Purification of a proteinase inhibitor from bovine serum with C1-inhibitor activity

This report describes the purification of a novel proteinase inhibitor from bovine serum. This protein was purified to apparent homogeneity employing affinity binding to sulfated dextran and precipitation by ammonium sulfate, followed by sequential chromatography on DEAE-cellulose, heparin-Sepharose and Sephacryl S-200. Quantitative enzyme-linked immunosorbent assays revealed that the concentration of this inhibitor is approximately 3 microM in bovine serum. The inhibitor is a single polypeptide chain with an estimated Mr of 83,000 as determined by SDS-polyacrylamide gel electrophoresis. An aspartic acid was found at the amino terminus of the protein; N-terminal amino acid sequence data indicated that there was no significant homology with other reported amino acid sequences. This bovine inhibitor covalently complexed the human proteinases C1-r, C1-s, factor XIIa and plasma kallikrein, which are also complexed and inactivated by human C1-inhibitor. In addition, the bovine inhibitor complexed and inactivated bovine chymotrypsin, a feature which functionally distinguishes it from human C1-inhibitor. Although the bovine inhibitor appears functionally very similar to C1-inhibitor, we found no evidence for structural homology with the human counterpart.

Biochemical investigations after burning injury: complement system, protease-antiprotease balance and acute-phase reactants

Seventeen burned patients were investigated--Group I (n=10) with a mean burned area expressed as unit burn standard (UBS) of 69 +/- 24 and Group II (n = 7) with a mean UBS of 23 +/- 8. Blood samples were collected immediately after admission, 6-12 h after injury, during the morning and evening of day 1, and then daily for 2 weeks. This prospective study demonstrated complement activation in vivo in all burned patients, measured by C3d/C3 ratio index which was not related to the extent of the burned surface. A significant protease-antiprotease imbalance, correlated to the severity of burns, was found, leukocyte elastase was increased throughout the observation period, alpha 2-macroglobulin drastically decreased in severely burned patients, and alpha 1-proteinase inhibitor promptly decreased below the normal level in patients with more than 40 UBS. Finally, there was a delayed but then persistent acute-phase reactant protein response involving C-reactive protein, haptoglobin and alpha 1-acid glycoprotein, the concentrations of which reached a plateau on days 6 or 7.

Serum alpha-thiol protease inhibitor concentrations in health and disease

Serum alpha-thiol protease inhibitor (alpha-TPI) concentration was assayed by radial immunodiffusion in normal subjects, pregnant women, and in a wide variety of diseases. The normal concentration (448 (SD 75) mg/l) increased significantly (p less than 0.001) in pregnancy to 575 (89) mg/l, and in prostatic cancer treated by oestrogens to 666 (87) mg/l. Inconsistent changes were observed in inflammatory and malignant disease and in liver disease. A temporary pronounced fall of alpha-TPI was seen after burn injury, and a sustained fall after bone marrow transplantation. Crossed immunoelectrophoresis showed that the serum alpha-TPI occurred in two forms, with alpha 2 and alpha 1 electrophoretic mobilities. A heavy demand on this antiprotease may result in suppression of the alpha 1 form.

Protein loss during acute graft-versus-host disease: diagnostic and clinical significance

In 31 consecutive patients who received an allogeneic bone marrow transplantation the loss of proteins during the period at risk for acute graft-versus-host disease (aGVHD) was studied in order to determine whether the quantity of protein loss could be used for grading the severity of aGVHD. It was shown that the grade classified on the basis of the severity of skin rash, the quantity of diarrhea and the seriousness of cholestasis, correlated with serum albumin loss, intestinal plasma loss (expressed by the intestinal alpha 1-antitrypsin clearance) and the occurrence of inflammatory cells (leukocytes) in feces. The quantity of albumin lost by intestinal route accounted for only one third of the total albumin loss. To investigate whether the remaining part of it could be explained by capillary leakage elsewhere in the body, leakage of antileukoprotease from the tissue of the respiratory tract into the blood was measured. It was shown that the serum concentration of this proteinase inhibitor correlated with albumin loss. This means that capillary leakage also occurs in the lung during aGVHD. In conclusion, the loss of proteins can be used as a parameter of the severity of aGVHD once the proper diagnosis has been established. It appears that a combination of the current 'familiar' grading system and SAL yields a more objective classification system with a greater prognostic value.

Three high molecular weight protease inhibitors of rat plasma. Isolation, characterization, and acute phase changes

Rat blood plasma contains three high molecular weight thiol ester-containing proteinase inhibitors, alpha 1-macroglobulin (alpha 1M), alpha 1-inhibitor III (alpha 1I3), and alpha 2-macroglobulin (alpha 2M). Rat serums have been analyzed using a two-dimensional gel electrophoretic technique which optimizes recovery of high molecular weight proteins. alpha 1M, and (alpha beta)4-tetramer in native solution, separated in the second sodium dodecyl sulfate-containing electrophoretic dimension as a disulfide-linked (alpha beta)2-dimer with an approximate Mr of 360 kDa. alpha 1I3 separated in the gels as a single 190-kDa polypeptide. It is also a monomer in native solution by ultracentrifugation criteria. Native rat alpha 2M is a tetramer, but it separates in the gels as a disulfide-linked dimer with an Mr of approximately 360 kDa. The kinetics of changes in concentration of these proteins during the induction of polyarthritis was also measured by quantitative immunoelectrophoresis. In rats with adjuvant-induced polyarthritis, the concentration of alpha 1I3 dramatically decreases and alpha 2M appears and continues to increase in a biphasic manner for 2 weeks. The alpha 1M concentration remains relatively constant. All three macroglobulins were purified utilizing modern rapid chromatographic techniques, and parallel comparisons of their native physicochemical properties were carried out. The N-terminal sequence of the alpha-chain of rat alpha 1M was also shown to share sequence homology with that of alpha 2M. In agreement, Esnard et al. (Esnard, F., Gutman, N., El Moujahed, A., and Gauthier, F. (1985) FEBS Lett. 182, 125-129) recently reported that alpha 1I3 also contains a thiol ester bond, as do alpha 1M and alpha 2M, since it reacts covalently with [14C]methylamine and is cleaved autolytically at 80 degrees C. We have examined negatively stained preparations of native, trypsin-treated, and methylamine-treated human alpha 2M, rat alpha 2M, and rat alpha 1M in the electron microscope. Trypsin appears to convert globular ring-shaped native molecules to rectangular box-like structures, in agreement with the conclusions of a recent report on human alpha 2M (Tapon-Bretaudiere, J., Bros, A., Couture-Tosi, E., and Delain, E. (1985) EMBO J. 4, 85-89).

Further studies of plasma protease inhibitors in the hedgehog, Erinaceus europaeus; collagenase, papain and plasmin inhibitors

Hedgehog plasma was separated by gel filtration on Sephacryl S-200, the fractions resolved by electrophoresis and the electrophoretograms characterized for collagenase, papain and plasmin inhibiting activities with the high mol. wt substrate casein. The three inhibitors previously identified as alpha 2-, alpha 2-beta- and beta-macroglobulins were found to inhibit all three proteases. These were the only collagenase inhibitors found in plasma. Hedgehog alpha 2-chymotrypsin inhibitor and beta-protease inhibitor were both found to also inhibit papain. Three new inhibitors specific for papain (gamma-, alpha 2- and alpha 1-cysteine protease inhibitors) and one for plasmin (alpha 2-antiplasmin) were also found, bringing the number of protease inhibitors in hedgehog plasma to 14. Immunological cross-reactivity as studied by immunoelectrophoresis showed homology between hedgehog alpha 2-macroglobulin and rat murinoglobulin I and between hedgehog alpha 2-antithrombin and rat antithrombin III.

Tammar wallaby plasma protease inhibitory (Pi) proteins

Electrophoretic examination (isoelectric focusing and polyacrylamide gel electrophoresis) of 157 plasmas from a Kangaroo Island population of tammar wallabies (Macropus eugenii) resulted in the identification of five putative condominant protease inhibitor alleles, F, I, M, P and S, which exhibited microheterogeneity due to variable terminal sialic acid content. The frequencies of the five alleles in this population were 0.041(F), 0.682(I), 0.194(M), 0.073(P) and 0.010(S). The proteins had isoelectric points in the pH range 3.94-4.38, Mr of 60,500 to 66,000 and were identified as protease inhibitors by their abilities to inhibit both trypsin and chymotrypsin. Protein blotting of the denatured proteins demonstrated cross reaction with antiserum to human alpha 1-protease inhibitor.

Acid-stable protease inhibiting polypeptides formed from denatured horse plasma by proteolysis

1. Trypsin digestion of perchloric acid precipitated horse plasma yielded polypeptides with inhibitory properties for trypsin, chymotrypsin and, to a small extent, kallikrein. 2. The Mr of the inhibitory polypeptides were 73,000 and 24,000. 3. The number, enzyme specificity and Mr of the inhibitory polypeptides differed from the values known for the human being. 4. The inhibitory polypeptides were purified by affinity chromatography on Sepharose-trypsin and by gel filtration through Sephadex G-75. 5. Protease inhibitory polypeptides were generated in the same manner by chymotrypsin, elastase, proteinase K, pronase, collagenase, papain and subtilisin. 6. The number and electrophoretic migration of the inhibitory polypeptides obtained with the different enzymes were variable. 7. The enzyme specificity was constant since all polypeptides inhibited only trypsin, chymotrypsin and kallikrein to a small extent. 8. None of the inhibitory polypeptides were immunologically related to native plasma proteins or plasma protease inhibitors.

Very low density lipoproteins stimulate cholesteryl ester formation in U937 macrophages. Heterogeneity and biologic variation among normal humans

Normolipidemic fasting VLDL stimulated the formation of cholesteryl ester in the human macrophage-like cell line, U937. VLDL from different persons exhibited heterogeneity over a 10-fold range in stimulating cholesterol esterification, and were 7% to 98% as active as human LDL. The effects of VLDL in U937 cells were highly correlated to those in normal human fibroblasts. VLDL did not induce cholesterol esterification in resident mouse peritoneal macrophages, nor in fibroblasts that lacked LDL receptors, suggesting that receptors for LDL, rather than for beta-VLDL, mediate the effects of VLDL. The active VLDL particles were found in the dense VLDL subfraction, Sf20 to 60, but not in Sf60 to 100 or Sf100 to 400. The activity of unfractionated VLDL was correlated directly with % cholesteryl ester in total or Sf20 to 60 VLDL, and inversely with VLDL triglycerides. Biologic variation of fasting VLDL activity in U937 cells was found in 13 normolipidemic ambulatory subjects. As compared to the correlation between the activity of two VLDL samples derived from a single aliquot of blood (r = 0.90), the correlation was lower (r = 0.60) between the activity of samples taken on successive days, and even less (r = 0.05) between VLDL samples obtained 2 weeks apart. Substantial biologic variation also occurred in VLDL composition except for VLDL unesterified cholesterol. These findings suggest an environmental influence on VLDL metabolism by macrophages.

Potential role of pregnancy-associated plasma protein-A in human reproduction

By radioimmunoassay, pregnancy-associated plasma protein-A (PAPP-A) was undetectable in matched follicular and luteal phase serum samples (n = 17) or in the peripheral circulation of normal males (n = 17). However, seminal plasma (91.5%), cervical mucus (100%) and pre-ovulatory follicular fluid (99.6%) were consistently PaPP-A positive. In addition to PAPP-A, four circulating protease inhibitors (PIs) were detected in pooled seminal plasma whereas pooled follicular fluid contained an additional six. Follicular concentrations of serum PIs were inversely related to molecular size. By contrast, PAPP-A formed a positive concentration gradient across the blood-reproductive tract barrier suggesting PAPP-A production within the reproductive tract. A minor proportion (1.7%) of ejaculated spermatozoa were coated with PAPP-A, as demonstrated by direct immunofluorescence. Since PAPP-A specifically inhibits leucocyte elastase, it is suggested that PAPP-A coated spermatozoa were "selected" to overcome localized phagocytic-proteolytic degradation. The physiological significance of these findings are discussed in relation to human reproduction.

Serum protease inhibitors in acute viral hepatitis

Serum levels of alpha 1-antitrypsin (alpha 1-AT) and alpha 2-macroglobulin (alpha 2-M) and, as controls, alpha 1-acid glycoprotein (alpha 1-AG) and haptoglobin were evaluated by means of laser nephelometry in 17 patients with acute viral hepatitis (AVH) type A, 16 with AVH-B, 12 with AVH-NANB and 8 with fulminant hepatitis B. On admission, alpha 1-AT levels were elevated in one third of AVH-A and AVH-B cases, but subsequently declined; alpha 2-M levels were elevated in about 40% of AVH-B patients during the 2nd, 3rd and 4th week after admission. No significant correlation was found between elevated levels of protease inhibitors and aminotransferase values or drug addiction and delta coinfection. alpha 1-acid glycoprotein and haptoglobin levels were always normal or low. Protease inhibitors did not show any elevation in fulminant hepatitis, while changes were found only in a few patients with AVH-NANB. Thus, no clearcut pattern of changes in protease inhibitors has been found in association with each type of hepatitis, although alpha 1-AT and alpha 2-M elevations are mainly found in AVH-B.

Plasma levels of main granulocyte components during hemodialysis: effects of immunosuppression

Plasma levels of granulocyte lactoferrin, granulocyte myeloperoxidase and granulocyte elastase in complex with alpha 1-proteinase inhibitor were investigated during hemodialysis in oliguric patients following cadaveric renal transplantation (CRT). The results were compared with those of patients undergoing regular hemodialysis treatment (RDT) using different membrane materials. In RDT patients, plasma lactoferrin levels increased from 61.9 +/- 10.2 to 417.9 +/- 96.7 using dialyzers made of cuprophane. Dialyzers made of polymethyl methacrylate induced an increase of lactoferrin from 166.6 +/- 28.5 to 712.5 +/- 165.9 and dialyzers made of polyacrylonitrile an increase from 122.6 +/- 23.5 to 647.7 +/- 203.6 ng/ml. In CRT patients, in contrast, plasma lactoferrin levels increased from 49.1 +/- 10.9 to 199.6 +/- 45.9 (cuprophane), from 30.1 +/- 6.9 to 252.5 +/- 46.9 (polymethyl methacrylate), and from 43.3 +/- 9.1 to 174.2 +/- 39.3 ng/ml (polyacrylonitrile). On the other hand, the plasma levels of myeloperoxidase and elastase in complex with alpha 1-proteinase inhibitor increased comparably in both groups of patients. Our data suggest that immunosuppression might prevent degranulation of specific granules independently of the used dialyzer membrane material, whereas no effect was observed on two main components of azurophilic granules.

Inflammatory mediators and modulators released in organ culture from rabbit skin lesions produced in vivo by sulfur mustard. III. Electrophoretic protein fractions, trypsin-inhibitory capacity, alpha 1-proteinase inhibitor, and alpha 1- and alpha 2-macroglobulin proteinase inhibitors of culture fluids and serum

This is the third report in a series on the inflammatory mediators and modulators released in organ culture from skin lesions of various ages, which were produced in vivo in rabbits by the military vesicant, sulfur mustard (SM). It describes the electrophoretic protein fractions and trypsin-inhibitory capacities of the various culture fluids and the amounts of alpha 1-proteinase inhibitor and alpha-macroglobulin proteinase inhibitors in these fluids. With one-dimensional electrophoresis, the albumin and beta-globulin fractions of protein in culture fluids varied little with the development and healing of the SM lesions. These fractions proportionally resembled the corresponding fractions found in serum. The alpha 1-globulin fraction was proportionally smaller than the corresponding fractions of serum as the lesions healed. The alpha 2-globulin fraction was proportionally smaller than the corresponding fractions of serum at all stages of lesion development and healing. The gamma-globulin fraction was proportionally larger as the lesions healed. With two-dimensional electrophoresis, about 68%, 46%, and 35% of the protein spots in culture fluids from representative 1-day and 6-day SM lesions and normal skin, respectively, matched those from serum. In each case, the large, diffuse, serum albumin spot represented about two-thirds of the protein present. Thus, gravimetrically, in normal skin and in both developing and healing lesions, the extracellular proteins were 80-90% of serum origin. The trypsin-inhibitory capacity (TIC) per milligram protein in the culture fluids of healing lesions was markedly less than the TIC per milligram protein in the fluids of peak lesions. This decrease correlates well with the decrease found in the alpha 1-globulin fraction, which contains alpha 1-antiproteinase (alpha 1-PI) (and alpha 1-macroglobulin [alpha 1M] in rabbits). The alpha 1PI and the alpha 1M-alpha 2M proteinase inhibitors were identified in the culture fluids by means of sodium dodecyl sulfate-polyacrylamide gel electrophoresis, Western blots, specific antibodies, and the immuno-peroxidase technique. The levels of both free and proteinase-complexed alpha 1PI and alpha M inhibitors in the culture fluids decreased as the lesions healed. In both developing and healing lesions, at least half of the alpha 1PI and alpha M inhibitors seemed to be complexed with proteinases. Thus, serum seems to be a major source of unbounded extracellular protein within acute inflammatory lesions, and serum proteinase inhibitors seem to be the host's major defense against local damage by proteinases from serum, infiltrating leukocytes, and activated fibroblasts.

Natural proteinase inhibitors: blood coagulation inhibition and evolutionary relationships

1. Natural proteinase inhibitors are divided into polysaccharides, plasma proteinase inhibitors and natural non-plasma inhibitors. 2. Polysaccharides are antithrombin-III and heparin co-factor-II dependent or independent regarding their biological activity. Knowledge of the inhibitory mechanism at a molecular level was gained by the study of heparin. 3. Antithrombin-III, heparin-co-factor-II and alpha 2-macroglobulin are the most important plasma proteinase inhibitors involved in coagulation. alpha 2-macroglobulin has a particular inhibitory mechanism. 4. Non-plasma proteinase inhibitors were isolated from many species. They inhibit mainly the contact activation and fibrinolysis. 5. The evolutionary relationships are poorly understood.

Human inter-alpha trypsin inhibitor and immunologically related inhibitors investigated by quantitative immunoelectrophoresis. I. Method and reference material

The concentration in serum of inter-alpha trypsin inhibitor (I alpha I) and its immunologically related inhibitor, the prealbumin-like proteinase inhibitor (pA-PI), was investigated by quantitative crossed immunoelectrophoresis (CIE) in 33 healthy persons. The corresponding urinary excretion over a 4 h period of the immunologically related urinary proteinase inhibitor (UPI) was measured by rocket immunoelectrophoresis. The concentration of pA-PI increased significantly (p less than 0.001) with age whereas that of I alpha I and the urinary excretion of UPI were independent of age. There was no significantly difference in the concentration of the inhibitors in serum between the sexes, but females were found to have a lower urinary excretion of UPI than males (p less than 0.05). Furthermore we found no significant variation in the concentration of the inhibitors during the course of the day or from day to day over a 5 day period. Results obtained by rocket immunoelectrophoresis correlated well with enzymatically measured trypsin inhibitory activity.

Resistance of horse alpha 1-proteinase inhibitor to perchloric acid denaturation and a simplified purification procedure resulting therefrom

Addition of perchloric acid (6.4% w/v final concentration) to horse alpha 1-proteinase inhibitor or to horse plasma neither precipitated nor inactivated alpha 1-proteinase inhibitor. None of the isoinhibitors of alpha 1-proteinase inhibitor was altered by dilute perchloric acid. This unexpected behavior led to a simplified procedure for the purification of horse alpha 1-proteinase inhibitor, consisting of removal of the bulk of plasma proteins, by perchloric acid precipitation and by gel filtration on Sephadex G-75 and G-200. The resulting preparations of alpha 1-proteinase inhibitor were immunogenically pure. The simplified purification procedure permitted the immunochemical comparison of the isoinhibitors of alpha 1-proteinase inhibitor, which proved to be immunologically identical.

Functional activities and nonenzymatic glycosylation of plasma proteinase inhibitors in diabetes

The functional activity of three of the major plasma protease inhibitors, alpha 1-proteinase inhibitor, antithrombin III and alpha 2-antiplasmin, has been measured in a series of persons with diabetes mellitus and compared with healthy controls. The mean specific functional activity of both diabetic plasma antithrombin III (50.8 +/- 7.0 U/mg) and alpha 1-proteinase inhibitor (35.3 +/- 5.6 mU/mg) was found to be significantly lower than in healthy controls (57.9 +/- 6.0 U/mg) and (42.2 +/- 10.7 mU/mg). No difference was detected in alpha 2-antiplasmin activity or levels. The glycosylated protein fraction of 83% of diabetic plasmas showed the presence of less than 1% of the total alpha 1-proteinase inhibitor when isolated by phenylboronate affinity chromatography. Incubation of normal plasma with 250 nmol/l glucose (a level approximately 6 X higher than encountered in uncontrolled diabetes) resulted in a 17% and 6% decrease in antithrombin III and alpha 1-proteinase inhibitor activities. We conclude that the decrease in specific activity of alpha 1-proteinase inhibitor is not related to nonenzymatic glycosylation, but the decrease in antithrombin III specific activity may be related.

Antiprotease capacity in acute pancreatitis

Serial measurements of circulating antiproteases were carried out on 42 consecutive patients admitted with acute pancreatitis. In the 7 days following admission the serum levels of alpha 1 antitrypsin (alpha 1 AT), alpha 1 antichymotrypsin (alpha 1 ACT) and the trypsin inhibitory capacity (TIC) increased by more than 300 per cent. The serum concentration of alpha 2 macroglobulin (alpha 2 M) alone showed a decline which was most profound in those patients with severe acute pancreatitis. Initial experience of fresh frozen plasma as a source of extrinsic antiproteases in severe acute pancreatitis is that it fails to prevent the decline in alpha 2 M or increase the already elevated TIC of the patients' serum.

Purification and characterization of a novel inhibitor of urokinase from human urine. Quantitation and preliminary characterization in plasma

Urokinase-related proteins in human urine occur mainly as a 1:1 complex of urokinase with an inhibitor (Stump, D. C., Thienpont, M., and Collen, D. (1986) J. Biol. Chem. 261, 1267-1273). BALB/c mice were immunized with this urokinase-urokinase inhibitor complex and spleen cells fused with mouse myeloma cells, resulting in hybridomas producing monoclonal antibodies. Three antibodies reacting with the complex but not with urokinase were utilized to develop a sensitive (0.5 ng/ml) enzyme-linked immunosorbent assay for the urokinase inhibitor, which was used for monitoring its purification by chromatography on zinc chelate-Sepharose, concanavalin A-Sepharose, SP-Sephadex C-50, and Sephadex G-100. A homogenous glycoprotein of apparent Mr 50,000 was obtained with a yield of 40 micrograms/liter urine and a purification factor of 320. One mg of the purified protein inhibited 35,000 IU of urokinase within 30 min at 37 degrees C. This protein was immunologically related to both the purified urokinase-urokinase inhibitor complex and to the inhibitor portion dissociated from it by nucleophilic dissociation. It was immunologically distinct from all known protease inhibitors, including the endothelial cell-derived fast-acting inhibitor of tissue-type plasminogen activator, the placental inhibitor of urokinase and protease nexin. In electrophoresis the protein migrated with beta-mobility. Inhibition of urokinase occurred with a second order rate constant (k) of 8 X 10(3) M-1 s-1 in the absence and of 9 X 10(4) M-1 s-1 in the presence of 50 IU of heparin/ml. The urokinase inhibitor was inactive towards single-chain urokinase-type plasminogen activator and plasmin, but it inhibited two-chain tissue-type plasminogen activator with a k below 10(3) M-1 s-1 and thrombin with a k of 4 X 10(4) M-1 s-1 in the absence and 2 X 10(5) M-1 s-1 in the presence of heparin. The concentration of this urokinase inhibitor in plasma from normal subjects determined by immunoassay was 2 +/- 0.7 micrograms/ml (mean +/- S.D., n = 25). The protein purified from plasma by immunoabsorption had the same Mr, amino acid composition, and immunoreactivity as the urinary protein. Furthermore, when urokinase was added to plasma, time-dependent urokinase-urokinase inhibitor complex formation was observed at a rate similar to that observed for the inhibition of urokinase by the purified inhibitor from urine. This urokinase inhibitor, purified from human urine, most probably represents a new plasma protease inhibitor.

[Activity of the prekallikrein-kallikrein system and characteristics of its regulation in various allergies]

Activity of kallikrein and content of prekallikrein were estimated in blood serum of 34 patients with atopy and of 17 patients with urticaria by means of the chromatographic procedure. In these patients activity of alpha 1-proteolytic inhibitor (alpha 1-PI) and alpha 2-macroglobulin (alpha 2-MG) was studied. At the acute period of pollinosis activation of the kallikrein-kinin system was found, which correlated with the disease aggravation. During specific immunotherapy of the patients with atopy activation of the kallikrein-kinin system occurred, which depended on the total concentration of allergen administered. At the same time, activation of the kallikrein-kinin system, observed under conditions of urticaria, was most distinct in the patients with chronic relapsing urticaria and was related to the degree of the disease aggravation. Preparations of proteinase inhibitors analogous to contrical were only short-term effective in chronic relapsing urticaria. In the patients with distinct aggravation of pollinosis inhibitory activity of alpha 2-MG was markedly increased which occurred apparently as a result of blood pachyemia simultaneously with activation of the kallikrein-kinin system. Distinct increase in the alpha 1-PI activity was not found in the patients with pollinosis and urticaria even at the step of pronounced aggravation. Phenotyping of the inhibitor in 10 patients with a marked decrease in its activity enabled to find 6 persons exhibiting the heterozygous genotype with a defect allele.