Leucocyte elastase in chronic inflammatory bowel diseases: a marker of inflammatory activity?

Leucocyte elastase is a neutral proteinase which plays an important role in the pathogenesis of inflammatory disorders. Infiltration of bowel mucosa by neutrophil and eosinophilic granulocytes is a characteristic feature of chronic inflammatory bowel diseases. We studied plasma elastase in 44 patients suffering from Crohn's disease or ulcerative colitis. Plasma levels were significantly higher in these patients compared to 7 patients with non-inflammatory bowel diseases or 53 healthy controls. Elevated plasma levels were more often found in patients with active inflammation than in those with inactive disease. Elastase did neither correlate with leucocyte counts, serum albumin, ESR, alpha 1-proteinase inhibitor and orosomucoid nor with clinical indices or the faecal excretion of 111In-labelled granulocytes. In serial studies of 15 patients, elastase did not always run parallel to the disease activity. We conclude that plasma elastase does not reliably indicate the inflammatory activity in chronic inflammatory bowel diseases.