Stool Tests Used in the Diagnosis of Ulcerative Colitis
Two separate markers of inflammation that are
detectable in stool specimens are calprotectin and lactoferrin. Both
tests reflect the presence of neutrophils in the intestine. These
tests may be particularly useful as a noninvasive means to assess
disease activity in ulcerative colitis and in Crohn’s disease
affecting the colon.2024
Fecal Lactoferrin
Lactoferrin is a multifunctional protein that
is found in milk, mucosal secretions, and in neutrophils. As a marker
of the presence of activated neutrophils, increased levels of lactoferrin
in feces correlate with intestinal inflammation. Lactoferrin is not
found in other types of leukocytes; its presence is both sensitive
and specific for neutrophils. Tests for fecal lactoferrin have been
shown useful in identifying the presence of inflammation and differentiating
between inflammatory and noninflammatory causes of diarrhea.2025,2024 Fecal lactoferrin does not differentiate between inflammatory
bowel disease and other inflammatory conditions such as bacterial
infection. The utility of this laboratory test is as a noninvasive
means to monitor disease activity and response to therapy.
Fecal Calprotectin
Calprotectin is a calcium-binding protein secreted
by neutrophils and measurable in stool. High levels of fecal calprotectin
have shown to reflect intestinal inflammation (especially colonic
inflammation), leading to use of this surrogate marker to measure
inflammation associated with inflammatory bowel disease (IBD). Elevated
levels of fecal calprotectin correlate with intestinal inflammation
and are predictive for relapse, although this test is most useful
in disease involving the colon (i.e., ulcerative colitis [UC] or extensive
Crohn’s colitis). The marker is not as sensitive in isolated
small-bowel and ileocecal Crohn’s disease.2026 Bunn,
et al., investigated the correlation between fecal calprotectin levels
and invasive measures of inflammation in children with IBD. Fecal
calprotectin levels correlated well with inflammation confirmed by
endoscopic and histologic evaluation, or technetium-99 white-cell
scanning.2709 Used
in the initial diagnostic evaluation of children with suspected inflammation,
Fagerberg and colleagues determined that fecal calprotectin demonstrated
a 95% sensitivity, 93% specificity, 95% positive predictive value,
and 93% negative predictive value for the detection of colonic inflammation.2028 In
a cohort of 49 children with suspected IBD, Canani, et al., demonstrated
increased sensitivity and specificity by using fecal calprotectin
in combination with other noninvasive tests (anti-Saccharomyces
cerevisiae antibodies/Perinuclear antineutrophil cytoplasmic
antibody, small intestine permeability and bowel wall ultrasonography).
Investigators concluded that the combination of the measures tested
demonstrated a greater than 99% probability of having IBD.2029
In addition to its utility in the initial diagnostic
evaluation of intestinal inflammation, calprotectin has utility as
a predictor of relapse, with increased levels demonstrating a 14-fold
risk of relapse in patients with UC. The test was significantly weaker
as predictor of relapse in CD.2030 As
with fecal lactoferrin, fecal calprotectin may be elevated in the
presence of non-IBD intestinal inflammation such as infection. It
may also be elevated due to enteropathy that results from use of nonsteroidal
anti-inflammatory drugs.2031 Fecal
calprotectin levels have been evaluated in unaffected first-degree
relatives and in spouses of patients with UC and compared with affected
individuals and healthy controls. Investigators found that fecal calprotectin
levels were highest in patients with UC and significantly higher than
controls in unaffected first-degree relatives. Fecal calprotectin
levels in spouses were higher than healthy control subjects, but lower
than first-degree relatives, a finding that further strengthens hypotheses
that stress the role of a combination of genetic predisposition and
environmental factors in the etiology of UC.2032
Content on this page was last reviewed
on
October 31, 2009.
Content on this page was last changed on
March 19, 2009.
References:
2024.
Fine KD, Ogunji F, George J, Niehaus MD, Guerrant RL. Utility of
a rapid fecal latex agglutination test detecting the neutrophil protein,
lactoferrin, for diagnosing inflammatory causes of chronic diarrhea.
Am J Gastroenterol.
1998;93(8):1300-1305.
2025.
Kane SV, Sandborn WJ, Rufo PA, et al. Fecal lactoferrin is a sensitive
and specific marker in identifying intestinal inflammation.
Am J Gastroenterol.
2003;98(6):1309-1314.
2026.
Tibble JA, Sigthorsson G, Bridger S, Fagerhol MK, Bjarnason I. Surrogate
markers of intestinal inflammation are predictive of relapse in patients
with inflammatory bowel disease.
Gastroenterology.
2000;119(1):15-22.
2028.
Fagerberg UL, Lööf L, Myrdal U, Hansson LO, Finkel Y. Colorectal
inflammation is well predicted by fecal calprotectin in children with
gastrointestinal symptoms.
J Pediatr Gastroenterol Nutr
. 2005;40(4):450-455.
2029.
Canani RB, de Horatio LT, Terrin G, et al. Combined use of noninvasive
tests is useful in the initial diagnostic approach to a child with
suspected inflammatory bowel disease.
J Pediatr Gastroenterol
Nutr.
2006;42(1):9-15.
2030.
Costa F, Mumolo MG, Ceccarelli L, et al. Calprotectin is a stronger
predictive marker of relapse in ulcerative colitis than in Crohn’s
disease.
Gut.
2005;54(3):364-368.
2031.
Tibble JA, Sigthorsson G, Foster R, et al. High prevalence of NSAID
enteropathy as shown by a simple faecal test.
Gut.
1999;45(3):362-366.
2032.
Montalto M, Curigliano V, Santoro L, et al. Fecal calprotectin in
first-degree relatives of patients with ulcerative colitis.
Am J Gastroenterol.
2007;102(1):132-136.
2709.
Bunn SK, Bisset WM, Main MJ, et al. Fecal calprotectin: validation
as a noninvasive measure of bowel inflammation in childhood inflammatory
bowel disease.
J Pediatr Gastroenterol Nutr
. 2001;33(1):14-22.
Fine KD, Ogunji F, George J, Niehaus MD, Guerrant RL. Utility of
a rapid fecal latex agglutination test detecting the neutrophil protein,
lactoferrin, for diagnosing inflammatory causes of chronic diarrhea.
Am J Gastroenterol.
1998;93(8):1300-1305.
Kane SV, Sandborn WJ, Rufo PA, et al. Fecal lactoferrin is a sensitive
and specific marker in identifying intestinal inflammation.
Am J Gastroenterol.
2003;98(6):1309-1314.
Tibble JA, Sigthorsson G, Bridger S, Fagerhol MK, Bjarnason I. Surrogate
markers of intestinal inflammation are predictive of relapse in patients
with inflammatory bowel disease.
Gastroenterology.
2000;119(1):15-22.
Fagerberg UL, Lööf L, Myrdal U, Hansson LO, Finkel Y. Colorectal
inflammation is well predicted by fecal calprotectin in children with
gastrointestinal symptoms.
J Pediatr Gastroenterol Nutr
. 2005;40(4):450-455.
Canani RB, de Horatio LT, Terrin G, et al. Combined use of noninvasive
tests is useful in the initial diagnostic approach to a child with
suspected inflammatory bowel disease.
J Pediatr Gastroenterol
Nutr.
2006;42(1):9-15.
Costa F, Mumolo MG, Ceccarelli L, et al. Calprotectin is a stronger
predictive marker of relapse in ulcerative colitis than in Crohn’s
disease.
Gut.
2005;54(3):364-368.
Montalto M, Curigliano V, Santoro L, et al. Fecal calprotectin in
first-degree relatives of patients with ulcerative colitis.
Am J Gastroenterol.
2007;102(1):132-136.
Bunn SK, Bisset WM, Main MJ, et al. Fecal calprotectin: validation
as a noninvasive measure of bowel inflammation in childhood inflammatory
bowel disease.
J Pediatr Gastroenterol Nutr
. 2001;33(1):14-22.