Proteomic techniques identify urine proteins that differentiate patients with interstitial cystitis from asymptomatic control subjects.
OBJECTIVE
The purpose of this study was to identify differences in urine proteins between patients with interstitial cystitis (IC) and asymptomatic control (AC) subjects with the use of proteomic techniques.


METHODS
Nine patients with IC and their age-, race-, and sex-matched AC subjects volunteered a urine specimen. Urine proteins were separated with the use of 2-dimensional polyacrylamide gels. Differing proteins underwent digestion and matrix-assisted laser desorption ionization-time of flight mass spectrometry. Computer-assisted data analysis was used to identify the corresponding protein. Differences in urine protein responses between patients with IC and AC subjects were evaluated by the Mann-Whitney U test to account for the nonnormal frequency distribution of the parameter estimate or chi-square when data were bimodal.


RESULTS
Four proteins differed significantly between patients with IC and AC subjects. The AC subjects had a greater concentration of a uromodulin (P = .019) and two kininogens (P = .023, .046). The patients with IC had a greater concentration of inter-alpha-trypsin inhibitor heavy chain H4 (P = .019).


CONCLUSIONS
These urine protein isoforms may be biomarkers for IC.
Canter
Maria P
MP
Division of Urogynecology, Department of Obstetrics and Gynecology, Virginia Hospital Center, Arlington, VA 22205, USA. mtpettit@hotmail.com
Graham
Carol A
CA
Heit
Michael H
MH
Blackwell
Linda S
LS
Wilkey
Daniel W
DW
Klein
Jon B
JB
Merchant
Michael L
ML
D000293:Adolescent; D000328:Adult; D000368:Aged; D000510:Alpha-Globulins / Q000652:urine; D015415:Biomarkers / Q000652:urine; D001798:Blood Proteins / Q000652:urine; D018856:Cystitis, Interstitial / Q000175:diagnosis* / Q000652:urine; D003937:Diagnosis, Differential; D004591:Electrophoresis, Polyacrylamide Gel; D005260:Female; D006023:Glycoproteins / Q000652:urine; D006801:Humans; D007704:Kininogens / Q000652:urine; D008297:Male; D008875:Middle Aged; D009088:Mucoproteins / Q000652:urine; D020033:Protein Isoforms; D053491:Proteinase Inhibitory Proteins, Secretory / Q000652:urine; D011506:Proteins / Q000032:analysis*; D040901:Proteomics; D011788:Quality of Life; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization; D014556:Urine / Q000737:chemistry*; D058949:Uromodulin
D000510:Alpha-Globulins; D015415:Biomarkers; D001798:Blood Proteins; D006023:Glycoproteins; C091236:ITIH4 protein, human; D007704:Kininogens; D009088:Mucoproteins; D020033:Protein Isoforms; D053491:Proteinase Inhibitory Proteins, Secretory; D011506:Proteins; C548612:UMOD protein, human; D058949:Uromodulin; C011877:inter-alpha-inhibitor