Search results for "Complement C1"
showing 10 items of 125 documents
The collagen-like component of the complement system, C1q, is recognized by 7 S autoantibodies and is functionally impaired in synovial fluids of pat…
1996
Cross-reactivity between type II collagen (CII) and C1q, the collagen-like subunit of the first component of complement, has been demonstrated in synovial fluid (SF) from rheumatoid arthritis (RA) patients. Many authors have studied autoimmunity to CII in RA, but little work has been done on autoimmunity to C1q in RA. In the data presented here, we have been able to show that in addition to native C1q, an altered form of C1q is present in SF from RA patients. Furthermore, a low molecular weight form of C1q is present in RA SF, although its role, if any, in the pathogenesis of RA is unclear. The presence in these RA SF of C1q-specific antibodies (IgG and IgM) has been studied and we have par…
Human macrophages simultaneously express membrane-C1q and Fc-receptors for IgG
2005
Membrane C1q (mC1q) of macrophages (MPhi) is a precursor of the IgG-binding serum protein C1q. Thus, mC1q potentially provides one of several Fcgamma binding sites of mature MPhi and we analyzed whether simultaneous expression occurs of established receptors for IgG, FcgammaRI, II, and III, and mC1q during in vitro differentiation of MPhi. Using flow cytometry, immunoprecipitation combined with Western blotting and Northern blot analysis mC1q was hardly detected in freshly isolated blood monocytes, but increasingly in developing monocyte-derived MPhi. Laser scanning fluorescence microscopy confirmed the membrane localization of mC1q. Two-color-staining flow cytometry experiments indicated t…
The Expanding Spectrum of Mutations in Hereditary Angioedema.
2021
The evolution in the knowledge of rare genetic diseases such as hereditary angioedema (HAE) has increased at a parallel pace with the development of new molecular tools. The deficiency of C1 inhibitor (C1-INH) has been recognized as the main cause of HAE (HAE-C1-INH) since the 1960s, but the discovery of the wide spectrum of mutations affecting the C1-INH gene (SERPING1) was possible only from the late 1980s, when Sanger sequencing became available and more accessible worldwide. Nevertheless, the involvement of other genes in HAE was discovered only in 2006 with the description of mutations in the F12 gene in patients with HAE and normal C1-INH. In the last 3 years, advanced next-generation…
Clinical studies of sudden upper airway obstruction in patients with hereditary angioedema due to C1 esterase inhibitor deficiency.
2003
Background Hereditary angioedema due to C1 esterase inhibitor deficiency is clinically characterized by recurrent and self-limiting skin, intestinal, and laryngeal edema. Asphyxiation by laryngeal edema is the main cause of death among patients who die of hereditary angioedema. This study describes the age at which laryngeal edema first occurs, the time between onset and full development, and the effectiveness of therapy and prophylaxis. Methods Information on 123 patients with hereditary angioedema was obtained from medical histories and reports by the general practitioners, emergency physicians, and hospitals involved. Results Sixty-one patients (49.6%) experienced a total of 596 laryngea…
Risk of laryngeal edema and facial swellings after tooth extraction in patients with hereditary angioedema with and without prophylaxis with C1 inhib…
2010
Objective Tooth extractions may trigger clinical symptoms of hereditary angioedema due to C1 inhibitor deficiency (HAE-C1-INH). The aim of this study was to determine how many tooth extractions were followed by symptoms of HAE-C1-INH in patients with and without preoperative short-term prophylaxis with C1 inhibitor concentrate. Study design Tooth extractions and clinical symptoms of HAE-C1-INH were determined from clinical record files of 171 patients with HAE-C1-INH. Results Facial swelling or potentially life-threatening laryngeal edema, or both, occurred in 124/577 tooth extractions (21.5%) without prophylaxis. Similar symptoms occurred in a fewer proportion of patients undergoing extrac…
Recurrent angioedema and the threat of asphyxiation.
2009
Angioedema (also known as Quincke disease) is the name given to edema lasting 1–7 days that recurs at irregular intervals. Target organs are the skin, tongue, glottis and larynx, gastrointestinal tract, and sometimes other soft organs. The clinical symptom referred to as angioedema forms part of a variety of disease entities (Box 1, Figure 1). In Germany, according to the present author’s estimate, several thousand patients suffer from one of the forms of recurrent angioedema. Cases of sudden asphyxiation are rare, but do occur every now and again (1). This review aims to draw attention to the various clinical features of recurrent angioedema and the practical steps for dealing with it, and…
Complement C1q and C8beta deficiency in an individual with recurrent bacterial meningitis and adult-onset systemic lupus erythematosus-like illness.
2008
Co-existing complement C8 deficiency ameliorated the SLE associated with C1q deficiency.
Involvement of complement pathways in patients with bacterial septicemia.
2007
The complement system is a major humoral portion of the innate immune system, playing a significant role in host defence against microorganisms. The biological importance of this system is underlined by the fact that at least three different pathways for its activation exist, the classical, the MBL and the alternative pathway. To elucidate the involvement of the classical and/or the MBL pathway during bacterial septicemia, 32 patients with gram-positive and 30 patients with gram-negative bacterial infections were investigated. In patients with gram-positive bacteria, a significant consumption of C1q (p=0.005) but not of mannose-binding lectin (MBL) (p=0.2) was found during the acute phase o…
Angioedema due to acquired C1-inhibitor deficiency: spectrum and treatment with C1-inhibitor concentrate
2018
Abstract Background Acquired angioedema due to C1-inhibitor (C1-INH) deficiency (AAE-C1-INH) is a serious condition that may result in life-threatening asphyxiation due to laryngeal edema. It is associated with malignant B-cell lymphoma and other disorders. The purpose of this study was to describe the characteristics and associated disorders of patients with AAE-C1-INH and assess the efficacy of plasma-derived C1-INH concentrate (pdC1-INH) in the treatment of AAE-C1-INH. Forty-four patients with AAE-C1-INH from the Angioedema Outpatient Service of Mainz were assessed for associated disorders. In 32 of these patients, the duration of swelling attacks was measured before and after treatment …
Prognostic Implications of the Complement Protein C1q in Gliomas
2019
The contribution of the complement system in the pathophysiology of brain cancers has been recently considered in light of its well-known involvement in carcinogenesis. Complement system represents an important component of the inflammatory response, which acts as a functional bridge between the innate and adaptive immune response. C1q, the first recognition subcomponent of the complement classical pathway, has recently been shown to be involved in a range of pathophysiological functions that are not dependent on complement activation. C1q is expressed in the microenvironment of various types of human tumors, including melanoma, prostate, mesothelioma, and ovarian cancers, where it can exer…