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At least 523 records · Page 29Linked to original sources
PubMed1980

Hereditary angioneurotic edema: immunochemical 'activity' without clinical expression.

An 11-year-old white female with focal glomerulonephritis was found to have an absence of functional C1 esterase inhibitor. C1 esterase inhibitor measured by immunochemical means, however, was only slightly reduced. After an initial time period marked by variable hypocomplementemia, presumably due to immune complex formation associated with the nephritis, immunochemical signs of active and severe hereditary angioneurotic edema (HANE) developed. These have been unremitting for 3 1/2 years. Clinical signs of HANE, however, have never developed. Thus, during this time, there have been no clinical abnormalities despite the fact that free C1 esterase activity has been persistently present in this patient's serum and serum levels of functional C1 esterase inhibitor, C2 and C4 have been continuously less than 2% of normal. It appears, therefore, that this patient has an unusual form of HANE mainifested solely by the complement alterations seen during symptomatic attacks but without clinical expression of that serologic activity.

Angioedema↗
PubMed1984

First case of acquired functional C1(-) INH deficiency: association with angioedema during Churg and Strauss vasculitis.

This report deals with the first case of acquired functional C1(-) INH deficiency with normal antigenic C1(-) INH level which was detected in a young girl with angioedema and Churg and Strauss vasculitis. This complement abnormality was associated with slightly depressed levels of CH50, C4 and C2, but a normal level of C3, and high levels of total IgE and IgM rheumatoid factors. Finally, most of these abnormalities disappeared after corticosteroid therapy and clinical improvement.

Adolescent↗
PubMed1990

Acquired C1 inhibitor deficiency: postmortem diagnosis.

Acquired C1 esterase inhibitor deficiency is a clinical syndrome closely resembling hereditary angioedema in which most patients have an associated malignancy of B cell lineage. Sera from 33 patients with B cell neoplasms were assayed for C1 esterase inhibitor level by rocket immunoelectrophoresis. The clinical summary of a patient who met the biochemical criteria for acquired C1 esterase inhibitor deficiency (low C1 esterase inhibitor, low C4) is presented. We hypothesize that this syndrome represents an autoimmune reaction involving tumor cell rejections and of potential benefit to the patient.

Adult↗
PubMed1989

Plasma concentrations of complement-modulating proteins (C1 inhibitor, C4 binding protein, factor H and factor I) in inflammatory dermatoses with special reference to psoriasis.

By using single radial immunodiffusion, plasma levels of four complement-modulating proteins, i.e. C1 inhibitor (C1INH), C4-binding protein (C4bp), factor H and factor I were measured in 42 psoriatic patients and in 60 patients with other inflammatory skin diseases in comparison with 27 normal controls. In psoriatic patients and those with related pustular dermatoses, the levels of C4bp, factor H and factor I were significantly increased. They correlated well with both extent of skin changes and disease activity. In contrast, in nonpsoriatic inflammatory dermatoses only factor H values were significantly increased in toxic erythema and factor I in atopic dermatitis. These results offer additional support for the hypothesis that the complement system is involved in psoriasis and related sterile pustular dermatoses.

Adult↗
PubMed1989

Inherited C1 inhibitor deficiency.

The paper reports our experience of a 15-year follow-up of 179 patients with hereditary angioedema (HAE). The disease is transmitted as an autosomal dominant trait and two variants have been described: type I characterized by functional and antigenic C1-inhibitor (C1-INH) deficiency and type II with normal or upper normal C1-INH antigenic levels but no functional activity. The clinical picture is characterized by self-limiting bouts of swelling in the subcutaneous and/or mucous tissues. Data about frequency, localization and possible triggering factors of HAE attacks are reported. Analysis of genomic DNA from our patients using a C1-INH cDNA probe demonstrated the presence of restriction fragment length polymorphisms tightly linked with the disease in a minority of them. Data concerning prophylaxis and treatment of HAE attacks are also shown.

Angioedema↗
PubMed1984

Quantification of C1-inhibitor functional activities by immunodiffusion assay in plasma of patients with hereditary angioedema--evidence of a functionally critical level of C1-inhibitor concentration.

The relationship of C1-inhibitor (C1-INH) concentration and apparent functional activity was investigated in 111 plasma samples from 21 patients with the common form of hereditary angioedema (HAE). Functional C1-INH was analyzed by means of a modified version of immunodiffusion assay. Down to a C1-INH level of approximately 0.075 g/l (38% of normal) apparent C1-INH functions were found within the normal range, while below this level functional adequacy of C1-INH could no longer be ascertained. When C4 concentrations, considered to reflect approximately functional C1-INH, were related to C1-INH antigen levels of individual samples, a relationship emerged which was identical to that between C1-INH concentration and apparent function. No attacks of edema could be associated with C1-INH concentrations above 0.075 g/l, while it was possible to associate attacks with concentrations below this level. In experiments where patient plasma and normal plasma were mixed in various ratios or where HAE plasma was replaced by purified C1-INH, an increase in C1-INH antigen to concentrations of 0.06-0.08 g/l was followed by a sharp rise in apparent functions to normal values. The rise of functional C1-INH became moderate when C1-INH antigen further increased. The results supported the idea of a functionally critical level of C1-INH in the common form of HAE.

Angioedema↗
PubMed1984

Inhibition of the complement activation by an adrenal androgen, dehydroepiandrosterone.

The effect of dehydroepiandrosterone (DEA), an adrenal androgen successfully used for preventing attacks in hereditary angioneurotic edema (HANE) patients was studied on the activation of classical and alternative complement pathway. The steroid inhibited both the spontaneous and immune activation of the classical complement pathway (CP), the former effect, however, was found to be more marked than the latter one. DEA exerted its inhibiting effect most probably by interfering with the internal activation of C1. Because DEA rendered HANE patients symptom free but induced only a slight increase in their serum C1-INH level, our present findings suggest that inhibition of CP activation may have a significance in the therapeutic effect of DEA and possibly of other androgens as well.

Angioedema↗
PubMed1977

Circulating immune complexes detected by 125I-Clq deviation test in sera of cancer patients.

The presence of circulating immune complexes in freshly drawn sera of patients with various forms of malignancies was detected by the 125I-Clq deviation test of Sobel et al. More than 50% of the 459 cancer sera showed a high inhibition of 125I-Clq uptake by sensitized sheep erythrocytes when compared with sera of 50 healthy laboratory personnel. The levels were compared with levels of total hemolytic complement and immunochemical determinations of Cl1 and C3. A correlation between high levels of circulating immune complexes and low levels of Clq was suggested. These immune complexes were separated by sucrose density gradient ultracentrifugation at low pH and were found to be heavier than 19S. Fluctuation of levels of immune complexes was evident when serial samples from the same patient were tested. Decrease of levels of immune complexes and a concomitant increase of Clq were detected after Calmette-Gueérin bacillus and autologous tumor cell treatment in some melanoma patients.

Antigen-Antibody Complex↗
PubMed1988

A common neoepitope is created when the reactive center of C1-inhibitor is cleaved by plasma kallikrein, activated factor XII fragment, C1 esterase, or neutrophil elastase.

The reactive center of C1-inhibitor, a plasma protease inhibitor that belongs to the serpin superfamily, is located on a peptide loop which is highly susceptible to proteolytic cleavage. With plasma kallikrein, C1s and beta-Factor XIIa, this cleavage occurs at the reactive site residue P1 (Arg444); with neutrophil elastase, it takes place near P1, probably at residue P3 (Val442). After these cleavages, C1-inhibitor is inactivated and its conformation is modified. Moreover, in vivo, cleaved C1-inhibitor is removed from the blood stream more rapidly than the intact serpin, which suggests that proteolysis unmasks sites responsible for cellular recognition and the uptake of the cleaved inhibitor. In the study reported here, we show, using an MAb, that an identical neoepitope is created on C1-inhibitor after the cleavage of its exposed loop by plasma kallikrein, C1s, beta-Factor XIIa, and by neutrophil elastase.

Animals↗
PubMed1989

Proteolytic inactivation of plasma C1- inhibitor in sepsis.

Activation of both the complement system and the contact system of intrinsic coagulation is implicated in the pathophysiology of sepsis. Because C1 inhibitor (C1-Inh) regulates the activation of both cascade systems, we studied the characteristics of plasma C1-Inh in 48 patients with severe sepsis on admission to the Intensive Care Unit at the Free University of Amsterdam. The ratio between the level of functional and antigenic C1-Inh (functional index) was significantly reduced in the patients with sepsis compared with healthy volunteers (P = 0.004). The assessment of modified (cleaved), inactive C1-Inh (iC1-Inh), and complexed forms of C1-Inh (nonfunctional C1-Inh species) revealed that the reduced functional index was mainly due to the presence of iC1-Inh. On SDS-PAGE, iC1-Inh species migrated with a lower apparent molecular weight (Mr 98,000, 91,000, and 86,000) than native C1-Inh (Mr 110,000). Elevated iC1-Inh levels (greater than or equal to 0.13 microM) were found in 81% of all patients, sometimes up to 1.6 microM. Levels of iC1-Inh on admission appeared to be of prognostic value: iC1-Inh was higher in 27 patients who died than in 21 patients who survived (P = 0.003). The mortality in 15 patients with iC1-Inh levels up to 0.2 microM was 27%, but in 12 patients with plasma iC1-Inh exceeding 0.44 microM, the mortality was 83%. The overall mortality in the patients with sepsis was 56%. We propose that the cleavage of C1-Inh in patients with sepsis reflects processes that play a major role in the development of fatal complications during sepsis.

Complement C1 Inactivator Proteins↗
PubMed1993

Endotoxin-induced pulmonary dysfunction is prevented by C1-esterase inhibitor.

In septic shock, hypotension, disseminated intravascular coagulation, and neutrophil activation are related to the activation of the blood coagulation contact system. This study evaluates in dogs the effect of the C1-esterase inhibitor (C1-INH), a main inhibitor of the blood coagulation contact system, on the cardiovascular and respiratory dysfunction associated with endotoxic shock. Two groups were included: controls, which received Escherichia coli endotoxin, and a C1-INH group in which C1-INH was infused before E. coli endotoxin administration. In both groups, endotoxin produced hypodynamic shock; however, the decrease in the systolic index and the ventricular systolic work indexes were greater in controls than the C1-INH group. In controls, the arterial O2 partial pressure decreased by 30% and the alveolo-arterial O2 difference increased by 625%, these parameters remained unchanged in the C1-INH group. Hypoxemia was associated with increased intrapulmonary shunt, decreased blood coagulation contact factors, and decreased C3c. In contrast, C1-INH administration prevented endotoxin-induced hypoxemia, the increase in intrapulmonary shunt, and the decrease in blood coagulation contact factors. This study shows that, in dogs with endotoxic shock, pulmonary dysfunction is associated with an activation of the blood coagulation contact phase system. An inhibition of this system by C1-INH prevented the hypoxemia induced by endotoxic shock.

Animals↗
PubMed1980

Hereditary angio-oedema: its pathogenesis and management.

Hereditary angio-oedema is a genetically-determined disease. Usually the disease is due to a deficiency of C1-inhibitor or less commonly to the production of a functionally inactive molecule. The pathogenesis and clinical features of the disease are reviewed, and discussed in relation to the homeostatic role of C1 inhibitor. Finally the therapeutic approach to the disease is described and the scientific bases for the newer therapeutic discussed.

Anabolic Agents↗
PubMed2000

Usefulness of detection of complement activation products in evaluating SLE activity.

Complement activation products, such as C1rs-C1inh, specific for the activation of the classical pathway, C3b(Bb)P, specific for the activation of the alternative pathway and SC5b-9, specific for common terminal pathway of the complement cascade, were measured in healthy donors and in patients with clinically active and inactive systemic lupus erythematosus (SLE). Plasma levels of C3b(Bb)P and SC5b-9 were moderately, those of C1rs-C1inhibitor (C1rs-C1inh) were markedly elevated in patients with clinically inactive SLE, compared with healthy controls. The difference between active and inactive stages of the disease was best reflected by C3b(Bb)P plasma concentration (P<0.001), which also showed the highest correlation with the SLEDAI (Rs=0.41 P<0.001) and which was the most useful in distinguishing active and inactive sample pairs as well. The difference between SC5b-9 levels in the active and inactive stages was also significant (P=0.007), while that of C1rs-C1inh did not differ significantly (P=0.136). The correlation of the SLEDAI with SC5b-9 was 0.3 (P=0.015), while with C1rs-C1inh it was 0.21 (P=0. 089). These findings suggest that the measurement of complement activation products, especially that of the alternative pathway, are sensitive markers of the activity of SLE and can be used for clinical purposes.

Adult↗
PubMed1993

Complement activation in newborn infants with early onset infection.

The complement system is an important element in host defense. Quantitative deficiencies of total hemolytic complement activity and decreased C3 levels were reported in sera from normal neonates. However, little is known about complement activation products in the newborn. In a prospective study, complement activation products were determined in 32 healthy term neonates, in 41 neonates with colonization of their mothers, in 15 colonized neonates, and in 10 neonates with early onset infection. In all newborns, EDTA plasma was obtained within the first 6 h of life. The anaphylatoxin C3a-desArg was determined with a novel ELISA using an MAb reacting with a neoepitope of C3a-desArg. C3bBbP (alternative pathway convertase) and C1rsC1-inactivator (activation product of classical pathway) were measured with double-sandwich ELISA. C3 was determined by radial immunodiffusion. Plasma concentrations of C3a-desArg were similar in healthy term neonates and healthy adults, whereas diminished C3 levels were observed in the newborn infants. There were no significant differences between healthy neonates, neonates with colonized mothers, and colonized neonates. In neonates with infection, a significant elevation of C3a-desArg was found at the onset of the disease, resulting from alternative pathway activation. In contrast, the C1rsC1-inactivator complex showed no significant differences among healthy, colonized, and infected neonates. The anaphylatoxin C3a mediates inflammatory reactions such as vasodilatation and an increase in microvascular permeability and might therefore play an important role in severe neonatal infection.

Complement Activation↗
PubMed1988

Haemostasis contact system and fibrinolysis in hereditary angioedema (C1-inhibitor deficiency).

Factors of the classical complement pathway, the contact system and fibrinolysis were evaluated both with functional and immunochemical methods, in patients with inherited deficiency of C1-inhibitor. Evaluations were performed under basal conditions, during acute attacks and during prophylaxis with low doses of anabolic steroids. Patients in the basal state showed no significant abnormalities of any of the parameters that we investigated. During acute attacks a slightly reduced prekallikrein concentration was registered. During treatment with low doses of danazol and stanozolol, protein C and plasminogen were found to be increased. Our data suggest that C1-inhibitor deficiency per se does not lead to a derangement of the fibrinolysis and coagulation contact system, and that the kinin system may be involved during acute attacks of angioedema.

Adolescent↗
PubMed1992

Hereditary angioedema: a case with ascites yet no symptoms in the family.

An interesting case of hereditary angioedema in a 26-year-old female is reported, with a finding of transient effusion of fluid into the peritoneal cavity during the attacks. The patient suffered from recurrent abdominal pain for several years, but no family members had any similar symptoms. In spite of repeated hospital admissions and many examinations, accurate diagnosis was not made until the most recent admission. The recognition of hereditary angioedema as a cause of acute and/or recurrent abdominal pain may avoid useless invasive procedures and lead to adequate treatment in other similar cases.

Abdominal Pain↗
PubMed1985

Involvement of complement in atopic dermatitis.

There is little information about the role of complement in atopic dermatitis (AD). We studied the levels of both normal complement components and activation products in peripheral blood of patients with mild to intermediate disease. 35 patients had not received systemic or topical steroid therapy 6 weeks prior to blood collection. C3, C4 and C1 INA were determined in serum by radioimmunodiffusion. C3a and C5a levels were measured in EDTA plasma by radioimmunoassay. Compared to healthy non-atopic controls C3, C4 and C1 INA were found to be increased significantly. There was a tendency towards increased C3a levels but the difference was not significant. No measurable amounts of C5a were detected. Elevations of C3a were correlated with elevated levels of C3. The results suggest that the complement system participates in the inflammatory process in AD.

Adolescent↗