Clinical and serological characteristics of 125 Dutch myositis patients

The idiopathic inflammatory myopathies (IIM) are a heterogeneous group of systemic diseases that include the familiar disease entities of dermatomyositis (DM), polymyositis (PM), and inclusion body myositis (IBM). A subset of patients has unique autoantibodies which are specific for IIM (myositis specific autoantibodies; MSAs). We studied the clinical and serological characteristics of IIM in 125 Dutch patients. Sera were analysed by immunoblotting, enzyme-linked immunosorbent assay, and immunoprecipitation. The most frequently encountered MSA was the anti-Jo-1 autoantibody (20%), followed by anti-tRNAHis (6%), anti-Mi-2 (6%), and anti-SRP (4%). The presence of certain MSAs was clearly associated with specific clinical characteristics. Anti-Jo-1 and anti-tRNAHis were associated with the anti-synthetase syndrome, anti-SRP with PM with severe myalgia and arthralgia and a moderate response to immunosuppressive treatment. A novel finding was the presence of anti-Mi-2, not only in DM, but also in PM. MSAs were frequently present in DM/PM sera, but were hardly ever detected in the sera of IBM patients. The few IBM patients with MSAs demonstrated a significant response to immunosuppressive treatment. It can be concluded that MSAs define specific clinical syndromes within the spectrum of IIM and that they can assist in the differential diagnosis and treatment plan of these enigmatic disorders by virtually excluding IBM by their presence, and by potentially identifying a subgroup of steroid-responsive IBM patients.     

Linomide (roquinimex) affects the balance between pro- and anti-inflammatory cytokines in vitro in multiple sclerosis

Objectives - Multiple sclerosis (MS) is characterized by high levels of circulating mononuclear cells (MNC) that respond to myelin proteins like myelin basic protein (MBP) in vitro by expressing mRNA of both pro-inflammatory cytokines, e.g. interferon-γ (IFN-γ), tumor necrosis factor-α (TNF-α) and lymphotoxin (LT) that may make MS worse, and anti-inflammatory cytokines like IL-4, IL-10 and transforming growth factor-β (TGF-β) that may act beneficially. Substances that down-regulate cytokines such as TNF-α or promote IL-10 or TGF-β can be anticipated to affect MS beneficially. Material and methods - In situ hybridization to detect and enumerate IFN-γ, TNF-α, LT, IL-4, IL-10 and TGF-β mRNA expressing blood MNC after stimulation with myelin basic protein (MBP), control antigens and without antigen in presence and absence of Linomide (roquinimex, LS-2616) was employed. In parallel, ELISPOT assay to detect MBP- and PHA-reactive IFN-γ secreting blood MNCLinomide was used. Results - Here we report that Linomide, a synthetic immunomodulator, at concentrations effective in vivo reduces the number of MBP-reactive TNF-a and increases MBP-reactive IL-10 and TGF-β mRNA expressing MNC from MS patients'blood when analysed in vitro. Compared to dexamethasone, Linomide up-regulated levels of blood MNC expressing mRNA of TGF-β after culture in presence of MBP. Conclusions - Changes of cytokine balance towards a production of anti-inflammatory cytokines could be a desirable effect to be evaluated in future drug studies of Linomide-like substances. At present, Linomide is not evaluable in MS clinical trials due to side-effects.     

Influence of IFN-β1b (Betaferon) on cytokine mRNA profiles in blood mononuclear cells and plasma levels of soluble VCAM-1 in multiple sclerosis

Inflammatory cell infiltration within the central nervous system (CNS) and upregulation of both pro- and anti-inflammatory cytokines are characteristic for multiple sclerosis (MS). Treatment with interferon-β1b (IFN-β1b) reduces the number and severity of MS relapses. To examine whether treatment with IFN-β1b affects levels of cytokine mRNA expressing blood mononuclear cells (MNC) we employed in-sit hybridization with synthetic oligonucleotide probes to detect and enumerate IFN-γ, TNF-α, IL-10, TGF-β and perforin mRNA expressing cells in MS patients before treatment with IFN-β1b and during tretmetn for 3–6 weeks and for 3–6 monts. Numbers of blood MNC spontaneously expressing TNF-α and IL-10 mRNA were lower after 3–6 months of treatment, while numbers of IFN-γ, TGF-β and perforin mRNA expressing MNC were not affected by treatment. IFN-β1b had no influence on levels of MBP-reactive IFN-γ, TNF-α, TGF-β, IL-10 or perforin mRNA expressing blood MNC determined after 3–6 weeks 3–6 months of treatment. Parallel measurements of plasma concentrations of soluble vascular cell adhesion molecule-1 (sVCAM-1) revealed elevated levels after 3–6 weeks of treatment and these levels remained higher after 3–6 months of treatment. The results suggest that IFN-β1b treatment upregulates plasma levels of sVCAM-1, but has little effects on numbers of blood MNC expressing mRNA of the pro- and anti-inflammatory cytokines under study.     

Alpha-chemokine receptors CXCR1–3 and their ligands in idiopathic inflammatory myopathies

The idiopathic inflammatory myopathies (IIM) are a heterogeneous group of neuromuscular disorders subdivided into polymyositis (PM), sporadic inclusion body myositis (sIBM) and dermatomyositis (DM). Chemokines play an essential role in sustained inflammation associated with IIM. We studied the distribution of the -chemokine receptors CXCR1, 2, 3 and their ligands interferon- (IFN-)-inducible T cell chemoattractant (I-TAC), IFN--inducible protein of 10 kDa (IP-10), monokine induced by IFN- (MIG) and growth-related oncogene (GRO) in IIM using immunohistochemistry, immunofluorescence and Western blotting. Abundant expression of IP-10 was observed on macrophages and T cells surrounding and invading non-necrotic muscle fibers in PM and sIBM and in T cells in perimysial infiltrates of DM. IP-10 was also localized to blood vessel endothelial cells in all inflammatory and normal muscle tissues. The distribution of other -chemokines was variable: Only low levels of MIG and I-TAC were detected; GRO was localized to the endomysial infiltrates of some PM and sIBM samples, but not in DM. Muscle tissues were invariably CXCR1 negative, while a subset of inflammatory cells in all IIM were CXCR2 positive. Strong CXCR3 expression was observed on the majority of T cells in each IIM. We describe the differential repertoire of -chemokines in IIM, and offer additional proof of the predominance of Th1-driven reactions in the immunopathogenesis of all three diagnostic subgroups. We suggest the Th1-mediated immunity in general, and the CXCR3/IP-10 interaction in particular, as potential targets for novel therapeutic intervention in IIM.     

Effect of high-dose methylprednisolone administration on immune functions in multiple sclerosis patients

Objectives – To investigate the in vivo effect of corticosteroid pulse therapy on immunocompetent cells in 18 patients given methylprednisolone to treat an acute episode of MS. Material and methods – Blood was sampled before and after 3 days of methylprednisolone administration at doses of 1 g/day. Lymphocyte subtyping was performed and whole blood cell cultures were used to measure the cytokine producing capacity for interleukin-1 (IL-1), interleukin-2 (IL-2), interferon-γ (IFN-γ), tumor necrosis factor-a (TNF-α) and interferon-α (IFN-α). In addition, serum levels of the immunoglobulin classes IgG, IgA and IgM were determined. Results – Before treatment, production of IL-1 was significantly increased in MS patients as compared to healthy controls. After therapy, production of all cytokines was significantly decreased, whereas there were significant increases in the numbers of monocytes, neutrophils and T and B lymphocytes. Treatment had no effect on serum immunoglobulin levels. Conclusion – An important mechanism for the antiinflammatory effect of corticosteroids in MS results from a suppression of the activation of the peripheral immune compartment through inhibition of cytokine production and lymphocyte endothelial adhesiveness.     

Expression of transglutaminase 2 does not differentiate focal myositis from generalized inflammatory myopathies

Objectives –  Idiopathic inflammatory myopathies (IIM), including dermatomyositis (DM), polymyositis (PM), sporadic inclusion-body myositis (s-IBM) and focal myositis (FM) are a heterogeneous group of autoimmune disorders of skeletal muscle. An increased transglutaminase 2 (TG2) expression has been found in DM, PM and s-IBM. The aim of our study was to investigate TG2 expression in FM in comparison with other IIM.
Materials and methods –  We re-examined tissue material we have gathered in the course of our previous studies on IIM, investigating muscle expression of TG2 in patients with FM in comparison with DM, PM and s-IBM using immunocytochemistry and real-time RT-PCR.
Results –  Immunocytochemistry revealed an increased TG2 signal in endomysial vessels, in atrophic and degenerating/regenerating muscle fibres in PM, DM, s-IBM and FM; in s-IBM, some vacuoles were immunostained too. Real-time RT-PCR study confirmed a significantly increased expression of TG2 in all IIM muscles examined.
Conclusions –  Our study demonstrates the presence of TG2 in FM muscles. The study suggests that TG2 expression does not represent a distinctive marker to differentiate FM from generalized IIM. TG2 over-expression in inflamed skeletal muscle does not seem have a pathogenetic role in such a disease, but it could represent a way to contain the inflammatory process.     

Beta-chemokine receptor expression in idiopathic inflammatory myopathies

Beta-chemokines attract and activate T cells and monocytes and have a key role in chronic inflammation. Certain beta-chemokines, such as monocyte chemoattractant protein-1 (MCP-1), have been reported to be upregulated in the idiopathic inflammatory myopathies (IIM). We studied the distribution of beta-chemokine receptors in polymyositis (PM), sporadic inclusion-body myositis (sIBM), dermatomyositis (DM), and control samples. CCR1-5 were localized to blood vessels in all samples. In addition, increased endothelial expression of CCR2A was observed in IIM. Subsets of inflammatory cells, identified as macrophages and T cells, in all three types of IIM expressed CCR2A, CCR2B, CCR3, CCR4, and CCR5. In contrast to an earlier report, we found CCR2B to be the most prominent MCP-1 receptor on inflammatory cells in IIM, especially in PM and sIBM. Strong CCR4 expression was present on myonuclei of regenerating muscle fibers. The prominence of the CCR2 receptors further underlines the importance of the interaction with their ligand MCP-1 in the immunopathogenesis of IIM and puts CCR2B forward as a potential target for future therapeutic intervention.     

Serum pro-inflammatory and anti-inflammatory cytokines and the pathogenesis of experimental autoimmune encephalomyelitis

Experimental autoimmune encephalomyelitis (EAE) as an experimental model of multiple sclerosis (MS) is characterized by demyelination, infiltration of inflammatory cells into the nervous system and dysregulation of serum inflammatory cytokines. We investigated the correlation of serum cytokines and other inflammatory markers with the EAE pathogenesis. After EAE induction, the levels of different serum cytokine/inflammatory mediators were measured. Furthermore, motor functions, myelination, and lymphocyte infiltration in EAE mice were also assessed. Our results revealed that the serum concentrations of T-helper 1 (Th1) and Th17 cytokines, interleukin (IL)-6, IL-1β, IL-1α and prostaglandin E2 in EAE mice were significantly higher than controls. The ratios of pro- to anti-inflammatory cytokines were different between the EAE and the control group. A statistically significant positive correlation was found between the IL-6/IL-10 ratio and the EAE severity, demyelination rate, and lymphocyte infiltration in EAE mice. Results indicate that the profiles of serum pro- and anti-inflammatory cytokines might be useful as biomarkers for monitoring the pathological manifestation of EAE. Furthermore, evaluating the dynamic interplay of serum cytokine levels and the correlation with pathogenic mechanisms of EAE may provide diagnostic and therapeutic insights for MS and some other inflammatory disorders.     

Changes in CSF acetyl- and butyrylcholinesterase activity after long-term treatment with AChE inhibitors in Alzheimer's disease

Jain A, Sharma MC, Sarkar C, Bhatia R, Singh S, Gulati S, Handa R. Detection of the membrane attack complex as a diagnostic tool in dermatomyositis.
Acta Neurol Scand: 2011: 123: 122–129.
© 2010 John Wiley & Sons A/S. Background – Currently there is no reliable diagnostic marker to distinguish between the subgroups of idiopathic inflammatory myopathies (IIMs), i.e. dermatomyositis (DM), polymyositis (PM) and inclusion body myositis (IBM). Membrane attack complex (MAC) has been shown to be involved in the pathogenesis of dermatomyositis but its role as a diagnostic marker has not been evaluated. Aim – To assess the diagnostic utility of MAC deposition in distinguishing dermatomyositis from other neuromuscular disorders. Material and methods – Immunohistochemical detection of MAC deposition on endomysial microvessels was carried out on 127 muscle biopsies comprising of 21 cases of dermatomyositis, 42 other IIMs and 64 non‐IIM neuromuscular diseases. Results – MAC deposition showed a high sensitivity (80.9%) and specificity (85%) to differentiate DM from other IIMs. Its specificity was higher (98.4%) in discriminating DM from non‐IIM muscular diseases and IIM from non‐IIMs. Conclusion – MAC deposition can serve as a reliable marker to distinguish DM from other IIMs (i.e. PM and IBM) as well as from non‐IIM diseases. It can also serve as a useful adjunct in diagnosis of IIMs when there is diagnostic dilemma with their morphologic similarities. These results provide further credence to the long‐standing view that MAC‐mediated capillary destruction is involved in the immunopathogenesis of DM.     

IL-1β and Interferon-γ Induce Schwann Cell Proliferation And Death

Schwann cell apoptosis (programmed cell death) has been recently observed during the development and in rare pathological conditions of the peripheral nervous system (PNS) characterized by demyelination-remyelination. However, the relevance of the phenomenon, and the characterization of the involved molecules are still controversial. This study has been designed to detect in Schwann cell tissue culture whether the administration of different doses of the two pro-inflammatory cytokines IL-1β and IFN-γ, singly or in combination, can induce Schwann cell proliferation and/or death via apoptosis. Our results indicate that the administration of IL-1β and IFN-γ induced cell proliferation and concomitant apoptosis in Schwann cells that is numerically related to the different type and dosage of the two pro-inflammatory cytokines. Moreover, Schwann cell apoptosis was maximal within 24 hours following the administration of 50 U/mL of IFN-γ, and we did not observe any synergistic action of the two pro-inflammatory molecules. These findings provide further "in vitro" evidence that cytokines can interact with Schwann cells through a mechanism that is probably mediated by the modulation in time and concentrations of these different pro-inflammatory molecules.     

Th17 cells in neuromyelitis optica spectrum disorder: a review

Neuromyelitis optica spectrum disorder (NMOSD) has been identified as a central nervous system (CNS) autoimmune inflammatory disorder, which has been recognized as a B cell-mediated humoral immune disease. However, cases have been reported indicating that some of the neuromyelitis optica (NMO) patients have been resistant to B cell-related treatments. Recently, more and more evidence has shown that T cell-mediated immunity may take part in the pathogenesis of NMOSD, especially in the Th17 phenotype. In our PUBMED search, we used the following keywords: Th17 cell, Th17 cell-related cytokines, T cells, B cells, B cell-related productions, NMO, NMOSD, recurrent/bilateral optic neuritis, recurrent transverse myelitis and longitudinally extensive transverse myelitis. We systemically reviewed the role of Th17 cells and Th17 cell-related cytokines in NMOSD. We found that Th17 cells and Th17-related cytokines, such as IL-6, IL-1β, IL-17, IL-21, IL-22, IL-23 and TGF-β, are not only directly involved in the pathogenesis but also collaborated with B cells and B cell-related antibody production to induce CNS lesions. Th17 cell-related therapy has also been reviewed in this article, and the data suggested that Th17 may be a new therapeutic target of NMOSD.     

Expression and distribution of the nitric oxide synthases in idiopathic inflammatory myopathies

Different immune effector mechanisms have been characterised in the idiopathic inflammatory myopathies (IIM): in polymyositis (PM) and sporadic inclusion body myositis (sIBM), T-cell-mediated cytotoxicity targets nonnecrotic muscle fibres, whereas in dermatomyositis (DM) the complement-mediated immune response is directed against the microvasculature. As nitric oxide (NO) has an important function in cell signalling and in the cytotoxicity displayed by activated macrophages, it is potentially involved in the immunopathogenesis of IIM. Using immunohistochemical, in situ hybridisation and Western blotting techniques, we visualised the three isoforms of NO synthase (NOS) in muscle tissues from normal controls and from patients diagnosed with IIM. The levels of both constitutive isoforms of NOS (endothelial, i.e., eNOS, and neuronal, i.e., nNOS) were unchanged in IIM as compared with normal muscle. Both protein and mRNA of the inducible form (iNOS) were detected in half of the control biopsies. Constant and increased iNOS protein expression was found in endomysial infiltrates of PM and sIBM, whereas perimysial inflammatory cells in DM were largely negative. We developed a quantitative Western blotting protocol which confirmed the constitutive nature of nNOS and eNOS and the significant induction of iNOS in PM. Our results appoint iNOS with a dual function: a limited and transient role in normal muscle physiology and an active cytotoxic role in PM and sIBM.     

Differential expression of stress proteins in human adult astrocytes in response to cytokines

Various lines of evidence suggest a close relationship between heat shock proteins (hsp) and several autoimmune diseases such as arthritis, diabetes and multiple sclerosis. While enhanced expression of hsp in autoimmune diseases is often regarded as a non-specific bystander effect of the inflammatory process, surprisingly little is known on hsp regulation by inflammatory mediators such as cytokines. In this study cytokine-induced expression of hsp60, hsp27 and alphaB-crystallin was studied in cultures of primary human adult astrocytes at the mRNA as well as at the protein level. We show differential hsp expression patterns in response to pro-inflammatory and immunoregulatory cytokines. Hsp60 expression was found to be enhanced in response to cytokines as diverse as IL-1beta, TNF-alpha, IL-4, IL-6 and IL-10. Upregulation of hsp27, however, was primarily induced by immunoregulatory cytokines like IL-4, IL-6 and TGF-beta whereas alphaB-crystallin expression was found to be enhanced by the pro-inflammatory cytokine TNF-alpha only. None of the cytokines studied was able to enhance expression of all three hsp simultaneously. These results show that in human astrocytes induced expression of hsp27 and alphaB-crystallin is dependent on the presence of a defined set of stimuli, while induced expression of hsp60 is a much less selective event. This highly differential pattern of hsp expression in response to inflammatory mediators known to play an important role in the pathogenesis of autoimmune diseases indicates that hsp responses are specific rather than non-specific bystander responses.     

Pentoxifylline, a phosphodiesterase inhibitor, induces immune deviation in patients with multiple sclerosis

The outcome of immune responses can be predicted by the lymphokine production pattern of the participating cells. Cytokines of the T helper type 1 (Th1) cells mediate inflammatory responses and delayed-type hypersensitivity (DTH), whereas Th2-like T cells predominantly produce cytokines, which stimulate antibody production by B cells. Immunoregulatory therapy of autoimmune diseases with unknown antigens may be achieved by inhibiting the production of inflammatory cytokines and induction of protective cytokines of Th2-like T cells. To determine the immunoregulatory capacity of the phosphodiesterase inhibitor pentoxifylline (PTX), which is known to suppress the production of tumor necrosis factor-alpha (TNF-α) and interferon-gamma (IFN-γ), this drug was used in mitogen and antigen-stimulated lymphocyte cultures as well as in patients with multiple sclerosis. PTX significantly decreased TNF-α and interleukin-12 (IL-12), whereas it increased IL-4 and IL-10 production. In addition, PTX inhibited cell proliferation, which was associated with a marked reduction in CD25 (IL-2 receptor α-chain) and CDS4 (intercellular adhesion molecule-1; ICAM-1) expression. Increasing doses of PTX significantly reduced TNF-α and IL-12 mRNA expression of blood mononuclear cells, but increased IL-4 and IL-10 expression in eight patients with relapsing-remitting multiple sclerosis. These results indicate that PTX modulates immune reactions favouring a Th2-like response and may therefore be useful for the treatment of autoimmune diseases with a dominant Th1-like T cell response.     

MHC-restriction,cytokine profile,and immunoregulatory effects of human T cells specific for TCR Vβ CDR2 peptides: Comparison with myelin basic protein-specific T cells

HLA-DR2+ patients with multiple sclerosis (MS) that respond to vaccination with TCR Vβ5.2-38-58 peptides have increased frequencies of TCR peptide-specific T cells, reduced frequencies of myelin basic protein (MBP)-specific T cells, and a better clinical course than non-responders. To evaluate possible network regulation of MBP responses by TCR peptide-specific T cells, we compared properties of both cell types. Both MBP- and TCR peptide-specific T cell clones were CD4⁺ and predominantly HLA-DR restricted. HLA-DR2, which is in linkage disequilibrium in MS patients, preferentially restricted TCR peptide-specific clones as well as MBP-specific responses in HLA-DR2 and DR2,3+ donors. Within the DR2 haplotype, however, both DRβ1*1501 and DRβ5*0101 alleles could restrict T cell responses to Vβ CDR2 peptides, whereas responses to MBP were restricted only by DRβ5*0101. TCR peptide-specific clones expressed message for Th2 cytokines, including IL-4, IL-5, IL-6, IL-10, and TGF-β, whereas MBP-specific T cell clones expressed the Th1 cytokines IFN-γ and IL-2. Consistent with the Th2-like cytokine profile, TCR peptide-specific T cell clones expressed higher levels of CD30 than MBP-specific T cells. Culture supernatants from TCR peptide-specific T cell clones, but not from MBP- or Herpes simplex virus-specific T cells, inhibited both proliferation responses and cytokine message production of MBP-specific T cells. These results demonstrate distinct properties of MBP and TCR peptide-specific T cells, and indicate that both target and bystander Th1 cells can be inhibited by Th2 cytokines secreted by activated TCR peptide-specific T cells. These data support the rationale for TCR peptide vaccination to regulate pathogenic responses mediated by oligoclonal T cells in human autoimmune diseases. © 1996 Wiley-Liss, Inc.