Anikó Végvári

Accelerated Atherosclerosis in Rheumatoid Arthritis

Abstract:  Cardiovascular disease is a leading cause of mortality in rheumatoid arthritis (RA). Endothelial dysfunction often precedes manifest atherosclerosis. Both traditional, Framingham risk factors and inflammation‐associated factors are involved in RA‐associated atherosclerosis. Among imaging techniques, the early determination of common carotid intima‐media thickness (ccIMT), flow‐mediated vasodilation (FMD), and nitroglycerine‐mediated vasodilation (NMD) may be useful to determine atherosclerosis and endothelial dysfunction. We and others found increased ccIMT and impaired FMD in RA patients. Among immunological and metabolic laboratory markers, anticyclic citrullinated peptide (anti‐CCP) antibodies, IgM rheumatoid factor, circulating immune complexes, pro‐inflammatory cytokines including tumor necrosis factor‐α (TNF‐α) and interleukin‐6 (IL‐6), Th0/Th1 T cells, homocysteine, dyslipidemia, decreased folate and vitamin B12 production, and impaired paraoxonase activity may all be involved in the development of vascular disease in RA. The early diagnosis of endothelial dysfunction and atherosclerosis, active immunosuppressive treatment, the use of drugs that control atherosclerosis, changes in sedentary lifestyle, and the close follow‐up of RA patients may help to minimize cardiovascular risk in these individuals.

Anti-Citrullinated Protein Antibodies in Rheumatoid Arthritis: As Good as it Gets?

Anti-citrullinated protein antibodies (ACPAs) have recently emerged as sensitive and specific serological markers of rheumatoid arthritis (RA), providing superior alternative of the rheumatoid factor (RF) test in the laboratory diagnostics of RA. The first members of this autoantibody family were anti-perinuclear factor (APF) and anti-keratin antibodies (AKA). It became evident that both APF and AKA recognize citrullinated epitopes of filaggrin. Citrullination is a post-translational modification of arginine by deimination, physiologically occurring during apoptosis, inflammation or keratinization. The presence of several citrullinated proteins has been demonstrated in the RA synovium. The identification of citrullinated epitopes as targets for anti-filaggrin antibodies led to the development of the first and later second generation anti-cyclic citrullinated peptide (anti-CCP) antibody assays. The widely used anti-CCP2 assays have high diagnostic sensitivity and specificity, and they also show important predictive and prognostic value in RA. The anti-Sa antibody has been identified a decade ago; however, recent studies confirmed that anti-Sa is directed against citrullinated vimentin, hence it is a new member of the family of ACPAs. The newly developed anti-mutated citrullinated vimentin (anti-MCV) assay has similar diagnostic performance than the anti-CCP2 ELISA; however, the diagnostic spectrum of the anti-MCV test is somewhat different from that of anti-CCP2. It’s especially useful in the diagnosis of RA in RF and anti-CCP2 seronegative patients. The combined application of anti-CCP2 and anti-MCV assays can improve the laboratory diagnostics of RA. The family of ACPAs is expected to expand; there is an increasing need for developing new diagnostic strategies after careful evaluation of the characteristics of the available assays.

Effects of Biologics on Vascular Function and Atherosclerosis Associated with Rheumatoid Arthritis

Endothelial dysfunction and accelerated atherosclerosis lead to increased cardiovascular morbidity and mortality in rheumatoid arthritis (RA). Sustained inflammation is a major risk factor. Apart from traditional vasculoprotective agents, biologics may also exert favorable effects on the vasculature. Indeed, tumor necrosis factor‐α (TNF‐α) inhibitors agents may transiently improve endothelial function. There are conflicting data regarding the effects of biologics on atherosclerosis and arterial stiffness. Infliximab stimulates the number and differentiation of endothelial progenitor cells that lead to vascular repair. There may be differences in the effects of TNF blockers on dyslipidemia, as long‐term infliximab therapy may be proatherogenic, while some studies suggest that etanercept and adalimumab may exert beneficial effects on lipids. TNF blockers may decrease the incidence of cardiovascular events in RA. Preliminary data suggest that rituximab may also improve endothelial function and dyslipidemia. Further studies are needed to determine the net effects of biologics on the vasculature.

Association of rheumatoid arthritis with HLA-DR1 and HLA-DR4 in Hungary.

Abstract: Susceptibility to and outcome for rheumatoid arthritis (RA) have been associated with particular HLA‐DR alleles, but these alleles vary among ethnic groups and geographic areas. The frequency of HLA‐DR1 (HLA‐DRB1*0101, DRB1*0102) and HLA‐DR4 (DRB1*0401, DRB1*0404) alleles is elevated among Caucasian patients with RA. We studied a northeastern Hungarian population of RA patients to determine the frequency of HLA‐DR1 and HLA‐DR4 phenotypes in this population and to compare it with healthy control subjects, as well as to investigate whether the presence of these alleles could be a marker for RA. We performed HLA‐DRB1 genotyping (DRB1*01‐DRB1*16) in 83 RA patients and 55 healthy controls using polymerase chain reaction with sequence‐specific primers (PCR‐SSP). In the case of HLA‐DR1‐ or HLA‐DR4‐positive patients, the DR1 and DR4 subtypes were also determined. The frequency of HLA‐DR4 alleles was significantly higher in RA patients than in controls (31.3 vs. 10.9%; P < .05). HLA‐DR1, in particular, tended to be more frequent in patients than in controls (32.5 vs. 18.1%). Among the HLA‐DR4 subtypes, DRB1*0401 and DRB1*0404 were the most common alleles found in both groups. However, no significant differences were seen in the frequency of HLA‐DRB1*0401 and HLA‐DRB1*0404 between RA patients and controls. In contrast, HLA‐DRB1*0405 and HLA‐DRB1*0408 were significantly more common in RA patients than in control subjects. Among HLA‐DR1 subtypes, the DRB1*0101 allele was most commonly detected, but HLA‐DRB1*0101 as well as DRB1*0102 and DRB1*0105 were similarly frequent in RA patients and controls. HLA‐DR12 was more common among controls than in RA patients (18.1 vs. 0%; P < .05). Our results generally agree with the findings in other Caucasian populations. Nonetheless, we found differences in the frequency of HLA‐DR1 and HLA‐DR4 subtypes among Hungarian patients compared with reports from other geographic regions (e.g., Finland and Asia). Our data suggest that in northeastern Hungary, HLA‐DR4 as well as its subtypes DRB1*0405 and DRB1*0408 may be involved in susceptibility to RA, but HLA‐DR1 may not. In addition, the presence of HLA‐DR12, at least in Hungary, may protect from this disease.

The genetic background of ankylosing spondylitis

It has long been known that the major histocompatibility complex (MHC) is essentially involved in genetic susceptibility to ankylosing spondylitis (AS). The HLA-B27 antigen has been accounted for 20 to 50% of the total genetic risk for this disease. However, susceptibility to AS cannot be fully explained by associations with the MHC. Recent studies including linkage analyses as well as candidate gene and, most recently, genome-wide association studies indicate significant associations of the interleukin-1 gene cluster, interleukin-23 receptor and ARTS1 genes as well as other possible loci with AS. In the murine model of proteoglycan-induced spondylitis, two susceptibility loci termed Pgis1 and Pgis2 were identified. Thus, AS is not a single-gene disease and the involvement of multiple non-MHC genes may account for the individual as well as geographical differences seen in AS.

Combined plasmapheresis and high-dose intravenous immunoglobulin treatment in systemic sclerosis for 12 months: follow-up of immunopathological and clinical effects

Systemic sclerosis (SSc) is an autoimmune disease which involves the skin, as well as several internal organs. Most therapies available in this disease are symptomatic. Authors present a case of diffuse SSc with progressive disease not responding to currently available treatments. Therefore a 12-month protocol of repeated plasmapheresis and high-dose intravenous immunoglobulin treatment was administered with good clinical efficacy. Apart from monitoring the clinical symptoms throughout the treatment, authors also assessed a number of humoral and cellular immunolaboratory markers in order to obtain information on the immunomodulatory effects of this combined treatment in SSc.

Two Major Interacting Chromosome Loci Control Disease Susceptibility in Murine Model of Spondyloarthropathy

Autoimmune spondylitis was induced in BALB/c mice and their MHC-matched (BALB/c × DBA/2)F1 and F2 hybrids by systemic immunization with cartilage/intervertebral disk proteoglycan (PG). As in human ankylosing spondylitis, the MHC was the major permissive genetic locus in murine PG-induced spondylitis (PGIS). Two major non-MHC chromosome loci with highly significant linkage were found on chromosomes 2 (Pgis2) and 18 (Pgis1) accounting for 40% of the entire F2 trait variance. The dominant spondylitis-susceptibility allele for Pgis2 locus is derived from the BALB/c strain, whereas the Pgis1 recessive allele was present in the disease-resistant DBA/2 strain. The Pgis1 locus significantly affected the disease-controlling Pgis2 locus, inducing as high incidence of spondylitis in F2 hybrids as was found in the spondylitis-susceptible parent BALB/c strain. Additional disease-controlling loci with suggestive linkage were mapped to the chromosomes 12, 15, and 19. Severity of spondylitis in F2 mice positively correlated with serum levels of amyloid A, IL-6, and Pg-specific Abs, and showed negative correlation with Ag-induced T cell proliferation, IFN-γ, IL-4, and TNF-α production. A major locus controlling serum IL-6 was found on chromosome 14 near osteoclast differentiation factor Tnfsf11. Locus on chromosome 11 near the Stat3 and Stat5 genes controlled serum level of the Ig IgG2a isotype. The two major genetic loci Pgis1 and Pgis2 of murine spondylitis were homologous to chromosome regions in human genome, which control ankylosing spondylitis in human patients. Thus, this animal model of experimentally induced spondylitis might facilitate the identification of spondylitis-susceptibility genes in humans.

Intracytoplasmic Cytokine Expression and T Cell Subset Distribution in the Peripheral Blood of Patients with Ankylosing Spondylitis

Objective To determine the role of inflammatory mediators in the pathogenesis of ankylosing spondylitis (AS), we investigated peripheral blood lymphocyte subsets and their intracellular cytokine production. Methods The percentages of T and B lymphocytes, natural killer (NK) cells, activated T lymphocytes, CD4+ T helper (Th), and CD8+ T cytotoxic (Tc) cells were determined by flow cytometry in 42 patients with AS compared to 52 healthy controls. In order to assess circulating Th1/Th2 and Tc1/Tc2 subsets, we used a whole-blood cytometric assay based on the intracellular interferon-γ, interleukin 4 (IL-4), and IL-10 expression of the cells. Results In the peripheral blood, the frequencies of CD4+ T helper and CD56+ NK cells were higher in AS (54.8% and 16.2%, respectively) compared to controls (45.3% and 10.8%) (p < 0.05). The frequencies of Th0 (1.9% vs 0.8%) and Tc0 (2.1% vs 0.8%) cells were higher, while that of Tc1 cells was lower (26.6% vs 40.1%) in patients with AS versus controls (p < 0.05). The percentage of IL-10-producing Tc cells was significantly higher in AS (18.4%) versus controls (8.5%) (p < 0.05). Finally, the active phase of AS was associated with significantly lower percentage of IL-10-producing Tc cells in the peripheral blood (6.6%) compared to patients with inactive AS (23.1%). Conclusion Our results provide further evidence for an altered T cell subset distribution and intracytoplasmic cytokine balance in AS.

Congenic strains displaying similar clinical phenotype of arthritis represent different immunologic models of inflammation.

Proteoglycan (PG)-induced arthritis (PGIA) is an autoimmune inflammatory disease controlled by multiple genes in the murine genome. BALB/c × DBA/2 congenic strains carrying four major PGIA chromosome loci were immunized, and positions of loci on chromosomes 3, 7, 8 and 19 (loci Pgia26, Pgia21, Pgia4 and Pgia12, respectively) were confirmed. Each congenic strain exhibited a different pattern of regulation of clinical and immunologic features of PGIA, and these features were significantly influenced by gender. Locus Pgia26 delayed PGIA onset in males and females, and the effect was associated with a lower rate of antigen-induced lymphocyte proliferation and lower production of interferon-γ (IFN-γ), tumor necrosis factor-α (TNF-α) and interleukin-4 (IL-4). Pgia12 similarly delayed onset in males, but the effect was achieved by elevated proliferation of PG-specific lymphocytes and enhanced production of IFN-γ and IL-4. The effect of the Pgia21 locus was arthritis-suppressive in females but PGIA-permissive in congenic males. These opposite effects are attributed to two-fold higher serum autoantibody and IL-6 levels in males than in females. Our study supports the idea that each congenic strain represents a different immunologic subtype of PGIA, providing an explanation for the complex etiology and various clinical phenotypes of rheumatoid arthritis.

Two Loci on Chromosome 15 Control Experimentally Induced Arthritis through the Differential Regulation of IL-6 and Lymphocyte Proliferation

Using genetic linkage analysis of proteoglycan-induced arthritis (PGIA), a murine model for rheumatoid arthritis, we identified two loci, Pgia8 and Pgia9, on chromosome 15 (chr15) that appear to be implicated in disease susceptibility. Immunization of congenic strains carrying the entire chr15 and separately each of the two loci of DBA/2 arthritis-resistant origin in susceptible BALB/c background confirmed locations of two loci on chr15: the major Pgia9 and lesser Pgia8 locus. Distal part of chr15 (Pgia9) showed a major suppressive effect on PGIA susceptibility in females (40%, p < 0.001), whereas the effect of this locus in congenic males was still significant but weaker. Proximal part of chr15 (Pgia8) demonstrated mild and transient effect upon arthritis; this effect was PGIA-promoting in males and suppressive in females. Pgia8 and Pgia9 loci demonstrated an additive mode of inheritance, since when they were both incorporated in consomic chr15 strain, the total effect was a sum of the two loci. Using F2 population of the intercross of wild-type and chr15 consomic strain, we confirmed and refined quantitative trait locus positions and identified a strong correlation between disease susceptibility and lymphocyte-producing cytokines of TNF-α and IL-6. Both Pgia8 and Pgia9 loci on chr15 appear to control IL-6 production in spleen cultures of arthritic mice, providing an important link to the mechanism of autoimmune inflammation.