Fecal excretion of human deoxyribonucleic acid as an index of inflammatory activity in ulcerative colitis.
OBJECTIVE
Several indices evaluate disease activity in ulcerative colitis, but most have drawbacks to their application (invasiveness, complexity, or lack of specificity), and discrepancies between them are frequent. Assuming that desquamation of epithelial and inflammatory cells increases in damaged colonic mucosa, we hypothesized that fecal excretion of human DNA is an index of mucosal inflammation and damage. The aim of our study was to determine whether excretion of human DNA is useful in the evaluation of disease activity in ulcerative colitis.


METHODS
Thirty-one controls and 36 ulcerative colitis patients were included. Ulcerative colitis patients and controls underwent colonoscopic examination after preparation by gut lavage with polyethylene-glycol electrolyte solution. In patients, disease activity was established using the clinical index of Rachmilewitz and an endoscopic score. Feces and gut lavage fluid were obtained and DNA levels were measured by quantitative polymerase chain reaction of the human beta-globin gene.


RESULTS
Fecal DNA excretion correlated with the clinical index (r = 0.59, P < 0.05) and the endoscopic score (r = 0.76, P < 0.01). Gut lavage fluid DNA levels also correlated with clinical and endoscopic activity scores (r = 0.41 and 0.51, respectively, P < 0.05). Fecal DNA excretion was significantly higher in patients with endoscopically or clinically active disease than in controls or patients in remission. Fecal DNA excretion discriminates between endoscopically active disease and remission (sensitivity 0.67, specificity 1.00, P < 0.01).


CONCLUSIONS
Excretion of human DNA in feces, as an expression of cellular desquamation, is a novel noninvasive technique to objectively assess disease activity in ulcerative colitis.
Digestive System Research Unit, Hospital Universitari Vall d'Hebron, Universitat Autònoma de Barcelona, Spain. fcasellas@vhebron.net
Francesc
F
Casellas
Maria
M
Antolín
Encarnación
E
Varela
Ana
A
García-Lafuente
Francisco
F
Guarner
Natalia
N
Borruel
José Ramón
JR
Armengol Miró
Juan-Ramón
JR
Malagelada
D000328:Adult; D000368:Aged; D015415:Biomarkers / Q000032:analysis; D003093:Colitis, Ulcerative / Q000276:immunology / Q000503:physiopathology*; D003106:Colon / Q000503:physiopathology; D003113:Colonoscopy; D004247:DNA / Q000032:analysis*; D005243:Feces / Q000737:chemistry*; D005260:Female; D006801:Humans; D007249:Inflammation / Q000503:physiopathology; D007413:Intestinal Mucosa / Q000503:physiopathology; D008297:Male; D008875:Middle Aged; D012720:Severity of Illness Index; D007507:Therapeutic Irrigation / Q000379:methods
D015415:Biomarkers; D004247:DNA