Fecal Calprotectin

Aqualab Signature Fecal Calprotectin

Calprotectin

Around 2 million people in Europe suffer from Inflammatory Bowel Diseases (IBD). These include a specific group of diseases, including Crohn’s Disease and Ulcerative Colitis, chronic and incurable diseases of the intestinal tract, characterized by recurrent episodes of inflammation of the gastrointestinal tract. The symptoms, agonizing, embarrassing and debilitating, are important indicators of the disease’s activity, but they can be subjective and appear very similar to other conditions of functional origin, like Irritable Bowel Syndrome, which makes an accurate diagnosis incredibly difficult.

An endoscopy with biopsy is the method of choice, "the golden standard" of monitoring Intestinal Inflammations. However, a new indicator has recently been introduced in Europe, simple, rapid, sensitive, specific, affordable and non-invasive, for the detection and monitoring of IBD. It is called Calprotectin, a highly protein distributed in the organism, carrying calcium and zinc. This protein belongs to the S100 group and is mostly derived from neutrophils. Increased levels of Calprotectin have been consistently detected in the feces of patients with active IBD.

Calprotectin is a 36 kDa protein abundant in the cytoplasm of neutrophils and, to a lesser extent, in the reactive monocytes and macrophages. The known functions of Calprotectin are associated with the defence process through zinc action (it displays antibacterial and antifungal activity). It can be detected in virtually any biological fluids and its concentration is directly correlated with the degree of inflammation in a sample. The plasma levels increase 5 to 40 times in the presence of infectious and inflammatory processes. In stool samples, Calprotectin is shown to be a viable biological marker as it remains especially stable for up to seven days at room temperature, and is resistant to proteolytic degradation of the feces.

Intestinal inflammation causes the loss of the barrier function of intestinal mucosa and the migration of neutrophilic granulocytes through the wall into the intestinal lumen, leading to increased concentration of Calprotectin in the feces. The level of fecal Calprotectin is directly related to the amount of neutrophilic granulocytes and other immune cells in the intestinal lumen. As such, Calprotectin concentrations are elevated in Inflammatory Bowel Diseases (IBD) and, to a lesser extent, in other situations such as nioplasias and polyps. Calprotectin levels in feces are approximately 6 times higher than those found in blood, making it a good indicator of intestinal inflammation.

Several authors indicate that Calprotectin may be used for identifying patients who require more invasive studies, such as colonoscopy, and, when using a cut-off point of 50 µg /g of stool, colonoscopy can no longer be performed in up to 50% of patients, going up to 67% of patients when using a cut-off point of 100 µg/g of feces.

Because it is a non-invasive method, the use of this parameter has been increasing in recent years and its adaptation to fully automated equipments makes it a simpler and more accurate method, which tends to gain more room as a diagnostic support tool.

For the determination of fecal Calprotectin it is necessary to send a recent bottled stool sample without preservatives. The dosing of fecal Calprotectin is performed by the AQUALAB ELiA methodology and the results are available within 7 days.