R.E. Voll, V. Urbonaviciute, M. Herrmann and J.R. Kalden
High mobility group box 1 is a nuclear protein participating in chromatin architecture and transcriptional regulation. When released from cells, HMGB1 can also act as a pro-inflammatory mediator or alarmin. Upon stimulation with lipopolysaccharides or tumor necrosis factor-alpha, HMGB1 is secreted from certain cells such as monocytes/macrophages and fosters inflammatory responses. In addition, HMGB1 is passively released from necrotic cells and mediates inflammation and immune activation. In contrast, during apoptotic cell death, nuclear HMGB1 gets tightly attached to hypo-acetylated chromatin and is not released into the extracellular milieu, thereby preventing an inflammatory response. There is accumulating evidence that extracellular HMGB1 contributes to the pathogenesis of many inflammatory diseases, including autoimmune diseases. Increased concentrations of HMGB1 have been detected in the synovial fluid of patients with rheumatoid arthritis. In animal models of RA, HMGB1 appears to be crucially involved in the pathogenesis of arthritis, since neutralization of HMGB1 significantly ameliorates the disease. Also, in the serum and plasma of patients with systemic lupus erythematosus we detected substantial amounts of HMGB1, which may contribute to the disease process. However, investigations of blood concentrations of HMGB1 and its relevance in human diseases are hindered by the lack of reliable routine test systems.
A. Kapitany, Z. Szabo, G. Lakos, N. Aleksza, A. Vegvari. L. Soos, Z. Karanyi, S. Sipka, G. Szgedi and Z. Szekanecz
Background: The presence of anti-cyclic citrullinated peptide autoantibody is highly specific for rheumatoid arthritis. Certain HLA-DR4 (HLA-DRB1*04) alleles, also known as the "shared epitope," are associated with increased susceptibility to RA. In addition, these alleles may also have relevance for disease outcome. Anti-CCP antibody positivity has been associated with the presence of HLA-DR4 alleles in patients with RA. However, there is little information available regarding any relationship between quantitative anti-CCP production (serum anti-CCP concentrations) and the shared epitope.
Objectives: To determine the association between anti-CCP antibody production and various HLA-DRB1 alleles.
Methods: Serum anti-CCP, rheumatoid factor and C-reactive protein levels were assessed in 53 RA patients. All these patients underwent HLA-DRB1 genotyping.
Results: Of the 53 patients 33 (62%) were positive for anti-CCP antibody. We found significant correlations between anti-CCP and RF positivity (chi-square = 6.717, P < 0.01), as well as between anti-CCP and HLA-DRB1*04 positivity (chi-square = 5.828, P < 0.01). There was no correlation between RF positivity and serum levels, CRP serum levels and HLA-DRB1*04 positivity. When quantitatively comparing serum anti-CCP levels with shared epitope positivity, patients carrying one or two copies of HLA-DRB1*04 alleles had significantly higher anti-CCP concentrations (530.0 ± 182.6 U/ml) compared to DRB1*04-negative patients (56.8 ± 27.4 U/ml) (P < 0.01). There was no difference in serum anti-CCP antibody concentrations between patients carrying only one HLA-DRB1*01 allele but no HLA-DRB1*04 allele (12.0 ± 8.6 U/ml) in comparison to SE-negative patients (76.8 ± 56.2 U/ml). Regarding non-SE HLA-DRB1 genotypes, all 6 patients (100%) carrying DRB1*15 alleles and 6 of 7 (85%) patients carrying DRB1*13 were anti-CCP positive. In addition, patients with HLA-DRB1*13 (282.5 ± 23.8 U/ml) and DRB1*15 (398.7 ± 76.2 U/ml) produced significantly more anti-CCP than did any other non-SE HLA-DRB1 subtypes (P < 0.01).
Conclusions: There is significant association between anti-CCP and RF, as well as between anti-CCP and SE positivity in RA. In addition, the presence of one or two copies of HLA-DRB1*04 alleles has been associated with higher serum anti-CCP antibody levels. Thus, patients carrying HLA-DRB1*04 alleles exhibited an overall tenfold increase in serum anti-CCP antibody levels in comparison to HLA-DRB1*04-negative subjects. Increased anti-CCP production may also be associated with other non-SE HLA-DRB1 genotypes, such as DRB1*13 or DRB1*15. In reports by other investigators, both anti-CCP concentrations
M. Blank and Y. Shoenfeld
Idiotypic analyses of anti-DNA autoantibodies were widely reported a decade ago. More than 100 studies were conducted on one of the main analyzed idiotypes, the 16/6 Id of the anti-ssDNA monoclonal antibody. In this review we summarize current knowledge on the characteristics of the 16/6 Id, its link to infection and its target epitopes on other molecules known so far. This includes the modulation of T and B cell responses and gene expression by the 16/6 mAb in vitro and in vivo. We focus on the ability and mechanisms by which this idiotype induces experimental lupus in naïve mice, manifested by autoantibody spread, kidney and brain involvement, and leukopenia associated with enhanced sedimentation rate. We also discuss various therapeutic modalities to treat 16/6 induced lupus in mice.
E. Mozes, U. Sela and A. Sharabi
M. Abu-Shakra, S. Codish, L. Zeller, T. Wolak and S. Sukenik
Atherosclerotic disease is common in systemic lupus erythematosus and is the result of multiple pathogenic mechanisms that include traditional risk factors as well as SLE-related factors. Endothelial dysfunction and arterial stiffness contribute significantly to the atherogenic process. Dobutamine stress echocardiogram has not been shown to detect subclinical coronary artery disease; however the high percentage of left ventricular outflow gradient requires further evaluation and follows-up studies.
M. Szyper-Kravitz, A. Altman, J.F. de Carvalho, F. Bellisai, M. Galeazzi, Y. Eshet and Y. Shoenfeld
The antiphospholipid syndrome is characterized by recurrent fetal loss, venous and/or arterial thrombosis, and thrombocytopenia associated with elevated titers of lupus anticoagulant and anticardiolipin antibodies. Although thrombosis is the characteristic vascular involvement in APS, the development of vascular aneurysms in patients with APS has been reported. We describe four patients with established APS, who developed abdominal aortic aneurysm, and review the literature on previous published cases of arterial aneurysms developing in patients with APS. In addition, we discuss the possible pathophysiological association between APS and the development of this vascular abnormality.
S. Bar-Sela and Y. Shoenfeld
Two patients working for several years in the operation and maintenance of photocopy machines developed an autoimmune disease. In both, early manifestations were thromboembolic phenomena associated with anticardiolipin antibodies. Joint and kidney involvement emerged later, with the appearance of other autoantibodies. These two patients were occupationally exposed to ultraviolet irradiation, ozone emission, and possibly some oxides of heavy metals. To our knowledge this is the first report of occupational autoimmune disease in photocopy machine workers, and the first description of antiphospholipid syndrome as an occupational disease. The possible cause-effect inter-relationship between their occupational exposure and autoimmune disease is discussed.
Y. Sherer, S. Kuechler, J. Jose Scali, J. Rovensky, Y. Levy, G. Zandman-Goddard and Y. Shoenfeld
Background: Systemic lupus erythematosus is an autoimmune disease with diverse clinical manifestations that cannot always be regulated by steroids and immunosuppressive therapy. Intravenous immunoglobulin is an optional immunomodulatory agent for the treatment of SLE, but the appropriate indications for its use, duration of therapy and recommended dosage are yet to be established. In SLE patients, most publications report the utilization of a high dose (2 g/kg body weight) protocol.
Objectives: To investigate whether lower doses of IVIg are beneficial for SLE patients.
Methods: We retrospectively analyzed the medical records of 62 patients who received low dose IVIg (approximately 0.5 g/kg body weight).
Results: The treatment was associated with clinical improvement in many specific disease manifestations, along with a continuous decrease in SLEDAI scores (SLE Disease Activity Index). However, thrombocytopenia, alopecia and vasculitis did not improve following IVIg therapy.
Conclusions: Low dose IVIg is a possible therapeutic option in SLE and is associated with lower cost than the high dose regimen and possibly fewer adverse effects.
S. Fuchs, T. Feferman, R. Meidler, T. Brenner, O. Laub and M.C. Souroujon
Backgraound: Intravenous immunoglobulin administration has been beneficially used for the treatment of a variety of autoimmune diseases including myasthenia gravis, although its mode of action and active components have not yet been fully identified.
Objectives: To isolate from IVIg a disease-specific fraction involved in the therapeutic activity in myasthenia and to identify its properties and function.
Results: IVIg administration in experimental autoimmune MG results in suppression of disease that is accompanied by decreased Th1 cell and B cell proliferation. Chromatography of IVIg on columns of IgG from rats with EAMG or from MG patients resulted in depletion of the suppressive activity that IVIg has on rat EAMG. Moreover, the minute amounts of IgG fractions eluted from the EAMG or MG-specific columns retained the immunosuppressive activity of IVIg.
Conclusions: Our study supports the notion that the therapeutic effect of IVIg is mediated by a minor disease-specific immunoglobulin fraction that is present in IVIg and is essential for its therapeutic activity.
V. Pordeus, O. Barzilai, Y. Sherer, R.R. Luiz, M. Blank, N. Bizzaro, D. Villalta, J-M. Anaya and Y. Shoenfeld
Background: Infectious agents are important in the pathogenesis of autoimmune disease since they are a major part of the environmental trigger of autoimmunity. A negative relationship between latitude and infectious disease species richness has been suggested.
Objectives: To examine whether their prevalence differs in two latitudinally different populations.
Methods: The prevalence of infections with Toxoplasma gondii, rubella virus, cytomegalovirus, Epstein-Barr virus and Treponema pallidum was compared between subjects from Italy and Colombia.
Results: We found high titers of antibodies against four of five microorganisms tested, Toxoplasma gondii (50.8%), rubella virus (German measles) (75%), cytomegalovirus (86.3%), Epstein-Barr virus (83.3%) and Treponema pallidum (6.3%) in completely healthy individuals from a tropical country (Colombia) and a European country (Italy). Differences between two groups of volunteers were noted regarding two infectious agents. The prevalence of immunoglobulin G anti-rubella antibodies was significantly higher among Italian subjects (85% vs. 67.9%, P = 0.002), whereas antibodies against CMV were less prevalent among Italian as compared to Colombian subjects (77% vs. 92.9%, P < 0.001).
Conclusions: These differences might also result in a different tendency towards development of autoimmune diseases associated with these infectious agents in different populations.