From the Guidelines
A positive lactoferrin stool test indicates the presence of inflammation in the GI tract.
Key Points
- The test has a sensitivity of 79% and a specificity of 93% for detecting organic disease as the cause of diarrhea 1.
- A threshold value of 4.0-7.25 mg/g is recommended to optimize sensitivity for inflammatory bowel disease (IBD) 1.
- Fecal lactoferrin has been proposed as a marker for inflammatory conditions, such as IBD 1.
- The test can be used to screen for IBD in patients presenting with chronic diarrhea 1.
- In patients with ulcerative colitis, a positive lactoferrin test can indicate active inflammation and inform treatment adjustment 1.
- However, the certainty of evidence supporting the use of fecal lactoferrin to rule in or rule out moderate to severe endoscopic inflammation is very low due to inconsistency and imprecision 1.
Clinical Considerations
- The test should be used in conjunction with other diagnostic tools and clinical evaluation to confirm the presence of inflammation and guide treatment decisions.
- A positive test result should be interpreted in the context of the patient's symptoms, medical history, and other diagnostic findings.
From the Research
Positive Lactoferrin Stool Test Indications
A positive lactoferrin stool test indicates the presence of intestinal inflammation, which is a characteristic of inflammatory bowel disease (IBD) [ 2, 3 ]. The test is sensitive and specific for detecting inflammation in chronic IBD, including ulcerative colitis (UC) and Crohn's disease (CD) [ 2, 3,4 ].
Key Findings
- Fecal lactoferrin levels are significantly higher in patients with active IBD than in those with inactive IBD, irritable bowel syndrome (IBS), or healthy controls [ 2, 3,5 ].
- The sensitivity and specificity of fecal lactoferrin for UC are 92% and 88%, respectively, and for CD are 92% and 80%, respectively [ 2 ].
- Elevated fecal lactoferrin levels can lead to the exclusion of IBS in clinical practice [ 2, 3 ].
- Fecal lactoferrin levels correlate well with clinical disease activity indices, laboratory measures of inflammation, and mucosal healing [ 4, 5,6 ].
Clinical Implications
- A positive lactoferrin stool test can be used to monitor disease activity and predict impending clinical relapse in IBD patients [ 5, 6 ].
- Fecal lactoferrin determination may be useful in predicting postsurgical recurrence in patients with Crohn's disease who have undergone ileocolonic resection [ 6 ].
- The test can be used as a noninvasive diagnostic tool for monitoring therapeutic efficacy, mainly on mucosal healing [ 4, 6 ].