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PubMed2005

Anti-heat shock protein 90beta antibodies decrease pre-oligodendrocyte population in perinatal and adult cell cultures. Implications for remyelination in multiple sclerosis.

Lesions in the CNS of patients with multiple sclerosis (MS) often fail to remyelinate, resulting in neurological dysfunction. A key factor seems to be the inefficiency of oligodendrocyte precursor cells (OPCs). We recently reported antibodies against heat shock protein 90beta (Hsp90beta) in MS patients that recognized the antigen on the OPC surface. This study investigates the mechanism and result of anti-Hsp90beta antibody attack. These antibodies induced OPC death in culture in a complement-dependent fashion. Anti-Hsp90beta antibody-induced, complement-mediated OPC death only operated in these cells and caused a significant reduction in the number of O4-positive pro-oligodendrocytes (pre-oligodendrocytes). Adult cultured OPCs also expressed Hsp90beta on their cell surface and were attacked by anti-Hsp90beta antibodies leading to a significant decrease in the pre-oligodendrocyte population. In the presence of low levels of anti-Hsp90beta antibody--i.e. in the range seen in the CSF of MS patients--the complement concentration was critical to reduce the pre-oligodendrocyte population (via attack to OPCs). Higher concentrations of anti-Hsp90beta antibodies and complement became extinct the pre-oligodendrocytes. Complement 1-esterase inhibitor prevented these effects in the pre-oligodendrocyte population. These findings demonstrate, for the first time in vitro, a feasible mechanism to decrease the production of new oligodendrocytes, thus limiting the possibility of remyelination.

Adult↗
PubMed1984

Acute pancreatitis in man. A clinical and biochemical study of pathophysiology and treatment.

The correlation between clinical course, protease inhibitors, complement and kinin activation was studied in vivo in 27 attacks of acute pancreatitis and also in vitro. The value of peritoneal lavage was retrospectively analyzed in 73 pancreatitis attacks. The effect of aprotinin was studied in vitro. Complement and kinin activation occurred in vitro when alpha-macroglobulin (alpha 2-M) concentration was below 35%, in spite of 90% free and reactive alpha 1-protease inhibitor. These low alpha 2-M levels were found in the general circulation in severe attacks. Functional alpha 2-M levels were lower than electroimmunoassay values during the acute disease. Complement and kinin activation was present both in blood and in peritoneal fluid. The extent of activation was closely correlated to the severity of the pancreatitis attack. Classical as well as alternative complement activation occurred. Kinin activation was caused by plasma kallikrein as well as by other kininogenases. Functional kallikrein inhibition was lower than electroimmunoassay values for the C1 inactivator. High levels of activated trypsin was found in complex with alpha 1-protease inhibitor in severe attacks. These findings together with the low functional alpha 2-M and a possible functional deficiency also of the C1 inactivator make trypsin-induced activation of the complement as well as the kinin system possible in acute pancreatitis. Changes in proteases and protease inhibitors were most pronounced in the peritoneal fluid, functional alpha 2-M and C1 inactivator being zero, indicating that the primary event occurs locally in and around the pancreas. Peritoneal lavage thus ought to be beneficial. The good results achieved with peritoneal lavage in the retrospective analysis of the 73 clinically severe attacks seem to verify this conclusion. The biochemical changes seen in vivo indicate alpha 2-M and C1 inactivator to be most important against proteolytic activation of the complement and kinin systems. Treatment with purified protease inhibitors might be beneficial. This also seems to be true of aprotinin, according to the in vitro results, provided very high doses are used. All antiprotease therapy seems to be most important intraperitoneally.

Acute Disease↗
PubMed2005

Interactions of the extracellular matrix proteoglycans decorin and biglycan with C1q and collectins.

Decorin and biglycan are closely related abundant extracellular matrix proteoglycans that have been shown to bind to C1q. Given the overall structural similarities between C1q and mannose-binding lectin (MBL), the two key recognition molecules of the classical and the lectin complement pathways, respectively, we have examined functional consequences of the interaction of C1q and MBL with decorin and biglycan. Recombinant forms of human decorin and biglycan bound C1q via both collagen and globular domains and inhibited the classical pathway. Decorin also bound C1 without activating complement. Furthermore, decorin and biglycan bound efficiently to MBL, but only biglycan could inhibit activation of the lectin pathway. Other members of the collectin family, including human surfactant protein D, bovine collectin-43, and conglutinin also showed binding to decorin and biglycan. Decorin and biglycan strongly inhibited C1q binding to human endothelial cells and U937 cells, and biglycan suppressed C1q-induced MCP-1 and IL-8 production by human endothelial cells. In conclusion, decorin and biglycan act as inhibitors of activation of the complement cascade, cellular interactions, and proinflammatory cytokine production mediated by C1q. These two proteoglycans are likely to down-regulate proinflammatory effects mediated by C1q, and possibly also the collectins, at the tissue level.

Amino Acid Sequence↗
PubMed2003

Acute upper airway angioedema secondary to acquired C1 esterase inhibitor deficiency: a case report.

PURPOSE: Adverse reactions to local anesthetics are widely reported. We report a case of acute upper airway angioedema presumed to be due to the local anesthetic articaine, which was subsequently diagnosed as acquired C1 esterase inhibitor deficiency. CLINICAL FEATURES: A 54-yr-old woman presented with a history of progressive facial and periorbital edema 24 hr after receiving articaine local anesthetic for a dental procedure. She was in mild respiratory distress but was not stridorous. After inhalational induction with sevoflurane in the operating room, direct laryngoscopy revealed marked edema of supraglottic structures including epiglottis, uvula and aryepiglottic folds and the larynx was not visualized. The patient's trachea was intubated under direct laryngoscopy. Seventy-two hours later, the endotracheal tube was removed and she made an uneventful recovery. Initially, the angioedema was thought to be caused by a hypersensitivity reaction to articaine. Later investigations showed normal C3 complement level, very low C4 complement and C1 esterase inhibitor levels confirming a diagnosis of C1 esterase inhibitor deficiency. Subsequently, the patient was started on androgen therapy. Her C1 esterase inhibitor level normalized and she remained symptom free nine months after initial presentation. CONCLUSION: We report a case of acute upper airway angioedema secondary to C1 esterase inhibitor deficiency requiring emergency airway management. Anesthesiologists should consider C1 esterase inhibitor deficiency in the differential diagnosis of patients with airway edema and be familiar with the acute and prophylactic treatment of patients with this diagnosis.

Acute Disease↗
PubMed1996

A point mutation in exon 7 of the C1-inhibitor gene causing type I hereditary angioedema.

The polymerase chain reaction and nucleotide sequence analysis have been used to characterize a point mutation in the seventh exon of one allele of the C1-inhibitor gene in a family with type I hereditary angioedema. A single base change (C-->T) at nucleotide 1482 in C1-inhibitor converted the codon for Gln-339 to a premature translation termination codon, TAG. Family studies suggest that this mutation is responsible for type I hereditary angioedema in a studied pedigree.

Amino Acid Sequence↗
PubMed1985

Acquired C1 inhibitor deficiency with angioedema symptoms in a patient infected with Echinococcus granulosus.

A patient with echinococcosis, acquired deficiency of the inhibitor of the activated first component of complement and angioedema symptoms has been studied. These symptoms started 7 months after the surgical removal of an echinococcus liver cyst. Eight years later, when the complement was investigated, a marked deficiency of the C1 inhibitor, C1, C4 and CH50 was present. The patient was therefore successfully treated with tranexamic acid. After 4 years, the woman needed another operation because of a relapse of echinococcosis; afterwards she was symptom-free without medications, while the complement profile remained unchanged. Circulating immune complexes were detected by the conglutinin method. The patient's serum was demonstrated to possess an anticomplementary activity without affecting the C1 inhibitor when incubated with normal human serum at 37 degrees C. At present, 16 years after the onset of the symptoms, there are no signs of lymphoproliferative disease.

Angioedema↗
PubMed1991

Effect of conditioned media of acute myeloid leukemia blast cells on complement synthesis by cultured human cells of monocyte and hepatocyte origin.

The effect of conditioned media of 3-day cultures of blast cells from peripheral blood of 5 patients with acute myeloid leukemia (CM-AML) was studied on the synthesis of C2, factor B (Bf) and C1 esterase inhibitor (C1-INH) by human monocyte-macrophage cultures and HepG2 hepatoma cell line. The level of C2 in the culture supernatants was measured by immune hemolysis, those of Bf and C1-INH by ELISA. CM-AML was added to the monocyte cultures on day 3 and replaced by culture fluid on day 6. Compared to the control cultures, CM-AML significantly increased C2 and Bf levels and slightly decreased C1-INH levels in the culture fluids on day 6. On day 9, Bf synthesis enhancement still could be observed but C2 and C1-INH levels did not significantly differ from those of the control. CM-AML significantly increased the synthesis of factor B by the HepG2 cells too. A strong correlation was found between the results of the Bf protein and RNA determinations, which means that the supernatants of AML blasts affect the gene expression of factor B at a pretranslational level. The selective complement synthesis modifying effect of CM-AML was not due to interferons (IFN) because neither IFN-alpha nor IFN-gamma could be detected in these conditioned media. The present findings indicate that the hypercomplementemia observed in AML patients can be due to unknown factor(s) produced by leukemic blast cells.

Blood Cells↗
PubMed1999

Adjuvant treatment of severe acute pancreatitis with C1 esterase inhibitor concentrate after haematopoietic stem cell transplantation.

BACKGROUND: With an incidence of 4%, acute pancreatitis is a common complication of bone marrow or peripheral haematopoietic stem cell transplantation, which contributes significantly to morbidity and mortality in these patients. In most cases, the pathogenesis of acute pancreatitis cannot be attributed to a single pathogenetic factor, as treatment toxicity, acute graft versus host disease, infection, and cholestasis may all contribute. Acute pancreatitis is characterised by inflammation and activation of digestive proenzymes leading to autodigestive destruction of the pancreas and systemic activation of protease cascades including the complement system. AIM: To describe the effects of human C1 esterase inhibitor in two children, who developed severe acute pancreatitis with considerable complement activation after allogeneic haematopoietic stem cell transplantation. METHODS: Both children showed clinical features resembling those observed in capillary leakage syndrome. In both patients, treatment with C1 esterase inhibitor concentrate contributed to a rapid clinical stabilisation. CONCLUSIONS: These observations strongly support the proposed pathophysiological concept that early treatment with C1 esterase inhibitor interferes with the activation of the complement system in acute pancreatitis. Inhibition of complement activation prevents its adverse effects on vascular function and permeability, and thus stabilises intravascular fluid status and prevents multiorgan failure in acute pancreatitis.

Acute Disease↗
PubMed1979

Acquired C1 inhibitor deficiency in a case of lymphosarcoma of the spleen. Reversal of complement abnormalities after splenectomy.

A patient with an extensive lymphosarcoma of the spleen without involvement of other lymphoid organs and hypogammaglobulinaemia showed the characteristic complement profile of an acquired C1-inhibitor deficiency. Both functional and immunochemical studies revealed extremely low levels of the inhibitor of C1-esterase. Correction of the low levels of early acting complement components and of the low C1-inhibitor level followed the splenectomy. In vitro tests showed that lymphosarcoma tissue pieces or cells were able to interact with complement, resulting in a depletion of the haemolytic activity. These findings provide evidence that tumour cells were responsible for the abnormalities of the complement system.

Aged↗
PubMed1992

[Hereditary angioneurotic edema associated with DIC and treated effectively by nafamostat mesilate].

A 36-year-old woman with disseminated intravascular coagulation syndrome (DIC) was admitted to the Third Department of Internal Medicine of the National Defense Medical College Hospital. Even after she recovered from DIC, she had a low level of C1-inactivator. Her past history, family history and family study revealed that she and her family showed hereditary angioneurotic edema (HANE). There have been no reports of HANE associated with DIC. She had two HANE attacks after discharge. We used nafamostat mesilate, a strong inhibitor of activated first complement component, to treat the attacks. She obtained subjective relief and her serological data were improved. Nafamostat mesilate was considered effective for HANE attack.

Adult↗
PubMed1985

Activation and inhibition of Hageman factor-dependent pathways and the complement system in uncomplicated bacteremia or bacterial shock.

Levels of components of the contact activation, coagulation, and complement systems and their main inhibitors were measured in 45 critically ill patients during 61 episodes of uncomplicated bacteremia or bacterial shock. Levels of Hageman factor (factor XII), prekallikrein, high-molecular-weight kininogen, factor XI, factor VII, total hemolytic complement, alternative pathway activity, and C3 were within the normal range during uncomplicated bacteremia (n = 29), but during fatal bacterial shock (n = 13) a significant decrease by 40%-50% was observed in all measurements. During nonfatal bacterial shock (n = 19) a moderate decrease was observed in most of these measurements. The capacity of plasma to inactivate kallikrein was significantly higher during bacteremia than during bacterial shock because of a significant increase in the level of C1 esterase inhibitor. Levels of antithrombin III and alpha 2-macroglobulin were below normal in all groups. Thus increased inhibition of the contact activation and complement systems is beneficial during bacteremia.

Angiotensin III↗
PubMed1994

Efficient detection of point mutations on color-coded strands of target DNA.

Presently available methods for screening large genetic regions for unknown point mutations are neither flawless nor particularly efficient. We describe an approach, especially well suited to identifying mutations present in the heterozygous state, that combines several improvements in a protocol called fluorescence-assisted mismatch analysis (FAMA). Appropriate gene regions of the wild-type and the putative mutant allele are simultaneously amplified from genomic DNA by using the polymerase chain reaction, and large DNA fragments, so far up to 800 bp, are end labeled with strand-specific fluorophores. Aliquots are denatured and reannealed to form heteroduplexes and subjected to conventional cytosine- and thymine-specific modifications. Cleavages occurring on opposite strands are detected by denaturing gel electrophoresis using an automated DNA sequencer. Since the DNA fragments derived from the mutant allele are also end labeled, the number of informative mispaired bases is doubled compared to conventional searches using wild-type probes. The sensitivity of detection is also increased, because differential fluorescent end labelling allows the identification and measurement of strand-specific background cleavages at matched cytosine or thymine residues. Automatic superimposition of tracings from different subjects allows mismatch detection at sites that, because of the nature of the bases involved and of the neighboring sequence, are known to be less susceptible to cleavage. The effects of the latter parameters have been studied quantitatively on a series of point mutations found in the human C1-inhibitor gene in patients affected by hereditary angioedema. Dilution experiments have demonstrated that most mutations are detected even when the mutant chromosome is diluted 10-fold or more compared with the normal one.

Angioedema↗
PubMed1971

Modulation of function of the activated first component of complement by a fragment derived from serum. I. Effect on early components of complement.

An activity designated Kf can be separated from human serum and shown to give a 100-300% enhancement in the hemolytic activity of fully activated, fractionated C1. The enhancement of C1 activity is not because of activation of precursor C1 and it is not attributable to an effect on C1 binding. EAC42 or EAC4 intermediates interacted with C1Kf exhibit a greater T(max) and shorter Z(max) than when such intermediates are reacted with the same number of hemolytic units of C1. C3 consumption by the EAC1Kf42 intermediate greatly exceeds that of the EAC142 intermediate produced from the same EAC4 cells by comparable inputs of the other two complement components. Taken together, these findings suggest that Kf-treated C1 achieves more efficient utilization of C4 and C2 to create a larger number of 42 sites as appreciated on the intermediates by shorter T(max) and a greater Z(max), and an increased capacity to utilize C3. The capacity of Kf to enhance C1 upon introduction into whole serum of a patient with hereditary angioedema (HAE) in a manner comparable to its effect on fractionated C1 suggests that the effect of Kf may be pertinent to certain pathophysiologic conditions of man.

Angioedema↗
PubMedDate not supplied

Angio-oedema in dentistry: management of two cases using C1 esterase inhibitor.

UNLABELLED: Angio-oedema is a rare condition; it may be a hereditary or acquired form. It results from biochemical defects which cause excessive activation of the complement cascade and result in deep swellings in the skin and alimentary tract, called angio-oedema. These swellings are painful rather than itchy and not associated with urticaria, which helps to differentiate angio-oedema from allergic reactions. Even mild trauma can give rise to swelling, which may be life-threatening in the oral region. Management of two cases, one hereditary and the other acquired angio-oedema, are reported to demonstrate the use of C1 esterase inhibitor prophylaxis. CLINICAL RELEVANCE: It is important that patients giving a history of angio-oedema are thoroughly investigated and, in discussion with the patient's medical team, appropriate prophylactic measures are taken to prevent swelling.

Adolescent↗
PubMed1990

Autoimmune angioedema: a new role for autoantibody in disease pathogenesis.

Angioedema may be due to hereditary forms of Cl-Inh deficiency, but recently an autoimmune form of angioedema has been described in which the mechanism is novel. While the peripheral blood monocytes of patients with autoimmune angioedema produce a normal, functionally active, 105 KD Cl-Inh in normal quantities, the Cl-Inh isolated from the patient's plasma exists in a dysfunctional lower molecular weight (96 KD) performance. Rather than bind and biologically inactivate the enzyme, a relatively common phenomenon in autoimmune disease, the autoimmune angioedema cleave the Cl-Inh molecule. The following sequence of events is proposed: structural and functionally normal Cl-Inh is synthesised and secreted, this secreted inhibitor is complexed by autoantibody and following enzyme interaction, denatured 96 KD Cl-Inh is proposed. This process depletes the pool of normal, functional Cl-Inh to critical levels and predisposes patients to episodes of oedema.

Angioedema↗
PubMedDate not supplied

[Angioedema: first manifestation of non-Hodgkin's lymphoma].

Angioedema can be hereditary or acquired. Hereditary angioedema is a genetic disease transmitted with an autosomal dominant mechanism. Acquired angioedema usually occurs after the second decade of life and is often related to an underlying disease. In a 48-year-old male patient a diagnosis of a non-Hodgkin lymphoma was made after two episodes of angioedema. No previously documented cases of angioedema in his family were reported; physical examination and routine blood samples were normal whereas the serum levels of C1-esterase inhibitor were reduced. Three months later he presented with epigastric pain after meals and weight loss. Abdominal ultrasonography and computed tomography showed two solid splenic masses infiltrating the greater curvature of the stomach and a 2 cm aortic lymph node. Digestive endoscopy confirmed the neoplastic infiltration. A diagnosis of anaplastic large-cells lymphoma CD30+, anaplastic lymphoma kinase negative was made. The disappearance of the neoplastic gastric infiltration and the decrease in size of the aortic lymph node and splenic mass were achieved after chemotherapy. Serum levels of C1-esterase inhibitor returned to normal. An adult onset not associated with a family history of angioedema should lead the physician to suspect the presence of a major disease.

Angioedema↗
PubMed1985

Unusual complement-mediated hemolytic kinetics at low ionic strength.

The dilution of human serum in relatively low ionic strength buffer (mu = 0.070) caused the spontaneous activation of C1 and a limited activation of C4 and C3 in the fluid phase. The unusual degree of activation of the complement system in the fluid phase suggested that the optimal functions of complement-regulatory systems such as C1 inhibitor might be reduced. As a function of the time of preincubation (PI) of diluted serum at 37 degrees C, under low ionic strength conditions, an unusual complement-mediated hemolytic kinetic pattern was observed upon adding sensitized erythrocytes (EA). For a 1:36 dilution of human serum, there was an initial progressive decrease in complement hemolytic activity (from 3 to 20 min PI, phase I), followed by an apparent functional reversal (increase) in hemolytic activity (20-50 min PI, phase II) and finally a gradual irreversible depletion of the hemolytic activity (after 50 min PI, phase III). This hemolytic pattern could only be adequately demonstrated using a kinetic assay which followed the course of lysis of EA in the presence of low dilutions of human serum as a complement source. Others might have missed this observation due to the use of end-point titration methods which required the use of relatively elevated serum dilutions at the time of EA addition. Mechanisms which governed the variations in hemolytic activity at low ionic strength were not clear. Speculatively, partial consumption of early complement components, generation of free C1q and generation of complement fragments might have accounted for the initial decrease in the hemolytic activity observed in phase I. The apparent functional reversal of hemolytic activity observed in phase II might have involved a critical depletion of C1 inhibitor which occurred secondary to C1 inhibitor binding to C1 (activated by low ionic strength effects) and to the C1 activated at the time of EA addition. Without sufficient regulation, a rapid unrestricted C1-mediated complement activation could have occurred, which resulted in a rapid deposition of complement on the EA. Finally, prolonged exposure of serum to low ionic strength effects appeared to induce a significant complement consumption, which caused a time-dependent irreversible depletion of complement hemolytic activity (phase III). Excess exogenous C1 inhibitor, when co-incubated with diluted serum at low ionic strength, reversed the time-dependent effects of low ionic strength and enhanced the subsequent specific complement-mediated hemolytic activity as compared to controls.(ABSTRACT TRUNCATED AT 400 WORDS)

Complement Activation↗
PubMed1980

Acquired angioedema and hypocompleentemia in a patient with myelofibrosis. Effect of danazol treatment.

This paper reports the findings of an "acquired" hereditary angioedema-like syndrome in a patient with myelofibrosis. No previous personal or family history of angioedema was present. The serum complement pattern showed a marked reduction of Cl esterase inhibitor, Clq and C4. All family members had a normal complement profile. Because of frequent attacks of laryngeal angioedema, prophylactic treatment with danazol was started. A striking clinical response was observed as well as a normalizing effect on the underlying biochemical abnormality.

Aged↗