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Results for “Complement C1 Inactivator Proteins”

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At least 505 records · Page 28Linked to original sources
PubMed1986

C1 esterase inhibitor deficiency in X-linked hypogammaglobulinaemia: an anomaly fostering anaphylactoid reactions following intramuscular gammaglobulin administration.

A patient with apparent X-linked agammaglobulinaemia was found to be inordinately susceptible to anaphylactoid reactions to intramuscular injections of gammaglobulin. The patient was found also to have low levels of C1 esterase inhibitor (C1 INH). The possibility that the C1 INH deficiency and in this patient, whether genetic or acquired, fostered the susceptibility to the production of anaphylactoid reactions after gammaglobulin injections urges further studies of the association of C1 INH deficiency and anaphylactoid reactions to gammaglobulin injections. The possibility that C1 INH levels like C1q levels may be low in hypogammaglobulinaemic patients as a consequence of increased catabolism of this regulator of the complement system when IgG levels are low is considered.

Adult↗
PubMed1993

Acquired C1 inhibitor deficiency with lymphoma causing recurrent angioedema.

A 52 year old man who developed recurrent, massive and generalized angioedema for the first time during adult life was found to have an acquired deficiency of C1q esterase inhibitor (C1 INH) in association with a B cell lymphoma producing a paraprotein. He had low levels of C4 and C1 INH during the attacks which returned to normal after the successful treatment of lymphoma. An underlying lymphoproliferative disease should always be considered in adult patients with this immunological profile, recurrent angioedema and a negative family history.

Angioedema↗
PubMed1999

Effect of C1-inhibitor in a rat model of necrotizing enterocolitis.

Our aim was to investigate the effect of C1-inhibitor (C1-INH) in a rat model of necrotizing enterocolitis (NEC). Twenty-four anesthetized and artificially ventilated rats received 0.1 mg/kg endotoxin. Fifteen minutes later, the animals in the study group (n = 12) were treated with 200 IU/kg C1-INH whereas the control animals (n = 12) received normal saline. In all animals, FiO(2) was reduced after 90 min from 0.21 to 0.05 and ventilation continued until 180 min or death. All animals developed shock symptoms. Drop in mean arterial blood pressure was more pronounced and survival time was shorter in the control group. Whereas the C1-INH activity increased in the study group, it decreased in the control group. The extent of macroscopic intestinal lesions did not differ between the groups. In conclusion, C1-INH did not prevent shock, but mitigated and delayed its course.

Animals↗
PubMedDate not supplied

Local and remote ischemia-reperfusion injury is mitigated in mice overexpressing human C1 inhibitor.

Activation of the classical complement pathway is crucially involved in complement-mediated endothelial cell damage in ischemia-reperfusion injury. C1 inhibitor is the only known physiological inhibitor of classical complement pathway activation. Transgenic mice overexpressing human C1 inhibitor were used in a surgical lower torso and a liver ischemia-reperfusion model. Organ-specific endothelial disruption was determined by 125I-tagged albumin extravasation. In the lower torso ischemia-reperfusion model, transgenic mice overexpressing the C1 inhibitor were protected in the muscle and the lungs from endothelial cell damage. In the liver ischemia-reperfusion model, endothelial cell integrity was preserved in transgenic animals in the liver, the gut and the lungs. Our data indicate that inhibiting complement activation by a transgenic approach is effective in protection against ischemia-reperfusion injury.

Albumins↗
PubMed1982

Complement factors and acute phase reactants in the Guillain-Barré syndrome.

The concentrations of C3, C4, C1 inactivator, C3 proactivator and orosomucoid were determined in sera from 13 patients with Guillain-Barré syndrome. The most severely affected patients had the highest levels of C3, C4 and orosomucoid in the acute phase with a slight decline over the following 3-8 weeks. The mildly affected patients had complement concentrations in the upper normal range. In the group of patients with the highest concentrations of C3, C4 and orosomucoid, 4 out of 6 developed residual weakness, while residual weakness was only found in 1 out of 7 with normal concentrations. The measurement of C3 and C4 may, therefore, be of value in estimating the severity and prognosis in the early phase of the disease.

Adolescent↗
PubMed1980

An immunological basis of schizophrenia and affective disorders?

In 48 patients with schizophrenia and 32 patients with affective disorders, different immune parameters were tested. Compared to blood-donors, IgG and IgM serum concentrations were increased in both the schizophrenic and affective disorders. However, these abnormalities did not differ from hospital control populations. The patients failed to show an association of antibodies considered to be characteristic of autoimmune diseases. In addition, no increased incidence of circulating immune compexes was detected. The only substantial serologic abnormality froun was an elevation of C4 levels in patients with biopolar psychosis.

Adult↗
PubMed1989

Studies on the dose dependence of endotoxin-induced in vitro activation of the complement system.

The dose and time dependence of in vitro endotoxin-induced activation of complement was studied in citrated pool plasma at 37 degrees C. C3 activation fragments (C3act) and the fluid-phase terminal complement complex (TCC) were used as indicators of initial and terminal activation, respectively. At 1 h marked elevation of C3act and TCC were found in plasma tested with the highest doses of endotoxin (2.10(9) and 2.10(8) ng/l). In test plasmas with 2.10(7) and 2.10(6) ng/l of endotoxin, no sign of activation was seen during the first 4 h, whereas both C3act and TCC values were increased at 12 h. In thest plasma with 2.10(5) ng/l of endotoxin and in control plasma no elevation of TCC values were seen during the observation period (24 h), whereas C3act values increased slightly and to the same extent in both at 24 h. Parallel to the increases in C3act and TCC concentrations, the functional C1 inhibitor (C1INH) values decreased. Changes in C1INH values, however, occurred with a time lag of approximately 6 h compared to the increases in C3act and TCC. Our in vitro study showed a dose-dependent endotoxin-induced activation of both the initial and the terminal part of the complement cascade evaluated by C3act and TCC.

Complement Activation↗
PubMed1981

Circulating immune complexes, complement factors C3, C4, C1-inhibitor, alpha-1-antitrypsin and immunoglobulins in asthmatic patients.

Sera from 159 adult asthmatic outpatients (extrinsic, n = 82, intrinsic, n = 65 and acetylosalicylic acid (ASA)-sensitive, n = 12) and from 100 controls were tested for total levels of IgG, IgM, IgA, IgE, complement factors C3, C4, C1-inhibitor, alpha 1-antitrypsin and circulating immune complexes. The following results were observed: (1) a marked increase of IgE in extrinsic asthma; (2) a slight increase of IgM, and (3) an equal increase of complement C4 levels in all three asthma groups; (4) normal mean values of C3 levels with a significantly larger standard deviation of the mean in all three asthma groups; (5) an equally slight decrease of protease inhibitors, such as C1-inhibitor and alpha 1-antitrypsin, and (6) the presence of circulating immune complexes in 22% of extrinsic, in 8% of intrinsic and 13% of ASA-sensitive asthmatics. Circulating immune complexes can be found in all three asthma groups and may correlate with complement deviation.

Adult↗
PubMed1978

Profiles of serum complement in patients with hepatobiliary diseases.

CH50 and the concentrations of C3, C4, C1 INH and factor B have been measured in sera from 34 control subjects and 178 patients with various hepatobiliary diseases, including primary biliary cirrhosis (PBC), chronic active hepatitis (CAH), cryptogenic cirrhosis (CC), alcoholic liver disease (ALD), Wilson's disease (WD), large duct biliary obstruction (LDBO) and viral hepatitis (VH). CH50 was decreased in CAH and CC. C3 was increased in PBC, LDBO and VH and decreased in CAH and CC. C4 was decreased in PBC, CAH, ALD and WD. C1 INH was increased in PBC, CAH, ALD, LDBO and VH. Factor B was increased in LDBO and VH and decreased in CC. In none of the patient groups was the mean C4 level increased or the mean C1 INH level decreased. All 5 indices of serum complement were lower in ascitic than nonascitic patients. Data on serum complement were similar in HBsAg positive and negative VH. Discriminant analysis facilitated separation of all the patient groups on the basis of complement data, except PBC and VA. Analysis of data using a within-group correlation matrix revealed a significant negative correlation between C4, the most discriminating variable of serum complement in CAH, and gamma-globulin concentration in CAH. The possible contribution of factors such as activation of complement, impaired hepatic synthesis of complement components, an acute phase response and cholestasis to altered serum complement profiles in different hepatobiliary diseases is discussed.

Adolescent↗
PubMed1978

Acquired C1-inhibitor deficiency in essential cryoglobulinemia and macrocryoglobulinemia.

In 5 patients with mixed cryoglobulinemia, 3 with Waldenström's disease and 2 with essential cryoglobulinemia, a C1-inhibitor (C1-INH) deficiency was discovered. The complement profile was characteristic of the acquired type: the total hemolytic activity and the early components were reduced, C3 was diminished in 1 patient only, C5 and C9 were normal or elevated. 1 atient with Waldenström's disease and 1 with essential cryoglobulinemia experienced episodes of angioedema. Circulating immune complexes were found in all patients' sera by the 125I-radiolabelled C1q binding activity (C1q BA) test. The values of the C1q binding activity were correlated with the depletion of the early complement components and that of C1-inh. 4 patients showed circulating 7S IgM. Our data support the hypothesis of a complement activation by the cryoprecipitating immune complexes; the C1-INH depletion is secondary to its consumption following C1 activation.

Complement C1 Inactivator Proteins↗
PubMed1976

Occurrence of C1 inactivator and other proteinase inhibitors in euglobulin fractions and their influence on fibrinolytic activity.

Considerable amounts of C1 inactivator and inter-alpha-trypsin inhibitor pecipitate during euglobulin fractionation of human plasma. The amount precipitated depends on the ionic strength and the pH during the fractionation procedure. In contrast, alpha1-anti-trypsin, alpha2-macroglobulinand antithrombin II are present in euglobulin fractions in trace amounts only. The fibrinolytic activity of the euglobulin fractions is inhibited by the endogenous C1 inactivator, particularly as shown by comparison of normal and hereditary angioneurotic edema (HANE) plasma.

Angioedema↗
PubMed1985

Evaluation of euglobulin methods for the study of blood fibrinolytic activity: results for patients with rheumatoid arthritis and in the postoperative period.

Euglobulin fractionation is a frequently employed pretreatment of plasma for the determination of fibrinolytic activity. The fractionation procedure suffers from possible in vitro artifacts, e.g., variable precipitation of C1-inactivator. This is illustrated by the following two situations. It is shown that increased amounts of C1-inactivator not related to an increased plasma concentration are present in euglobulin fractions in cases of classic rheumatoid arthritis. Similarly, postoperatively, a disproportional increase in C1-inactivator in euglobulin fractions occurs. In both cases, an artificially reduced fibrinolytic activity is recorded due to increased inhibition by C1-inactivator. This is circumvented and recognized by adding sodium flufenamate or C1s-esterase to euglobulin fractions to uniformly eliminate C1-inactivator. Two specific assays for tissue-type plasminogen activator activity in euglobulin fractions (as C1-inactivator-resistant activator activity and a parabolic rate assay on a synthetic substrate) correlate excellently (r = 0.8728; p less than 0.001; n = 108). The first mentioned is corrected for variable endogenous C1-inactivator; the latter assay is found to be insensitive to inhibition by C1-inactivator. It is concluded that with euglobulin methods a misinterpretation of blood fibrinolytic activity is possible in rheumatoid arthritis patients. In the postoperative period, the fibrinolytic shutdown concerns tissue-type plasminogen activator activity; the pattern of the shutdown can be misjudged in using traditional euglobulin methods.

Abdomen↗
PubMed1976

Inactivator of the first component of human complement (C1INA). Enhancement of C1INA activity against C1s by acidic mucopolysaccharides.

Acidic mucopolysaccharides enhanced C1INA activity against C1s. The presence of heparin in the reaction mixture of C1INA and C1s markedly enhanced the inactivation of C1s by potentiating C1INA activity. Treatment of serum with C1s resulted in the inactivation of C4 hemolytic activity, but this inactivation of C4 by C1s was prevented by the presence of heparin presumably due to the enhancement of C1INA activity normally present in serum. The other acidic mucopolysaccharides, chondroitin sulfates A, B and C, were also effective on potentiating C1INA activity against C1s, but they were less active than heparin. The enhancement of C1INA activity by heparin was not observed in the reaction between C1INA and plasmin.

Chondroitin Sulfates↗
PubMed1980

Effect of aspirin on complement in vivo.

Following ingestion of aspirin (1 g) complement consumption could be demonstrated in 18/20 healthy volunteers. A slight to moderate decrease of whole complement activity (CH50) and of the components C1, C4 and C2 was found. In addition, reduced levels of the C1 inactivator (C1 IA) were measured in 19/20 probands. The drop in C titers and C1 IA was only detectable within a short period of time and 30 min after ingestion of the drug the titers were usually returning to normal. In view of these findings, the possible role of complement in adverse reactions to aspirin is discussed.

Aspirin↗
PubMed1980

Effect of aspirin on the complement system in vitro.

Aspirin (acetylsalicylic acid), ASA and sodium salicylate (NaSA) activate the complement system in vitro. The activation involves the components of the classical pathway. It is, however, antibody independent. Evidence for activation are (1) consumption of C and C component activities; (2) activation of C1 evidenced by release of C1s from the macromolecular complex, and (3) C3 and C5 conversion.

Aspirin↗