• [ 4 ] Patients with MPGN are more likely to have low C3 levels and the presence of C3 nephritic factor (C3NeF). (medscape.com)
  • Lipodystrophy is often associated with glomerulonephritis, low C3 serum complement levels, and the presence of a C3 nephritic factor. (medscape.com)
  • C3 nephritic factor is a serum immunoglobulin G that interacts with the C3bBb alternative pathway convertase to activate C3. (medscape.com)
  • C3 nephritic factor induces the lysis of adipocytes that secrete adipsin, a product identical to complement factor D. The distribution of the lipoatrophy is postulated to be dictated by the variable amounts of adipsin secreted by the adipocytes at different locations. (medscape.com)
  • Around 83% of APL patients had low complement 3 (C3) levels and the presence of polyclonal immunoglobulin C3 nephritic factor. (wikipedia.org)
  • More than 80% of patients with MPGN II are positive for serum C3 nephritic factor (C3NeF), an autoantibody directed against C3bBb, the convertase of the alternative pathway of the complement cascade. (findzebra.com)
  • 1987) studied a family in which 3 female sibs had undetectable levels of factor H and C3 nephritic factor, low levels of factor B, C3, and C5 (see 120500), and normal levels of C4-binding protein (120830), factor I (217030), and classic pathway factors. (findzebra.com)
  • C3 nephritic factor and SLE: report of four cases and review of the literature. (medscape.com)
  • Activation of an alternate complement pathway, C3 hypocomplementemia with lysis of adipocytes induced by C3NeF, has been implicated. (medscape.com)
  • 2006) summarized features of MPGN relevant to the complement cascade. (findzebra.com)
  • Patients with MPGN type II without C3NeF often have mutations in the CFH gene, which also results in prolonged activation of C3 convertase. (findzebra.com)
  • Clinical presentations are similar for the three types of MPGN, but they manifest somewhat different mechanisms of complement activation and predisposition to recur in kidney transplants. (medscape.com)
  • Model of the adipocyte destruction in acquired partial lipodystrophy showing complement activation at the adipocyte surface resulting in adipocyte lysis. (medscape.com)
  • 1986) reported a consanguineous Algerian family in which 2 brothers had early-onset glomerulonephritis with C3 deposits and low levels (less than 10% of normal) of complement factor H . The factor H deficiency was defined by undetectable complement hemolytic activity by the classic (CH50) and alternate (AP50) pathways, and low levels of C3 and factor B (138470). (findzebra.com)
  • Patients usually have decreased serum C3 levels, normal levels of C1 and C4, and high levels of C3NeF (autoantibody), which may indicate the presence of renal involvement. (wikipedia.org)
  • Lupus nephritis was excluded because serum complement and anti-dsDNA antibody, anti-Smith antibody, and anti-cardiolipin antibody tests were negative. (bvsalud.org)
  • Adipocytes synthesize C3, factor B, and factor D (adipsin), which allows C3bBb to be formed locally, but which usually does not result in the activation of the terminal lytic part of the complement pathway (C5-9).The IgG antibody, C3Nef, prevents the alternative complement C3-convertase C3Bb from dissociative inactivation, resulting in adipocyte lysis. (medscape.com)
  • Activation of alternate complement pathway has been demonstrated in most patients. (medscape.com)
  • Small amounts of C3b are constantly being formed in the circulation, which are inactivated by factors H and I. The binding of C3b to a foreign antigen decreases its affinity for factor H and allows for the formation of increasing amounts of the alternate pathway convertase. (medscape.com)
  • The classic and alternate pathway convertases cause C3 activation, forming C3a and C3b. (medscape.com)
  • Hypocomplementemia results from increased catabolism and decreased C3 synthesis. (medscape.com)
  • Complement dysfunction may predispose some patients to bacterial infections. (wikipedia.org)
  • Electron microscopy of renal biopsies from both patients were typical for intramembranous dense deposit disease, but immunofluorescence microscopy showed an atypical pattern with abundant granular C3 deposits within the mesangium and along the capillary walls. (findzebra.com)
  • Low C3 levels are present in approximately 75% of patients with this condition. (medscape.com)
  • Evidence of ongoing complement activation on adipose tissue was documented in a child with this syndrome. (medscape.com)
  • Laboratory features usually include decreased serum levels of factor H , complement component C3 (120700), and a decrease in other alternative pathway components, indicating activation of the alternative complement pathway. (findzebra.com)
  • C3b is an opsonin itself, and C3 convertase facilitates the activation of the terminal pathway and the formation of the membrane attack complex C5b-9. (medscape.com)
  • Complement factor H deficiency (CFHD) can manifest as several different phenotypes, including asymptomatic, recurrent bacterial infections, and renal failure. (findzebra.com)
  • Welch (2002) discussed the role of complement in renal disease. (findzebra.com)
  • Adipocytes synthesize factor D, the limiting component of the alternative complement pathway, which cleaves C3-bound factor B to its active enzymatic form. (medscape.com)
  • In 1 family, of Polish origin, a teenaged male had vasculitis, thrombocytopenia, proteinuria, and depressed levels of serum factor H and complement component C3. (findzebra.com)
  • The alternative pathway utilizes C3 and factors B and D to form the alternative pathway convertase C3b,Bb. (medscape.com)
  • Another form of lipodystrophy that fits the classification of "acquired partial" not involving the complement pathway is associated with hematopoietic stem cell transplantation (HSCT) to treat leukemia or neuroblastoma. (medscape.com)
  • [ 4 ] Patients with MPGN are more likely to have low C3 levels and the presence of C3 nephritic factor (C3NeF). (medscape.com)
  • The serum of patients with membranoproliferative glomerulonephritis (MPGN) often exhibits C3 nephritic factor activity (C3NeF) associated with autoantibodies directed against the C3bBb alternative complement pathway C3 convertase. (nih.gov)
  • Lipodystrophy is often associated with glomerulonephritis, low C3 serum complement levels, and the presence of a C3 nephritic factor. (medscape.com)
  • C3 nephritic factor is a serum immunoglobulin G that interacts with the C3bBb alternative pathway convertase to activate C3. (medscape.com)
  • C3 nephritic factor induces the lysis of adipocytes that secrete adipsin, a product identical to complement factor D. The distribution of the lipoatrophy is postulated to be dictated by the variable amounts of adipsin secreted by the adipocytes at different locations. (medscape.com)
  • Around 83% of APL patients had low complement 3 (C3) levels and the presence of polyclonal immunoglobulin C3 nephritic factor. (wikipedia.org)
  • Individuals with C3G typically present with hematuria, proteinuria, hematuria and proteinuria, acute nephritic syndrome or nephrotic syndrome, and low levels of the complement component C3. (nih.gov)
  • The disappearance of C3NeF activity in patient's IgG was selective in that no change in activity of two other autoantibodies and of one antibody against a non-self antigen was observed with time, indicating that the decrease in C3NeF activity was not related to a non-specific effect of immunosuppressive therapy. (nih.gov)
  • Model of the adipocyte destruction in acquired partial lipodystrophy showing complement activation at the adipocyte surface resulting in adipocyte lysis. (medscape.com)
  • Multimerization and the presence of complement overcome the limited ability of monomeric antibody to mediate internalization of HIV-1 virions and may thus provide a therapeutic approach to clearing virus. (bvsalud.org)
  • Therefore, antibody multimerization in combination with complement may overcome the limited ability of monomeric antibody to mediate internalization of HIV-1 virions. (bvsalud.org)
  • COMPLEMENT FACTOR I ). This abnormally stabilized enzyme induces a continuous COMPLEMENT ACTIVATION and generation of C3b thereby promoting the assembly of MEMBRANE ATTACK COMPLEX and cytolysis. (nih.gov)
  • Complement inhibition with a terminal pathway blocker may alter disease course in some individuals. (nih.gov)
  • The presence of complement, however, greatly augmented internalization of immune complexes formed with the multimeric MAb but had little impact on monomeric MAb-mediated internalization. (bvsalud.org)
  • We found that, in the absence of complement, immune complexes consisting of HIV-1 virions and VRC01 multimers were slightly more efficiently internalized than were complexes formed with monomeric VRC01. (bvsalud.org)
  • At that time, plasma levels of C3 and factor B had returned to normal values. (nih.gov)
  • Loss of C3NeF activity was not related to the generation of anti-idiotypic antibodies against C3NeF. (nih.gov)
  • C3NeF activity in the patient's purified serum IgG decreased with time from the first month after transplantation and became undetectable after forty-five weeks. (nih.gov)