| 2020 | Anaphylaxis to Agaricus bisporus ingestion. | Einstein (Sao Paulo) | A 33-year-old male with house dust mite allergic rhinitis and asthma reported an episode of facial and lip angioedema, dyspnea, cough and dysphagia at the age of 25, minutes after eating a mushroom ( Agaricus bisporus ) pizza. He denied any drug intake, hymenoptera stings or other possible triggers, and no identifiable cofactors were present. Since then he avoided all types of mushrooms, however an accidental contact occurred with mushroom sauce that resulted in angioedema of the lip within minutes. The allergy workup included measurements of total IgE and specific IgE to mushroom, and skin prick test to aeroallergens sources, possible food allergen sources and mushroom extract, a prick to prick test with raw and cooked A. bisporus , in addition to a SDS-PAGE and immunoblotting assay. The study revealed a specific IgE to mushroom of 0.76kUA/L positive skin prick test to mushroom extract, and prick to prick test positive to white and brown A. bisporus (raw and cooked). The immunoblotting identified two IgE binding proteins with 10kDa and 27kDa. We report a case of A. bisporus anaphylaxis probably due to primary mushroom sensitization. We detected two IgE-reactive proteins with 10kDa and 27kDa as possible culprit allergens. |
| 2017 | The Search for Biomarkers in Hereditary Angioedema. | Front Med (Lausanne) | The unpredictable nature of attacks of tissue swelling in hereditary angioedema requires the identification of reliable biomarkers to monitor disease activity as well as response to therapy. At present, one can assess a C4 level (by ELISA) to assist in diagnosis but neither C4 nor C1 inhibitor levels reflect clinical course or prognosis. We will here review a collection of plasma proteins involved in blood coagulation, fibrinolysis, and innate immunity (Figure 1). A main focus is those proteins that are key to the formation of bradykinin (BK); namely, factor XII, plasma prekallikrein/kallikrein, high-molecular weight kininogen, and BK itself since overproduction of BK is key to the disease. Considerations include new approaches to measurement of active enzymes, ELISA methods that may supersede SDS gel analysis of bond cleavages, and examples of changes outside the BK cascade that may reflect when, where, and how an attack of swelling is initiated. We will discuss their usefulness as biomarker candidates, with pros and cons, and compare the analytical methods that are being developed to measure their levels or activity. |
| Prognostic factors in outcome of angioedema in the emergency department. | Allergy Asthma Proc | Angioedema is a transient, localized swelling caused by two distinct mechanisms, mediated by histamine and bradykinin, respectively, although a proportion of cases remain idiopathic. Studies that characterize undifferentiated angioedema presenting in emergency departments (EDs) are limited. This study investigates the presentation patterns of undifferentiated angioedema in the ED based on the presumed mechanism of swelling. Medical records from all ED visits to two tertiary care hospitals from July 2007 to March 2012 were electronically reviewed. Records with documented visible swelling on general inspection and/or fiberoptic laryngoscopy and a diagnostic code for anaphylactic shock, angioneurotic edema, allergy unspecified, defects in the complement system, or unspecified drug adverse effects were included. Demographic, clinical, and outcome data were collected via a standardized form. Data were analyzed descriptively, including frequencies and percentages for categorical data and means and SDs for continuous data. Predictors for admission were identified using multivariate logistic regression models. ED records from 527 visits for angioedema by 455 patients were included in the study. Annual rate of angioedema was 1 per 1000 ED visits. Urticaria was associated with peripheral (p = 0.008) and lip angioedema (p = 0.001), and the absence of urticaria correlated with tongue angioedema (p = 0.001) and trended toward correlation with pharyngeal angioedema (p = 0.056). Significant predictors of admission included nonsteroidal anti-inflammatory drug-induced angioedema (odds ratio [OR], 15.3), epinephrine treatment (OR, 8.34), hypotension (OR, 15.7), multiple-site angioedema (OR, 4.25), and pharyngeal (OR, 1.23) and tongue angioedema (OR, 4.62). Concomitant urticaria was associated with a significant longer stay in the ED (p < 0.001). The presence of urticaria correlated with the location of angioedema, need for airway management, length of ED visit, and recurrence. A detailed drug and family history, screening blood work for C1 esterase inhibitor deficiency when indicated, and prompt management of angioedema based on presumed mechanism of swelling are crucial steps in managing undifferentiated angioedema in ED. |
| 2012 | Characterization of recombinant human C1 inhibitor secreted in milk of transgenic rabbits. | J Biotechnol | C1 inhibitor (C1INH) is a single-chain glycoprotein that inhibits activation of the contact system of coagulation and the complement system. C1INH isolated from human blood plasma (pd-hC1INH) is used for the management of hereditary angioedema (HAE), a disease caused by heterozygous deficiency of C1INH, and is a promise for treatment of ischemia-reperfusion injuries like acute myocardial or cerebral infarction. To obtain large quantities of C1INH, recombinant human C1INH (rhC1INH) was expressed in the milk of transgenic rabbits (12 g/l) harboring genomic human C1INH sequences fused to 5' bovine αS(1) casein promoter sequences. Recombinant hC1INH was isolated from milk to a specific activity of 6.1 U/mg and a purity of 99%; by size-exclusion chromatography the 1% impurities consisted of multimers and N-terminal cleaved C1INH species. Mass spectrometric analysis of purified rhC1INH revealed a relative molecular mass (M(r)) of 67,200. Differences in M(r) on SDS PAGE and mass spectrometric analysis between rhC1INH and pd-hC1INH are explained by differential glycosylation (calculated carbohydrate contents of 21% and 28%, respectively), since protein sequencing analysis of rhC1INH revealed intact N- and C-termini. Host-related impurity analysis by ELISA revealed trace amounts of rabbit protein (approximately 10 ppm) in purified batches, but not endogenous rabbit C1INH. The kinetics of inhibition of the target proteases C1s, Factor XIIa, kallikrein and Factor XIa by rhC1INH and pd-hC1INH, indicated comparable inhibitory potency and specificity. Recently, rhC1INH (Ruconest(®)) has been approved by the European Medicines Agency for the treatment of acute attacks of HAE. |
| 2011 | Cleavage of kininogen and subsequent bradykinin release by the complement component: mannose-binding lectin-associated serine protease (MASP)-1. | PLoS One | Bradykinin (BK), generated from high-molecular-weight kininogen (HK) is the major mediator of swelling attacks in hereditary angioedema (HAE), a disease associated with C1-inhibitor deficiency. Plasma kallikrein, activated by factor XIIa, is responsible for most of HK cleavage. However other proteases, which activate during episodes of angioedema, might also contribute to BK production. The lectin pathway of the complement system activates after infection and oxidative stress on endothelial cells generating active serine proteases: MASP-1 and MASP-2. Our aim was to study whether activated MASPs are able to digest HK to release BK. Initially we were trying to find potential new substrates of MASP-1 in human plasma by differential gel electrophoresis, and we identified kininogen cleavage products by this proteomic approach. As a control, MASP-2 was included in the study in addition to MASP-1 and kallikrein. The proteolytic cleavage of HK by MASPs was followed by SDS-PAGE, and BK release was detected by HPLC. We showed that MASP-1 was able to cleave HK resulting in BK production. MASP-2 could also cleave HK but could not release BK. The cleavage pattern of MASPs is similar but not strictly identical to that of kallikrein. The catalytic efficiency of HK cleavage by a recombinant version of MASP-1 and MASP-2 was about 4.0×10(2) and 2.7×10(2) M(-1) s(-1), respectively. C1-inhibitor, the major inhibitor of factor XIIa and kallikrein, also prevented the cleavage of HK by MASPs. In all, a new factor XII- and kallikrein-independent mechanism of bradykinin production by MASP-1 was demonstrated, which may contribute to the pro-inflammatory effect of the lectin pathway of complement and to the elevated bradykinin levels in HAE patients. |
| 2007 | Aniseed-induced nocturnal tongue angioedema. | J Investig Allergol Clin Immunol | Aniseed is a spice native to the eastern Mediterranean region. Cases of simultaneous hypersensitivity to celery, mugwort pollen, and spices of the Umbelliferae family have been described as the celery-mugwort-spices syndrome. We report a case of aniseed-induced tongue angioedema. Skin prick tests to foods proved positive only to aniseed. Serum-specific immunoglobulin (Ig) E determination by enzyme allergosorbent test was 0.4 kU/L to aniseed extract and 0.6 kU/L to tare and cumin seeds. The molecular mass of the IgE-binding proteins studied by sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) immunoblotting revealed a broad IgE-binding band of 12.9-13.7 kd in aniseed and tare extract assays and a broad band of 15-17.5 kd in cumin extract. This is the first case of type I hypersensitivity due to aniseed liqueur ingestion reported. SDS-PAGE immunoblotting study showed a broad specific IgE-binding band of 12.9-13.7 kd when aniseed extract was incubated with the patient's serum; this band might correspond to the protein responsible for the described symptoms. |
| 2006 | Identification of oleosins as major allergens in sesame seed allergic patients. | Allergy | The prevalence of sesame allergy is increasing in European countries. Cases of severe allergy lack any evidence of specific immunoglobulin (Ig)Es by prick tests and CAPSystem-FEIA. The reasons for this negativity are unknown.In 32 patients displaying immediate symptoms such as anaphylactic shock, asthma, urticaria, angioedema, sesame allergy was diagnosed by double-blind placebo-controlled food challenge (DBPCFC) or convincing clinical history. However, 10 patients had negative prick tests and CapSystem-FEIA. The specificity of IgEs was further investigated by enzyme-linked immunosorbent assay (ELISA), isoelectrofocalisation (IEF)-blotting, and sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) blotting using total sesame extracts and purified fraction of oil bodies. Monospecific rabbit antibodies directed to two oleosin isoforms (15 and 17 kDa) were used.By ELISA, white sesame seed extract allowed the detection of higher levels of IgE than brown sesame extract. In all sera, numerous bands binding IgEs were detected by IEF or SDS-PAGE. In reducing conditions, two bands (15-17 kDa), could be separated from 2S albumin. Oleosins, present in oil bodies fractions, were recognized by IgEs from all sera.Oleosins are major allergens of sesame seeds and may be relevant to severe anaphylaxis. Falsely negative prick tests could be due to the lack of oleosins in presently available extracts, or to the fact that epitopes might be buried in the inner molecule. Detection tests currently used to identify sesame allergens based on sesame vicillins or other storage proteins could be insufficient for the detection of sesame seed contamination. Oleosins have been named Ses i 4 (17 kDa) and Ses i 5 (15 kDa), in accordance with the IUIS Nomenclature Committee. |
| 2005 | Allergy to mammal's meat in adult life: immunologic and follow-up study. | J Investig Allergol Clin Immunol | Allergy to bovine meat and Bovine serum albumin (BSA) is exceptional, especially in the adult life. BSA is considered a minor allergen in cow's milk allergy, but there is little information about this antigen in reactions produced by other beef products as meat. To our knowledge, evolutive studies of beef's allergic patients have not been reported.To present one patient with several allergic reactions (urticaria-angioedema) after eating different mammals' meat.The patient underwent allergy testing through skin prick test (SPT), specific IgE detection and SDS-PAGE Immunoblotting and Immunodot inhibition studies. Periodic determinations of specific IgE to meats and epithelia were performed.Routine studies for chronic urticaria were normal or negative. SPT showed positive responses to pork, cow, rabbit and lamb meat, and dog, pork, sheep and cow epithelia. It was negative to cat, horse, guinea pig, rabbit, lamb, mouse epithelia, mixture of feathers, cow milk, soybean, mustard, mites and chicken meat and Anisakis simplex. Intradermal testing to BSA was positive. Determinations of specific IgE were positive to beef meat, lamb meat, pork meat and rabbit meat, dog, cat, cow, sheep and pork dander, cow's milk, and negative to chicken meat. Immunoblot and immunodot studies showed IgE recognition bands to bovine and lamb meat which were totally inhibited by BSA. A progressive reduction of the total and specific IgE, the latter until its total negativization, has been observed in the following three-year period.We report a case of IgE-mediated urticaria-angioedema due to BSA hypersensitivity, possibly induced by a subclinical sensitivity to dog and cat epithelium. The exclusion diet in patients allergic to these foods may be a progressive loss of clinical allergy. |
| 2004 | Allergy to pigeon tick (Argas reflexus): demonstration of specific IgE-binding components. | Int Arch Allergy Immunol | The European tick, Argas reflexus, is an urban pest parasitizing urban pigeons and may cause a wide range of allergic reactions.Specific IgE to A. reflexus, SDS-PAGE and IgE immunoblotting, performed with tick extract, were carried out in the sera of 6 patients who reported allergic reactions after tick bite.Specific IgE to A. reflexus (RAST class ranging from 1 to 3) were detected in the sera of 6 patients who reported allergic reactions (urticaria and angioedema in 2 and anaphylaxis in the other 4 patients) after tick bite. IgE reactivity to two bands of 22 and 40 kDa were identified in the patient sera.Allergy to A. reflexus has to be considered in allergic patients living in buildings where pigeons have their nests. The powerful sensitizing property of tick allergen is underlined by the observation that none of our patients was atopic. |
| Non-occupational allergy caused by the pine processionary caterpillar (Thaumetopoea pityocampa). | Allergol Immunopathol (Madr) | Contact with the pine processionary caterpillar induces dermatitis, usually located in exposed areas, and, less frequently, ocular lesions through a toxic-irritative mechanism. Recently, the existence of an immediate hypersensitivity mechanism has been demonstrated, mainly in occupationally exposed patients.To present four patients who experienced allergic reactions (urticaria-angioedema and rhinitis-asthma) after non-occupational exposure to pine processionary caterpillar.The four patients underwent allergy testing through skin prick tests (SPT), specific IgE detection and SDS-PAGE immunoblotting. One patient also underwent a specific bronchial challenge test with the pine processionary antigen.In all patients, both SPT with the caterpillar extract and specific IgE were positive. Western blotting showed several IgE-binding bands with molecular mass values ranging from 18 to 107 kDa. A shift in the electrophoretic mobility of some of the relevant allergens occurred under the presence of a reductive agent (beta -mercaptoethanol). The specific bronchial challenge test with pine processionary antigen performed in one of the patients also produced positive results.The results of this study show an immunologic IgE-mediated immediate hypersensitivity mechanism in these reactions. The processionary caterpillar's airborne urticating hairs or spicules should be considered, at least in some locations, not only as contact and occupational allergens, but also as seasonal aeroallergens. |
| [Angioedema due to sensitization to chicken meat]. | Allergol Immunopathol (Madr) | Egg is the most frequent cause of food allergy in children. The bird-egg syndrome, found in a group of patients sensitized to egg through bird proteins, was infrequent in children. We report a patient with former history of hypersensitivity to egg who developed episodes of angioedema after ingestion of hen meat.Prick testing with egg and their different antigenic protein fractions, alpha-livetin and chicken meat was performed. Antigens of hen meat were used for the skin prick test and prick-by-prick. Serum-specific IgE was identified with use of the CAP techniques and SDS-PAGE Immunoblotting.Prick test was positive with egg yolk, alpha-livetin and chicken meat. A prick-by-prick test with hen meat resulted positive in our patient, but the same test in four controls patients were negative. Serum specific IgE was positive for egg yolk and hen meat.Allergy reactions to hen meat are exceptional. We report a case of children with allergy to egg proteins and hen meat that suggest an IgE mediated hypersensitivity reaction. Skin test reveal sensitivity to egg yolk and alpha-livetin, but this pattern of sensitization was infrequent in children. |
| 2002 | Activation of the bradykinin-forming cascade on endothelial cells: a role for heat shock protein 90. | Int Immunopharmacol | Bradykinin is a major mediator of swelling in C1 inhibitor deficiency as well as the angioedema seen with ACE inhibitors and may contribute to bronchial hyper-reactivity in asthma. Formation of bradykinin occurs in the fluid phase and along cell surfaces requiring interaction of Factor XII, prekallikrein and high molecular weight kininogen (HK). The mechanism by which initiation occurs is uncertain. Recent data suggest that activation of the kinin-forming cascade can occur on the surface of endothelial cells, even in the absence of Factor XII. We demonstrate herein that during a 2-h incubation time, plasma deficient in either Factor XII or high molecular weight kininogen (HK) fail to activate kinin-forming cascade as compared to normal plasma. With more prolonged incubation, Factor XII deficient plasma gradually activates and HK deficient plasma does not. Our data support both Factor XII-dependent (rapid) and Factor XII-independent (slow) mechanisms; the latter may require a cell-derived protein (possibly protease) to activate prekallikrein in the presence of zinc ion and HK. To further define this cellular factor, we demonstrated that both cytosolic and membrane fractions from endothelial cells possessed the ability to catalyze prekallikrein conversion to kallikrein in the presence of HK and zinc ion. We purified this factor from cytosol by affinity chromatography employing corn trypsin inhibitor (CTI) as ligand. The fractions with peak activity were subjected to SDS-PAGE analysis, ligand blotted with biotinylated CTI, and positive bands were sequenced. Heat shock protein 90 (Hsp90) was identified as one of the proteins. Zinc-dependent activation of the prekallikrein-HK complex on endothelial cells was inhibited upon the addition of polyclonal antibody to Hsp90 in a dose-dependent manner. Although the mechanism by which Hsp90 activates the kinin-forming cascade is not yet clear, this protein represents the cellular contribution to the reaction and may become the dominant mechanism in pathologic circumstances in which Hsp90 is highly expressed or secreted. |
| Severe tomato allergy (Lycopersicon esculentum). | Allergy Asthma Proc | Although tomatoes are a commonly consumed food, severe allergic reactions to tomatoes are unusual or rarely reported. Previously reported allergic manifestations to tomato include urticaria/angioedema, dermatitis, oral allergy syndrome, rhinitis, and abdominal pain. The aim of this study was to report two patients with significant immediate hypersensitivity reactions to tomato and characterize the responsible allergen. We reviewed the history and documentation of tomato-specific immunoglobulin E (IgE) of two patients with adverse symptoms after ingesting tomato. Fresh tomato extracts prepared from the skin, seeds, and flesh of red, ripe tomatoes were evaluated for total protein content and sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) was performed to characterize the tomato protein. IgE enzyme-linked immunosorbent assay (ELISA) using the patients' serum against the various tomato extracts was accomplished and IgE immunoblot was performed. Percutaneous skin tests or radioallergosorbent tests (RASTs) were positive to tomato in both patients. Both adults experienced laryngeal edema and one had anaphylaxis. Similar total protein contents were found in each of the tomato extracts and gel electrophoresis revealed similar protein profile for skin and seed extracts with protein bands discernible at molecular weights of 21, 33, and 43 kDa. One patient reacted specifically to a 43-kDa protein band on IgE immunoblot. The two cases show that severe allergic reactions to tomato occur in adults and one is associated with IgE binding to a 43-kDa protein. |
| Barnacle hypersensitivity. | Allergol Immunopathol (Madr) | the aim of the present study is to investigate the responsible mechanism of different adverse reactions suffered by five patients, aged between six and thirty years-old, after consumption of barnacle. The symptoms were angioedema, dyspnea, generalized urticaria, conjunctivitis and one of them suffered from anaphylactic reaction. Four patients had personal atopic history.the allergic study included prick by prick test with raw and boiled barnacle and prick-test with a standardized battery of shellfish and neumoallergens, specific-IgE determination to barnacle, crustacean and house-dust-mite and SDS-PAGE immunoblotting to barnacle. Even though an oral challenge was proposed to three of the patients, they were reluctant to do the test and eventually the challenges were not carried out.prick to prick tests were positive to barnacle for all of them. Specific-IgE was found in four patients. The western blotting results showed an IgE-binding band whose apparent molecular mass ranged between 58 and 68 kDa.barnacle could induce IgE-mediated adverse reaction. Our study has demonstrated the presence of an IgE-binding protein in barnacle extracts ranged between 58 and 68 kDa of molecular mass. It has not been previously described a crustacean allergen with the same molecular mass, so it could be a specific allergen from barnacle. We believe that further study will confirm this is the case. |
| 2002 | Heat shock protein 90 catalyzes activation of the prekallikrein-kininogen complex in the absence of factor XII. | Proc Natl Acad Sci U S A | Bradykinin is a major mediator of swelling in C1 inhibitor deficiency as well as the angioedema seen with ACE inhibitors and may contribute to bronchial hyperreactivity in asthma. Formation of bradykinin occurs in the fluid phase and along cell surfaces requiring interaction of factor XII, prekallikrein, and high M(r) kininogen (HK). Recent data suggest that activation of the kinin-forming cascade can occur on the surface of endothelial cells, even in the absence of factor XII. We sought to further define this factor XII-independent mechanism of kinin formation. Both cytosolic and membrane fractions from endothelial cells possessed the ability to catalyze prekallikrein conversion to kallikrein, and activation depended on the presence of HK and zinc ion. We fractionated the cytosol by ion exchange chromatography and affinity chromatography by using corn trypsin inhibitor as ligand. The fractions with peak activity were subjected to SDS gel electrophoresis and ligand blot with biotinylated corn trypsin inhibitor, and positive bands were sequenced. Heat shock protein 90 (Hsp90) was identified as the protein responsible for zinc-dependent prekallikrein activation in the presence of HK. Zinc-dependent activation of the prekallikrein-HK complex also depended on addition of either alpha and beta isoforms of Hsp90 and the activation on endothelial cells was inhibited on addition of polyclonal Ab to Hsp90 in a dose-dependent manner. Although the mechanism by which Hsp90 activates the kinin-forming cascade is not understood, this protein represents the cellular contribution to the reaction and may become the dominant mechanism in pathologic circumstances in which Hsp90 is highly expressed or secreted. |
| 2001 | Identification of carmine allergens among three carmine allergy patients. | Allergy | There have been several reports of carmine allergy; however, identification of the responsible carmine allergens has not been widely documented.Three female patients presented with a history of anaphylaxis and/or urticaria/angioedema after ingestion of carmine-containing foods. All three patients had 4+ skin prick tests to carmine. Among them, two patients were confirmed to have carmine allergy by blinded, placebo-controlled food challenges to carmine. SDS-PAGE of cochineal insects and carmine, immunoblotting for IgE antibody with sera from all three patients, and immunoblotting inhibition with carmine were performed.SDS PAGE of minced cochineal insects revealed several protein bands of 23-88 kDa. Several of these bands were variably recognized by our three patients' sera, and this reactivity was inhibited by carmine. Although no protein bands could be visualized on SDS-PAGE of carmine in Coomassie brilliant blue staining, three protein bands were recognized by two of the three patients' serum.These results suggest that commercial carmine retains protein-aceous material from the source insects. These insect-derived proteins (possibly complexed with carminic acid) are responsible for IgE-mediated carmine allergy. Patient reactivity to these proteins may vary. |
| Allergic reactions to honey and royal jelly and their relationship with sensitization to compositae. | Allergol Immunopathol (Madr) | Honey and royal jelly are complex etherogeneous mixtures of flowers' nectar, sugars, proteins and bee's glandular secretions. The existence of a type I hypersensitivity to honey is still matter of debate, while an aetiological role of Compositae pollens in the clinical manifestations following honey ingestion has been envisaged. We describe two cases of severe systemic reactions (anaphylaxis and generalized urticaria/angioedema) due to honey and royal jelly ingestion in patients sensitized to compositae (mugwort). Both patients had a skin and RAST positivity to mugwort and a positive prick-by-prick to the offending foods. Moreover, in one of the two patients the RAST-inhibition assay showed the strong cross-reactivity between the proteins of honey and mugwort and the SDS-PAGE analysis showed that the major proteic bands from honey and mugwort extracts are largely superimposable. Both the clinical data and the laboratory analysis support the hypothesis of a strict link between sensitization to compositae and adverse reactions to honey and jelly. |
| 1998 | Mechanism of action of anti-C1-inhibitor autoantibodies: prevention of the formation of stable C1s-C1-inh complexes. | Mol Med | Acquired C1-inhibitor (C1-inh) deficiency is usually associated with the presence of circulating C1-inh autoantibodies. These autoantibodies have been shown previously to bind to two synthetic peptides corresponding to C1-inh amino acid residues 438-449 (peptide 2) and 448-459 (peptide 3) but not to peptide 1 (residues 428-440).Affinity-purified C1-inh autoantibodies from two patients with acquired C1-inh deficiency were studied for their effects on the inhibition of C1s activity by C1-inh using SDS-PAGE and hydrolysis of a synthetic ester.Functional studies confirmed that the anti-C1-inh autoantibodies abrogated C1-inh activity, and their maximum effect was produced when the concentrations of C1-inh and autoantibody were approximately equimolar. The autoantibodies prevent the formation of the C1s-C1-inh complex, but they do not dissociate the preformed complex, suggesting that the autoantibodies act prior to the formation of the enzyme-inhibitor complex. In the presence of autoantibodies, C1s cleaves C1-inh, and a stable covalent bond between C1s and C1-inh does not form. Peptides 2 and 3, but not peptide 1 inhibited autoantibody activity, thus C1-inh inhibitory activity for C1s was expressed fully.Our data indicate that the anti-C1-inh autoantibodies convert C1-inh to a substrate by preventing the formation of the stable covalent protease-serpin complex. The data also suggest a possible therapeutic use for peptides 2 and 3 or their derivatives in the management of patients with type II acquired angioedema (AAE). |
| 1996 | Characterization of C1 inhibitor-Ta. A dysfunctional C1INH with deletion of lysine 251. | J Biol Chem | Dysfunctional C1 inhibitor (C1INH)-Ta is a naturally occurring mutant from a patient with type II hereditary angioedema. This mutant has a deletion of the codon for Lys-251, which is located in the connecting strand between helix F and strand 3A, overlying beta sheet A. Deletion of this Lys modifies the amino acid sequence at this position from Asn-Lys-Ile-Ser to Asn-Ile-Ser and creates a new glycosylation site. To further characterize the mechanism of dysfunction, we have analyzed the recombinant normal and Ta proteins expressed by COS cells in addition to the proteins in serum and isolated from serum. Recombinant C1INH-Ta revealed an intermediate thermal stability in comparison with the intact and reactive center cleaved normal proteins. Analysis of the reactivity of this recombinant protein with target proteases demonstrated no complex formation with C1s, C1r, or kallikrein. Inefficient complex formation was, however, clearly detectable with beta-factor XIIa. Each protease produced partial cleavage of the recombinant mutant inhibitor. Recombinant C1INH-Ta, on 7.5% SDS-polyacrylamide gel electrophoresis and by size fractionation on Superose 12, showed a higher molecular weight fraction that was compatible in size with dimer formation. However, no multimerization of C1INH-Ta isolated from serum or of C1INH-Ta in serum, was observed. The C1INH-Ta dimer expressed the epitopes that normally are expressed only on the protease complexed or the cleaved inhibitor. These epitopes were not expressed on the monomeric inhibitor. The data suggest that the mutation in C1INH-Ta results in a folding abnormality that behaves as if it consists of two populations of molecules, one of which is susceptible to multimerization and one of which is converted to a substrate, but which retains residual inhibitory activity. |
| 1996 | Activation of factor XII and cleavage of high molecular weight kininogen during acute attacks in hereditary and acquired C1-inhibitor deficiencies. | Immunopharmacology | Hereditary and acquired C1-inhibitor (C1-INH) deficiencies (hereditary angioedema, HAE and acquired angioedema, AAE) are characterized by episodic increases in vasopermeability due to kinin release. Despite continuously defective C1-INH levels, symptoms only recur occasionally suggesting an episodic generation of pathogenetic factors induced by activation of the protease systems regulated by C1-INH. We evaluated activation of factor XII by measuring plasma levels of FXIIa with a commercial ELISA and cleavage of high molecular weight kininogen by performing SDS PAGE and immunoblotting analysis during 5 attacks in 5 different patients with HAE and during 7 attacks in 3 patients with AAE. The patients were also studied during remission. We confirmed our previous data indicating that during attacks both HAE and AAE patients had very high levels of cleaved HK (p < 0.0001) whereas during remission cleaved HK levels were normal in HAE and significantly increased in AAE (p < 0.0001). Both in HAE and in AAE, plasma levels of FXIIa were normal during remission and significantly increased during acute attacks (p = 0.0126; p = 0.0003). Our data suggest that the activation of a contact system is required to produce clinical symptoms. |
| 1995 | Severe anaphylactic reaction to bovine serum albumin at the first attempt of artificial insemination. | Allergy | A 33-year-old woman without history of previous atopic diseases or drug allergies developed a severe anaphylactic reaction with asthma, vomiting, itching, generalized urticaria, and angioedema during artificial insemination with her husband's sperm. The sperm-processing medium contained bovine serum albumin (BSA). Skin prick test and RAST demonstrated an IgE-mediated hypersensitivity to BSA as well as a polyvalent atopic sensitization to pollens, animal danders, cow's milk, beef, pork, and mutton. SDS-PAGE studies indicated serum albumin to be the appropriate allergen with a high degree of cross-reactivity between serum albumin from different animal species. Artificial insemination with fluid containing potential allergens can, therefore, represent an unnecessary risk for atopic females, even in the absence of prior clinical symptoms of allergic diseases. Preoperative testing with the medium is recommended. |
| 1991 | Anaphylaxis to annatto dye: a case report. | Ann Allergy | Annatto dye is an orange-yellow food coloring extracted from the seeds of the tree Bixa orellana. It is commonly used in cheeses, snack foods, beverages, and cereals. Previously reported adverse reactions associated with annatto dye have included urticaria and angioedema. We present a patient who developed urticaria, angioedema, and severe hypotension within 20 minutes following ingestion of milk and Fiber One cereal, which contained annatto dye. Subsequent skin tests to milk, wheat, and corn were negative. The patient had a strong positive skin test to annatto dye, while controls had no response. The nondialyzable fraction of annatto dye on SDS-PAGE demonstrated two protein staining bands in the range of 50 kD. Immunoblotting demonstrated patient IgE-specific for one of these bands, while controls showed no binding. Annatto dye may contain contaminating or residual seed proteins to which our patient developed IgE hypersensitivity. Annatto dye is a potential rare cause of anaphylaxis. |
| 1990 | Dysfunctional C1 inhibitor Ta: deletion of Lys-251 results in acquisition of an N-glycosylation site. | Proc Natl Acad Sci U S A | Hereditary angioneurotic edema is inherited as an autosomal dominant disorder and is characterized by potentially life-threatening episodic angioedema. In type II hereditary angioneurotic edema, a dysfunctional C1 inhibitor molecule is present together with low levels of normal C1 inhibitor. About 70% of these dysfunctional proteins result from reactive center (Arg-444) mutations. We describe the deletion of nucleotides encoding Lys-251 (AAG) in C1 inhibitor Ta, the dysfunctional C1 inhibitor from a family with type II hereditary angioneurotic edema. DNA sequence analysis was derived from clones obtained through polymerase chain reaction amplification of blood monocyte C1 inhibitor mRNA. As expected, clones with both normal and abnormal sequence were isolated. The deletion was verified by protein sequence analysis. These data, together with biochemical analysis of the protein and cell-free translation studies, suggest that this deletion, by altering the normal amino acid sequence from Asn-Lys-Ile-Ser to Asn-Ile-Ser, creates a new glycosylation site. The additional carbohydrate accounts for the larger size on SDS/PAGE and very likely interferes with protein function. |
| 1988 | Detection and quantitation of cleaved and uncleaved high molecular weight kininogen in plasma by ligand blotting with radiolabeled plasma prekallikrein or factor XI. | Thromb Haemost | A method for the quantitative assay of native single chain and kallikrein cleaved two-chain high molecular weight (HMW)-kininogen in plasma is described. Sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) of whole plasma is followed by electrotransfer of the electropherogram to nitrocellulose membranes and detection of the blotted HMW-kininogen with its physiologic ligands, radiolabeled plasma prekallikrein or radiolabeled factor XI. Using unreduced SDS-PAGE cleaved two-chain HMW-kininogen (Mr approximately 107,000 and 95,000), is electrophoretically separated from uncleaved single chain HMW-kininogen (Mr approximately 150,000). Counting the radioactivity of the nitrocellulose pieces corresponding to cleaved HMW-kininogen permits its quantitative measurement by comparison with standards consisting of decreasing amounts of fully dextran sulfate activated normal human plasma. Single chain HMW-kininogen is similarly assayed using reduced SDS-PAGE and unactivated normal human plasma standards. This technique is highly specific and sensitive to about 50 ng of either cleaved or uncleaved HMW-kininogen. Varying amounts of cleaved HMW-kininogen were found in a small series of plasmas from patients suffering from various inflammatory conditions. Higher levels of in vivo cleaved HMW-kininogen were observed during acute attacks of hereditary angioedema due to Cl-inhibitor deficiency. This technique may be useful for the assessment of the degree of in vitro or in vivo activation of the contact system. |
| 1986 | Detection of in vitro and in vivo cleavage of high molecular weight kininogen in human plasma by immunoblotting with monoclonal antibodies. | Blood | Purified human high-mol-wt kininogen (HMWK), the cofactor of the contact phase of blood coagulation, migrated as a single band (approximately 110,000 mol wt) in a continuous buffer sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE), but appeared as two separated bands (approximately 120,000 and 105,000 mol wt) when analyzed in a discontinuous buffer SDS-PAGE system. After elution from SDS polyacrylamide gels, each of the two bands showed coagulant activity. Six murine monoclonal antibodies (Mabs) against HMWK were produced and purified. In immunoblotting studies, three Mabs bound to the isolated alkylated heavy chain and one to the alkylated light chain of HMWK, whereas the remaining two bound only to the single-chain or unreduced two-chain molecule. None of the Mabs inhibited the clotting activity of HMWK or its binding to kaolin. Two of the Mabs, one directed against the light chain and one against the heavy chain, were used as specific probes to study HMWK in plasma samples using an immunoblotting technique. The anti-light chain Mab identified two distinct bands (approximately 120,000 and approximately 105,000 mol wt) in normal human plasma, but not in plasma from patients with hereditary HMWK deficiency. The anti-heavy chain Mab detected two additional bands (approximately 60,000 and approximately 54,000 mol wt) corresponding to low-mol-wt kininogen (LMWK) in normal plasma. A sensitive and specific quantitative immunoblotting assay of HMWK antigen in plasma was developed. Moreover, the immunoblotting technique with the anti-light chain Mab was used to detect the cleavage of HMWK in plasma samples after in vitro or in vivo activation of the contact system. The anti-light chain Mab demonstrated in vivo activation and cleavage of HMWK during an angioedema attack in a patient with hereditary angioedema and C1-inhibitor deficiency. |
| 1984 | Inactivation of factor XII active fragment in normal plasma. Predominant role of C-1-inhibitor. | J Clin Invest | To define the factors responsible for the inactivation of the active fragment derived from Factor XII (Factor XIIf ) in plasma, we studied the inactivation kinetics of Factor XIIf in various purified and plasma mixtures. We also analyzed the formation of 125I-Factor XIIf -inhibitor complexes by sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE). In purified systems, the bimolecular rate constants for the reactions of Factor XIIf with C-1-inhibitor, alpha 2-antiplasmin, and antithrombin III were 18.5, 0.91, and 0.32 X 10(4) M-1 min-1, respectively. Furthermore, SDS-PAGE analysis revealed that 1:1 stoichiometric complexes were formed between 125I-Factor XIIf and each of these three inhibitors. In contrast, kinetic and SDS-PAGE studies indicated that Factor XIIf did not react with alpha 1-antitrypsin or alpha 2-macroglobulin. The inactivation rate constant of Factor XIIf by prekallikrein-deficient plasma was 14.4 X 10(-2) min-1, a value that was essentially identical to the value predicted from the studies in purified systems (15.5 X 10(-2) min-1). This constant was reduced to 1.8 X 10(-2) min-1 when Factor XIIf was inactivated by prekallikrein-deficient plasma that had been immunodepleted (less than 5%) of C-1-inhibitor. In addition, after inactivation in normal plasma, 74% of the active 125I-Factor XIIf was found to form a complex with C-1-inhibitor, whereas 26% of the enzyme formed complexes with alpha 2-antiplasmin and antithrombin III. Furthermore, 42% of the labeled enzyme was still complexed with C-1-inhibitor when 125I-Factor XII was inactivated in hereditary angioedema plasma that contained 32% of functional C-1-inhibitor. This study quantitatively demonstrates the dominant role of C-1-inhibitor in the inactivation of Factor XIIf in the plasma milieu. |