Fecal M2-PK in children with Crohn's disease: a preliminary report

Although active inflammatory changes in chronic Crohn's disease (CD) can be detected with serum inflammatory markers, these have low specificity and sensitivity. Stool markers of inflammation, such as M2-pyruvate kinase (M2-PK), permit more direct assessment of mucosal inflammation. The aim of this study was to assess levels of M2-PK in children with active CD and to compare to levels in healthy control children.

Fecal levels of M2-PK were measured by immunoassay using stored stool samples from children with untreated (active) CD and healthy control children. Correlations between M2-PK levels and disease activity scores and serum inflammatory markers were performed. Comparison was also made between M2PK and a second fecal inflammatory marker, S100A12.

Mean fecal M2-PK levels were higher in the 17 patients with active CD than in the 21 healthy controls (p = 0.0007). M2-PK levels did not correlate with disease activity scores or serum inflammatory markers. There was a trend for children with ileocolonic disease to have higher levels of M2-PK in their stool compared to those with colonic disease or isolated ileal disease. Fecal M2PK did not correlate with fecal S100A12 in children with active CD.

Fecal M2-PK is increased in children with active CD, indicating that this marker may be a useful non-invasive marker for gut inflammation. Further studies of M2PK are required in additional settings with larger cohorts of children with CD and with comparison to other stool markers.