Quantitative cytochemistry of human leukocyte elastase compared with plasma elastase and acute phase proteins in inflammatory diseases.

Plasma levels of human leukocyte elastase, a serine proteinase stored in the azurophilic granules of polymorphonuclear granulocytes, increase in the early stages of several inflammatory diseases. We studied the intracellular enzyme activity by cytochemical quantitative image analysis and the amount of elastase released in plasma by an automatic immunoactivation immunoassay method in 66 patients with inflammatory diseases and in a control group. The patients were divided into two groups with infective disease (severe and moderate) and one group with non-infective inflammation. Intracellular activity and plasmatic levels of elastase were also compared with other inflammatory markers, i.e. erythrocyte sedimentation rate, C-reactive protein, alpha 1-antitrypsin, haptoglobin, alpha 1-acid glycoprotein and fibrinogen. Our studies suggest that plasma and leukocyte elastase are correlated both with etiology and with the severity of the inflammation.

Automated dibucaine number measurement with DuPont Dimension ES and AR analyzers.

We report a fully automated method for determining dibucaine number (DN) in a single-run procedure involving Dimension cholinesterase (CHE) Flex pseudo-(P)CHE reagents. The method was developed and optimized with the "open channels" and "kinetic" software facilities of the Dimension-ES instrument, where the DN is calculated automatically by an algorithm from the ratio of the uninhibited and inhibited rates, measured bichromatically, from a single analysis. The protocol was satisfactorily assessed for substrate depletion, linearity, reagent stability. and the effects of different dibucaine concentrations. Validation was performed across a range of CHE activities (1.5-22 kU/L) representing the three main genotypes, UU, UA, and AA. The respective DNs (mean +/- SD), determined on the Dimension-ES, were 82.0 +/- 1.6 (n = 32), 71.0 +/- 3.1 (n = 10), and 23.0 +/- 2.7 (n = 14), with corresponding imprecisions (CV) of 0.3%, 0.6%, and 5.2% (intraassay) and 0.7%, 0.7%, and 8.6% (interassay). Comparisons with reference (x) laboratory values and the DuPont aca (x') procedure (n = 53) gave regression equations of: y = 0.88x + 11.2, r = 0.99, and y = 0.85x' + 11.9, r = 0.99. A separate trial conducted with a Dimension-AR instrument gave similar performances. We conclude that the new DN method is fast, efficient, and appropriate for clinical use.

Serum lipase assay. A test of choice in acute pancreatitis.

We evaluated the clinical accuracy of an automated turbidimetric assay for serum lipase determination in order to screen for acute pancreatic damage. Seventy patients with pancreatic and thirty with nonpancreatic digestive diseases were studied. Fifty-two healthy subjects were also studied as controls. Serum lipase concentrations were abnormally high in all patients with acute pancreatitis and in 3 (10%) in the group of 30 patients with nonpancreatic acute abdomen. In the 35 patients with chronic pancreatitis studied during clinical remission, serum lipase levels were abnormally high in 8 (23%), and abnormally low in 3 (9%). In the 9 patients with pancreatic cancer, 4 (44%) had abnormally elevated serum lipase values and 1 (11%) abnormally low. The results indicate that serum lipase determination is useful in the emergency diagnosis of acute pancreatic damage because of its high sensitivity and specificity. In patients with chronic pancreatitis and in patients with pancreatic carcinoma serum lipase determination is of limited value.