Fecal calprotectin in first-degree relatives of patients with ulcerative colitis.

OBJECTIVES

The pathogenesis of inflammatory bowel disease seems to depend on the combination of genetic and environmental factors. To evaluate genetic susceptibility, one approach is to search for specific markers in apparently unaffected family members of patients. Our aim was to evaluate fecal calprotectin concentrations (FCCs) in first-degree relatives of patients with ulcerative colitis (UC).

PATIENTS

Fifty-five patients with UC and 167 healthy first-degree relatives were recruited; 38 of the patients' spouses were also enrolled. One hundred fifty healthy subjects participated as the control group.

METHODS

FCCs were determined by ELISA. FCCs were compared among the groups by Kruskal-Wallis analysis of variance (ANOVA) test followed by Mann-Whitney U test.

RESULTS

Significantly greater FCCs were found in first-degree relatives of patients with UC (76.0 [34.7-129.6] microg/g) as compared with controls (31.6 [17.0-45.0]) (P < 0.0001). Fecal calprotectin levels in patients with UC (256.0 [153.0-356.0] microg/g) were significantly higher as compared with first-degree relatives, spouses (43.8 [18.6-89.0] microg/g), and controls (P < 0.0001 for all comparisons). FCC of relatives was significantly higher than FCC of spouses (P = 0.01). FCC of spouses had a significantly higher FCC with respect to controls (P = 0.01).

CONCLUSIONS

First-degree relatives of patients with UC had greater FCC values and could have a subclinical intestinal inflammation. It needs to be clarified if this finding is the consequence of genetic predisposition, of environmental factors, or the interaction of both, and if relatives with high FCC have a greater risk of developing the disease.