Neutrophil-elastase in chronic inflammatory bowel disease: a marker of disease activity?

Neutrophil elastase is a proteinase which exists in granulocytes and plays an important role in the pathogenesis of inflammatory disorders. In inflammatory bowel disease there is a leukocyte infiltration of the bowel mucosa. The purpose of this study was to examine whether plasma elastase represents a reliable laboratory marker for establishing the activity of chronic inflammatory bowel disease.

We measured plasma elastase concentrations in 61 patients suffering from either Crohn's disease or ulcerative colitis and compared these data with other clinical and laboratory findings and with elastase concentrations in 40 healthy controls. The sensitivity and specificity of the elastase values in chronic IBD were calculated with the use of concomitant measurements of CRP and ESR.

Plasma levels were found to be significantly higher in patients (49 micrograms/l) compared with healthy controls (23 micrograms/l). Patients with active disease had higher plasma levels than patients in remission. In general, the sensitivity of elastase to detect active inflammatory bowel disease was about 60%; the specificity was 65%. For patients in remission, the sensitivity was higher than 80%. However, there was a wide range of overlapping values between chronic inactive patients and those with moderately active disease.

We conclude that plasma elastase is a useful independent marker of disease activity in inflammatory bowel disease. Especially for identifying patients in remission, the measurements of elastase seem to be more suitable than other parameters of inflammation, like CRP or ESR.