Intensity of the production of rheumatoid factor in patients with different degree of sensitization to Borrelia garinii antigens

The content of rheumatoid factor and serum IgA, IgM and IgG in patients with different degree of sensitization to B. garinii antigens is evaluated. An increase in the titer of rheumatoid factor in patients with a high content of antibodies to Borrelia was established. In addition, an increased concentration of serum immunoglobulins in the presence of Borrelia infection was registered. The mechanisms of autoimmune reactions are discussed, proceeding from the biological properties of the causative agent of Lyme disease.     

The complement regulator factor H binds to the surface protein OspE of Borrelia burgdorferi

Spirochete bacteria of the Borrelia burgdorferi sensu lato complex cause Lyme borreliosis. The three pathogenic subspecies Borrelia garinii, Borrelia afzelii, and Borrelia burgdorferi sensu stricto differ in their disease profiles and susceptibility to complement lysis. We investigated whether complement resistance of Borreliae could be due to acquisition of the main soluble inhibitors of the alternative complement pathway, factor H and the factor H-like protein 1. When exposed to nonimmune EDTA-plasma, the serum-resistant B. afzelii and B. burgdorferi sensu stricto strains bound factor H/factor H-like protein 1 to their surfaces. Assays with radiolabeled proteins showed that factor H bound strongly to the B. burgdorferi sensu stricto strain. To identify factor H ligands on the borrelial surface, we analyzed a panel of outer surface proteins of B. burgdorferi sensu stricto with the surface plasmon resonance technique. The outer surface lipoprotein OspE was identified as a specific ligand for factor H. Using recombinant constructs of factor H, the binding site for OspE was localized to the C-terminal short consensus repeat domains 15-20. Specific binding of factor H to B. burgdorferi sensu stricto OspE may help the pathogen to evade complement attack and phagocytosis.     

Radioimmunoassay of IgG and IgM rheumatoid factors reacting with human IgG.

Although IgG rheumatoid factor may play a central role in the pathogenesis of rheumatoid arthritis, previously there have been no precise methods for its specific measurement in serum and synovial fluid. This paper describes a solid phase radioimmunoassay for the independent quantification of IgM and IgG rheumatoid factor reacting with the Fc fragment of human IgG. As measured by this assay, serum IgG rheumatoid factor levels differed significantly between patients with seropositive and seronegative rheumatoid arthritis and normal control subjects. In addition, several sera and joint fluids from patients with seropositive rheumatoid arthritis, even without vasculitis, were shown by gel chromatography to have acid-dissociable complexes of IgG rheumatoid factor suggestive of IgG-IgG dimer or trimer formation.     

不同RF型类风湿性关节炎患者Th17相关细胞因子表达研究

目的:探讨类风湿因子阳性与阴性类风湿关节炎(rheumatoid arthritis,RA)患者外周血中辅助T细胞(Th17)及相关细胞因子白介素17(interleukin,IL-17),白介素6(interleukin,IL-6)表达的差异。方法:收集RA患者51例,根据RF测定分为RF+、RF-组,健康查体者(对照组)20例,采用流式细胞术检测受检者外周血单个核细胞(PBMC)的Th17细胞的百分率;以酶联免疫吸附法(ELISA)检测受检者血浆中IL-17,IL-6的水平。结果:RA患者CD4+IL-17+T细胞,IL-17、IL-6水平均高于对照组,RF因子阳性与阴性RA患者之间CD4+IL-17+T细胞,IL-17、IL-6表达水平均存在差异有统计学意义。结论:在RA中不同RF型免疫反应和炎症表达的不同,可能与Th17及相关细胞因子表达差异有关。     

阿达木单抗注射液联合白芍总苷治疗甲氨蝶呤不耐受型类风湿关节炎的临床疗效

目的:探讨阿达木单抗注射液联合白芍总苷治疗甲氨蝶呤不耐受风湿关节炎患者的临床疗效。方法:收集我院治疗的86例甲氨蝶呤不耐受的类风湿关节炎患者,随机分为实验组和对照组,每组43例。对照组患者给予阿达木单抗注射液治疗,实验组患者在对照组基础上给予白芍总苷胶囊治疗。观察并比较两组患者的晨僵时间、血沉(ESR)、类风湿因子(FR)以及临床疗效进行检测并比较。结果:与治疗前相比,治疗后两组患者的晨僵时间、血沉(ESR)、类风湿因子(FR)水平均下降(P0.05);与对照组相比,实验组患者的晨僵时间、血沉(ESR)、类风湿因子(FR)水平较低(P0.05),临床治疗有效率较高(P0.05)。结论:阿达木单抗注射液联合白芍总苷能够降低甲氨蝶呤不耐受的类风湿关节炎患者的ESR、FR水平,改善患者的临床症状,临床疗效较好。     

Low Incidence of Rheumatoid Factor and Autoantibodies in Nigerian Patients with Rheumatoid Arthritis

Sera from 53 Nigerian patients satisfying the American Rheumatism Association criteria for a diagnosis of definite or probable rheumatoid arthritis and sera from sick and healthy Nigerian controls were tested for rheumatoid factor, autoantibodies, and immunoglobulin levels. Rheumatoid factor and autoantibodies were found no more frequently in patients with rheumatoid arthritis than in controls. These findings confirm the clinical impression that Nigerian patients with polyarthritis satisfying the criteria for a diagnosis of rheumatoid arthritis differ from Caucasian patients with the disease in a number of important respects. They suggest that either these patients do not have rheumatoid arthritis but a distinct clinical syndrome or that in Nigeria the course of rheumatoid arthritis is modified by genetic or environmental factors.     

Early Cytokine Release in Response to Live Borrelia burgdorferi Sensu Lato Spirochetes Is Largely Complement Independent

Aim

Here we investigated the role of complement activation in phagocytosis and the release of cytokines and chemokines in response to two clinical isolates: Borrelia afzelii K78, which is resistant to complement-mediated lysis, and Borrelia garinii LU59, which is complement-sensitive.

Methods

Borrelia spirochetes were incubated in hirudin plasma, or hirudin-anticoagulated whole blood. Complement activation was measured as the generation of C3a and sC5b-9. Binding of the complement components C3, factor H, C4, and C4BP to the bacterial surfaces was analyzed. The importance of complement activation on phagocytosis, and on the release of cytokines and chemokines, was investigated using inhibitors acting at different levels of the complement cascade.

Results

1) Borrelia garinii LU59 induced significantly higher complement activation than did Borrelia afzelii K78. 2) Borrelia afzelii K78 recruited higher amounts of factor H resulting in significantly lower C3 binding. 3) Both Borrelia strains were efficiently phagocytized by granulocytes and monocytes, with substantial inhibition by complement blockade at the levels of C3 and C5. 4) The release of the pro-inflammatory cytokines and chemokines IL-1β, IL-6, TNF, CCL20, and CXCL8, together with the anti-inflammatory IL-10, were increased the most (by>10-fold after exposure to Borrelia). 5) Both strains induced a similar release of cytokines and chemokines, which in contrast to the phagocytosis, was almost totally unaffected by complement blockade.

Conclusions

Our results show that complement activation plays an important role in the process of phagocytosis but not in the subsequent cytokine release in response to live Borrelia spirochetes.     

Enhanced Mitochondrial Radical Production in Patients with Rheumatoid Arthritis Correlates with Elevated Levels of Tumor Necrosis Factor alpha in Plasma

Mitochondrial dysfunction contributes to cell damage in a number of human diseases. One significant mechanism by which mitochondria damage cells is by producing reactive oxygen species from the respiratory chain. In this study we measured the production of reactive oxygen species by leukocyte mitochondria in blood from rheumatoid arthritis patients. To do this we used the chemiluminescence of lucigenin, which is accumulated by mitochondria within cells and reacts with superoxide to form a chemiluminescent product. By using specific inhibitors we could distinguish between the production of reactive oxygen species by mitochondria and by NADPH oxidase. There was a five-fold increase in mitochondrial reactive oxygen species production in whole blood and monocytes from patients with rheumatoid arthritis, when compared to healthy subjects or patients with non-rheumatic diseases. There was no increase in mitochondrial reactive oxygen species production by neutrophils from rheumatoid arthritis patients. The enhanced mitochondrial radical production in rheumatoid arthritis patients correlated significantly with increased levels of tumor necrosis factor alpha in plasma (p<0.0001). As tumor necrosis factor alpha is known to increase mitochondrial reactive oxygen species production the elevated mitochondrial radical formation seen in rheumatoid arthritis patients may be due to activation of the mitochondrial radical production. These data suggest that elevated mitochondrial oxidative stress contributes to the pathology of rheumatoid arthritis.     

Gene expression profile analysis of rheumatoid synovial fibroblast cultures revealing the overexpression of genes responsible for tumor-like growth of rheumatoid synovium

To elucidate the aberrant growth properties of rheumatoid synoviocytes, we have examined the gene expression profile of rheumatoid synovial fibroblasts (RSFs) and compared with that of normal synovial fibroblasts (NSF). Gene expression profile analysis was conducted with synoviocyte cultures obtained from five rheumatoid arthritis (RA) patients and five control cases using a commercial cDNA array containing the defined 588 cancer-related genes. The results were confirmed by real-time RT-PCR. Gene expression levels for the platelet-derived growth factor receptor alpha (PDGFRalpha), plasminogen activator inhibitor-1 (PAI-1), and stromal cell derived factor 1A (SDF1A) are constitutively augmented in RSF compared with NSF. The mRNA levels of PDGFRalpha, PAI-1, and SDF1A in RSF over NSF were 4.6-, 14-, and 2.8-fold, respectively, by real-time RT-PCR. In fact, we found that RSFs showed greater sensitivity to the cell proliferative effect of PDGF. T his aberrant gene expression profile suggests that RSF may have retained the premature phenotype of primordial synoviocytes.     

Nature of double-stranded DNA binding activity in seropositive rheumatoid arthritis: formation of low avidity DNA/rheumatoid factor/IgG/low density lipoprotein complexes

Sera from majority of patients with seropositive rheumatoid arthritis, which generally lacked detectable anti-double stranded DNA in Farr, Crithidia luciliae, and microcomplement fixation assays, exhibited high levels of dsDNA binding in the presence of 3.5% polyethylene glycol when using intrinsically labeled 3H-PM2 DNA as antigen. Except for SLE, such increased dsDNA binding was absent in normal and a variety of other disease sera, including those from patients with seronegative rheumatoid arthritis. In contrast to the situation in SLE, in which dsDNA binding is mediated by specific anti-DNA antibody, the increased dsDNA binding activity in seropositive rheumatoid arthritis was shown to be dependent upon complex low avidity interactions involving DNA, IgG, IgM rheumatoid factor, and low density lipoproteins. Analysis of the composition of the polyethylene glycol serum precipitates by 2-dimensional gel diffusion, immunoelectrophoresis, and sodium dodecyl sulfate polyacrylamide gel electrophoresis failed to reveal the presence of additional DNA-binding proteins unique to seropositive rheumatoid arthritis. The only feature distinguishing high DNA binding sera from those with low DNA binding activity was an increased amount of polyethylene glycol-insoluble IgG in the former, presumably reflecting IgG/IgG and/or IgG/IgM complexes. The significance of these unusual DNA/low density lipoprotein/IgG/rheumatoid factor complexes with respect to the diagnostic specificity and pathophysiology of the DNA/anti-DNA system is discussed.     

Rheumatoid arthritis: relation of serum C-reactive protein and erythrocyte sedimentation rates to radiographic changes.

Serum C reactive protein (CRP) levels and erythrocyte sedimentation rates (ESR) were measured in 56 patients with rheumatoid arthritis. Radiographical damage, based on a count of erosions, was significantly more likely to occur when serum CRP and ESR were persistently raised, irrespective of the presence or absence of rheumatoid factor. Measurements of both CRP and ESR were more helpful than either alone, but CRP was probably the more informative. Serial measurements of CRP and ESR provide a reliable means of discriminating between drugs that provide symptomatic relief only and those with a more profound effect in rheumatoid arthritis.     

Synovial Mononuclear Cells Consist with T Cells Which Produce High Levels of Tumor Necrosis Factor α

To determine whether synovial mononuclear cells include a population of tumor necrosis factor α-produeing T cells, we measured tumor necrosis α levels in culture supernatants of synovial mononuclear cells by ELISA and analyzed tumor necrosis α mRNA-positive cell frequencies. There were no significant differences in the spontaneous levels of TNF α between synovial mononuclear cells and peripheral mononuclear cells. The frequency of tumor necrosis factor α mRNA-positive cells in synovial mononuclear cells was higher than that of peripheral mononuclear cells. When stimulated with a superantigen, mononuclear cells from the synovial fluid of rheumatoid arthritis patients showed higher levels of tumor necrosis factor α production (1,035 ± 817 pg/ml) than did mononuclear cells from their peripheral blood (236 ± 180 pg/ml). In addition, we observed that a few T cell clones were resistant to superantigenic restimulation in vitro. We conclude that when these types of T cells persist in the synovium, they play a role in the development of rheumatoid arthritis via a mechanism involving tumor necrosis factor α production.     

Flow cytometrical determination of interleukin 1beta, interleukin 6 and tumour necrosis factor alpha in monocytes of rheumatoid arthritis patients; relation with parameters of osteoporosis.

Experimental data suggest that pro-inflammatory cytokines such as interleukin 1beta (IL-1beta), interleukin 6 (IL-6) and tumour necrosis factor alpha (TNF-alpha) are important in the pathogenesis of osteoporosis in rheumatoid arthritis. Therefore we compared the production of these cytokines by monocytes in 10 rheumatoid arthritis patients and 10 controls. Cytokine levels in rheumatoid arthritis patients were related to disease activity parameters, bone mineral density (BMD) corrected for age and sex (Z scores) and osteocalcin as a laboratory parameter of bone remodelling. Cytokines were determined by a flow cytometrical technique. There was a tendency for higher IL-1beta levels in patients compared with controls. A positive correlation between erythrocyte sedimentation rate and spontaneous production of monocytic cytokines was found. Z scores of the lumbar spine showed a negative correlation with spontaneous production of IL-1beta and IL-6. Plasma osteocalcin levels were positively correlated with spontaneous production of IL-1beta, IL-6 and TNF-alpha. In conclusion, the correlation of the levels of these cytokines with parameters of bone metabolism and osteoporosis suggest that especially IL-1beta and IL-6 are associated with more pronounced osteoporosis in active rheumatoid arthritis.     

Effect of Dexamethasone and Nitrogen Mustard on the Production of Rheumatoid Factor in Rheumatoid Arthritis

The effect of dexamethasone and nitrogen mustard on the production of rheumatoid factor, as measured by sensitized sheep cell and latex agglutination tests, was studied in 19 patients with classical rheumatoid arthritis. Dexamethasone was given orally in a daily dose of 6-8 mg. which was slowly reduced after a two-week period. Nitrogen mustard was infused in the usual therapeutic dose of 0.3 mg./kg. The level of circulating rheumatoid factor decreased, following administration of each agent, after a latent period of 10 days. The effect was most marked at around 30 days. Dexamethasone was more potent than nitrogen mustard. Both drugs together caused transient disappearance of rheumatoid factor in one patient.It is concluded that dexamethasone and nitrogen mustard have the capacity to suppress the formation of the macroglobulins associated with rheumatoid arthritis.     

Treponematosis and Lyme borreliosis connections: Explanation for Tchefuncte disease syndromes?

A convergence of evidence from macroscopic, radiographic and histologic examination indicates that treponemal infection was present in the 16ST1 Tchefuncte Indian burial population, dated 500 B.C. to 300 A.D. Pattern and nature of lesions suggests that chronic infection induced by variants of the spirochete Treponema pallidum, causing endemic syphilis and/or yaws, resulted in third-stage osseous response. It is suggested that Tchefuncte Indians acquired partial immunity to treponemal infection by exposure to a variant of the related spirochete, Borrelia burgdorferi, the causative agent of Lyme disease. Partial immunity would help explain the relatively mild expression of the treponemal disease process in the 16ST1 skeletal population and the apparent absence of venereal syphilis. Presence of the Borrelia burgdorferi spirochete might be linked to a single incidence of juvenile rheumatoid arthritis. © 1994 Wiley-Liss, Inc.     

Determination of the rheumatoid factor in gouty patients

The authors have examined the incidence of the rheumatoid factor in the serum of a group of 100 patients, 95 males and 5 females, suffering from gout, of whom only 6 suffered from chronic gout. The rheumatoid factor in the serum was measured by RA-test (1:40) and by Waaler-Rose test (1:32). The rheumatoid factor was not present in the examined subjects and so we can state that such serum parameter does not represent, for its negativity, a laboratory index of any evidence in the gout and it doesn't represent a reason for diagnostic doubts with other forms with the rheumatoid factor in the serum.     

Early rheumatoid arthritis is characterized by a distinct and transient synovial fluid cytokine profile of T cell and stromal cell origin

Pathological processes involved in the initiation of rheumatoid synovitis remain unclear. We undertook the present study to identify immune and stromal processes that are present soon after the clinical onset of rheumatoid arthritis (RA) by assessing a panel of T cell, macrophage, and stromal cell related cytokines and chemokines in the synovial fluid of patients with early synovitis. Synovial fluid was aspirated from inflamed joints of patients with inflammatory arthritis of duration 3 months or less, whose outcomes were subsequently determined by follow up. For comparison, synovial fluid was aspirated from patients with acute crystal arthritis, established RA and osteoarthritis. Rheumatoid factor activity was blocked in the synovial fluid samples, and a panel of 23 cytokines and chemokines measured using a multiplex based system. Patients with early inflammatory arthritis who subsequently developed RA had a distinct but transient synovial fluid cytokine profile. The levels of a range of T cell, macrophage and stromal cell related cytokines (e.g. IL-2, IL-4, IL-13, IL-17, IL-15, basic fibroblast growth factor and epidermal growth factor) were significantly elevated in these patients within 3 months after symptom onset, as compared with early arthritis patients who did not develop RA. In addition, this profile was no longer present in established RA. In contrast, patients with non-rheumatoid persistent synovitis exhibited elevated levels of interferon-γ at initiation. Early synovitis destined to develop into RA is thus characterized by a distinct and transient synovial fluid cytokine profile. The cytokines present in the early rheumatoid lesion suggest that this response is likely to influence the microenvironment required for persistent RA.     

Production of tumor necrosis factor alpha by Treponema pallidum, Borrelia burgdorferi s.l., and Leptospira interrogans in isolated rat Kupffer cells

Stimulation of isolated rat Kupffer cells by viable Leptospira interrogans, Treponema pallidum and Borrelia garinii elicited cellular responses resulting in the release of different tumor necrosis factor alpha (TNF-alpha) levels, depending on the spirochetes. L. interrogans induced TNF-alpha levels higher than those achieved with B. garinii and T. pallidum (in this order), but lower than the levels achieved with lipopolysaccharide (LPS). In contrast to L. interrogans, pretreatment of borreliae and treponemes with polymyxin B did not substantially diminish the ability of B. garinii and T. pallidum to stimulate Kupffer cells. Purified T. pallidum lipoproteins TpN47, TmpA, TpN15-TpN17, and B. garinii OspA induced TNF-alpha responses comparable to that achieved by LPS. This response was almost insensitive to the action of polymyxin B.     

Identification and characterization of a linear-plasmid-encoded factor H-binding protein (FhbA) of the relapsing fever spirochete Borrelia hermsii

In North America, tick-borne relapsing fever (TBRF) is caused by the spirochete species Borrelia hermsii, Borrelia parkeri, and Borrelia turicatae. We previously demonstrated that some isolates of B. hermsii and B. parkeri are capable of binding factor H and that cell-bound factor H can participate in the factor I-mediated cleavage of C3b. Isolates that bound factor H expressed a factor H-binding protein (FHBP) that we estimated to be approximately 19 to 20 kDa in size and thus, pending further characterization, temporarily designated FHBP19. Until this report, none of the FHBPs of the TBRF spirochetes had been characterized. Here we have recovered the gene encoding the FHBP of B. hermsii YOR from a lambda ZAP II library and determined its sequence. The gene encodes a full-length protein of 22.7 kDa, which after processing is predicted to be 20.5 kDa. This protein, which we redesignate factor H-binding protein A (FhbA), is unique to B. hermsii. Two-dimensional pulsed-field gel electrophoresis and hybridization analyses revealed that the B. hermsii gene encoding FhbA is a single genetic locus that maps to a linear plasmid of approximately 220 kb. The general properties of FhbA were also assessed. The protein was found to be surface exposed and lipidated. Analysis of the antibody response to FhbA in infected mice revealed that it is antigenic during infection, indicating expression during infection. The identification and characterization of FhbA provides further insight into the molecular mechanisms of pathogenesis of the relapsing fever spirochetes.     

Anti-idiotypic antibodies in a patient with monoclonal rheumatoid factor after pneumococcal bacteremia

A 51-yr-old Japanese female patient with monoclonal IgM gammopathy with rheumatoid factor activity was admitted because of pneumococcal bacteremia. About 2 wk after admission, her rheumatoid factor activity became undetectable by RAHA test and radioimmunoassay, subsequent to the initial marked elevation. The suppressive capacity of the patient's IgG fraction on the rheumatoid activity of her monoclonal IgM on January 11 was determined. The IgG fraction obtained on February 22 blocked the binding of the rheumatoid factor to rabbit IgG. The suppressive activity in the IgG fraction of February 22 was shown to be localized within the F(ab')2 fragment. Furthermore, the specificity of the suppressive serum factor was shown by the inability to block the binding of SRBC coupled with diazotized phosphorylcholine to anti-pneumococcal antibody. Thus, the marked reduction of rheumatoid factor activity was considered to result from anti-idiotypic antibody transiently appearing in her serum after pneumococcal bacteremia.