HOW IS ASSESSMENT OF FAECAL CALPROTECTIN USED TODAY?
- Fecal calprotectin testing is widely used as a diagnostic tool to distinguish between inflammatory bowel disease (IBD) and irritable bowel syndrome (IBS) . However, it is not a tool for diagnosing IBD alone as elevated calprotectin levels could be attributed to other causes such as colorectal cancer.
- There is a strong positive correlation between the disease activity (grade and extent of inflammation) in IBD and the fecal calprotectin level. The test can therefore be successfully used to monitor the effect of treatment.
- The test is able to identify patients who do not respond to a specific treatment, thereby helping the doctor to make optimal therapeutic decisions.
- When the calprotectin values decrease to a low and persistent stable level below 150 -200 mg/kg a “true” or sustained remission is achieved, and the medication can be adjusted accordingly.
- Increasing calprotectin concentrations from the stable level mentioned above indicates relapse which in this way is revealed at an early stage. This is favorable for the patient and his quality of life, making early and appropriate treatment available, thereby shortening the period of fulminant symptoms.
- The ability of fecal calprotectin to differentiate between organic and functional disorders makes it a useful and cost effective tool for the clinician, identifying patients with GI symptoms who may or may not require endoscopy or other invasive analyses. Many patients are spared for an uncomfortable examination! This is particularly important in endoscopy of children; general anesthesia is required for this procedure.
- Fecal calprotectin is a very convenient marker in the diagnosis of necrotizing enterocolitis in newborn children.
- Calprotectin in bile is a promising disease marker in patients with primary sclerosing cholangitis with possible prognostic value.
- The diagnosis gastrointestinal graft versus host disease (GI-GVHD), which is a serious complication after allogeneic stem cell transplantation, is based on clinical symptoms and histological findings. No biomarkers are routinely used to predict GVHD. However, recent data demonstrate that elevated fecal calprotectin levels were significantly associated with presence of GI- GVHD, making this marker a promising tool in early diagnosis.
As the original inventor of fecal calprotetin assays the cut off value 50 mg/kg between normal and pathological levels were established by Calpro, based on ground breaking scientific publications. Calpro has kept this critical cut off unchanged since 2000, and this cut off value was confirmed in a study comparing different ELISAs by Labaere. Since 2005 several manufacturers have launched calprotectin ELISAs; each company does their own independent calibration. However, despite values between assays differ considerably and ELISAs from different manufacturers cannot be used interchangeably, they have all adopted 50 mg/kg as cut off.