Calprotectin is a protein primarily found within neutrophils, a type of white blood cell involved in the body’s immune response. When intestinal inflammation occurs, these neutrophils migrate to the inflamed area and release calprotectin, which then mixes with the stool. The presence of calprotectin in stool serves as a marker for intestinal inflammation. This article aims to explain why a child might have elevated calprotectin levels and what this result could signify.
Calprotectin and Fecal Testing
Fecal calprotectin is a biomarker for intestinal inflammation, released by neutrophils in the gut lining when inflammation is present. The amount detected in a stool sample is proportional to the degree of intestinal inflammation.
A fecal calprotectin test is a non-invasive stool test used to detect this protein. It is commonly employed in children experiencing gastrointestinal symptoms, particularly when inflammatory bowel disease (IBD) is a concern. This test helps clinicians determine if inflammation is contributing to a child’s symptoms, such as abdominal pain or diarrhea, and can guide decisions on whether more invasive diagnostic procedures are necessary.
Key Reasons for Elevated Levels
Elevated fecal calprotectin levels in children can stem from various underlying inflammatory conditions within the digestive system. Inflammatory Bowel Disease (IBD) is a primary concern when calprotectin levels are high. IBD encompasses chronic inflammatory conditions like Crohn’s disease and ulcerative colitis, where the immune system mistakenly attacks the digestive tract, leading to persistent inflammation.
Gastrointestinal infections are another common cause of temporary spikes in calprotectin. Bacterial infections like Clostridioides difficile (C. diff), Salmonella, or viral infections such as norovirus can trigger an inflammatory response in the gut. These infections cause acute inflammation, leading to a temporary increase in calprotectin that often resolves once the infection clears.
Food allergies and sensitivities can also contribute to elevated calprotectin levels. Conditions like cow’s milk protein allergy (CMPA) or celiac disease involve an immune reaction to certain food components, resulting in intestinal inflammation. In infants with CMPA, calprotectin levels have been observed to decrease significantly after an elimination diet.
Other inflammatory conditions can also lead to increased calprotectin. These include appendicitis (an inflammation of the appendix), eosinophilic gastroenteritis (an allergic condition where eosinophils accumulate in the digestive tract), and even non-steroidal anti-inflammatory drugs (NSAIDs) which can irritate the gut lining.
In infants, necrotizing enterocolitis (NEC), a serious intestinal disease, is another potential cause for elevated calprotectin. A high calprotectin result indicates inflammation but does not diagnose a specific condition on its own.
Next Steps After a High Result
A high fecal calprotectin result serves as a marker of intestinal inflammation, not a definitive diagnosis of a specific disease. This necessitates further investigation to identify the underlying cause. The initial step involves consulting with a pediatrician or a pediatric gastroenterologist, who specializes in children’s digestive health.
The physician will consider the child’s symptoms, medical history, and calprotectin level to determine the next steps. Diagnostic procedures might include blood tests to assess for other markers of inflammation or nutritional deficiencies. Imaging studies, such as MRI or ultrasound, can visualize the digestive tract and identify structural abnormalities or inflammation. In some cases, an endoscopy or colonoscopy may be recommended for direct visualization of the intestinal lining and tissue sampling for microscopic examination. The specific combination of tests will be tailored to the child’s clinical presentation, guiding diagnosis and management.