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Results for “Complement C1 Inactivator Proteins”

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At least 469 records · Page 26Linked to original sources
PubMed1989

Lymphocytic lymphoma and acquired C1 esterase inhibitor deficiency.

We report a 59-year-old woman who had progressive symptoms of angioedema for 3 years, culminating in an attack of laryngeal stridor. C1 esterase inhibitor deficiency was confirmed and treatment with tranexamic acid produced considerable clinical benefit and improvement in complement levels. Two years later she developed clinical evidence of lymphocytic lymphoma. Splenectomy resulted in rapid correction of complement abnormalities. The patient received 6 months of chemotherapy after surgery and remained asymptomatic with normal complement levels 4 years later.

Angioedema↗
PubMed1977

Haemostatic and complement changes in a family with 'allergic' disorders.

A family with allergic manifestations, haemostatic disturbances, total absence of haemolytic activity of the complement system and low IgG levels is described. It is suggested that this functional abnormality of the complement system and the decreased level of immunoglobulin G may be due to immune complex reactions.

Adolescent↗
PubMed2005

C1 inhibitor deficiency: diagnosis.

This is the first of two articles on C1 inhibitor deficiency based on a recent UK consensus document covering diagnosis and management of the disorder in both adults and children. This paper focuses on diagnosis of this disorder.

Abdominal Pain↗
PubMed1992

An association between homozygous C3 deficiency and low levels of anti-pneumococcal capsular polysaccharide antibodies.

Inherited deficiencies of complement components are associated with an increased risk of infection by encapsulated, high grade bacterial pathogens such as Streptococcus pneumoniae, Haemophilus influenzae type b and Neisseria meningitidis. Hence, the levels of antibodies to bacterial capsular polysaccharide antigens were measured using ELISA in 65 patients with inherited deficiencies covering the classical, alternative and terminal components of the complement cascade. Three of the four C3-deficient individuals studied were found to be almost totally deficient in specific anti-pneumococcal capsular polysaccharide (PCP) antibodies. These individuals had a history of recurrent pneumococcal sepsis. While single individuals with C1r, C2 and C1Inh deficiency were found to have low anti-PCP antibody levels, no other group of complement deficiency had significantly reduced anti-PCP antibody levels compared with 100 controls. Antibody levels to the other two polysaccharides were not significantly lower in the patient groups. These findings suggest that C3 may be able to provide a stimulatory signal to promote the production of anti-PCP antibodies.

Adolescent↗
PubMed1992

Functionally active complement is present in human ovarian follicular fluid and can be activated by seminal plasma.

Human ovarian preovulatory follicular fluids (FF) from 10 women were analysed for their complement contents. Functionally active complement was detected in all the fluids studied in amounts similar to those present in normal human serum. Pooled FF was challenged by seminal plasma in order to determine whether seminal plasma could activate FF complement, the pattern of such an activation and the possible consequences on the reproductive function. FF complement activation occurred during the incubation with seminal plasma with features including alternative pathway activation, factor B and C3 conversion and reduction in total haemolytic complement, as well as an inhibition by seminal plasma of the FF complement response to a new activating challenge. Possible consequences for fertilization, implantation of a fertilized ovum and local defence mechanisms against viruses and bacteria are discussed.

Complement Activation↗
PubMed1995

C3 is activated in hereditary angioedema, and C1/C1-inhibitor complexes rise during physical stress in untreated patients.

Seven patients with hereditary angioedema (HAE) were studied to understand further how physical exercise may induce attacks. The most pronounced differences between patients and controls, however, were independent of the controlled bicycle run (mean values in patients/ controls); C4(g/L): 0.12/0.28 (P = 0.0122); C4bc (AU/ml): 137.0/18.0 (P = 0.0002); C4d (mg/mL): 5.03/2.35 (P = 0.0004); C3bc (AU/ml): 8.4/6.3 (P = 0.0049); C3a (AU/ml): 11.1/5.6 (P = 0.0102). The ratio C4bc to C4 was 1141 versus 64. Consequently, a substantial part of the low amount of C4 left in HAE patients consists of activation products, and the authors show for the first time that a mild but significant activation of C3 occurs in HAE. The two HAE patients treated with danazol had values of C1-INH function and antigen, C4, and C2 in-between those of normal and untreated patients, and lower levels of split products from C4 and high molecular weight kininogen than untreated patients. As a result of the exercise, fibrinolysis increased significantly in both patients and controls, while C1/C1-INH complexes rose significantly only in the five HAE patients without treatment when compared to the seven controls (P = 0.0089). This study thus suggests that complement activation is enhanced in untreated HAE patients following physical stress.

Angioedema↗
PubMed1979

Hereditary complement (C2) deficiency with discoid lupus erythematosus and idiopathic atrophoderma.

A family with hereditary deficiency of the second component of complement was studied. Three siblings were homozygous for C2 deficiency and two of them had associated skin diseases. One sister presented with idiopathic atrophoderma and the other had clinical and pathological manifestations of discoid lupus erythematosus. This is the first description of an association between idiopathic atrophoderma and C2 deficient state.

Adolescent↗
PubMed1978

The presence of active C1 (C-1) on peripheral human lymphocytes.

We have shown that the first component of complement C1 is present in an active form on the surface of washed human peripheral lymphocytes but not on platelets or erythrocytes. This active C1 (C-1) was detected by its ability to transfer to sensitized cells carrying C4, i.e., EAC4, forming EAC-1,4. Active C1 was also able to consume C4. Treatment of these lymphocytes with 0.02 M EDTA removed C-1. EDTA-treated lymphocytes were able to bind exogenous purified human C-1. Comparative studies with sentized erythrocytes (EA) and EDTA treated lymphocytes showed that although fewer molecules of exogenous C1 could bind to the EDTA-treated lymphocytes than to EA, the consumption of C4 by C-1 bound to lymphocytes was significantly higher than that observed with EAC-1. When lymphocytes obtained from 2 patients with chronic lymphocytic leukemia and hypocomplementemia were tested, the release of C1, the C4 consumption and the binding of C-1 to EDTA-treated cells were highly inefficient.

Blood Platelets↗
PubMed1990

Interferon-mediated transcriptional and post-transcriptional modulation of complement gene expression in human monocytes.

The addition of lymphoblastoid interferon alpha, fibroblast interferon beta and recombinant interferon gamma to in vitro monocyte cultures produced dose-dependent increases in transcription rates of the genes encoding the second component of complement (C2), factor B (B) and C1 inhibitor, and the abundance of their respective mRNA. Interferon gamma was the most effective at stimulating transcription of the C1-inhibitor gene whereas interferons alpha and beta were more effective at increasing the transcription of the C2 and B genes. Transcription of the C3 gene was reduced by interferon gamma. None of these cytokines altered the level of transcription of the actin gene. Interferon-induced changes in the levels of transcription of the C2, B and C1-inhibitor genes occurred rapidly, with significant changes occurring within 30 min of exposure to these cytokines. Within 4 h of removal of the interferons from the culture fluid, the level of transcription of the C1-inhibitor, C2, B and C3 genes returned to control values, as did abundance of C2, B and C3 mRNA. However, the abundance of C1-inhibitor mRNA remained elevated in interferon-gamma-treated monocytes. Combinations of interferons produced less than additive effects on the stimulation of the transcription of C2, B and C1-inhibitor genes, whereas measurements of C1-inhibitor mRNA and B mRNA showed that interferon gamma acted synergistically with interferon gamma to increase the abundance of the mRNA. Their effects on C2 mRNA abundance were less than additive. The half-lives of C1-inhibitor, C2, B and C3 mRNA were not altered by interferon alpha, whereas interferon gamma shortened the half-life of C2 mRNA by approximately 50%, and prolonged the half-lives of B and C1-inhibitor mRNA approximately twofold and fivefold, respectively. The half-life of C3 mRNA was unaltered by either interferon. These results show that the large increase in C1-inhibitor synthesis which occurs in interferon-gamma-treated monocytes, is due to a combination of increased transcription and increased C1-inhibitor mRNA stability. They also suggest that the synergistic effects of interferon alpha together with interferon gamma on C1-inhibitor and factor B synthesis is also dependent upon increased transcription and increased mRNA stability.

Complement C1 Inactivator Proteins↗
PubMed1977

The complement system in infectious mononucleosis.

The complement system was investigated in 34 patients with infectious mononucleosis. Three had specific complications: one haemolytic anaemia, one severe arthralgia/myalgia and one proliferative glomerulonephritis. Complement changes consistent with classical pathway consumption were seen in ten of the uncomplicated group and the patients with haemolytic anaemia and arthralgia/myalgia. The patient with glomerulonephritis showed evidence of alternative pathway utilisation including C3 splitting activity and the deposition of properdin on renal biopsy. The complement findings suggest that circulating immune complexes are common in such patients and are likely to play a role in the pathogenesis of the complications. It is proposed that both complement pathways may be required for the effective clearance of viral material from the circulation.

Complement C1 Inactivator Proteins↗
PubMed1990

Effect of parenteral oestrogen on the coagulation system in patients with prostatic carcinoma.

Patients with prostatic carcinoma on oral oestrogen therapy have an altered coagulation system and suffer cardiovascular side effects. Oestrogens--especially oral oestrogens--are potent inducers of liver synthesised proteins, including coagulation factors. We have assessed the effect of non-oral oestrogen on the coagulation system in patients with prostatic carcinoma. Twelve patients were given monthly intramuscular injections of 320 mg polyoestradiol phosphate (PEP). No additional oestrogens were given. No change was found in any of the coagulation factors, including factor VII, with the exception of a significant decrease in antithrombin III. No patient, including 38 patients treated with PEP, had any cardiovascular complications after a mean follow-up period of 12.9 +/- 0.7 months; 76% of the patients responded to treatment. Parenteral administration of oestrogen caused a less marked change in the coagulation system than oral administration and should be the treatment of choice for prostatic carcinoma.

Antithrombin III↗
PubMed1984

Sperm antibodies, immunoglobulins, and complement in human follicular fluid.

The levels of immunoglobulins (IgG, IgA, IgM), complement (C3, C4, C1EI) and sperm antibodies were determined in plasma and follicular fluid samples from 26 patients undergoing in vitro fertilization (IVF) treatment. The results show that IgG, IgA, C3, C4, and C1EI concentrations in follicular fluid are similar to plasma concentrations (63.1-96.1% of plasma levels). The follicular fluid concentration of IgM was severely reduced, however, being only approximately 10% of plasma concentrations. Sperm antibody titres were compared in three patients using sperm agglutination, immobilization, and immunobead binding. The titres in plasma and follicular fluid were similar, apart from antibodies of IgM class, which were undetectable in follicular fluid.

Antibodies↗