Effect of acute-phase proteinase inhibitors on chemotaxis of rat polymorphonuclear leukocytes in vitro

Rat serum obtained at 24 h after subcutaneous injection of carrageenin significantly suppressed chemotaxis of rat polymorphonuclear leukocytes (PMNs) in vitro. alpha 2 Acute-phase macroglobulin (alpha 2APM), alpha 1 proteinase inhibitor (alpha 1 PI) and cysteine-proteinase inhibitors (CPIs) are present at high concentration in the 24-h serum and known as acute-phase reactants in rats. These acute-phase proteinase inhibitors were purified from inflamed rat serum or exudate and their effect on PMN chemotaxis was studied by Boyden's method in vitro. alpha 2 APM (4 mg/ml) significantly suppressed PMN chemotaxis while alpha 1M was without effect, though both alpha 2APM and alpha 1M had a similar anti-proteinase activity. The results suggest that alpha 2APM suppressed PMN chemotaxis through the mechanism unrelated to its anti-proteinase activity. On the other hand, alpha 1PI (1 and 3 mg/ml) slightly but significantly suppressed PMN chemotaxis, whereas CPI-1 and CPI-2 had no inhibitory effect. These results suggest that alpha 2APM and alpha 1PI play a role in suppression of PMNs infiltration into the inflammatory site in the late-phase of acute inflammation.

Monitoring of the inflammatory response in early peritonitis

The inflammatory response which is similar in all forms of peritonitis was recorded by determining the levels of parameters shown to represent the activation state of plasmatic and cellular systems as well as the inhibitory capacity of the plasma. In a selected series of patients with different underlying diseases, blood sampling was started at the time of admission when the clinical finding of an acute abdomen led to emergency laparotomy. Depending upon the duration of the illness and the severity of the peritonitis, a significant increase in fibrinopeptide A and of C3a could be detected within a few hours, which was followed by an increase in the elastase alpha-1-proteinase inhibitor complex. Differences due to variable cause could not be found. There was a striking correlation between the preoperative values of these three parameters and the postoperative course of the patients. Additionally, there was a significant enhancement of an endothelial proliferation-inhibiting capacity in the serums of the lethal group, whereas endotoxin could only be detected in trace amounts in four patients with intraabdominal infection in the preoperative period.

Evaluation of granulocyte-releasing products and chemiluminescence during cytapheresis

During the procedures of centrifugation leukapheresis and plateletpheresis, donors occasionally experience adverse clinical reactions. The possibility of whether the activation of granulocytes and the subsequent release reactions, which may have been triggered by this extracorporeal circuit, were responsible for these adverse effects was evaluated. Six blood samples were obtained at set intervals during cytapheresis. Of these samples, four were taken directly from the donor. The remaining two were drawn from the efferent lines, i.e., those which return blood from the cytapheresis machine to the donor. Reactive oxygen species produced by granulocytes were measured by chemiluminescence (CL) using microamounts of whole blood or isolated granulocytes. Furthermore, secreted granulocyte products such as neutral proteinase elastase, which is present in plasma in a complex with alpha-1-proteinase inhibitor (E-alpha-1-PI), and lysosomal beta-glucuronidase were examined. A complete blood cell count and the values of hemoglobin, hematocrit, lactate dehydrogenase, protein, albumin, and proteinase inhibitors such as alpha-2-macroglobulin and alpha-1-proteinase inhibitor were also determined. Clinical chemical and cytologic values, with the exception of those for E-alpha-1-PI, were 10 to 17 percent lower than values before apheresis. These results can be attributed to inherent plasma volume expansion. Reduced CL was observed on the stimulation of phagocytes in the whole blood assay, as well as with stimulated granulocytes. Unstimulated granulocytes, on the other hand, showed an increased native CL. These data do not indicate a cytapheresis-mediated activation of the oxidative metabolism of granulocytes, and the concomitant discharge of proteolytic enzymes remains, therefore, of no clinical importance.

Inactivation of various proteinase inhibitors and the complement system in human plasma by the 56-kilodalton proteinase from Serratia marcescens

The interaction of the 56-kilodalton (kDa) proteinase from Serratia marcescens with human plasma activated C1 (C1) inhibitor, alpha 2-antiplasmin, and antithrombin III was investigated. The 56-kDa proteinase was not affected by these inhibitors; on the contrary, all the inhibitors were inactivated by the 56-kDa proteinase within 2 to 6 h. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis indicated that all three inhibitors showed decreases in molecular weight of approximately 8,000 to 10,000 as a result of proteolytic cleavage by the 56-kDa proteinase. The 56-kDa proteinase also inactivated serum complement within 2 to 6 h. The loss of inhibitory activity caused by the 56-kDa proteinase, together with the effects of endogenous serine proteinases, may facilitate tissue destruction and inflammation.

[Evaluation of a radioimmunoassay of alpha 1-microglobulin (alpha 1-m) with simplified procedures]

A newly established double antibody radioimmunoassay (RIA) was fundamentally and clinically evaluated. Original procedures were partially modified as follows: Sample volume for serum and urine was changed to 25 microliters, and thus 200 mg/l of alpha 1-m standard was prepared using 50 microliters of original standard solution (100 mg/l). The results were satisfactory in sensitivity (0.3 mg/l obtained from -2SD method), intra-assay precision with its coefficient variation (CV) ranging from 3.0 to 7.4%, interassay precision with its CV ranging from 3.0 to 10.7%, and recovery with the mean value of 102.4% in serum and 108.2% in urine respectively. There were no changes about alpha 1-m value between diluted (2 times) and undiluted with high concentration samples. Normal levels of alpha 1-m were less than 25 mg/l in serum and less than 10 mg/l in urine. The present results indicate that the determination of alpha 1-m could be very simple and useful for the most sensitive screening test for the evaluation of renal function.

Comparative studies on the primary structure of human cystatin as from epidermis, liver, spleen, and leukocytes

We have studied the primary structure of human cystatin As from epidermis, liver, spleen, and leukocytes. These molecules were indistinguishable on PAGE in the presence and absence of SDS, by fast protein liquid chromatography (FPLC) chromatofocusing on a Mono P column, and in amino acid composition. The NH2- and COOH-terminal amino acid sequences of human cystatin As from epidermis, liver, and spleen were identical with those of human leukocyte cystatin A previously reported except for the lack of the NH2-terminal methionine residue in human epidermal cystatin A. The peptides obtained upon digestion of four human cystatin As with Achromobacter protease I (AP) showed identical peptide maps on HPLC except for different retention times of the NH2-terminal peptides. Furthermore, the amino acid compositions of corresponding separated peptide quartets were identical. We also determined the complete amino acid sequence of human epidermal cystatin A by sequencing peptides obtained from AP digestion and cyanogen bromide (CNBr) cleavage. It consisted of 97 amino acid residues, and was identical with those of human cystatin As from liver, spleen, and leukocytes except for the lack of the NH2-terminal methionine residue.

The use of monoclonal antibodies to define levels of cystatin C in normal human serum

We established four hybridoma cell lines which secreted monoclonal antibodies against human cystatin C. These monoclonal antibodies were of IgA(kappa), IgG2a(lambda), IgG1(kappa), and IgG1(lambda) isotypes, respectively. The association constants (Ka) of the three IgG monoclonal antibodies ranged from 3.6 x 10(9) M-1 to 7.3 x 10(10) M-1. An ELISA technique for the measurement of cystatin C was established by using one of these monoclonal antibodies. The assay procedure was highly specific, sensitive, and reproducible. The lower detectable limit of cystatin C by this procedure was 1.9 ng/ml. The level of cystatin C in normal human serum was 1.16 +/- 0.91 micrograms/ml (mean +/- S.D., n = 274).

[The protease inhibitor system of macaques. The identification of alleles using isoelectric focusing and family analysis]

Five alpha-1-antitrypsin (alpha-1-AT) phenotypes have been revealed by isoelectrofocusing (IEF) in sera of 215 crab-eating macaques. Alpha-1-AT was monomorphic in sera of 250 Rhesus monkeys. A new allele of macaque Pi-system, designated as B' was postulated in addition to existing two (B and C) on the basis of IEF data. The above conclusion was supported by family analysis, based on 35 monkey birth cases. Alpha-1-AT phenotype frequencies were in agreement with Hardy-Weinberg equation both in wild and capture born crab-eating macaques. Alpha-1-AT was found to be microheterogeneous: several zones of the protein were revealed by IEF and Western blotting with anti human alpha-1-AT serum. The pregnancy caused a sharp increase of one band. This may lead to false identification of alpha-1-AT phenotypes, particularly when acid starch gel electrophoresis is used for alpha-1-AT identification. Such misinterpretation during alpha-1-AT phenotyping may explain the disagreement with Hardy-Weinberg equation described earlier for crab-eating macaques.

Beta-2-microglobulin and main granulocyte components in hemodialysis patients

Plasma levels of granulocyte elastase in complex with alpha 1-proteinase inhibitor (E-alpha 1-PI) increased during hemodialysis from 110 +/- 10 to 506 +/- 66 micrograms/L using dialyzers made of polyamide, from 95 +/- 2.2 to 211 +/- 54 micrograms/ml with hemophane and from 114 +/- 10 to 203 +/- 25 using dialyzers made of polysulfone. Plasma lactoferrin values were also significantly higher during hemodialysis with polyamide (772 +/- 110 micrograms/L) compared with hemophane (268 +/- 2.2) and the polysulfone (278 +/- 31 micrograms/L) dialyzer. After dialysis each dialyzer was rinsed. We found the lowest concentration of lactoferrin (902 +/- 254 micrograms/L) and E-alpha 1-PI (739 +/- 162 micrograms/L) after rinsing polysulfone dialyzers, whereas the highest concentrations were observed after rinsing the polyamide dialyzer (lactoferrin: 2,426 +/- 314; E-alpha 1-PI: 1,134 +/- 144 micrograms/L). Hemodialysis with polysulfone dialyzers caused significantly lower plasma levels of beta-2-microglobulin compared with polyamide or hemophane membranes despite significantly lower levels in the rinsing solutions. Our data indicate that low plasma levels of main granulocyte component observed with polysulfone and hemophane dialyzers are not the result of higher membrane adsorption of E-alpha 1-PI and lactoferrin. These main granulocyte components are not related to beta-2-microglobulin levels of both plasma and rinsing solutions.

[Detection of the degree of activity of ulcerative colitis. Behavior of serum alpha 1-proteinase inhibitor and alpha 2-macroglobulin]

The study of two proteins, acute phase reactants, alpha 1-proteinase inhibitor and alpha 2-macroglobulin, has demonstrated their utility in the diagnosis of the activity of ulcerative colitis. Alpha 1-proteinase inhibitor presented serum increases parallel to the degree of activity, permitting differentiation of asymptomatic, mild, moderate and severe phases of the disease. Increases in alpha 2-macroglobulin coincided with less-intense phases of the disease. The possible biological basis of this different behavior is discussed, as well as its potential inclusion among the biological tests currently used in clinical practice.

Inhibition and active-site modelling of prolidase

Consideration of the active-site model of prolidase led us to examine azetidine, pyrrolidine and piperidine substrate analogs as potential in vivo inhibitors of the enzyme. One of these, N-benzyloxycarbonyl-L-proline, was shown to be a potent competitive inhibitor of porcine kidney prolidase (Ki = 90 microM); its rapid protein-mediated permeation of human and sheep erythrocytes suggests that it may be effective in vivo. The higher homolog, N-benzyloxycarbonyl-L-pipecolic acid, was also a potent inhibitor of the enzyme while the antihypertensive drugs, captopril and enalaprilat, were shown to have mild and no inhibitory effects, respectively. Analysis of inhibitor action and consideration of X-ray crystallographic data of relevant Mn2+ complexes allowed the active-site model of prolidase to be further refined; a new model is presented in which the substrate acts as a bidentate ligand towards the active-site manganous ion. Various aspects of the new model help to explain why Mn2+ has been 'chosen' by the enzyme in preference to other biologically available metal ions.

Relationship between neopterin and granulocyte elastase plasma levels and the severity of multiple organ failure

In a series of 56 patients (24 uncomplicated postoperative and 32 septic patients), neopterin and elastase alpha 1 protease inhibitor complex (E-alpha 1 PI) plasma levels were measured daily. The clinical course of each patient was evaluated with the Multiple Organ Failure (MOF) score according to Goris. Neopterin could differentiate between septic and nonseptic patients (p less than .001), and E-alpha 1 PI between septic nonsurvivors and nonseptic patients only (p less than .01). In septic patients, acute pulmonary insufficiency was indicated by elevated E-alpha 1 PI values (greater than or equal to 400 micrograms/L) 1 day before mechanical ventilation was performed with a sensitivity of 81% and a specificity of 82%. Defining a patient with MOF whose score was greater than or equal to 5 as a high-risk septic patient, a comparison neopterin greater than or equal to 40 nmol/L and E-alpha 1 PI greater than or equal to 400 micrograms/L, measured 1 day before the evaluation of an MOF score of greater than or equal to 5 yielded a sensitivity of 91% and a specificity of 99% when patients fulfilled both criteria. We conclude that neopterin and E-alpha 1 PI might be useful parameters for the diagnosis of septicemia and monitoring of the clinical course in septic patients. Moreover, they might indicate the possible central role of macrophage and PMN activation in the development of MOF.

[Metabolic indices of proteolysis of the blood serum in dogs in the early period following uniform whole-body gamma irradiation]

Free amino acid concentration and proteinase inhibitor content were studied during the first 48 h following whole-body uniform gamma irradiation of dogs (LD30/50 and LD90/45). The contribution of metabolic profile features to individual radiosensitivity is discussed on the basis of the retrospective analysis of the initial level of metabolic indices in animals survived and died after irradiation. The comparison of the dynamics of changes in the indices under study in the animals died after exposure to different radiation doses permitted to suggest the important role that early hyperactivation of proteolysis played in the development of metabolism decompensation which promoted the fatal outcome of the affection.

Purification and characterization of plasma T-kininogen from Wistar and brown Norway rats

A rapid and convenient three-step purification scheme has been developed for the purification of T-kininogen (alpha 1-cysteine proteinase inhibitor) from rat plasma. The purification process includes chromatography on hydroxyapatite, immunoaffinity chromatography and gel filtration. This procedure is applied to plasma from the brown Norway rat which is known to be deficient in high and low molecular weight kininogens. The method furnished large amounts of T-kininogen from turpentine-treated Wistar rats as well as from untreated and turpentine-treated deficient brown Norway rats. The amino acid and hexose content of the three T-kininogens has been determined. While the composition of the molecules isolated from both injured rats was similar, the neutral sugar content of T-kininogen purified from untreated brown Norway rats was lower and its amino acid composition showed slight differences. The three molecules have identical behaviour and similar physicochemical and immunological properties when analysed by SDS electrophoresis, isoelectrofocusing and two-dimensional immunoelectrophoresis.

Studies of protease inhibitors in the sera of patients with amyotrophic lateral sclerosis

Serum levels of 4 protease inhibitors, alpha-1-antitrypsin, C1-inactivator, alpha-2-macroglobulin and antithrombin-III were measured in 11 patients with amyotrophic lateral sclerosis (6 males and 5 females) and a control group without neurologic disease. Our results indicated no significant differences in the level of serum alpha-2-macroglobulin between the 2 groups. We found slight but significantly lower levels of serum antithrombin-III in ALS. The possibility of the participation of proteases or protease inhibitors in the pathogenesis of ALS is discussed.

Inhibition and complexation of activated protein C by two major inhibitors in plasma

To determine the major physiologic inhibitors of activated protein C (APC), plasma was incubated with APC or with Protac C and subjected to immunoblotting. APC:inhibitor complexes gave two major bands reacting with antiprotein C antibodies when immunoblotted on nondenaturing gels, and additional minor bands that varied between serum and plasma. Formation of one of the two major bands of APC:inhibitor complex, but not the other, was stimulated by heparin and only this band reacted with antibodies to the previously described APC inhibitor that is here designated PCI-1. Plasma immunodepleted of PCI-1 formed complexes with APC as visualized with antiprotein C but not anti-PCI-1 antibodies, and exhibited heparin-independent inhibition of APC activity, providing evidence for the existence of a second major physiologic APC inhibitor, PCI-2. Formation of APC:PCI-2 complexes in PCI-1-depleted plasma paralleled inhibition of APC amidolytic activity. PCI-2 was separated from PCI-1 and partially purified using column chromatography. PCI-2 formed inactive complexes of approximately 110,000 molecular weight (mol wt) with APC suggesting PCI-2 has an approximate mol wt of 50,000. Thus, inhibition of APC in plasma involves two major distinct 50,000 mol wt inhibitors, the heparin-dependent PCI-1 and the heparin-independent PCI-2.

C-reactive protein, antiproteases and complement factors as objective markers of severity in acute pancreatitis

In a series of patients with acute pancreatitis we have studied complement factors, antiproteases (alpha 2-macroglobulin and alpha 1-antiprotease) and C-reactive protein to determine the value of their sequential measurement in the prediction of outcome relative to clinical assessment and current multiple factor scoring systems. Complement factors were unhelpful in predicting the severity of an attack. alpha 2-Macroglobulin levels were significantly lower in complicated attacks during days 3-8 and alpha 1-antiprotease levels were significantly higher during days 4-8. C-reactive protein concentrations showed the best discrimination between mild and complicated attacks, levels rising higher and persisting for longer in complicated attacks; these differences were highly significant from day 2 (the morning after admission) to day 8. The concentrations providing the best discrimination were found to be greater than or equal to 210 mg/l for the peak C-reactive protein (on the second, third or fourth day) and greater than or equal to 120 mg/l for the C-reactive protein at the end of the first week. Analysis demonstrated both the peak or seventh-day C-reactive protein concentration to be of similar accuracy to either the Ranson or Glasgow multiple factor scoring systems and slightly better for attacks associated with gallstones. The C-reactive protein assay is simple, quick to perform, provides useful clinical information and is more likely to be of value and to be adopted into routine clinical practice than multiple factor scoring systems.

Quantitative estimation of elastase-alpha 1-proteinase inhibitor (E-alpha 1 PI) complex in leukemia: marked elevation in cases of acute promyelocytic leukemia

The concentrations of elastase-alpha 1-proteinase inhibitor (E-alpha 1 PI) complex were assayed in 43 patients with various types of leukemia. Marked to moderate elevation of E-alpha 1 PI complex levels was observed in patients with acute myelocytic leukemia (AML), acute promyelocytic leukemia (APL), acute myelomonocytic leukemia (AMMoL), or chronic myelocytic leukemia (CML) at diagnosis. The ratio of E-alpha 1 PI complex concentrations in plasma to leukocyte counts markedly elevated in the patients with APL, especially. During the course of remission induction therapy, levels of E-alpha 1 PI complex decreased in parallel with decline of leukocyte counts in the patients with leukemia other than APL, however the E-alpha 1 PI complex was persistently elevated regardless of leukopenia in some patients with APL. In APL, concentrations of fibrin/fibrinogen degradation products (FDP) markedly increased even when levels of plasmin-alpha 2-antiplasmin complex were within normal limits. However, levels of E-alpha 1 PI complex usually increased in these cases. From these results, it is strongly suggested that promyelocytes contain markedly elevated amounts of elastase which participates in degradation of fibrin or fibrinogen in some cases of APL.

[Clinical significance of alpha 1-proteinase inhibitor in myocardial infarct]

The authors analyze data of determination of alpha 1 proteinase inhibitor in patients with myocardial infarction depending on the severity of the disease. It is suggested that the quantitative values of alpha 1 proteinase inhibitors of the blood plasma may be used in the diagnosis and prognosis of the disease in the sense of correction inhibitor therapy and individual management.

[Antiproteolytic activity of the blood serum in adolescents with pulmonary tuberculosis]

The antiproteolytic activity of the blood serum was examined in the course of hospital treatment of 128 adolescents with prevailingly torpid forms of pulmonary tuberculosis and in 19 adolescents with tubercular infection (control). A direct correlation has been found between the degree of clinico-roentgenological manifestations of the disease and level of serum alpha 1-inhibitor of proteinases as well as between the efficacy of treatment and normalization of the antiproteolytic activity of the blood of the patients. It proposed to use the determination of alpha 1-inhibitor of proteinases as an additional criterion of evaluation of the clinical course and outcomes of the disease in adolescents.

Pathobiochemistry and early CT findings in acute pancreatitis

Extrapancreatic findings at computed tomography (CT), performed within 24 h in 42 consecutive episodes of acute pancreatitis, were classified according to a scoring system (EP score) and were correlated to Ranson's prognostic signs, to duration of hospital stay, biochemical changes in plasma and pancreatic ischaemia found at CT with contrast enhancement. Increasing EP score was found to be related to increasing number of positive Ranson's signs, longer hospital stay and pancreatic ischaemia. Plasma levels of immunoreactive cationic trypsin and amylase were not proportional to EP score. alpha 1-protease inhibitor, antichymotrypsin but not immunoreactive pancreatic secretory trypsin inhibitor increased proportionally to EP score. No changes related to EP score were seen in alpha 2-macroglobulin levels. Serum levels of trypsin-alpha 1-protease inhibitor complex were maximal after 3 days and most pronounced in cases with high EP scores. Plasma levels of factor X, alpha 2-antiplasmin and C1-esterase inhibitor were found to be inversely proportional to EP score.