Plasma levels of inhibitor-bound leukocytic elastase in rheumatoid arthritis patients

Formation of polymorphonuclear leukocyte elastase: alpha 1 proteinase inhibitor complex and A alpha (1-21) fibrinopeptide in human blood stimulated with the calcium ionophore A23187. A model to characterize inhibitors of polymorphonuclear leukocyte elastase

Incubation of human blood with the secretagogue A23187 resulted in the formation of increased plasma concentrations of polymorphonuclear leukocyte (PMN) elastase: alpha 1 proteinase inhibitor (PMNE:alpha 1 PI) complex as well as A alpha(1-21) fibrinopeptide [A alpha(1-21)]. The formation of these species was both time and A23187 concentration dependent. Using a sandwich ELISA and a radioimmunoassay, we determined the comparative potencies of several compounds to inhibit the formation of PMNE: alpha 1 PI complexes and A alpha(1-21), respectively. L-658,758, a substituted cephalosporin, essentially irreversible elastase inhibitor, inhibited the formation of PMNE: alpha 1 PI and A alpha(1-21) with IC50 values of 38 and 15 microM, respectively. L-683,845, a monocyclic beta-lactam, was much more potent against isolated PMNE than L-658,758. However in this system it was approximately equivalent to L-658,758 with an IC50 of 15 microM against both species. ICI-200,880, a competitive slow-binding elastase inhibitor, was significantly less potent to inhibit A alpha(1-21), having an IC50 of 75 microM, while Declaben, a reversible noncompetitive inhibitor, was inactive at concentrations as great as 200 microM. We propose that evaluating inhibitors in the complex milieu of blood will provide a useful method to predict their therapeutic potential in vivo.

Enhanced attachment and elastase-releasing capacity of neutrophils after surgery

Perioperative changes in neutrophil attachment level and neutrophil elastase-releasing capacity were examined in patients who underwent surgery for either esophageal or gastric cancer. The neutrophil attachment level was significantly increased in both groups to approximately three times that of the preoperative value. The elastase-releasing capacity of nonstimulated neutrophils was not significantly changed, but it was significantly increased in neutrophils stimulated by N-formyl-L-methionyl-L-leucyl-L-phenylalanine (FMLP). Moreover, both neutrophil attachment and elastase-releasing capacity of FMLP-stimulated neutrophils were more enhanced in patients with postoperative complications than in patients without complications. Peak levels of serum interleukin 6, serum alpha 1 proteinase inhibitor, and plasma neutrophil elastase were also significantly higher in patients with postoperative complications than in patients without. These results suggest that during the postoperative period, neutrophils may be primed and activated in response to inflammatory mediators such as cytokines, and that such an alteration of neutrophil functions may reflect the extent of inflammation and may, at times, be implicated in postoperative complications.

Circulating interleukin 6 as a useful marker for predicting postoperative complications

We examined postoperative serial changes in the levels of serum interleukin 6 (IL-6), serum acute phase reactants (APRs) and plasma neutrophil elastase (NE) in patients with various cancers and reviewed these changes in patients who did, and did not, show postoperative complications. Serum IL-6 level was elevated after surgery, peaking on the first postoperative day. Elevation of serum APRs and plasma NE levels also followed. There was a significant correlation between the serum peak level of IL-6 and those of APRs and NE (P less than 0.01). Moreover, there was a significant difference in the serum IL-6 level in patients with and without complications. The relationship between the serum IL-6 greater than 400 pg/ml and the incidence of postoperative complications was also marked. These results suggest that circulating IL-6 is a clinically useful marker for the earliest detection and prediction of postoperative complications.

Response of serum interleukin-6 in patients undergoing elective surgery of varying severity

1. Recent studies have suggested that interleukin-6 is a major mediator of the acute-phase protein response in man. The aim of the present study was to investigate the relationships between the response of serum interleukin-6 to surgery, the type of surgical procedure performed and the response of serum C-reactive protein. 2. Timed venous blood samples were taken from 26 patients in five broad surgical categories (minor surgery, cholecystectomy, hip replacement, colorectal surgery and major vascular surgery). C-reactive protein and interleukin-6 were measured in each sample. 3. Serum interleukin-6 rose within 2-4 h of incision in all patients and the magnitude of the response differed among the various surgical groups. The response of interleukin-6 correlated (r = 0.80, P less than 0.001) with the duration of surgery. In contrast, serum C-reactive protein was not detectable after minor surgery (less than 10 mg/l) and the response of C-reactive protein did not differ among the more major surgical groups. The response of interleukin-6 showed a weak, but significant, correlation with the response of C-reactive protein (r = 0.67, P less than 0.001). 4. We conclude that serum interleukin-6 is a sensitive, early marker of tissue damage. In general, the greater the surgical trauma, the greater the response of serum interleukin-6 and the greater the peak serum concentration of interleukin-6. Our results are consistent with a role for interleukin-6 in the induction of C-reactive protein synthesis.

Plasma and synovial fluid levels of granulocytal elastase-alpha-1-protease inhibitor complex in patients with rheumatoid arthritis

Plasma and synovial fluid levels and granulocytal elastase-alpha-1-protease inhibitor complex (EIC) in patients with rheumatoid arthritis (RA) were measured by enzyme-linked immunoassay and the results compared with those in patients with osteoarthrosis (OA). It was found that the plasma and synovial fluid levels of EIC in RA patients were higher than those in OA patients. There was a positive correlation between plasma EIC level in RA patients in Lansbury's index score of disease activity, as this tends to be higher when titer of RAHA in the plasma is high. The level of EIC in the synovial fluids correlated positively with granulocyte count and alpha-1-protease inhibitor (alpha-1-PI) level, and this, too, tends to be higher when titer of RAHA in synovial fluid is high. The results suggested that the level of EIC in the plasma or synovial fluids can be a good marker for the systemic or localized activation of the granulocytes and that IgM rheumatoid factor (IgMRF) is involved in the mechanism of the release of elastase.

Measurement of plasma concentrations of polymorphonuclear elastase-alpha 1 proteinase inhibitor (elastase-alpha 1 antitrypsin) in patients with rheumatoid arthritis: interference by rheumatoid factor

The plasma concentration of granulocyte elastase in complex with alpha 1 proteinase inhibitor was determined in 32 patients with rheumatoid arthritis and eight with seronegative spondarthritis complicated by peripheral joint synovitis. Most patients had concentrations of complex which were within the range of the control group when measured by an 'in-house' enzyme linked immunosorbent assay, though several of the patients with rheumatoid arthritis had raised concentrations. When the complexes were measured by a commercially available assay, however, much higher values were obtained for many of the patients with rheumatoid arthritis. Evidence is presented indicating that the commercially available assay may suffer seriously from interference by rheumatoid factor. The possibility is discussed that most patients with rheumatoid arthritis may have plasma concentrations of elastase-alpha 1 PI which are normal or only slightly raised, and that previously published reports using assay systems similar to that available commercially might also have produced falsely raised values for many individuals with rheumatoid arthritis.

Perioperative fluctuation in plasma levels of granulocyte elastase and alpha-1-antitrypsin: the influence of the severity of surgical intervention and their effect on the respiratory index

In order to examine whether granulocyte elastase is related to surgical stress and postoperative respiratory function, the perioperative plasma levels of granulocyte elastase and alpha 1-antitrypsin were periodically measured in 49 patients who underwent various operations and the correlation between these levels and the respiratory index was examined. A strong correlation between elevated plasma levels of granulocyte elastase and the degree of aggressiveness of surgery was quite conspicuous; as the operative intervention became more severe, the plasma levels of granulocyte elastase were higher. The plasma level of alpha 1-antitrypsin was in inverted relation to granulocyte elastase. Moreover, marked and prolonged elevation of plasma granulocyte elastase levels induced postoperative pulmonary complications. A highly significant positive correlation was found between the plasma level of granulocyte elastase and the respiratory index. Elevated granulocyte elastase and/or decreased alpha 1-antitrypsin may therefore be implicated in the etiology of postoperative respiratory dysfunction. Thus, an abnormal elevation of plasma granulocyte elastase may allude the existence of postoperative respiratory dysfunction.

Granulocyte elastase as a new biochemical marker in the diagnosis of chronic joint diseases

Human granulocyte elastase (EC 3.4.21.37) is released from granulocytes in large amounts in chronic inflammatory joint diseases and is therefore of special pathogenic and diagnostic importance. In order to examine the diagnostic significance of this enzyme as a clinico-chemical parameter, we determined the concentration of granulocyte elastase in complex with alpha 1-proteinase inhibitor by an enzyme immunoassay in synovial fluids and plasma of patients with chronic joint diseases. In inflammatory synovial fluids the concentration of complexed elastase correlates well with the granulocyte number and may increase to an extremely high level. In 90% of patients with manifest rheumatoid arthritis increased elastase levels are also observed in the plasma, probably due to the large gradient between the synovial fluid and plasma concentration, whereas in osteoarthrosis normal plasma concentrations were observed. Thus, these results indicate that normal plasma concentrations in patients with chronic joint diseases exclude the diagnosis of rheumatoid arthritis with high probability. The simultaneous determination of complexed elastase in plasma and synovial fluid improves the nosological differentiation of chronic joint diseases. Elastase activity on a specific chromogenic substrate, which was found in many inflammatory synovial fluids, is mainly attributed to elastase alpha 2-macroglobulin complexes. In some purulent synovial fluids, however, we were able to detect free elastase, which has been shown to play an important role in the destruction of articular cartilage.

Circulating human leucocyte elastase in rheumatoid arthritis

Elastase-inhibitor complex (EIC) levels were determined in EDTA-plasma samples of 40 patients with connective tissue disease by a double antibody immuno-assay technique. In active rheumatoid arthritis (RA) and systemic lupus erythematosus (SLE), EIC levels were significantly higher than in the normal controls (P less than 10(-8) and fell on remission. The mean EIC level in active RA was significantly greater than in inactive disease (P = 0.0001) but there was no statistically significant difference between the EIC levels in the acute and inactive disease states in SLE (P = 0.49). In active RA, there was a positive correlation between EIC levels and white blood cell count (WBC) but not with erythrocyte sedimentation rate (ESR). In SLE there was no significant correlation between EIC levels and ESR or WBC. EIC measurement may be useful in the objective assessment of activity in RA.