Faculty Opinions recommendation of Fecal calprotectin concentrations in cancer patients with Clostridium difficile infection.

Fecal calprotectin (fCPT) has been used as a surrogate marker for assessment of intestinal inflammation. We explore the utility of fCPT values as a diagnostic aid in cancer patients with suspected Clostridium difficile infection (CDI). A total of 232 stool specimens submitted for GeneXpert C. difficile PCR testing were included in the study. All specimens were tested for fCPT and toxin/GDH antigens. Clinical severity of CDI cases was determined by the IDSA/SHEA criteria. Significant differences of median fCPT values (g/g) between CDI (n=117, Median 183.6 g/g) and non-CDI (n=115, 145.6 g/g, p=0.006) patients were seen. In CDI patents, significantly lower f CPT values were found in patients with mild to moderate (n=95, 182.1 g/g) than those with severe & severe to complicated (n=22, 218.5 g/g, p=0.014) scores, and among those that were toxin positive (n=24, 200.2 g/g) versus toxin negative (n=86, 182.8 g/g, p=0.044). Despite this overall trend, wide variations in fCPT values were found in all categories examined. A logistic regression analysis revealed that the fCPT values correlated independently with the severity of clinical manifestations (OR=2.021, 95%CI=1.132-3.608); however, it did not correlate with other clinical outcomes. Our study findings show that high fecal calprotectin levels correlate with toxin positive and clinically severe CDI; however wide variations in individual measurements preclude establishment of reliable cut-offs for routine diagnostic use in cancer patients.