Circulating neutrophil elastase in infectious diseases in geriatric patients

Enzyme-linked immunosorbent assay has been used to measure elastase proteinase inhibitor complex (EPIC) and C-reactive protein (CRP) in the elderly, with and without infection. Median EPIC levels in the elderly with infection, hospital controls, healthy elderly residents in old people's homes and healthy blood donors were 300, 104, 96 and 74 ng/ml respectively. Ninety-five per cent of the patients with infection had EPIC levels well above the normal range. The median EPIC level in the elderly with infection showed a statistically significant difference from that in the control groups (p less than 0.0001, Mann U test). CRP showed similar results. Elevation of EPIC or CRP did not depend on the type of infection or bacteria isolated. We would conclude that neutrophil inhibitor-bound elastase could be used as a marker of inflammation in old people.