PubMed Health⌕ Search

SEARCH · PubMed Health

Results for “Complement C3 Nephritic Factor”

Explore indexed PubMed citations for clinical trials, systematic reviews and public health research. Read source abstracts and follow each citation to its original PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 109 records · Page 6Linked to original sources
PubMed1990

Determination of C3 nephritic factor activity by a microassay based on the peroxidase-like activity of the heme group.

We report a modification of a method for measuring the C3 nephritic factor, using the peroxidase activity of the heme group. This modification increases the sensitivity of the method, approximately seven-fold when NEF activities are measured in U/mL. It is less time-consuming and it allows the simultaneous testing of a larger number of samples, simplifying the screening of sera and ensuring an easy and simple test for the detection of NEF in purification processes as well as in in vitro production. The method could also be useful in other hemolytic assays.

Biological Assay↗
PubMed1988

Retinal pigment epithelial change and partial lipodystrophy.

Cuticular drusen and retinal pigment epithelial changes were found incidentally in a 27 year old Lebanese woman during assessment of partial lipodystrophy. Her vision was normal despite involvement of both maculae. The patient had hypocomplementaemia, but serum C3 nephritic factor was absent and renal function was normal. She had impaired glucose tolerance and a continuous infusion of glucose with model assessment (CIGMA) test revealed low normal tissue insulin sensitivity and high normal pancreatic beta cell function. Mild fasting hypertriglyceridaemia (2.0 mmol/l) may have been secondary to impaired insulin sensitivity. Endocrine function was otherwise normal apart from a completely absent growth hormone response to adequate hypoglycaemia. The simultaneous occurrence of partial lipodystrophy and retinal pigmentary epithelial and basement membrane changes appears to be a newly recognized syndrome.

Adult↗
PubMed1992

On the origin of C3 nephritic factor (antibody to the alternative pathway C3 convertase): evidence for the Adam and Eve concept of autoantibody production.

The antibody to the alternative pathway C3 convertase, designated C3 nephritic factor or C3NeF, is an autoantibody that is produced in everyone from the time of birth. The elaboration of C3NeF utilizes germline V-region genes which undergo antigen-driven affinity maturation, resulting in an autoantibody that is produced in large amounts with high affinity and narrow specificity. Our data also suggest that under normal conditions, the idiotypic network may play an important part in the control of this autoantibody. Further, a defect in the network with loss of control or inappropriate stimulation may be an underlying mechanism in the unrestricted production of C3NeF in patients with membranoproliferative glomerulonephritis.

Adult↗
PubMed1985

[Immunologic and transplantation biology studies in patients with terminal renal failure].

Best possible tissue compatibility is a fundamental precondition for a successful organ transplantation. The desirable tissue compatibility is mainly defined by transplantation-antigens of the donor and the recipient and therefore--beside ABO antigens--the characteristics of HLA-system are the focal point of the preoperative immunological diagnosis. Based on the results of comperative examinations it is demonstrated, that HLA-antisera have such a widespread biological variability, that they lead sometimes to a faulty diagnosis which in turn causes the biological importance of the HLA-system to be doubted. The preoperative immunologic diagnosis should include an estimation of the risk factors in the patient. The consideration of the crossmatch between donor and recipient is a decisive factor in organ transplantation. The starting point is the preoperative antibody monitoring which checks the patients serum reactions against a panel of blood donors to see, whether the patient is a "high" or "low"-- responder to allogenetic stimuli. A positive reaction in the crossmatch is brought about by different kinds of antibodies whereby only in the presence of auto-antibody or cold-reactive B-cell antibody a transplantation may take place. The antibody characterisation in preoperative diagnosis is supported by the results of the immunologic antibody monitoring, whereby--because of the results here presented-- it can be confirmed, that through the knowledge of the antibody specifities which have been checked in a positive crossmatch transplantation on highly sensitized patients can take place with a prospect of success. Supplementing the "Eurotransplant" results the HLA-DRw6 antigen is shown not only to be an indication of risk in transplantation, but may also be an aetiopathogenetic factor. In the presentated statistics it can be shown, that in patients suffering from glomerulonephritis or pyelonephritis and requiring dialysis treatment the HLA - DRw6 antigen occur more frequently than in the control group of healthy blood donors. In glomerulonephritis patients there is additionally a significant change in distribution favourable to HLA - DRw10 shown. The determination of genetically caused risk factors is appreciably supported by characterisation of lymphocyte subpopulations and diagnosis of changes in the Complement-system. Changes in T-lymphocyte subpopulations pointing to proceedings of immunostimulation and conditions of the activated Complement-system represent warning signals in organ transplantation.

Adult↗
PubMed1986

Membranoproliferative glomerulonephritis, type II and partial lipodystrophy in an adult.

Membranoproliferative glomerulonephritis, type II is commonly seen in patients with the rare disorder, partial lipodystrophy. This disease complex, although usually seen in the pediatric or young adult age group, should be considered in older patients with characteristic loss of facial fat and signs and symptoms of nephritis. A case of partial lipodystrophy with membranoproliferative glomerulonephritis, type II in an older patient demonstrates the characteristic ultrastructural renal findings.

Basement Membrane↗
PubMed1989

[Partial lipodystrophy and membranoproliferative glomerulonephritis. Apropos of a case].

We have studied a girl seven and a half years old with a renal disease manifested by proteinuria and nephrotic syndrome combined with initial macroscopic hematuria normal blood pressure and persistent depression of the complement C3 levels with the complement activating gamma globulin (C3 Nef) present in serum. The anatomopathological study showed findings of membranoproliferative glomerulonephritis type II with intramembranous deposit (dense deposit disease). An unusual association with partial lipodystrophy was present in this case. A follow-up of five years, and a few considerations about etiopathogenic theories were presented.

Child↗
PubMed1978

Membranoproliferative glomerulonephritis (MPGN type I) and dense deposit disease (DDD) in children.

A review of the histologic findings in 27 patients originally classified as having some form of membranoproliferative glomerulonephritis (MPGN) revealed 13 with MPGN Type I and 14 with dense deposit disease (DDD). In all 14 cases where electron microscopy was performed, the histologic diagnosis was confirmed. In nine cases the diagnosis of DDD was easily made in histologic sections on the basis of ribbon-like, brightly PAS positive thickening of the GBM, without "splitting" and with relatively slight mesangial proliferation. However, in five cases the picture closely resembled MPGN Type I, with hypercellularity, "splitting" and only focal ribbon-like thickening of the GBM, which required oil immersion for recognition. There was no correlation between the serum C3 levels and the morphologic diagnosis: nine (4 MPGN Type I, 5DDD) had persistently low C3 levels, two (1 MPGN Tye I, 1DDD) were normocomplementemic, and in 16, the C3 levels varied. C3 levels increased with time in nearly all patients. The clinical course was similar in patients with MPGN Type I and DDD. Significant correlations between the rate of development of renal failure and sex, age of onset, nephrotic syndrome or therapy could not be made. The five year survival rate was 87%; 12 developed renal insufficiency by five years. Although morphologically distinct, these findings suggest that DDD is clinically indistinguishable from MPGN Type I.

Cell Membrane↗
PubMed1987

Differences between membranoproliferative glomerulonephritis types I and III in clinical presentation, glomerular morphology, and complement perturbation.

Data for 26 patients with membranoproliferative glomerulonephritis, type I (MPGN I) and 22 with membranoproliferative glomerulonephritis, type III (MPGN III), as distinguished by glomerular ultrastructure, were analyzed to determine differences in presentation, complement perturbation, and glomerular morphology by light microscopy. MPGN III was detected with greater frequency by the chance discovery of hematuria and proteinuria in the otherwise healthy individual (MPGN III, 63%; MPGN I, 30%; P = .01) and never, in the absence of renal failure, presented with systemic symptoms such as ease of fatigue, weight loss, and pallor, as may patients with MPGN I. The more frequent detection of MPGN III by chance is evidence that its onset is insidious and that for long periods it produces no symptoms or signs. Glomerular proliferation is also less than in MPGN I. Further, in MPGN III, the complement perturbation and glomerular immunofluorescence give no evidence of classical pathway activation, for which there is abundant evidence in MPGN I. Even with severe hypocomplementemia in MPGN III, C3 nephritic factor, another cause of hypocomplementemia, is rarely detectable and then in very low concentration. The cause of the complement perturbation in MPGN III has so far escaped identification. Although these observations give evidence that MPGN III is distinct from MPGN I, there is compelling evidence from other studies that a predisposition to both types is inherited and that similar genetic factors are operative in the two types. Because their genetic basis appears to be the same, it must be concluded that despite their differences, types I and III are variants of the same disease.

Complement C3↗
PubMed1986

[Subacute septicemia caused by Meningococcus of serogroup Y and acquired deficiency of complement C3 fraction].

The high frequency of meningococcal infections in patients with congenital deficiency of a component of the complement terminal pathway emphasizes the critical role of this system in host resistance against Neisseriaceae. We report the observation of a subacute septicaemia due to N. meningitidis serogroup Y. This girl had an acquired deficit of the C3 fraction of complement due to a high titre of C3 nephritic factor (C3NeF). There was no evidence of partial lipodystrophy or biological symptoms of glomerular disease. The meningococcal infection revealed this biological abnormality.

Child↗
PubMed1970

Characteristics of a non-complement-dependent C3-reactive complex formed form factors in nephritic and normal serum.

When serum from a patient with membrano-proliferative glomerulonephritis and normal serum are mixed at 37 degrees C, C3 is rapidly broken down to two more rapidly migrating components. In the mixture, a heat-labile pseudoglobulin, designated as the C3 nephritic factor or C3NeF, reacts with a pseudogolbulin in the normal serum, designated as cofactor, to form a C3 inactivator. By analogy with the cobra venom factor, the C3 inactivator is most likely a complex of the nephritic factor and cofactor. The complex has been designated as the C3 lytic nephritic factor or C3LyNeF. The reaction which results in the Formation of C3LyNeF requires the presence of Mg(++), is highly temperature sensitive but occurs very rapidly at 37 degrees C. In 20 min at 37 degrees C, C3LyNeF can break down over 80% of the C3 in a mixture of normal and nephritic serum. The two-step reaction which leads to C3 breakdown has an optimum pH ranging from 6.0 to 9.0. Experiments employing serum depleted of C4 and C2, as well as certain characteristics of the C3NeF system provide evidence that C3 breakdown with nephritic serum is not dependent on complement-inactivating immune complexes or on the action of convertase (C4, 2). Data relating rate of C3 breakdown to the concentrations of C3NeF, C3, and C3LyNeF in the reaction mixture are similar to those for the reaction of enzyme with substrate. The biological significance of C3LyNeF in the production of glomerular inflammation has not been established.

Antigen-Antibody Reactions↗
PubMed1990

Quantitation of C4 nephritic factor by an enzyme-linked immunosorbent assay.

We have developed an enzyme-linked immunosorbent assay (ELISA) for the quantitation of C4 nephritic factor (C4NeF). Incubation of the C4NeF-positive serum from patient M.I. with normal human serum (NHS) in the presence of human aggregated IgG (AHG) resulted in the formation of stable C4-C2 complex. No complex was formed in EDTA or under the condition free of AHG. The reaction mixture was filtered through an ACA 22 column, from which the C4-C2 complex was eluted at the first protein peak. When IgG purified from M.I. serum was incubated with NHS and AHG, C4-C2 complex also increased in proportion to dose of the purified M.I. IgG. These results show that C4NeF in M.I. serum stabilizes C4b2a convertase of the classical complement pathway, and is quantified by the ELISA. C4NeF activity was measured, using the ELISA method, in patients with various glomerular diseases, and found elevated in three of 24 patients with membranoproliferative glomerulonephritis (MPGN) type I and slightly but distinctly positive in seven of 24. No C4NeF was detected in two C3 nephritic factor-positive patients with MPGN type II and six with active systemic lupus erythematosus. The new method was more simple and quantitative than C4b2a stabilization assay for C4NeF.

Animals↗
PubMed1989

Mesangiocapillary glomerulonephritis type II (dense-deposit disease): clinical features of progressive disease.

Twenty-seven patients presenting to the Royal Melbourne Hospital between 1968 and 1988 with mesangiocapillary glomerulonephritis type II with intramembranous dense deposits (dense-deposit disease, DDD) are analyzed. Patients were divided into two groups on the basis of whether renal function deteriorated (14 patients) or remained stable (13 patients). At presentation or during the course of the disease, heavy proteinuria, macroscopic hematuria, and high quantitative urinary red cell or white cell counts characterized patients with progressive disease. Patients with crescents on their initial renal biopsy or with large numbers of polymorphs in glomerular capillaries corresponding with sterile pyuria were more likely to have deterioration of renal function. The average time from onset of symptoms to development of end-stage renal disease was over 16 years. The patient's clinical course could not be anticipated by serum complement profiles, the presence of C3 nephritic factor, or partial lipodystrophy. Pregnancy did not affect the course of the disease. Six patients underwent renal transplantation and the disease recurred on renal biopsy in four. However, only two individuals lost renal allografts due to recurrent DDD.

Adolescent↗