Impact of bispectral index for monitoring propofol remifentanil anaesthesia. A randomised clinical trial.

BACKGROUND: Previous research has shown that the use of the bispectral index (BIS) monitor to measure the depth of anaesthesia reduces the amount of anaesthetics administered and the recovery time from general anaesthesia. The effect of BIS on recovery from anaesthesia and consumption of anaesthetics in a paediatric population receiving total intravenous anaesthesia (TIVA) with propofol and remifentanil has not been studied. METHODS: A single-blind, single-centre clinical trial. One hundred fifty-seven patients were enrolled. They were scheduled for ear, nose, and throat surgery and stratified according to age groups (1-3 years, 4-11 years, 12-17 years, 18-65 years) and type of operation, yielding a total of nine subgroups. Patients were randomly allocated to receive either a TIVA with propofol and remifentanil according to conventional clinical practice (control) or guided by BIS. Normalised propofol (µg/kg/min) and remifentanil (µg/kg/min) consumption and time to extubation (s) were the outcome measures. RESULTS: Children aged 1-3 years in the BIS group had a longer time to extubation compared with controls (P: 0.04). Patients aged 12-17 years in the BIS group received higher maintenance infusion rates of propofol compared with controls (P = 0.02). No significant difference for the outcome variables was evidenced in the other age groups. CONCLUSION: BIS monitoring for guidance of propofol-remifentanil anaesthesia does not result in reduced consumption of anaesthetics and does not reduce time to extubation in adult and children compared with conventional practice.

Safety and immunogenicity of the epicutaneous reactivation of pertussis toxin immunity in healthy adults: a phase I, randomized, double-blind, placebo-controlled trial.

OBJECTIVES: Protection induced by acellular vaccines can be short, requiring novel immunization strategies. Objectives of this study were to evaluate safety and capacity of a recombinant pertussis toxin (PTgen) -coated Viaskin® epicutaneous patch to recall memory responses in healthy adults. METHODS: This double-blind, placebo-controlled randomized trial (Phase I) assessed the safety and immunogenicity of PTgen administered on days 0 and 14 to healthy adults using Viaskin® patches applied directly or after epidermal laser-based skin preparation. Patch administration was followed by Boostrix®dTpa on day 42. Antibodies were assessed at days 0, 14, 28, 42 and 70. RESULTS: Among 102 volunteers enrolled, 80 received Viaskin-PT (Viaskin-PT 25 µg (n = 25), Viaskin-PT 50 µg (n = 25), laser + Viaskin-PT 25 µg (n = 5), laser + Viaskin-PT 50 µg (n = 25)), Viaskin-placebo (n = 10) or laser + Viaskin-placebo (n = 2). Incidence of adverse events was similar across groups (any local event: 21/25 (84.0%), 24/25 (96.0%), 4/5 (80.0%), 24/25 (96.0%), 8/10 (80.0%), 10/12 (83.0%), respectively). Direct application induced no detectable response. On day 42, PT-IgG geometric mean concentrations were significantly higher following laser + Viaskin-PT 25 µg and 50 µg (139.87 (95% CI 87.30-224.10) and 121.76 (95% CI 95.04-156.00), respectively), than laser + Viaskin-placebo (59.49, 95% CI 39.37-89.90). Seroresponse rates were higher following laser + Viaskin-PT 25 µg (4/5 (80.0%), 95% CI 28.4-99.5) and 50 µg (22/25 (88.0%), 95% CI 68.8-97.5) than laser + Viaskin-placebo (0/12 (0.0%), 95% CI 0.0-26.5). CONCLUSIONS: Viaskin-PT applied after laser-based epidermal skin preparation showed encouraging safety and immunogenicity results: anti-PT booster responses were not inferior to those elicited by Boostrix®dTpa. This study is registered at ClinicalTrials.gov (NCT03035370) and was funded by DBV Technologies.

Pathogenesis of the glomerulonephritis of NZB/W mice.

The development of glomerulonephritis in NZB/W mice is closely related to the formation of antinuclear, particularly anti-DNA, antibodies. The developing inflammatory glomerular lesions are characterized by the deposition of gammaG- and beta(1C)-globulins plus DNA and possibly other nuclear antigens, presumably as complexes, in a granular to lumpy pattern along the capillary walls and in the mesangia. Elution studies revealed the gammaG-globulin in the glomeruli to be largely gammaG(2A)-type antibody to soluble nuclear antigens. Enhancement of the antinuclear antibody response by active immunization of young NZB/W mice with DNA-methylated BSA hastens the development and increases the severity of the glomerulonephritis. Similarly, injections of soluble DNA into NZB/W mice with circulating anti-DNA antibodies but with as yet little nephritis causes rapid progression of nephritis.

In vitro demonstration of a particular affinity of glomerular basement membrane and collagen for DNA. A possible basis for a local formation of DNA-anti-DNA complexes in systemic lupus erythematosus.

In vitro, collagen and collagen-like material in GBM, were demonstrated to have a particular high affinity for any DNA tested (mammalian, bacterial, viral, and plant). GBM fixed DNA 40-80 times more than HGG and BSA and 10-40 times more than bacterial LPS. GBM has a higher affinity for SSDNA than for DSDNA. This binding was inhibited at low pH, low ionic strength, and in the presence of anionic detergents, indicating that the highly negatively charged DNA may interact with the basic site on collagen or GBM by electrostatic forces. This interaction was competitively interfered with by DNA-binding proteins such as Clq. Complexes formed of DNA and anti-DNA antibodies did not exhibit the same binding property as free DNA. However, DNA which was already bound to GBM or to collagen could very efficiently bind anti-DNA antibodies and form immune complexes which would remain on these structures. The biological significance of the binding of DNA to GBM or to collagen should be particularly considered in relation to the pathogenesis of SLE. It is possible that DNA released from disrupted or degenerating cells would bind to surrounding collagen fibers or to basement membranes and then act as an immunoabsorbant for circulating anti-DNA antibodies. Some evidence for an in vivo binding of SSDNA to renal structures was obtained in mice treated with bacterial LPS 2 days before the injection of SSDNA.

Comparison of the immune responsiveness of NZB and NZB X NZW F1 hybrid mice with that of other strains of mice.

The immune responsiveness of (NZB x NZW) F(1) hybrid mice (NZB/W) has been compared with that of three other strains of mice, A/J, BALB/c, and CBA/J. The antigens used included sheep red blood cells (SRBC), keyhole limpet hemocyanin (KLH), bovine serum albumin (BSA), and human gamma-globulin (HGG). It was found that important strain differences existed in the amount of antibody produced, but the relative immune responsiveness depended very much upon the nature of antigen. By comparison with the other strains tested, NZB/W mice had a higher antibody production to some antigens (SRBC and BSA) but were low responders to others (KLH). Induction of unresponsiveness to HGG by treatment with ultracentrifuged HGG was studied in the strains cited above. NZB/W mice became tolerant after injection of HGG ultracentrifuged at 100,000 g for 2 hr. Similar experiments carried out with another preparation of HGG (centrifuged at 20,000 g for 30 min) failed to reveal any abnormal behavior of NZB/W mice as compared to BALB/c or A/J mice. These results do not support the concept that NZB/W mice possess a general immune hyperreactivity or a relative inability to be made tolerant to protein antigens. However, they do not rule out the possibility that these mice have a genetically determined hyperresponsiveness to some antigens, in particular to nuclear antigens.

Deposition of idiotype-anti-idiotype immune complexes in renal glomeruli after polyclonal B cell activation.

We investigated the possible role of idiotypic interactions in the pathogenesis of the glomerular lesions observed in mice undergoing polyclonal B cell activation. BALB/c mice were studied for the presence of renal deposits of T15 idiotype-anti-T15 idiotype-immune complexes (IC) after injection of bacterial lipopolysaccharides (LPS). The T15 idiotype is the major idiotype of BALB/c mice anti-phosphorylcholine (PC) antibodies, which are cross-reactive with the idiotype of the TEPC-15 myeloma protein. This model was used because T15 idiotype-anti-T15 idiotype IC have been detected in the circulation of BALB/c mice after polyclonal B cell activation. First, an idiotype-specific immunofluorescence technique allowed us to detect T15 idiotype-bearing immunoglobulins in glomeruli from day 6 to day 28 after LPS injection. Second, fluorescein isothiocyanate-conjugated TEPC-15 myeloma protein was found to localize in the glomeruli after in vivo injection 18 d after LPS administration. This renal localization was shown to be idiotype-specific and could be quantified in a trace-labeling experiment. Third, kidney-deposited immunoglobulins of mice injected with LPS were eluted, radiolabeled, and analyzed by radioimmunoassay. Both T15 idiotype-bearing immunoglobulins and anti-T15 idiotype antibodies were detected in the eluates, providing further evidence for a renal deposition of T15 idiotype-anti-T15 idiotype IC. Polyclonal B cell activation is likely to result in a simultaneous triggering of many idiotypic clones and of corresponding anti-idiotypic clones represented in the B cell repertoire. This could lead to the formation of a variety of idiotype-anti-idiotype IC that could participate in the development of glomerular lesions.

Release of DNA in circulating blood and induction of anti-DNA antibodies after injection of bacterial lipopolysaccharides.

The present data demonstrate the induction of antisingle-stranded (SS) DNA and antidouble-stranded DNA antibodies in various strains of mice, including athymic C57BL/6 nude mice, after the injection of bacterial lipopolysaccharide (LPS). This anti-DNA response is dose dependent and varies quantitatively according to the strain of the injected mice. It is not correlated to the H-2 histocompatibility locus nor to the immune response to LPS. The lipid A fraction appears to be the active part of the LPS molecule for this particular effect. In addition, it was found that DNA is released in circulating blood a few hours after the injection of LPS. Most of the DNA released has physicochemical and immunochemical characteristics of SS DNA. Therefore, the anti-DNA response induced by injections of LPS may be the result of a release of DNA in a particularly immunogenic form at a time when the immune system, in particular the B lymphocytes, is rendered capable by LPS of developing an immune response to such a soluble antigen. These effects of LPS may account for the triggering or the exacerbation of ante-DNA antibodies during infections with gram-negative bacteria, and a similar mechanism may be involved in the pathogenesis of systemic lupus erythematosus.

Induction of acute thrombocytopenia and infection of megakaryocytes by Rauscher murine leukemia virus reflect the genetic susceptibility to leukemogenesis.

Acute thrombocytopenia and megakaryocyte infection have been investigated during the preleukemic phase of the disease induced by the Rauscher murine leukemia virus (RMuLV) in mice. Injection of RMuLV, either intravenously or intraperitoneally, rapidly induced thrombocytopenia, possibly as a result of direct interaction between platelets and viral particles. The susceptibility to this acute thrombocytopenia was genetically controlled and was inherited as a dominant trait. Murine strains with H-2d or H-2k haplotype, which are susceptible to the induction of leukemia by RMuLV, developed thrombocytopenia, whereas leukemia-resistant H-2b and H-2q strains of mice failed to develop thrombocytopenia. Using B10 H-2-congenic and intra-H-2-recombinant mice, it was shown that the susceptibility to RMuLV-induced thrombocytopenia was controlled by gene(s) in or closely linked to the D region of the H-2 complex. Megakaryocytes may be one of the first sites for the replication of RMuLV. Indeed, among bone marrow cells, only megakaryocytes expressed viral antigens gp70 and p30 during the initial phase of RMuLV infection. In addition, megakaryocytes from infected mice were able to transfer preleukemic thrombocytopenia as well as leukemia in syngeneic mice. The infection of megakaryocytes by RMuLV appears to be genetically controlled in a manner similar to the induction of thrombocytopenia, since only the megakaryocytes from mice developing thrombocytopenia were infected by RMuLV. These results indicate that the gene(s) governing the induction of thrombocytopenia by RMuLV may be the same gene(s) (or closely linked to the gene) that controls the susceptibility to leukemogenesis, and would be consistent with the expression of the gene product, presumably a receptor-like molecule for RMuLV, on platelet and megakaryocyte membranes.

Schistosoma mansoni shares a protective carbohydrate epitope with keyhole limpet hemocyanin.

The glycanic epitope of the 38,000 Mr Schistosoma mansoni schistosomula major immunogen defined by the IPLSm1 protective mAb was identified in the hemocyanin of the marine mollusc Megathura crenulata, better known as KLH. This antigenic community was exploited to investigate further the biological properties of this epitope. KLH was shown to strongly inhibit the binding of IPLSm1 mAb to its 38,000 Mr target antigen. Immunization of naive LOU rats with KLH elicited the production of anti-S. mansoni antibodies capable of immunoprecipitating the 38,000 Mr schistosomulum antigen. Antibodies to KLH mediated a marked eosinophil-dependent cytotoxicity and passively transferred immunity towards S. mansoni infection. Finally, rats immunized with KLH were significantly protected against a challenge with S. mansoni cercariae. The deglycosylation of KLH completely abolishes its immunological and functional KLH properties, indicating the participation of an oligosaccharidic epitope of the native KLH that is also recognized by the sera of S. mansoni-infected patients. These observations provide new opportunities of access to the well-defined structure of a glycanic epitope potentially available for the immunoprophylaxis and seroepidemiology of schistosomiasis, and a new approach to the isotypic response towards a well-chemically defined epitope.

Features of systemic lupus erythematosus in mice injected with bacterial lipopolysaccharides: identificantion of circulating DNA and renal localization of DNA-anti-DNA complexes.

After injection of lipopolysaccharides (LPS) in mice, there is first a release of DNA into plasma and secondly an induction of anti-DNA antibodies. The circulating DNA was purified from plasma and physico-immunochemically characterized. This DNA has a similar density to mammalian cellular DNA,is 4--6S insize, and probably represents a mixture of single-stranded DNA (SSDNA) and double-stranded DNA (DSDNA) or DSDNA with some single-stranded regions. This purified DNA was shown to react with anti-DNA antibodies which appeared as early as 3 days after a single injection of LPS in mice. In serum, DNA-anti-DNA complexes were not detected, although unidentified circulating immune complex-like material was demonstrated 5-8 days after the injection of LPS. In tissues, particularly in renal glomeruli, fine granular immune complex-type immunoglobulin deposits appeared along the glomerular capillary walls and in the mesangium 3 days after the injection of LPS. There is a direct correlation between the level of anti-DNA antibodies and the intensity of glomerular deposits and about 40% of immunoglobulins eluted from kidneys are anti-DNA antibodies, indicating that some of the immune complexes localized in kidneys are DNA-anti-DNA complexes. Based on these observations, the following hypothetical mechanism for the glomerular localization of DNA-anti-DNA complexes after the injection of LPS in mice is proposed. First, DNA, which has been released in circulating blood after injection of LPS, might bind to renal glomeruli, probably on glomerular basement membranes (GBM) through a high affinity of GBM for DNA; secondly, circulating anti-DNA antibodies, which appear later, might react with the glomerular-bound DNA and form immune complexes independently of circulating immune complexes. However, the possibility of direct deposition of immune complexes is not ruled out.

Prevention of experimental cerebral malaria by anticytokine antibodies. Interleukin 3 and granulocyte macrophage colony-stimulating factor are intermediates in increased tumor necrosis factor production and macrophage accumulation.

IL-3 and granulocyte/macrophage colony stimulating factor (GM-CSF) are two cytokines released by activated T lymphocytes that stimulate the growth and differentiation of various hematopoietic cell lines, among which are macrophages. It has been shown that TNF/cachectin, another cytokine that is released mostly by activated macrophages, plays a central role in experimental cerebral malaria (CM), an acute and lethal neurological syndrome induced by Plasmodium berghei ANKA infection in CBA mice. Since CM requires functional CD4+ T lymphocytes to occur, we explored, by injecting rabbit antibodies to murine rIL-3 and/or GM-CSF, whether these cytokines are intermediates in the marked TNF release leading to CM. Treatment of infected mice with each antibody separately had no protective effect. In contrast, when both anti-rGM-CSF and anti-rIL-3 antibodies were injected together; (a) the occurrence of neurological syndrome was prevented in 90% of the cases; (b) the rise in serum TNF was prevented; and (c) macrophage accumulation in the spleen was significantly reduced. Murine CM appears to involve a cytokine cascade in which IL-3 and GM-CSF lead to the accumulation of TNF-releasing macrophages in vivo.

Interleukin 6 production in experimental cerebral malaria: modulation by anticytokine antibodies and possible role in hypergammaglobulinemia.

The production of Interleukin 6 (IL-6) was studied during experimental cerebral malaria (ECM) induced by Plasmodium berghei ANKA (PbA) infection. IL-6 is present in the serum of mice with ECM, the highest concentrations being observed in mice with full-blown neurological syndrome. High IL-6 levels were also observed, however, in the absence of pathology in nonlethal malaria infection. These data suggest that IL-6 is produced in large amounts during malaria infection, but does not play a major role in the pathogenesis of ECM. A modulation of IL-6 production in ECM was achieved by in vivo treatment with other anticytokine antibodies: antibodies to interferon (IFN-gamma) or to tumor necrosis factor (TNF) abolished the rise of IL-6, while anti-IL-3 and anti-granulocyte/macrophage colony-stimulating factor antibodies only partially prevented this rise, suggesting that the two cytokines IFN-gamma and TNF are important intermediates in IL-6 production. Passive immunization against IL-6 did not prevent ECM, but significantly reduced serum IgG levels in malaria-infected mice. Thus, by its effects on B cells, IL-6 may be involved in hypergammaglobulinemia and immune-complex diseases, e.g., glomerulonephritis observed during malaria infection.

Tumor necrosis factor (cachectin) as an essential mediator in murine cerebral malaria.

Tumor necrosis factor, or cachectin (TNF-alpha), a protein with a wide range of biological activities, is produced mainly by macrophages and may be important in inflammatory processes. The role of TNF-alpha in the pathogenesis of cerebral malaria was investigated in a murine model. Most CBA mice infected with Plasmodium berghei anka die between days 6 and 14 with acute neurological manifestations unrelated to the level of parasitemia, whereas mice of some other strains have malaria of the same severity that ends in death after 3 to 4 weeks without neurological manifestations. The activity of serum TNF-alpha was considerably increased in CBA/Ca mice with cerebral malaria but not in Plasmodium berghei-infected mice that did not develop this complication. One injection of rabbit antibody to TNF-alpha on day 4 or 7 fully protected infected mice from cerebral malaria without modifying the parasitemia, whereas immunoglobulins from normal rabbit had no effect. In mice with cerebral malaria, the cerebral vessels showed focal accumulations of packed macrophages often containing infected erythrocytes; this lesion was not seen in mice treated with antibody to TNF-alpha or in untreated mice without cerebral malaria. These findings indicate that TNF-alpha has an important role in the pathogenesis of cerebral malaria in this murine model and suggest that local accumulation and activation of macrophages may lead to the predominance of lesions in the central nervous system.

Immune complexes in serum and in cerebrospinal fluid in African trypanosomiasis. Correlation with polyclonal B cell activation and with intracerebral immunoglobulin synthesis.

The possible occurrence of immune complexes (IC) in serum and in cerebrospinal fluid (CSF) has been studied in 36 patients with African trypanosomiasis (Trypanosoma brucei gambiense). In serum, very high levels of IC were detectable by the (125)I-C1q-binding and by the conglutinin-binding assays with positive results in 94 and 87%, respectively, of untreated patients. Circulating IC were found in both early and late stages of the disease, without significant quantitative differences; their size was 15-25S. There was a significant negative correlation between C3 values and C1qBA. Our studies suggest that circulating IC occurring during trypanosomiasis may be the expression of a polyclonal B cell activation. Indeed, there was a significant correlation (P < 0.001) between the levels of circulating IC and either the levels of IgM (mean value 12.5+/-7.2 mg/ml) or with the levels of rheumatoid factor-like antiimmunoglobulin antibodies that were detected by solid phase radioimmunoassay in 74% of the patients.IC were detected in 31 of 35 CSF samples, with a marked elevation in patients with definite involvement of the central nervous system as compared with earlier stages of sleeping sickness. The occurrence of IC in CSF was not related to an impairment of the blood-brain barrier as shown by analysis of CSF/serum albumin ratios. The level of IC in CSF did not correlate with the serum level and, therefore, circulating IC do not appear to cross efficiently an unimpaired blood-brain barrier. The analysis of IgG, IgM, and albumin concentrations in serum and CSF demonstrates a marked intracerebral immunoglobulin synthesis in patients with manifestations of meningoencephalitis. There was a correlation between CSF-C1q binding assay and this local IgG synthesis. These data are consistent with a local formation of IC in CSF in patients with active meningoencephalitis. The results obtained in eight patients followed during therapy suggest that the presence of IC in CSF may be an indicator of a continuing central nervous system disease and that the quantitation of CSF-IC may be useful for monitoring patient care.

Complement breakdown products in plasma from patients with systemic lupus erythematosus and patients with membranoproliferative or other glomerulonephritis.

A dynamic estimation of the involvement of the complement system in various diseases was obtained by the direct quantitation of breakdown products of C3 and of properdin factor B. The methods used were based, first on the separation of native and fragmented molecules according to their molecular size through a precipitation with polyethylene glycol and, secondly, on an immunochemical quantitation, using specific antisera for the major antigens of C3 and factor B. The sensitivity and the specificity of these methods were demonstrated by activation of complement in vitro with generation of C3 and factor B fragments. A clinical investigation was carried out in 41 patients with systemic lupus erythematosus (SLE), 31 with membranoproliferative glomerulonephritis (MPGN), 26 with other types of glomerulonephritis, and 6 with severe alcoholic cirrhosis of the liver. The following observations were made: (a) an elevated plasma level of C3d fragment of C3 was found in 68% of SLE patients, in 87% of MPGN patients, in 62% of patients with other hypocomplementemic nephritis, and in 15% of those with normocomplementemic nephritis, but in only 33% of patients with liver cirrhosis and very low levels of C3; (b) a significant difference was observed between the levels of C3 obtained with either anti-"native" C3 or anti-C3c sera for immunochemical quantitation, in patients with SLE or MPGN, indicating the presence of "altered" or fragmented C3 in plasma; (c) an elevated plasma level of Ba fragment of properdin factor B was found in 46% of SLE patients, in 67% of MPGN patients, in 50% of patients with other hypocomplementemic nephritis, and in 9% of patients with normocomplementemic nephritis, while the level of properdin factor B was only slightly decreased in these diseases; (d) in SLE and MPGN there was an inverse correlation between the levels of C3d and Ba and the level of C3 in plasma. The level of these fragments was directly correlated with the clinical manifestations of SLE; (e) some patients with a normal C3 level exhibited an elevated plasma concentration of C3 and factor B fragments, suggesting the coexistence of an increased synthesis with a hypercatabolism of complement components. Therefore, the quantitation of complement breakdown products by simple immunochemical methods provides additional information concerning the involvement of complement in disease and new features for the evaluation of the intensity of immune reactions during immune complex diseases.

Detection of anti-glomerular basement membrane antibodies by radioimmunological technique. Clinical application in human nephropathies.

A radioimmunoassay for detection of anti-glomerular basement membrane (GBM) antibody was set up with a 70,000 mol wt GBM antigen, labeled with Iodine-(125)I and containing both types of oligosaccharidic chains present in the whole membrane. Separation of free radioactive antigens from antigens bound to immunoglobulins was obtained by precipitation with polyethylene glycol (mol wt, 6,000), at a final concentration of 20%. In the presence of normal human or rabbit sera, less than 20% of labeled antigens were precipitated. In the presence of rabbit anti-human GBM antibodies, up to 82% of GBM antigens were precipitated, while in the presence of sera or of kidney eluate from a patient with Goodpasture's syndrome, the precipitation of GBM antigens reached 43%. The avidity of rabbit anti-GBM antibodies for human GBM antigens is higher than that of human anti-GBM antibodies. In the case of Goodpasture's syndrome, the binding of anti-GBM antibodies to labeled antigens was inhibited more efficiently by the disaccharide-containing glycopeptide than by the heteropolysaccharide-containing glycopeptide purified from whole GBM.Anti-GBM antibodies were searched for in the serum of 300 normal blood donors, of 120 patients with glomerulonephritis (GN) and granular deposits, and of 14 patients with GN and linear deposits of immunoglobulins. After correction for the "nonspecific" precipitation, the average percentage (+/-1 SD) of labeled antigens precipitated in the serum of normal blood donors was 0.3+/-3.2%; 12 patients with GN and linear deposits exhibited high circulating anti-GBM antibody titers, while 8% of the patients with GN and granular deposits presented significant, albeit lower, anti-GBM activity in their sera.

Distinct clonotypes of anti-DNA antibodies in mice with lupus nephritis.

Clonotypes of IgG anti-DNA antibodies were studied by isoelectric focusing in various autoimmune mice with or without lethal lupus nephritis. MRL/MpJ-lpr/lpr mice exhibited the most heterogeneous spectrotypes of anti-DNA antibodies in the pH range from 6.5 to 8.5, with marked variation in individual mice. Female (NZB X NZW)F1 mice expressed rather uniform DNA-binding bands composed of at least five to six distinct subgroups, having isoelectric points from 6.5 to 8.0. Male BXSB mice showed major characteristic bands confined to alkaline pH range from 7.8 to 8.5, similar to C57BL/6J-lpr/lpr mice, which showed markedly restricted bands in this region. Both AKR/J-lpr/lpr and C3H/HeJ-lpr/lpr mice expressed DNA-binding bands mostly focused between pH 6.5 and 8.2. The aging study indicated that three autoimmune mice (MRL/MpJ-lpr/lpr, [NZB X NZW]F1, and male BXSB) that developed fatal glomerulonephritis showed clonal expansion of anti-DNA antibodies throughout their life. In contrast, such age-dependent expansion of anti-DNA clonotypes was not evident in three lpr cogenic mice (C57BL/6J-lpr/lpr, AKR/J-lpr/lpr, and C3H/HeJ-lpr/lpr) that developed only mild glomerulonephritis; rather, their expression of anti-DNA spectrotypes diminished as they aged. Anti-DNA activities in renal eluates from nephritic autoimmune mice were mostly distributed in the pH range from 6.5 to 8.0, without significant concentrations in the high alkaline range of more than pH 8.0. These results suggest that there exist distinct anti-DNA clonotypes in each mouse strain and that the development of lupus nephritis does not appear to be associated with particular spectrotypes of anti-DNA antibodies. Rather, the age-dependent expansion of anti-DNA clonotypes may be a feature more characteristic of mice developing lethal lupus nephritis.

Circulating immune complexes in the serum in systemic lupus erythematosus and in carriers of hepatitis B antigen. Quantitation by binding to radiolabeled C1q.

A sensitive and reproducible procedure for the detection of soluble immune complexes in sera from patients with various immunopathological disorders is reported. Radiolabeled C1q is reacted with sera containing immune complexes. Separation of free from complex bound [(125)I]C1q is achieved by selective precipitation with polyethylene glycol (PEG). The method is based on both the large molecular size and the C1q-binding property characterizing immune complexes. The minimal amount of aggregated immunoglobulins thus detected is about 10 mug and that of soluble human IgG-anti-IgG complexes is about 3 mug of complexed antibody. Some immune complexes formed in large antigen excess (Ag(2)Ab) can still be detected by this radiolabeled C1q binding assay. The specificity of the radiolabeled C1q binding test was documented by the inability of antigen-F(ab')(2) antibody complexes to lead to a precipitation of [(125)I]C1q in PEG. In a second step, this radiolabeled C1q binding assay was applied to an experimental model of immune complex disease and was shown to be efficient for the detection of in vivo formed immune complexes.Finally, the technique could be applied to the study of sera from patients with systemic lupus erythematosus (SLE) or to carriers of the hepatitis B antigen (HB-Ag). Significantly increased [(125)I]-C1q binding values were observed in 52 sera from SLE patients when compared to values obtained with healthy blood donors (P<0.001). Particularly high values were seen in active disease, a finding which was confirmed by follow-up studies performed with four SLE patients. No increased [(125)I]C1q binding was seen in 18 healthy carriers of the HB-Ag; whereas, sera from carriers with hepatitis appear to precipitate increased [(125)I]C1q percentages: 7/24 cases with acute transient and 4/7 cases with chronic persistent hepatitis were found to increasingly bind [(125)I]C1q. The results were also used for a correlative study of [(125)I]C1q binding to IgG levels in the sera but increased [(125)I]C1q binding could not be attributed to high serum IgG levels which are likely to account for gammaglobulin aggregates. These examples suggest the utility of the radiolabeled C1q binding assay for the evaluation of immune complex diseases in human pathology.

Decreased heat-labile opsonic activity and complement levels associated with evidence of C3 breakdown products in infected pleural effusions.

Heat-labile opsonic activity was measured simultaneously in serum and pleural fluid of patients with transudates, infectious exudates (with positive or negative bacterial culture) and neoplastic exudates, using two different complement-dependent phagocytic tests: the killing of Staphylococcus aureus Wood 46 variant strain (K50 opsonic titers) and the assessment of ingestion rate of endotoxin-coated paraffin particles (Oil Red 0 uptake test). K50 opsonic titers were lower in culture-positive pleural effusions as compared to culture-negative (P < 0.002) or neoplastic effusions (P < 0.002). These results were corroborated by the Oil Red 0 uptake test. The data obtained with the two assays showed a significant correlation (P < 0.001). The hemolytic activity of complement (CH50) as well as the levels of C3 breakdown product, C3d, were measured in the same sera and pleural fluid samples and in an additional group of patients with pleural effusions of the same etiology. Effusions with positive cultures showed lower CH50 values (P < 0.01) and higher C3d values (P < 0.05) when compared to culture-negative pleural fluids. Finally, evidence for immune complexes in pleural effusions and sera was looked for by determination of Clq binding activity. Levels were higher in culture-positive effusions when compared to culture-negative fluids (P = 0.005).K50 opsonic titers showed a positive correlation with CH50 values (P < 0.001) for all fluids tested. Similarly Clq binding activity correlated with C3d levels in effusions of infectious origin (P = 0.05). Recovery experiments using the various bacterial species isolated from culture-positive pleural effusions showed evidence of complement inactivation upon incubation with pooled sera at concentrations of 10(7)-10(8) microorganisms/ml. These results indicate that one important reason for bacterial persistence in empyema may be decreased opsonization secondary to local consumption of complement.

Circulating complement breakdown products in patients with rheumatoid arthritis. Correlation between plasma C3d, circulating immune complexes, and clinical activity.

Quantitative determination of the small C3 breakdown product, C3d, was used to investigate complement activation in 45 plasma samples from 30 patients with rheumatoid arthritis (RA). The mean plasma C3e level in these samples (3.0 +/- 1.3 mg/100 ml) was significantly increased (P less than 0.001) as compared to patients with degenerative joint disease (0.9 +/- 0.4 mg/100 ml) and healthy blood donors (0.8 +/- 0.5 mg/100 ml). C3d levels were increased by more than s SD in 79% of RA samples. Plasma C3d levels were compared with C3d concentrations in synovial fluid. In most RA patients, the C3d levels were higher in synovial fluid than in plasma. A very significant correlation between plasma C3d levels and circulating immune complexes, as measured by determination of Clq binding activity (Clq BA), was observed (P less than 0.001). C3d levels were more elevated in RA patients with extra-articular disease manifestations (3.8 +/- 1.2 mg/100 ml) as compared to patients with joint disease alone (2.2 +/- 1.0 mg/100 ml). C3d levels and Clq BA were also significantly correlated (P less than 0.001) with the RA disease activity expressed by an index derived from sedimentation rate, joint score, and duration of morning stiffness. A close relationship between C3d levels, Clq BA, and the clinical activity further appeared during follow-up studies. The present observations suggest that a parallel but rather independent activation of the complement system may be induced by immune complexes in circulating blood and in the joint spaces during the course of rheumatoid arthritis.