Fecal Calprotectin as a Correlative Marker in Clinical Severity of Infectious Diarrhea and Usefulness in Evaluating Bacterial or Viral Pathogens in Children

Background: Calprotectin is a marker associated with intestinal inflammation. The aim of this study is to explore the diagnostic value of fecal calprotectin in predicting bacterial/viral diarrhea and the application of fecal calprotectin in the clinical course of infectious diarrhea. Methods: Patients ages from 3 months to 10 years with infectious diarrhea were enrolled, and from each patient, 2 to 3 stool samples were collected. Fecal calprotectin levels were determined by enzyme-linked immunosorbent assay and compared by pathogen and disease activity. A univariate linear regression was used to determine the correlation between fecal calprotectin and the clinical parameters, and generalized estimating equations (GEEs) were used for the time course analyses. Results: The data include 451 evaluations for 153 individuals across 3 different time points. The fecal calprotectin level was higher in patients with Salmonella infection (median with range 765 [252-1246] mu g/g) or Campylobacter infection (689 [307-1046] mu g/g) compared with patients with rotavirus infection (89 [11-426] mu g/g), norovirus infection (93 [25-405] mu g/g), or adenovirus infection (95 [65-224] mu g/g). Fecal calprotectin concentrations were elevated in patients with severe (843 [284-1246] mu g/g) or moderate (402 [71-995] mu g/g) disease activity compared with those with mild (87 [11-438] mu g/g) disease activity (P<0.05). GEE analysis suggests that fecal calprotectin is correlated with clinical severity (eg, Vesikari score) and may provide information for disease management. Conclusions: Fecal calprotectin levels increased during bacterial infection and as disease severity increased, and its levels on the initial evaluation and follow-up visit are correlated with clinical severity. Fecal calprotectin may be a useful marker for application in children during infectious diarrhea.