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PubMed1988

Lumbar disc surgery and variations in C-reactive protein, erythrocyte sedimentation rate and the complement split product C 3 d.

Lumbar disc surgery was performed in fifty consecutive patients and variation in erythrocyte sedimentation rate (ESR), complement C 3 d, and C-reactive protein (CRP) levels before and after surgery were recorded. Preoperative values were within normal limits in all patients. Postoperatively, CRP increased immediately, with a maximum of 28.5 mg/l on the 2nd day and were normalized within 6 days. The maximum ESR elevation occurred after the 6th day and was followed by a slow decrease. After 12 weeks some patients still had an elevated ESR. Plasma C 3 varied pari passu with the ESR. Uncomplicated recovery after lumbar disc surgery seems to be indicated by a normalization of CRP, regardless of ESR values. Therefore, ESR may not be so useful as an indicator of disc space inflammation as previously accepted.

Adult↗
PubMedDate not supplied

Differences among acute, subacute, and chronic chorioamnionitis based on levels of inflammation-associated proteins in cord blood.

The serum concentration of inflammation-associated proteins and several complement components in the cord blood of 215 newborns with and without chorioamnionitis (CAM), who were delivered between 17 and 42 weeks of gestation, were measured. We investigated the relationship of levels of serum proteins to acute, subacute, and chronic CAM, and to subacute necrotizing funisitis (SNF). Complement components C3d, C3, and C4 levels increased in subacute CAM (P = 0. 0002, P = 0.0007, P = 0.0029, respectively), whereas factor B increased in each type of CAM (P = 0.0001, P = 0.0009, P = 0.0004, respectively). Among the immunoglobulins, IgG levels were unrelated to the presence or type of CAM, IgM levels increased in subacute CAM (P < 0.0001), and IgA levels increased in chronic CAM (P < 0.0001). Among the acute phase reactants (APR), haptoglobin and C-reactive protein (CRP) levels increased in acute (P < 0.0001, P = 0.0022, respectively) and chronic CAM (P = 0.0035, P = 0.0345, respectively), whereas orosomucoid levels increased in chronic CAM (P = 0.0003). IL-6 levels increased in acute (P = 0.0011) and subacute (P = 0. 0475) CAM. C3d (P = 0.0063), C3 (P = 0.0289), C4 (P = 0.0491), and IgM (P < 0.0001) levels were increased in SNF. These findings suggest that the histologic distinction of acute, subacute, and chronic CAM is a useful indicator of the inflammatory mediator status of the infants. The infants with SNF may have ended their initial active inflammatory states, but they still have subacute immune activation.

Acute Disease↗
PubMed1987

Reinvestigations into the formation and assay of C3bBbP complexes.

C3bBbP complex formation was studied by an enzyme linked immunosorbent assay (ELISA). Microtitre plates were coated with anti-P to trap the complexes and peroxidase labelled anti-C3 was used to detect them with the help of substrates of peroxidase. Incubation of normal serum pool (NSP) at 37 degrees C in the presence of high concentrations (greater than or equal to 0.5 mmol/l) of Mg2+, usually used in alternative pathway (AP) assay systems, caused the generation of C3bBbP complexes. This generation was not observed when NSP was incubated in the presence of low Mg2+ concentration (less than or equal to 0.2 mmol/l) or EDTA. The concentration of Mg2+ required for maximum complex formation was 2.0 mmol/l under the experimental conditions. Complexes could not be generated in B-depleted serum. Incubation of NSP with endotoxin or CoVF in the presence of 0.2 mmol/l Mg2+ caused the generation of the complexes. The generation was influenced by ionic strength in the incubation mixture. Endotoxin and Mg2+-dependent generation of complexes could not be detected when peroxidase-labelled anti-B was used instead of peroxidase-labelled anti-C3. Serum incubated with 0.2 mmol/l Mg2+ or EDTA apparently detected in vivo formed complexes whereas that incubated with 0.2 mmol/l Mg2+ and endotoxin reflected the complex forming capacity of the serum. The serum of a patient with Raynaud's phenomenon having 45% of normal AP activity did not show increased amounts of preformed complexes but had the ability to generate the complexes to a level of about 45% of that attainable by NSP. These observations suggest that the ELISA used here has the potential of detecting activation as well as the integrity of the AP under carefully controlled conditions.

Complement C3↗
PubMed1989

Preparation of monoclonal antibodies to C3b by immunization with C3b(i)-sepharose.

We have prepared and characterized four monoclonal antibodies (MAbs) to human C3b of high specificity and affinity. Our procedure did not require a purified source of C3b for immunization. Instead, C3b and C3bi were deposited on Sepharose 4B via the alternative pathway of complement activation in normal human serum, and this C3b(i)-Sepharose served as the immunogen. C3b(i)-Sepharose was also prepared from a number of primate and non-primate sources, and this allowed us to demonstrate that the anti-human C3b MAbs cross-reacted with primate-derived C3b, but not with C3b from non-primates. The procedures we have developed may be useful in the further investigation of species-specific C3 fragment-binding proteins from both primate and non-primate sources.

Animals↗
PubMed1989

Hairy leukoplakia: Epstein-Barr virus receptors on oral keratinocyte plasma membranes.

Hairy leukoplakia (HL) is an oral white lesion associated with, and probably caused by, the Epstein-Barr virus (EBV) among persons who are seropositive for infection with human immunodeficiency virus. A unique feature of HL is its localization to the lateral portion of the tongue. To determine site differences for EBV receptors according to epithelial phenotype, these receptors were mapped in oral mucosa with the use of monoclonal antibodies HB5 and B2(specific for the Complement Fraction 3d/EBV receptor on B lymphocytes). Immunoperoxidase and immunofluorescence techniques were employed with the use of both cytologic suspensions and frozen tissue sections of oral epithelium. Pericellular plasma membrane immunoreactants were localized to upper spinous layer cells of the parakeratin phenotype; basal and parabasilar layers as well as all strata of orthokeratinized epithelia were negative. Those cells harboring EBV DNA as detected by in situ hybridization corresponded to cells with C3d/EBV receptors.

Antibodies, Monoclonal↗
PubMedDate not supplied

Sequential occurrence of IgM, IgM/IgG, and gp120-IgM/IgG complement complexes on CD4+ lymphocytes in relation to CD4+ blood lymphocyte depletion in HIV+ hemophilia patients: results of a 10-year study.

The concept of autoimmune mechanisms playing an integral role in the pathogenesis of HIV disease is rapidly gaining ground. In this study, we determined IgM and IgG antibodies, complement fragments and gp120 on the surface of CD4+ lymphocytes using double-fluorescence flow cytometry. Sequential analysis demonstrated an inverse relationship of autoantibodies and CD4+ lymphocyte counts in the peripheral blood. HIV+ patients without autoantibodies (16/104 = 15%) had the highest CD4+ blood cell counts (324 +/- 264/microliters; mean +/- SD). CD4+ counts were successively lower in patients with complement-fixing IgM (243 +/- 240/microliter), complement-fixing IgG and IgM (139 +/- 138/microliter), or gp120-IgM/IgG complement complexes on the surface of CD4+ cells (38 +/- 45/microliter, P = 0.03). Individual patient profiles show that IgM autoantibodies typically are formed early after HIV infection and appear to deplete CD4+ lymphocytes very slowly, whereas complement-fixing IgG autoantibodies are generated at a later stage and deplete CD4+ lymphocytes more efficiently. The presence of both soluble gp120 and complement-fixing autoantibodies on CD4+ lymphocytes is associated with very low CD4+ cell counts and coincides with progression to terminal disease. Early during HIV infection autoantibody production is rather unstable, but it becomes more stable with disease progression and persists in advanced stages of the disease. These data suggest that autoantibody formation against CD4+ lymphocytes is a pathogenic mechanism for CD4+ cell depletion.

Antigen-Antibody Complex↗
PubMed1989

Effect of methylprednisolone on endotoxemia and complement activation during cardiac surgery.

The influence of high doses of methylprednisolone on complement activation and endotoxin concentration was investigated in two groups of eight patients undergoing coronary artery bypass grafting. Group 1 received methylprednisolone, 30 mg/kg, at the induction of anesthesia; group 2 served as the control group. The endotoxin concentrations increased significantly in both groups at the start of cardiopulmonary bypass. During cardiopulmonary bypass, the endotoxin concentrations were significantly higher in the steroid group compared with the control group (p less than 0.01). After completion of surgery, the endotoxin concentrations declined to almost zero within seven days in both groups. Complement activation was significantly reduced in the steroid-treated group during cardiopulmonary bypass compared with the control group (P less than 0.01). The clinical outcome after the first postoperative week was the same in the two groups. It appears that high-dose steroids can reduce complement activation during cardiopulmonary bypass, although the clearance of endotoxins may also be reduced.

Aged↗
PubMedDate not supplied

Role of Akata cell membrane fluidity in susceptibility to Epstein-Barr virus infection.

Infection by Epstein-Barr virus (EBV), a B lymphotropic human herpesvirus, of its target cells is initiated by the binding of the viral envelope glycoprotein gp350/220 to a 145-kDa cell membrane glycoprotein (CD21, CR2) which also serves as the receptor for the complement fragment C3d (Fingeroth et al., 1984; Nemerow et al., 1987). We used the fluorescent probe 1-6-diphenyl-1,3,5-hexatriene (DPH), extremely sensitive to the polar environment, in order to analyse the membrane viscosity distribution in single cells of two lymphoid cell lines, Raji and Akata. Lipid analysis on both cell lines showed a slightly lower cholesterol:phospholipid molar ratio on Akata than on Raji cells. Measurements of cell fluidity by DPH polarization in native cells and after cholesterol enrichment indicated that the apparent Akata membrane viscosity was lower than the viscosity of Raji cells. To examine the possibility that this difference could be correlated to a difference in the behaviour of Akata and Raji cells in expressing EBV early antigens, both lines were superinfected with the EBV non-transforming P3HR1 strain. We report here evidence that lipid composition can regulate EBV entry into cells.

Antigens, Viral↗
PubMed1996

Aortobifemoral surgery induces complement activation and release of interleukin-6 but not tumour necrosis factor-alpha.

The aim of the present study was to determine the inflammatory response by an extended analysis of complement in 16 patients undergoing aortobifemoral bypass surgery. The patients were randomized to receive either a bifurcated expanded polytetrafluoroethylene graft (n = 8; group I) or a collagen-impregnated knitted Dacron graft (n = 8; group II) to determine whether differences in graft surface properties might influence the inflammatory response during and after the procedure. The following components of complement: C1q, C4, C3, C3d, C5a and terminal complement complexes were all analysed. C-reactive protein and interleukin-6 were also determined to assess the acute phase response. The complement data were corrected for haemodilution, which was assessed from alpha 2-macroglobulin concentrations. A significant decrease of C1q (P < 0.0001) and an increase in C5a (P < 0.0005) was observed in both groups. C4 and C3 levels showed slight fluctuations in group I, whereas in group II these proteins increased significantly (P < 0.05, P < 0.005, respectively) between 2 and 7 days after surgery. Terminal complement complexes remained unchanged in both groups. Interleukin-6 levels peaked at 12-24 h and the C-reactive protein at 24-72 h. Higher interleukin-6 levels (P < 0.05) were found in group II 6 h after surgery compared with group I; no release of tumour necrosis factor-alpha was identified. An early inflammatory response was found in all patients. The patterns of the complement proteins varied with a C1q depletion and a C5a increase, interpreted as complement activation. Whether the variations between the two graft groups represent any differences in graft surface properties has to be further elucidated.

Aged↗
PubMed2006

[Antireceptor and antichannel autoantibodies].

This review of literature concerns the different autoantibodies directed against membrane receptors and ion channels. The target antigens, the associated pathologies, the pathogenesis and the methods of detection of these autoantibodies will be addressed. Some of these autoantibodies are thought to be closely related to the auto-immune disease whereas for some others their pathogenesis role is still unclear. Overall, the roles of antibodies are different between diseases, but the presence of such autoantibodies support the basis of intervening immunotherapy, antibody titers predicted the activity of the diseases and some of them are very specific and become the useful markers for the diagnosis. Some autoantibodies are detected routinely as the antiacetylcholine receptor, voltage-gated potassium and calcium channels autoantibodies whereas most of them are detected very rarely and only by specialized laboratories. This review will be divided in three parts with the following classification: the first group of autoantibodies directed against membrane receptors included receptors with an enzymatic activity (mostly tyrosine kinase) with one transmembrane domain, receptors associated to G protein with seven transmembrane domains, ion channels and receptors associated to the membrane by the glycosylphosphatidylinositol and the second group of intracellular receptor autoantibodies directed to the estrogens, androgens, lamin and kinesin receptors.

Asialoglycoprotein Receptor↗
PubMedDate not supplied

The covalent interaction of C3 with IgG immune complexes.

Antigens (Ags) are converted into immune complexes (antigen-antibody complexes, IC) as soon as they encounter their specific antibodies (Abs). In fluids containing complement, the process of IC formation and fixation of complement components occur simultaneously. Hence, the formation of Ag-Ab-complement complexes is the normal way of eliminating Ags from a host. C3b-C3b-IgG covalent complexes are immediately formed on interaction of serum C3 with IgG-IC. These C3b-C3b dimers constitute the core for the assembly of C3/C5-convertase on the IC, which are subsequently converted into iC3b-iC3b-IgG by the complement regulators. These complexes are detected on SDS-PAGE by two bands of molecular composition, C3alpha65-C3alpha43 (band A) and C3alpha65-heavy chain of the Ab (band B), which correspond to C3b-C3b and C3b-IgG covalent interaction respectively, and that identify opsonized IC (C3b-IC). C3b can attach to Fab and Fc regions of the Ab molecule with similar efficiency. The presence of multiple C3b binding regions on IgG is considered an advantageous characteristic that facilitates the elimination of Ags in the form of C3b(n)-IC. Ab molecules on the IC recognize the Ag, and also serve as a very good acceptor for C3b binding. In this way, Ags, even if they have no acceptor sites for C3b, can be efficiently processed and removed. When C3 is activated in serum by IC or other activators, secondary C3b-IgG covalent complexes are generated, with bystander monomeric circulating IgG, and thus constitute, physiological products of complement activation. These complexes gain importance when IgG concentration is extremely high as in cases of infusion of intravenous IgG (IVIG) in several pathologies. The covalent attachment of activated complement C3 (C3b, iC3b, C3 d,g) to Ags or IC links innate and adaptative immunity by targeting Ags to different cells of the immune system (follicular dendritic cells, phagocytes, B cells). Hence C3b marks Ags definitively, from the earliest contact with the innate immune system until their complete elimination from the host.

Amino Acid Sequence↗
PubMed1998

Complement activation and CD59 expression in the motor facial nucleus following intracranial transection of the facial nerve in the adult rat.

Intracranial transection of the facial nerve has been shown to cause a massive neuronal cell death in the motor facial nucleus. Complement activation has been proposed to contribute to neuronal degeneration following axotomy. Using immunocytochemistry and in situ hybridization we show in the present study that there is complement activation in the facial nucleus after intracranial facial nerve transection as well as increase of the complement regulators CD59 and clusterin. We propose a neuroprotective role for the complement regulators CD59 and clusterin against homologous attack of complement to facial motor neurons.

Age Factors↗
PubMed1998

A clinical and virological study of hepatitis C virus-related cryoglobulinemia in Germany.

BACKGROUND/AIMS: Several reports, especially from Southern Europe, have demonstrated a close association between hepatitis C virus (HCV) infection and mixed cryoglobulinemia. In this study we have analyzed the significance of HCV-related cryoglobulinemia in Germany. METHODS: Sera from 79 patients with cryoglobulinemia of type I (n=21), II (n=28) or III (n=30) were investigated for HCV markers. Furthermore, 132 consecutive patients with chronic hepatitis C were studied for the presence of cryoglobulins. Genotypes of HCV were determined according to Simmonds, and HCV-RNA concentrations were measured in patients with and without cryoglobulinemia. RESULTS: In 79 patients with cryoglobulinemia we found anti-HCV antibodies in 17 (22%) and HCV-RNA in 11 patients (14%). HCV antibodies were more frequent in essential (44%) compared to secondary mixed cryoglobulinemia (15%). In 132 patients with chronic HCV infection cryoglobulins were detected in 37 patients (28%), in 21 of them at low levels. Clinical symptoms due to cryoglobulinemia were observed in eight of the 37 patients, severe vasculitis in three patients with high cryocrit-levels and cryoprecipitation at room temperature. HCV genotype 1 and subtype 1b were most prevalent, both in patients with and without cryoglobulinemia, and mean HCV-RNA levels were not different between the two groups. Comparison of HCV-RNA levels in cryoprecipitates, supernatant and native serum suggests binding of HCV-RNA to the cryoprecipitate with different affinity in individual patients. CONCLUSIONS: The lower prevalence of HCV-related cryoglobulinemia in our study compared with data from Italy and France suggests a south-north gradient in the prevalence of HCV-associated cryoglobulinemia in Europe.

Adult↗
PubMed2003

Severe IgA-mediated auto-immune haemolytic anaemia in a 48-yr-old woman.

Auto-immune haemolytic anaemia (AIHA) is characterised by haemolysis associated with the presence of the immunoglobulins IgG, IgM or IgA, and/or components of the complement system on the red cell membrane. The immunoglobulins react as auto-antibodies against the red cell antigens of the patient. IgG antibodies and the complement component C3d can be detected by the direct antiglobulin test (DAT); however, IgM and particularly IgA antibodies may not necessarily be detected by the broad-spectrum anti-human-globulin serum. We present the case of a 48-yr-old woman with severe AIHA. The initial polyspecific direct antiglobulin test (DAT), using a broad-spectrum antiserum, was negative. Testing with monospecific antisera led to the diagnosis of AIHA due to warm-acting auto-antibodies solely of the IgA class, which is a very rare finding. As therapy with steroids alone did not lead to a lasting remission, splenectomy was performed 10 months after initial diagnosis. There has been no relapse of AIHA since, even after steroid medication was withdrawn and even though the monospecific IgA-DAT has remained positive. This case demonstrates the importance of performing a monospecific antiglobulin test if there is a strong suspicion of AIHA in apparently "Coombs-negative" haemolytic anaemia. In AIHA caused by solely IgA antibodies, the polyspecific direct antiglobulin test may be negative or only weakly positive because of a limited content of anti-IgA antibodies in the polyspecific anti-human-globulin serum. First-line treatment of warm-type AIHA is the administration of high-dose glucocorticosteroids; splenectomy is indicated in steroid-refractory patients.

Anemia, Hemolytic, Autoimmune↗
PubMed2002

Effects of antioxidants on pyridinoline cross-link formation in culture supernatants of fibroblasts from normal skin and hypertrophic scars.

Free radicals are normally generated in many metabolic pathways. They are closely associated with inflammatory diseases. The aim of this study was to investigate the effects of free radicals and their antioxidants on the formation of pyridinoline using human fibroblasts from normal skin and hypertrophic scars. The significance of the increase in pyridinoline cross-links is that large quantities have been found in hypertrophic scars formed post-burn than in normal skin, and that catalase was effective in reducing the pyridinoline cross-link formation in hypertrophic scars. The pyridinoline cross-link concentration expressed in nM/ micro g hydroxyl proline was found to be higher in the culture supernatants of the fibroblasts from hypertrophic scars (9.04 +/- 2.74) than that of normal skin (7.55 +/- 2.1). When the human fibroblasts from normal skin and hypertrophic scar were subject to hydroxyl radicals generated by the Fenton reaction, there was no significant increase in pyridinoline cross-link concentration (nm/ micro g hydroxyl proline) in the supernatants compared with the control. When the controls plus various treatments with free radicals were subject to different antioxidants, including superoxide dismutase, catalase, glutathione peroxidase, and desferrioxamine, it was found that catalase alone was most effective in scavenging hydroxyl radicals as determined by the decrease in pyridinoline cross-links.

Amino Acids↗