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Biomedical subjects

I E Lundberg

Publications and source records attributed to I E Lundberg.

17 recordsLinked to original sources
PubMed2006

Signs of inflammation in both symptomatic and asymptomatic muscles from patients with polymyositis and dermatomyositis.

OBJECTIVES: To determine whether muscle weakness is correlated with inflammation, expression of interleukin 1alpha (IL1alpha) and major histocompatibility complex (MHC) class I and II antigens on muscle fibres. METHODS: Biopsy specimens from clinically symptomatic (proximal muscles) and asymptomatic (all distal but two proximal) muscles in eight patients with polymyositis, three patients with dermatomyositis and six healthy controls were analysed by immunohistochemistry for the presence of T cells and macrophages, and expression of IL1alpha and of MHC class I and II antigens. RESULTS: were evaluated by conventional light microscopy and by computerised image analysis. Results: Inflammatory infiltrates with T cells and macrophages were observed to an equal degree in both symptomatic and asymptomatic muscle. The numbers of capillaries with IL1alpha expression were significantly higher (p<0.05) in the symptomatic and asymptomatic muscles of patients than in controls. The total IL1alpha expression per tissue section assessed by computerised image analysis was significantly higher in symptomatic muscles but not in asymptomatic muscles compared with that in controls. Neither the number of IL1alpha-positive capillaries nor the total IL1alpha expression differed significantly between symptomatic and asymptomatic muscles. Expression of MHC class I and II antigens on muscle fibres was detected in both symptomatic and asymptomatic muscles but rarely in healthy controls. CONCLUSIONS: Presence of inflammatory infiltrates, T cells and macrophages, and expression of MHC class I and II antigens and of IL1alpha on muscle fibres were independent of clinical symptoms, and were present to an equal degree in both proximal and distal muscles. Thus, other factors seem to determine the development of clinical symptoms. One such factor could be variations in physical demands.

Adult↗
PubMed2006

Anti-signal recognition particle autoantibodies: marker of a necrotising myopathy.

OBJECTIVE: To elucidate the clinical importance of the anti-signal recognition particle (SRP) autoantibody in patients with myositis. METHODS: Retrospective systematic assessment of the clinical, laboratory and histological characteristics of 23 anti-SRP-positive patients from six European centres. Data were compared with a large group of anti-SRP-negative patients with myositis published previously. RESULTS: Clinically, patients with anti-SRP autoantibodies often had a severe symmetric proximal muscle weakness resulting in marked disability, dysphagia and highly elevated levels of serum creatine kinase. Three patients had typical dermatomyositis rashes. The disease was associated with the occurrence of extramuscular signs and symptoms including interstitial lung disease. No association was found with an increased risk of cardiac involvement, and the disease carried a reasonably favourable prognosis with most patients responding to treatment. None of the patients had the typical histological features of myositis. Most muscle biopsy specimens showed the presence of necrotic muscle fibres and no inflammatory infiltrates. CONCLUSIONS: Anti-SRP autoantibodies are associated with a syndrome of a necrotising myopathy in the spectrum of immune-mediated myopathies that differs from typical polymyositis. Further studies are needed to elucidate the pathogenesis and to clarify the role of the anti-SRP autoantibodies in this unique disease.

Adult↗
PubMed2006

Citrullination is an inflammation-dependent process.

OBJECTIVES: To study the presence of citrullinated proteins in inflammatory conditions and in clinically non-affected tissues of controls. METHODS: Synovial biopsy specimens from 19 patients with rheumatoid arthritis and 10 healthy controls were investigated by immunohistochemistry. Additionally, muscle tissue from 5 patients with polymyositis and from 7 healthy controls, intestinal tissue from macroscopically affected and non-affected areas from 10 patients with inflammatory bowel disease (IBD) and tonsil tissues from 4 chronically inflamed tonsils were studied. RESULTS: Citrullinated proteins were present in all synovial biopsy specimens from patients with rheumatoid arthritis, whereas only three of 10 healthy synovial biopsy specimens showed scarce amounts of citrullination. Citrullination was also present in all myositis-affected muscles, whereas it was absent in the muscle tissues of controls. All tonsil biopsy specimens studied were positive for citrulline. Even though more frequently detected in the macroscopically affected colonic areas, no marked difference was observed in the pattern or extent of citrullination between the macroscopically affected and non-affected intestinal IBD tissues. CONCLUSION: Citrullination is present in a wide range of inflammatory tissues, suggesting that this process is inflammation dependent rather than disease dependent.

Arthritis, Rheumatoid↗
PubMed2006

The heart in dermatomyositis and polymyositis.

Cardiovascular manifestations constitute a major cause of death in myositis. Despite this, clinically manifest cardiac involvement in polymyositis and dermatomyositis is relatively rare. In contrast, subclinical manifestations are frequently reported and are predominated by conduction abnormalities and arrhythmias detected by ECG. The most frequently reported clinically overt manifestations are congestive heart failure, conduction abnormalities, that may lead to complete heart block, and coronary artery disease. The underlying pathophysiological mechanisms that may cause cardiac manifestations involve myocarditis and coronary artery disease as well as involvement of the small vessels of the myocardium.

Cause of Death↗
PubMed2006

Clinical characteristics of patients with myositis and autoantibodies to different fragments of the Mi-2 beta antigen.

OBJECTIVES: To assess the clinical implications of autoantibodies directed against different parts of the Mi-2 beta autoantigen in patients with myositis. METHODS: A systematic assessment of the clinical, laboratory, and histological characteristics of 48 anti-Mi-2 positive patients from six European centres was made. Anti-Mi-2 autoantibodies were determined with an ELISA using four overlapping fragments spanning the entire amino acid sequence of the autoantigen. Data were compared with results for a large group of anti-Mi-2 negative patients with myositis published previously. RESULTS: Anti-Mi-2 autoantibodies were found in dermatomyositis, polymyositis, and inclusion body myositis. In general, myositis with anti-Mi-2 autoantibodies was characterised by relatively mild disease, sometimes accompanied by extra-muscular symptoms, including arthralgia, arthritis, Raynaud's phenomenon, and interstitial lung disease. Cardiac disease was not seen, and treatment response was fair. No differences were found between patients with autoantibodies to different fragments of the Mi-2 beta antigen, except for a potentially increased risk of cancer in patients with antibodies directed to the N-terminal fragment of the autoantigen. CONCLUSIONS: Anti-Mi-2 autoantibodies are not a marker of a specific subtype of myositis. No significant differences between patients with autoantibodies to different fragments of the Mi-2 beta autoantigen are found, with the possible exception of an increased risk of cancer in patients with antibodies to the N-terminal fragment.

Adenosine Triphosphatases↗
PubMed2005

Cardiac involvement in autoimmune myositis and mixed connective tissue disease.

The clinical cardiac manifestations most frequently reported in idiopathic inflammatory myopathies, myositis, are congestive heart failure, conduction abnormalities, that may lead to complete heart block and coronary artery disease. Although clinically overt cardiac involvement is rarely reported in myositis patients, subclinical manifestations are frequently observed and are predominated by conduction abnormalities and arrhythmias detected by ECG. Furthermore, cardiovascular manifestations constitute a major cause of death in myositis, thus cardiac involvement maybe overlooked in these patients. Also children with juvenile dermatomyositis may develop cardiac involvement although the frequency seems to be low. The underlying pathophysiologic mechanisms that may cause cardiac manifestations could involve myocarditis and coronary artery disease as well as involvement of the small vessels of the myocardium. In patients with mixed connective tissue disease (MCTD) clinically significant cardiac involvement is also rare, the most frequently reported manifestations being pericarditis and pulmonary hypertension, the latter often attributable to small vessel disease, and often a prognostic unfavourable manifestation.

Autoantibodies↗
PubMed2004

Interstitial lung disease, a common manifestation of newly diagnosed polymyositis and dermatomyositis.

OBJECTIVES: To estimate the prevalence and predictors of interstitial lung disease in newly diagnosed polymyositis and dermatomyositis. METHODS: A prospective study in which consecutive patients with newly diagnosed poly- and dermatomyositis, regardless of clinical symptoms of pulmonary disease, were investigated with chest x ray, high resolution computed tomography (HRCT), pulmonary function tests, and biochemical and autoantibody analysis. Patients with inclusion body myositis, malignancy, other defined inflammatory connective tissue diseases (CTDs), or antibody profile indicating other CTDs were excluded. RESULTS: Between March 1998 and September 2000, 26 new cases of poly- or dermatomyositis were diagnosed; 17 of those patients were included in the study. Interstitial lung disease (ILD), defined as radiological signs on chest x ray examination/HRCT or restrictive ventilatory defect, were found in 11 (65%) patients and were more common in men than in women. Arthritis and occurrence of anti-Jo-1 antibodies were found more often in patients with ILD than in those without. There was no statistically significant association between respiratory symptoms, other serological or laboratory variables and ILD. CONCLUSIONS: ILD is a common early manifestation in patients with poly- and dermatomyositis and is not always related to clinical symptoms. Chest x ray examination, HRCT, pulmonary function tests, and analysis of anti-Jo-1 antibodies should be included in the initial investigation of patients with myositis regardless of respiratory symptoms.

Adult↗
PubMed2003

International consensus outcome measures for patients with idiopathic inflammatory myopathies. Development and initial validation of myositis activity and damage indices in patients with adult onset disease.

OBJECTIVE: To devise new tools to assess activity and damage in patients with idiopathic myopathies (IIM). METHODS: An international multidisciplinary consensus effort to standardize the conduct and reporting of the myositis clinical trials has been established. Two tools, known as the myositis intention to treat index (MITAX) and the myositis disease activity assessment visual analogue scale (MYOACT), have been developed to capture activity in patients with IIM. In addition, the myositis damage index (MDI) has been devised to assess the extent and severity of damage developing in different organs and systems. These measures have been reviewed by the myositis experts participating in the International Myositis Assessment and Clinical Studies (IMACS) group and have been found to have good face validity and to be comprehensive. The instruments were assessed in two real patient exercises involving patients with adult dermatomyositis and inclusion body myositis. RESULTS: The reliability of MITAX, MYOACT and MDI, measured by the intraclass correlation coefficient among the physicians, and the inter-rater reliability, as assessed by variation in the physicians' rating of patients, was fair to good for most aspects of the tools. Reliability and inter-rater agreement improved at the second exercise after the participants had completed additional training. CONCLUSIONS: The MITAX, MYOACT and MDI tools, which are now undergoing validity testing, should enhance the consistency, comprehensiveness and reliability of disease activity and damage assessment in patients with myositis.

Acute Disease↗
PubMed2001

Skeletal muscle fibers express major histocompatibility complex class II antigens independently of inflammatory infiltrates in inflammatory myopathies.

The aim of our study was to address the question of whether muscle fibers express major histocompatibility complex (MHC) class II in inflammatory myopathies. For this purpose we performed a systematic study of MHC class II antigen expression on muscle fiber membranes in muscle tissue from polymyositis and dermatomyositis patients in various stages of disease activity. Thirty-two patients with classical clinical signs of myositis were divided into subgroups depending on duration of clinical signs of myositis and presence or absence of inflammatory infiltrates in muscle tissue. Immunohistochemistry as well as double-immunofluorescence stainings were used to identify the presence of MHC class II in muscle tissue. MHC class I was included for comparison. Quantification of positive staining was performed using an image analysis system in addition to evaluation by manual microscopic scoring and laser confocal microscopy. It was demonstrated that a significant proportion of skeletal muscle fibers in inflammatory myopathies express MHC class II as well as MHC class I and that MHC antigen expression is independent of the inflammatory cell infiltration. Furthermore, there were no differences in staining pattern between polymyositis and dermatomyositis patients. Our results indicate that MHC class II and MHC class I molecules may be involved in initiating and maintaining the pathological condition in myositis rather than only being a consequence of a preceding local inflammation.

Adult↗
PubMed2001

The physiology of inflammatory myopathies: an overview.

The idiopathic inflammatory myopathies (IIMs) encompass a group of muscle disorders of unknown origin and pathogenesis characterized by symmetrical, proximal muscle weakness and by inflammatory infiltrates in muscle tissue. The mechanisms behind the loss of muscle function are largely unknown. It is often anticipated that the muscle weakness is caused by the inflammatory cells. However, inflammatory infiltrates are not always present in the muscle tissue and the infiltrates sometimes have a patchy distribution, which makes it difficult to explain the generalized muscle weakness merely by infiltration of inflammatory cells. We investigated patients at different stages of myositis: early myositis without detectable inflammatory infiltrates, active myositis with pronounced inflammatory infiltrates and chronic myositis with persisting muscle weakness but without detectable inflammatory cells in muscle tissues. In these studies, a better correlation was observed between the clinical symptoms and involvement of the capillaries with expression of the cytokine interleukin (IL)-1alpha and by the presence of major histocompatibility complex (MHC) class I expression on muscle fibres. Whether these molecules could affect muscle function is not known. Using phosphorus P-31 magnetic resonance spectroscopy decreased values of adenosine triphosphate (ATP) and phosphocreatine (PCr) levels were observed at rest. These metabolic abnormalities were further accentuated by exercise and increased PCr levels correlated with improved clinical status. The underlying mechanisms responsible for these biochemical abnormalities have not been defined but could be related to a disturbed tissue oxygenation.

Cytokines↗
PubMed2001

Longitudinal study of interleukin-10, tumor necrosis factor-alpha, anti-U1-snRNP antibody levels and disease activity in patients with mixed connective tissue disease.

OBJECTIVE: To investigate the levels and relationship between IL-10, TNF-alpha, anti-U1snRNP antibodies and disease activity in longitudinally collected serum samples from patients with mixed connective tissue disease (MCTD). METHODS: Six patients followed for 17-138 months were investigated with ELISA for estimation of cytokine levels and antibodies to the different epitopes of the U1snRNP. Disease activity was assessed by systemic lupus activity measure (SLAM). RESULTS: IL-10 and TNF-alpha levels fluctuated with time in at least half of the patients. Three patients had increased IL-10 levels and two had increased TNF-alpha in all samples. There was no correlation between cytokine levels and disease activity or clinical manifestations. All patients had increased levels of antibodies to the main components of the U1snRNP. Both antibody levels and disease activity decreased with time. A correlation between TNF-alpha and U1snRNP antibody levels were observed in five patients. CONCLUSIONS: Increased and fluctuating levels of IL-10 or TNF-alpha without correlation to disease activity were observed in MCTD patients. In some patients increased cytokine levels were observed over several years irrespective of disease activity indicating that they could be constitutively increased in these individuals.

Adult↗
PubMed2001

Increased endothelial expression of HLA-DQ and interleukin 1alpha in extra-articular rheumatoid arthritis. Results from immunohistochemical studies of skeletal muscle.

OBJECTIVE: To investigate markers of endothelial activation in muscle biopsies from rheumatoid arthritis (RA) patients with and without extra-articular manifestations (ExRA). PATIENTS AND METHODS: Nine consecutive ExRA patients were compared with nine RA controls without ExRA, matched for age, sex and duration of RA. Muscle biopsies were obtained from the lateral vastus or anterior tibial muscle. Macrophage and lymphocyte CD markers, HLA molecules, cytokines and adhesion molecules were investigated using immunohistochemistry, and stainings were evaluated using computer image analysis and conventional microscopy. Serum concentrations of soluble adhesion molecules, tumour necrosis factor alpha (TNF-alpha) and rheumatoid factor (RF) were determined using immunoassays. RESULTS: The number of HLA-DQ-positive capillaries (P=0.039) and the expression of interleukin 1alpha (IL-1alpha) in endothelial cells (mean pairwise difference 0.26%; 95% confidence interval 0-0.52) were increased in ExRA patients compared with non-ExRA controls. There were no signs of inflammatory cell infiltrates or fibre degeneration. Serum levels of TNF-alpha, the soluble form of intercellular adhesion molecule 1, the soluble form of vascular cell adhesion molecule 1 and IgM RF were increased in the ExRA group. CONCLUSION: The increased expression of HLA-DQ and IL-1alpha may indicate systemic endothelial activation in extra-articular RA, which could be of importance for cardiovascular comorbidity and mortality in such patients.

Aged↗
PubMed2001

Percutaneous conchotome muscle biopsy. A useful diagnostic and assessment tool.

OBJECTIVE: To evaluate the diagnostic yield, performance simplicity, and safety of the percutaneous conchotome muscle biopsy technique for clinical and research purposes in an outpatient rheumatology clinic. METHODS: Biopsies taken by rheumatologists in an outpatient clinic during 1996 and 1997 were evaluated for histopathological and clinical diagnoses. RESULTS: A total of 149 biopsies were performed on 122 patients. Physicians learned the method easily. Samples were of adequate size and quality to allow for diagnostics. In total 106 biopsies were taken due to different diagnostic suspicions: 24 polymyositis (PM) or dermatomyositis (DM); 43 PM, DM, or vasculitis in addition to another rheumatic condition; 19 systemic vasculitis; and 20 myalgias. Criteria for definite or probable PM/DM were fulfilled in 21 patients, 18 with positive biopsies. Thirteen patients received vasculitis as clinical diagnosis, 3 with positive biopsies. No patient with myalgia had a biopsy with inflammatory changes. Fifteen of 43 rebiopsies performed to assess disease activity had signs of active inflammation. In 48% there were changes in immunosuppressive therapy after biopsy results. Four complications occurred; one was a serious subfascial hematoma. CONCLUSION: The percutaneous conchotome muscle biopsy technique gives a good size sample that allows for diagnostic evaluation and has a high yield in patients with myositis. It is a simple procedure, easy to learn and to perform, with a low complication rate and minimum discomfort for the patient. The method can preferably be used as a diagnostic tool and to perform repeated biopsies to assess the effect of a given therapy for both clinical and research purposes.

Adolescent↗
PubMed2000

The role of cytokines, chemokines, and adhesion molecules in the pathogenesis of idiopathic inflammatory myopathies.

Cytokines, chemokines, and adhesion molecules are important mediators in chronic inflammation and in immune regulation. In idiopathic inflammatory myopathies (IIM), increased expression of proinflammatory cytokines particularly interleukin (IL)-1alpha and IL-1beta, tumor necrosis factor (TNF)-alpha and macrophage inflammatory proteins (MIP)-1alpha, as well as of the inhibitory cytokines transforming growth factor (TGF)-beta was observed in muscle. There was no difference in cytokine and chemokine pattern between polymyositis, dermatomyositis, and inclusion body myositis, which could indicate that similar pathogenetic mechanisms are involved in these subsets of myositis. A prominent finding of IL-1alpha expression in endothelial cells, both in patients with active inflammation and in patients with chronic persisting muscle weakness without inflammation, makes this an interesting molecule in understanding the mechanisms for the pathogenesis of muscle weakness. Involvement of the blood vessels in the pathogenesis of myositis was further supported by increased expression of adhesion molecules and by a phenotypical expression of endothelial cells, resembling high endothelium venules in all three subsets of IIM. The molecular studies to date indicate a role of the microvessels in the pathogenesis of IIM not only in DM, as was previously suggested, but also in PM and IBM. The studies also indicate that IL-1alpha could be a target molecule for new therapeutical interventions.

Cell Adhesion Molecules↗
PubMed1998

New developments in the role of cytokines and chemokines in inflammatory myopathies.

Cytokines and chemokines are important molecules in the inflammatory response and in immune regulation. Investigations of the production of these molecules in the target organ of inflammation is of particular interest to obtain increased knowledge of the pathogenesis of chronic inflammatory disorders. By investigations of muscle tissue from patients with polymyositis, inclusion-body myositis (IBM), and dermatomyositis a predominance of the cytokines interleukin-1 alpha and -1 beta and transforming growth factor beta was observed. Among the chemokines investigated, macrophage inflammatory protein 1 alpha was the most commonly found molecule. A similar pattern of cytokines and chemokines was present in polymyositis, IBM, and dermatomyositis. This was also true for the pronounced interleukin-1 alpha expression in the endothelial cells of capillaries and venules. The results of these studies suggest a major role of the proinflammatory cytokines interleukin-1 alpha and -1 beta and the importance of the endothelial cells in the pathogenesis not only in dermatomyositis, as previously suggested, but also in polymyositis and IBM. Furthermore, the pronounced interleukin-1 expression in the inflammatory myopathies makes this molecule an interesting potential target for development of future therapies for these disorders.

Chemokines↗