Protein profiles of peripheral blood mononuclear cells are useful for differential diagnosis of ulcerative colitis and Crohn's disease.
BACKGROUND
Effective biomarkers for discrimination between ulcerative colitis (UC) and Crohn's disease (CD) have not been established yet. In this study, we analyzed protein profiles of peripheral blood mononuclear cells (PBMCs) of the patients to find such a biomarker.


METHODS
Peripheral blood mononuclear cell proteins from 17 UC patients, 13 CD patients, and 17 healthy controls were separated by two-dimensional gel electrophoresis. The intensities of individual protein spots were subjected to discriminant analysis of UC and CD using the SIMCA-P+program.


RESULTS
We found that 547 protein spots were commonly detected among the UC, CD, and healthy groups. Orthogonal partial least squares-discriminant analysis using 276 protein spots clearly discriminated the UC patients from the CD patients (R (2) 0.994; Q (2) 0.462). A similar analysis using a further selected 58 protein spots showed higher performance for discrimination of the diseases (R (2) 0.948; Q (2) 0.566). Eleven out of the 58 protein spots were successfully identified; these were functionally related to inflammation, oxidation/reduction, the cytoskeleton, endocytotic trafficking, and transcription. In addition, the PBMC protein profiles were useful for the prediction of disease activity in the UC and the CD patients, and they were also useful for predicting disease severity and responses to treatments in the UC patients.


CONCLUSIONS
PBMC protein profiles are useful for the discrimination of UC from CD. The profiles could be a potent biomarker for the differential diagnosis of these diseases. Further investigation of the proteins which contributed to the discrimination could promote elucidation of the pathophysiology of UC and CD.
Hatsugai
Moriaki
M
Clinical Proteomics and Molecular Medicine, St. Marianna University Graduate School of Medicine, Miyamae-ku, Kawasaki, Japan.
Kurokawa
Manae S
MS
Kouro
Takefumi
T
Nagai
Kohei
K
Arito
Mitsumi
M
Masuko
Kayo
K
Suematsu
Naoya
N
Okamoto
Kazuki
K
Itoh
Fumio
F
Kato
Tomohiro
T
D000293:Adolescent; D000328:Adult; D000368:Aged; D015415:Biomarkers / Q000097:blood; D001798:Blood Proteins / Q000378:metabolism*; D016022:Case-Control Studies; D003093:Colitis, Ulcerative / Q000097:blood* / Q000175:diagnosis* / Q000473:pathology; D003424:Crohn Disease / Q000097:blood* / Q000175:diagnosis* / Q000473:pathology; D003937:Diagnosis, Differential; D016002:Discriminant Analysis; D005260:Female; D006801:Humans; D016018:Least-Squares Analysis; D007963:Leukocytes, Mononuclear / Q000378:metabolism*; D008297:Male; D008875:Middle Aged; D011237:Predictive Value of Tests; D015203:Reproducibility of Results; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization; D055815:Young Adult
D015415:Biomarkers; D001798:Blood Proteins