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PubMed1994

Glomerulonephritis in Henoch-Schöenlein purpura without mesangial IgA deposition.

Ten patients with Henoch-Schöenlein purpura (HSP) were selected for study because their early renal biopsies showed focal and segmental hypercellularity, with IgA present only in deposits at the periphery of the lobules. Mesangial deposits of IgA were absent. All had laboratory evidence of nephrotic syndrome and/or renal compromise. The glomerular hypercellularity was largely the result of the infiltration of monocytes whose cytoplasm often contained tubular lysosomes and wrapping lysosomal membranes, evidence of monocyte activation. Mean levels of C3 were normal but those of C4 and properdin significantly depressed. This complement profile, as well as a glomerular monocytic infiltrate, are also seen in essential cryoglobulinemia in the adult. Of follow-up biopsies in six patients, the glomeruli were normal in three, with no IgA deposition. In the other three, mesangial deposits of IgA typical of HSP were present. The initial focal-segmental glomerulitis of these patients appeared to be the benign first phase of a disease which had the potential to culminate in mesangial IgA deposition. Patients like the three who escaped mesangial IgA would be among those responsible for the observed dissociation between severity of the initial illness and ultimate prognosis.

Adolescent↗
PubMed1992

The molecular basis of X-linked immunodeficiency disease.

The molecular bases of the X-linked immunodeficiency diseases remain largely undetermined. Two of the genes involved in these diseases have been isolated, namely the genes for X-linked chronic granulomatous disease and properdin deficiency, and substantial progress has now been made in identifying the genes which are defective in the other five diseases, Wiskott-Aldrich syndrome, X-linked severe combined immunodeficiency, X-linked agammaglobulinaemia, X-linked hyper-IgM and X-linked lymphoproliferative syndrome. We review here the nature of the diseases, progress made in identifying and isolating the genes involved and the prospects for improved prenatal detection, carrier status determination and treatment of these life-threatening conditions.

Granulomatous Disease, Chronic↗
PubMed1995

Inherited complement deficiency in children surviving fulminant meningococcal septic shock.

UNLABELLED: We evaluated the complement system in 29 children (mean age: 4.5 years) who survived fulminant meningococcal septic shock. No terminal complement deficiencies were found. One patient, who experienced the most dramatic disease course, had a decreased haemolytic activity in the haemolysis-in-gel test for the alternative pathway. The properdin concentration in serum of this patient was < 0.1 microgram/ml (n = 17.1-27.7 micrograms/ml). Coagulation studies revealed a heterozygeous type I protein C deficiency as well. He was the only patient with a Neisseria meningitidis group Y infection. CONCLUSION: Fulminant meningococcal disease due to uncommon serogroups should lead to screening of the alternative pathway of complement activation.

Adolescent↗
PubMed1993

The complement system and systemic sclerosis.

Serum concentrations of the various complement components including the classical and the alternative pathways were determined in 58 control healthy subjects and 80 patients with systemic sclerosis (SSC). The mean concentrations of C1q, C2, C5, C6, C7, C9, and factor B were significantly increased in the SSC patients in comparison to controls, while the increases were not significant for C3 and C8. C4 was an exception in that the mean levels were found to be decreased, with 18 patients having levels < 65% of the mean normal value. Properdin was also found to be decreased, but not significantly. We found a similarity between the pattern of serum complement component concentrations in SSC patients and patients with primary biliary cirrhosis, two disorders frequently associated in the same patients. The significance of complement component patterns in these diseases is discussed.

Complement Activation↗
PubMed1975

Alternative C3 pathway activiation in pneumococcal glomerulonephritis.

Glomerulonephritis following pneumococcal infection has been observed, but possible immunopathologic mechanisms have not been adequately explored. Multiple serologic studies as well as light, immunofluorescence and electron microscopic evaluation of kidney biopsy tissue from a 4 year old girl with pneumococcal glomerulonephritis were performed. Clinical studies at the onset of the disease showed normal serum C3 and C4 levels (third and fourth components of complement) with progression to selective C3 hypocomplementemia from days 2 to 58. A serum factor capable of breaking down C3 in normal human serum was present during the period of maximum C3 hypocomplementemia. Renal glomerular histology revealed a mesangial proliferative glomerulonephritis. Glomerular bound C3 and type 14 pneumococcal antigen were associated with similar, but less extensive, deposits of properdin. Minimal immunoglobulin M (IgM) and C4 were seen, but immunoglobulin G (IgG) and fibrinogen were absent. Ultrastructurally, subepithelial "humps" and intramembranous electron dense deposits were noted. It is hypothesized that the pneumococcal polysaccharide can activate the alternate complement pathway and may be responsible for a limited course of glomerulonephritis.

Antigens, Bacterial↗
PubMed1976

Recurrence of membranoproliferative glomerulonephritis following kidney transplantation. Serum complement component studies.

Sixteen patients with membranoproliferative glomerulonephritis who required kidney transplantation because of renal failure were evaluated for evidence of recurrence of the original disease by serologic and morphologic studies. Of the 12 patients with transplant tissue available for study, seven showed membranoproliferative glomerulonephritis by light morphology. Four of these seven also had hypocomplementemia, and this hypocomplementemia was characterized by decreased serum CH50, C3 beta1A or C3-C9 but norma serum C1, C4 and C2 by hemolytic assay. Immunofluorescent microscopy demonstrated more intense glomerular deposition of C3 and properdin in the hypocomplementemic patients. Ultrastructural studies demonstrated intramembranous deposits typical of dense deposit disease in one patient who also had marked hypocomplementemia. One patient who had two transplant biopsies and persistent hypocomplementemia showed progression from predominantly mesangial glomerular changes to both capillary wall and mesangial abnormalities. This study has shown a high rate of recurrence of membranoproliferative glomerulonephritis in the transplanted kidneys. A high death rate was noted in persistently hypocomplementemic patients. The serum C profile in hypcomplementemic patients who received translants was similar to that seen before transplantation, but the signficance of this finding remains unknown.

Adolescent↗
PubMed1977

Activation of protein mediators of inflammation and evidence for endotoxemia in Borrelia recurrentis infection.

Fifteen patients with Borrelia recurrentis infection were studied to evaluate the role of certain plasma proteins and endotoxin in the pathophysiology of both the acute illness and the Jarisch-Herxheimer-like reaction. The causative spirochetes disappeared from the blood during the Jarisch-Herxheimer-like reaction, which occurred about 2 hours after antibiotic therapy. The mean titers of Hageman factor, plasma prekallikrein and serum hemolytic complement activity were decreased at the time of admission and 2 hours after treatment, and rose to normal values during convalescence. Serum properdin titers were decreased in 14 patients at the time of admission, in 12 patients 2 hours after treatment, and in none during convalescence. The frequency of elevated levels of fibrinogen-related antigens increased from three patients at the time of admission to 12 patients 2 hours after treatment. Results of plasma limulus tests for endotoxin-like material were positive in 11 patients at the time of admission and in 13 patients 2 hours after treatment. These findings demonstrated that Hageman factor, prekallikrein and proteins of the complement system are activated in B. recurrentis infection and that endotoxin may play a role in both the acute illness and in the development of the Jarisch-Herxheimer-like reaction after treatment.

Adolescent↗
PubMed1975

The use of cholinesterase in severe head injury.

White rats were subjected experimentally to head injury, and also observations were made on them and on 12 patients with head injuries. It was found that injection of cholinesterase brought back to normal function the endogenous cholinesterase system, the adrenal cortex and the properdine--albumin complex system. Stabilization of these indices of homeostatic activity improved the chances of survival of the animals and patients. It was concluded that it would be desirable to administer cholinesterase more frequently in the treatment of head injury.

17-Hydroxycorticosteroids↗
PubMed1977

Decreased opsonization for Streptococcus pneumoniae in sickle cell disease: studies on selected complement components and immunoglobulins.

Opsonic activity for Streptococcus pneumoniae in the sera of patients with sickle cell disease was reduced in comparison to the opsonic activity of sera from age-matched normal children. No difference in opsonic activity for Escherichi coli was observed in the sera from patients or normals. Total hemolytic complement, conversion of C3 by inulin and cobra venom factor, and levels of C3, factor B, properdin, C3b inactivator, and immunoglobulins G, A, and M were normal in patients' sera. The opsonic abnormality for S. pneumoniae was attributed to a deficiency of serum proteins rather than to an inhibitor of opsonic function. The data suggest that decreased opsonization was not associated with a deficiency of those complement components or immunoglobulins measured in this study.

Adolescent↗
PubMed1975

C1-bypass complement-activation pathway in patients with chronic urticaria and angio-oedema.

During the routine screening of 152 patients with urticaria or angio-oedema for hypocomplementaemia, 4 patients were found to have low serum levels of the third component of complement (C). These patients were noteworthy and differed from previous reports of patients with urticaria-like skin lesions and hypocomplementaemia because of the absence of immune-complex disease. In addition to the low C3, 2 of these patients were unique on the basis of low serum levels of haemolytic C1, C1q, C1s, and properdin factor B, but normal concentrations of C4 and C2. These C abnormalities may reflect a new clinical entity, and these cases form the first description in man of the C1-bypass complement-activation pathway.

Adult↗
PubMed1989

Complement deficiencies in patients over ten years old with meningococcal disease due to uncommon serogroups.

46 patients in whom meningococcal disease due to serogroups X, Y, Z, W135, or 29E had developed after the age of 10 years were investigated retrospectively for complement deficiency. Complement deficiency was found in half of the patients: properdin deficiency in 9 patients, C3 deficiency syndromes in 5, and homozygous deficiency of a terminal component (C5, C6, C7, or C8) in 9. Meningococcal infections recurred in 5 of the 9 patients with terminal complement component deficiencies but not in the other complement-deficient patients. The findings show that meningococcal disease due to uncommon serogroups is often associated with complement deficiency.

Adolescent↗
PubMed1983

Recurrent meningococcal meningitis due to partial complement defects and poor anti-meningococcal antibody response.

An otherwise healthy young man had three episodes of meningococcal meningitis within three years. The last episode was caused by group A, and occurred four weeks after the patient received group A vaccine, thus representing one of the very few failures of this vaccine. The specific susceptibility to meningococcal infections was connected with half-normal levels of several components of the complement system (C3, C4, C9, factor B, properdin), and reduced antibody responses to group A and group C meningococcal polysaccharides, but not to several other polysaccharide or protein antigens.

Adolescent↗
PubMed1996

Discordant renal histopathologic findings and complement profiles in membranoproliferative glomerulonephritis type III.

Patients with membranoproliferative glomerulonephritis (MPGN) type III and a low serum C3 concentration tend to have evidence for a nephritic factor of the terminal complement pathway (Nft). Complement profiles were studied in three patients with MPGN type III and low serum C3 concentrations. Serum C3 concentrations were 52, 21, and 14 mg/dL (normal range, 83 to 177 mg/dL). Serum Clq, C2, C4, properdin, and C5 concentrations were normal in all patients, whereas two had a slight decrease of C7 or C8. This pattern of complement activation resembles that seen with MPGN type II in which a nephritic factor activates the amplification loop (NFa). We conclude that in patients with MPGN type III the previously reported profile/presence of Nft is not always found, at least in the chronic stage of the disease, despite a low C3 value.

Biopsy↗
PubMed1993

Detection of mosaic protein mRNA in human astrocytes.

Mosaic proteins consist of a group of proteins that may be comprised of one or more types of a variety of different structural modules and have a diverse range of functions. We have examined primary human astrocyte cultures for the presence of three mosaic proteins, B2I and the complement proteins factor H and properdin. Using the polymerase chain reaction and an enhanced chemiluminescence detection technique, we were able to show that mRNA transcripts for each of these proteins are expressed in human astrocytes.

Astrocytes↗
PubMed1976

Arthritis associated with intestinal-bypass procedure for morbid obesity. Complement activation and characterization of circulating cryoproteins.

Five patients were studied after intestinal-bypass operations for morbid obesity to determine if the arthritis observed in three of these patients was associated with circulating cryoproteins. Only serum from the three patients with acute arthritis contained cryoprotein complexes. The complexes comprised IgG, IgM, IgA, complement components C3, C4, C5 and IgG antibody against Escherichia coli and Bacillus fragilis. The C3-activator fragment of the properdin complex was identified in fresh serum samples obtained from two of the three patients with circulating cryoprotein complexes and arthritis. These observations suggest that systemically absorbed intestinal bacterial antigens may lead to (or contribute to) the formation of circulating cryoprotein complexes. Circulating cryoprotein complexes activated both the classical and alternate complement pathways and may be important in the pathogenesis of the arthritis associated with the intestinal-bypass procedure for morbid obesity.

Adult↗
PubMed1977

Linkage between the gene (or genes) controlling synthesis of the fourth component of complement and the major histocompatibility complex.

In an attempt to map the gene (or genes) controlling the synthesis fo the fourth component of complement (C4), we performed linkage studies in a family with hereditary C4 deficiency. The proband, a seven-year-old boy with lupus erythematosus, consistently lacked deteftable serum C4 by both functional and protein measurements. The complement defect was transmitted as an autosomal recessive disorder. Eight of 15 family members were considered to be heterozygotes, seven because of low C4 levels and one because of genetic data (obligate heterozygote). The gene (or genes) coding for C4 deficiency appeared to be linked to the major histocompatibility complex (A2,B12,DW2 on the maternal side and A2,BW15,LD108 on the paternal side) and to other markers known to be in close proximity to the histocompatibility complex on chromosome 6 (phosphoglucomutase-3, glyoxalase-1 and properdin factor B).

Child, Preschool↗
PubMed1977

Activation of the alternative complement pathway due to resistance of zymosan-bound amplification convertase to endogenous regulatory mechanisms.

The surface of zymosan (Zy), by affording a protected microenvironment for C3b and the amplification convertase stabilized by properdin, P,C3b,Bb, shifts the alternative complement pathway from slow fluid phase turnover to the amplification phase of its expression. This mode of activation is in contradistinction to that of the classical pathway, which follows conversion of a proenzyme, Cl, to its active form, C1. Under conditions in which the control proteins, C3b inactivator (C3bINA) and beta1H, completely, inactivated C3b on the sheep erythrocyte intermediate, EAC4b,3b, the activity of C3b bound to Zy,ZyC3b, was diminished by only one-third. Further, when ZyC3b was converted to ZyC3b,Bb,P there was an additional point of deregulation in that the convertase was resistant to beta1H-mediated decay-dissociation while P,C3b,Bb on the sheep erythrocyte exhibited the usual susceptibility to beta1H. That Zy alone could indeed promote rapid C3 cleavage by the alternative pathway through assembly and protection of the amplification convertase on its surface was demonstrated with a mixture of alternative pathway proteins, C3,B,D,P, C3bINA, and beta1H, that had each been purified to homogeneity. Interaction of these proteins at one-tenth their relative serum concentrations with Zy permitted low-grade inactivation of C3 and B to advance to the level of amplification after a 15 min lag period. Because the reaction of the purified proteins proceeded spontaneously when either regulatory protein was deleted, the effect of Zy was attributed to deregulation rather than to conversion of one of the proteins to a specific initiating state. The alternative pathway, through the normal presence of D, interacts with a microbial surface, such as Zy, to amplify deposition of C3b by circumvention of endogenous regulatory mechanisms, thereby augmenting host defense.

Animals↗
PubMed2000

Thrombospondin type 1 repeats interact with matrix metalloproteinase 2. Regulation of metalloproteinase activity.

Thrombospondins are thought to function as inhibitors of angiogenesis. However, the mechanism(s) of this activity is not well understood. In this study, we have used the yeast two-hybrid system to identify proteins that interact with the thrombospondins 1 (TSP1) and 2 (TSP2) properdin-like type 1 repeats (TSR). One of the proteins identified that interacted with both TSR was matrix metalloproteinase 2 (MMP2). The isolated MMP2 cDNA clone encoded amino acid residues 237-633, which include the fibronectin-like gelatin binding region flanking the catalytic center and the carboxyl hemopexin-like region. Further testing of this clone demonstrated that the TSR interacted with the NH(2)-terminal region of the MMP2 that contains the catalytic domain. The protein interaction observed in yeast was further demonstrated by immunoprecipitation and Western blotting using purified intact TSP1, TSP2, MMP2, and MMP9. Although MMP2 interacted with TSP1 and TSP2 via its gelatin-binding domain or a closely mapping site, neither TSP1 nor TSP2 was degraded by MMP2 in vitro. Tissue culture and in vitro assays demonstrated that the presence of purified TSR and intact TSP1 resulted in inhibition of MMP activity. The ability of TSP1 to inhibit MMP3-dependent activation of pro-MMP9 and thrombin-induced activation of pro-MMP2 suggests that the TSPs may inhibit MMP activity by preventing activation of the MMP2 and MMP9 zymogens.

Animals↗