ImIn particular, fecal calprotectin was found to be a valid marker of GIT pathology and now, it has been established as a routine investigation at variable centers in the UK. Since the discovery that calprotectin can be extracted and quantified from fecal samples, there has been increased interest in using this as a marker for a variety of gastrointestinal disorders. In 1992, Roseth et al.
developed the first FCC measurement method using ELISA. Neutrophil determination in stool is inefficient because its brief lifetime makes it mandatory that the sample should be examined within a few hours of its collection. FC is a highly stable protein resistant to proteolytic fecal degradation. Samples may be stored for up to 5 days at room temperature with no apparent loss of calprotectin concentration. To reduce the risk of a misleading low calprotectin value, it is recommended to obtain samples from the first morning stool.
All methods of fecal calprotectin measurement are dependant on immunochemical studies and use polyclonal or monoclonal antibodies agains several epitopes on the molecule of calprotectin. They can be divided into those that produce a quantitative result and those that produce qualitative result (positive or negative). The first procedures were all in-house enzyme-linked immunosorbent assay techniques but, now commercial assays are widely used. The result can either be read visually or with a metering device.
A new and more efficient procedure has been developed in which only approximately 0.1 g of a stool sample is extracted with 5 mL buffer in a closed tube and this new assay has higher diagnostic accuracy. It also has the advantage of ease of application and reduced risk of contamination. Patients with liver cirrhosis often have important comorbidities and endoscopy may be necessary. Patient selection for endoscopy based on symptoms is not reliable and therefore a non-invasive test such as fecal calprotectin could be clinically useful