kidney transplantation is an invasive procedure with some risk to the patient. Consequently, a noninvasive test for transplanted kidney health would provide a significant advantage over current clinical practice.


METHODS
Urines from kidney donors before nephrectomy, pretransplant patients with native kidney disease, and posttransplant kidney recipients were examined for protein biomarkers to diagnose or prognose kidney disease. Proteins were extracted by C4 reverse phase affinity and analyzed by matrix assisted laser desorption/ionization time-of-flight mass spectrometry.


RESULTS
Urine from individuals with healthy kidneys showed few components other than two ubiquitous saposin B glycoisoforms. Patients with kidney disease lacked saposin B and showed new components in two patterns: the most common contained beta-2 microglobulin (B2M, m/z=11,732) plus one or more peaks at m/z=10,350, 9480, 4337, and 4180. Pattern 2 lacked beta-2 microglobulin but contained several degradation products of alpha-1 antitrypsin. Other pathologic components included urinary protein 1 (m/z=15,835), transthyretin (m/z=13,880), and a component at m/z=13,350.


CONCLUSIONS
Patients with acute rejection showed profiles that ranged from those of kidney donors to those of advanced kidney disease. The range of patterns may be useful for analysis of transplant patients without complications and persons with developing kidney disease before or after transplant.
Zhang
Yan
Y
Department of Biochemistry, Molecular Biology, and Biophysics, University of Minnesota, Minneapolis, MN 55455, USA.
Oetting
William S
WS
Harvey
Stephen B
SB
Stone
Matthew D
MD
Monkkonen
Teresa
T
Matas
Arthur J
AJ
Cosio
Fernando G
FG
Nelsestuen
Gary L
GL
D000293:Adolescent; D000328:Adult; D002648:Child; D002846:Chromatography, Affinity; D003920:Diabetes Mellitus / Q000652:urine; D005260:Female; D006801:Humans; D007668:Kidney / Q000166:cytology / Q000502:physiology*; D016030:Kidney Transplantation / Q000473:pathology / Q000502:physiology*; D008297:Male; D008875:Middle Aged; D009392:Nephrectomy; D010455:Peptides / Q000302:isolation & purification / Q000652:urine*; D007690:Polycystic Kidney Diseases / Q000652:urine; D012016:Reference Values; D049231:Saposins / Q000652:urine; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization; D014184:Transplantation, Homologous / Q000502:physiology; D055815:Young Adult
D010455:Peptides; D049231:Saposins