Fas and Fas ligand interaction induces apoptosis in inflammatory myopathies: CD4+ T cells cause muscle cell injury directly in polymyositis.
OBJECTIVE: To investigate the involvement of the Fas/Fas ligand (Fas/FasL) system in the inflammatory myopathies. METHODS: Frozen muscle sections obtained from 7 patients with polymyositis (PM), 4 patients with dermatomyositis (DM), and 3 controls were studied by immunochemistry. Apoptosis was detected by DNA electrophoresis and in situ labeling using the TUNEL method. RESULTS: Fas was detected on muscle fibers and infiltrating mononuclear cells (MNC) in 6 PM patients and 2 DM patients. FasL was expressed mainly on CD4+ T cells and some CD8+ T cells, and on macrophages surrounding Fas-positive muscles in 4 PM patients and 1 DM patient. In 3 of the 5 patients with FasL-positive MNC, the TUNEL method showed that both invaded myonuclei and MNC underwent apoptosis. Chromosomal DNA from the muscle tissue of these patients showed ladder formation. CONCLUSION: Fas/FasL is involved in muscle cell apoptosis in at least 2 of the inflammatory myopathies, PM and DM. Although CD8+-mediated cytotoxicity is thought to be the main mechanism of muscle injury in PM, our data suggest that CD4+ T cells also directly cause muscle cell damage. (+info)
Pneumocystis carinii pneumonia in patients with connective tissue diseases: the role of hospital experience in diagnosis and mortality.
OBJECTIVE: Pneumonia due to Pneumocystis carinii has been increasingly reported in patients with connective tissue diseases, but the frequency of this complication is not known. We sought to determine the frequency of P carinii pneumonia (PCP) in patients with connective tissue diseases, and to determine the role that a hospital's acquired immunodeficiency syndrome (AIDS)-related experience may have in the diagnosis of PCP in these patients. METHODS: We used a state hospitalization registry to identify all patients with PCP and either rheumatoid arthritis, systemic lupus erythematosus, Wegener's granulomatosis, polymyositis, dermatomyositis, polyarteritis nodosa, or scleroderma who had an emergent or urgent hospitalization in California from 1983 to 1994. We compared patient and hospital characteristics between these patients and patients with connective tissue diseases hospitalized with other types of pneumonia. RESULTS: Two hundred twenty-three patients with connective tissue diseases were diagnosed with PCP in the 12-year study period. The frequency of PCP ranged from 89 cases/10,000 hospitalizations/year in patients with Wegener's granulomatosis to 2 cases/10,000 hospitalizations/year in patients with rheumatoid arthritis. Compared with 5,457 patients with connective tissue diseases and pneumonia due to other organisms, patients with PCP were more likely to be younger, to be male, to have private medical insurance, and to have systemic lupus erythematosus, Wegener's granulomatosis, inflammatory myopathy, or polyarteritis nodosa rather than rheumatoid arthritis, and were less likely to be African American. Hospital size, teaching status, urban/rural location, proportion of admissions due to AIDS or PCP, and proportion of patients with pneumonia undergoing bronchoscopy were each associated with the likelihood of diagnosis of PCP in univariate analyses, but only the number of patients with PCP being treated at a hospital (odds ratio [OR] 1.03 for each additional 10 cases/year, 95% confidence interval [95% CI] 1.01-1.05) was associated with the likelihood of diagnosis of PCP in multivariate analyses. Patients were also somewhat more likely to be diagnosed with PCP if there had previously been a case of PCP in a patient with a connective tissue disease at the same hospital (OR 135, 95% CI 0.98-1.85). In-hospital mortality was 45.7%, and was unrelated to hospital characteristics. CONCLUSION: PCP is an uncommon, but often fatal, occurrence in patients with connective tissue disease. A hospital's prior experience with patients with PCP is associated with the likelihood that this condition is diagnosed in patients with connective tissue diseases who present with pneumonia, suggesting that diagnostic suspicion is an important factor in the correct identification of affected patients. (+info)
Dermatomyositis associated with invasive thymoma.
We report a case of dermatomyositis (DM) associated with invasive thymoma in a 22-year-old woman who was admitted to our hospital complaining of dyspnea which required ventilation support. The reddened elevated scaly eruptions were prominent over the extensor surfaces. Chest X-ray and computed tomography showed mediastinal masses, which were diagnosed as mixed type thymoma. Muscle and skin biopsy specimens were compatible with DM. She was treated with methylprednisolone pulse therapy followed by extended removal of the anterior mediastinal tumor and subsequent radiotherapy. She has had a good clinical course without recurrence of thymoma or DM for more than 3 years. The role of thymoma in the development of DM is discussed. (+info)
Prevalence and antigen specificity of anti-histone antibodies in patients with polymyositis/dermatomyositis.
Anti-histone antibodies have been detected in the sera of patients with various autoimmune diseases. The existence of anti-histone antibodies in patients with polymyositis/dermatomyositis, however, has not been reported. We found anti-histone antibodies in eight (17%) of 46 sera from patients with polymyositis/dermatomyositis by an enzyme-linked immunosorbent assay. One serum was positive for both IgG anti-histone antibodies and IgM anti-histone antibodies. Six sera were positive only for IgG anti-histone antibodies. One serum was positive only for IgM anti-histone antibodies. An indirect immunofluorescence analysis using HEp-2 cells as the substrate showed that all sera positive for anti-histone antibodies produced homogeneous nuclear fluorescence. This immunofluorescence pattern disappeared after absorption of anti-histone activity with total histones. An immunoblotting analysis demonstrated that the anti-histone antibodies were predominantly directed against histone H1 in all seven sera with IgG anti-histone antibodies. Weak reactivity with H2B and H4 were also found in three sera from the patients with polymyositis/dermatomyositis. Sera from two patients with polymyositis/dermatomyositis displayed anti-H2A and H3 activity. One of the two sera showed IgM anti-histone antibodies in the enzyme-linked immunosorbent assay reacted with H1, H2A, H2B, H3, and H4, whereas the other serum reacted with no fractions of total histones. The activity of anti-histone antibodies disappeared in immunoblotting after absorption with total histones. All of the patients with anti-histone antibodies were free from lung fibrosis or internal malignancies. Thus, our data indicate that the presence of anti-histone antibodies is classified as one of the serologic abnormalities observed in polymyositis/dermatomyositis. (+info)
Genetic risk and protective factors for idiopathic inflammatory myopathy in Koreans and American whites: a tale of two loci.
OBJECTIVE: To better understand genetic contributions to autoimmunity, immunogenetic markers were studied in two racially discrete and geographically isolated populations of patients with idiopathic inflammatory myopathy (IIM). METHODS: Clinical characteristics, as well as clinical and autoantibody subsets, were defined in 151 American white patients and 50 Korean patients with IIM. HLA-DRB1 and DQA1 genotyping was performed on patients and racially matched controls by standard molecular techniques. Gm allotypes and phenotypes were determined by the hemagglutination-inhibition method. RESULTS: HLA-DRB1*0301, the linked allele DQA1*0501, and DRB1 alleles sharing the first hypervariable region motif 9EYSTS13 were major genetic risk factors for the development of myositis in whites (corrected P [Pcorr] < 0.0004, odds ratio [OR] 11.2, 4.5, and 3.1, respectively, for each factor versus controls). Although both the white and Korean patients had a similar distribution of clinical characteristics, autoantibody profiles, and clinical groups, no HLA-DRB1 nor DQA1 allele or motif was found to be a risk factor for IIM in the Korean patients. However, DRB1*14 was a protective factor in Korean patients without myositis-specific autoantibodies (Pcorr = 0.004, OR 0.046). In addition, although no Gm phenotype or allotype was identified as a risk factor in whites, Gm 21 was a protective factor for the development of IIM in Koreans (Pcorr = 0.024, OR 0.3). CONCLUSION: Although myositis patients in the US and Korea share similar clinical and serologic features, the immune response genes predisposing to and protecting from myositis in each of these ethnic groups differ at two chromosomal loci. These data suggest that multiple genetic loci should be studied to identify risk and protective factors for some autoimmune diseases in various ethnic populations. (+info)
Autoantibodies to the extracellular matrix microfibrillar protein, fibrillin-1, in patients with scleroderma and other connective tissue diseases.
A duplication in the fibrillin-1 gene has been implicated as the cause of the tight skin 1 (tsk1) phenotype, an animal model of scleroderma or systemic sclerosis (SSc). In addition to the production of abnormal fibrillin-1 protein, the tsk1 mouse also produces autoantibodies to fibrillin-1. Among a population of Choctaw Native Americans with the highest prevalence of SSc yet described, a chromosome 15q haplotype containing the fibrillin-1 gene has been strongly associated with SSc. With a recombinant human fibrillin-1 protein, autoantibodies to fibrillin-1 were detected in the sera of Native American SSc patients that correlated significantly with disease. Abs to fibrillin-1 also were detected in sera from Japanese, Caucasian, and African-American SSc patients. Compared with other ethnic groups, Japanese and Native American SSc patients had significantly higher frequencies of anti-fibrillin-1 Abs. Sera from patients with diffuse SSc, calcinosis, Raynaud's, esophageal dysmotility, sclerodactyly, and telangiectasias syndrome and mixed connective tissue disease also had significantly higher frequencies of anti-fibrillin-1 Abs than sera from controls or patients with other non-SSc connective tissue diseases (lupus, rheumatoid arthritis, and Sjogren's syndrome). Ab specificity for fibrillin-1 was demonstrated by the lack of binding to a panel of other purified autoantigens. The results presented demonstrate for the first time the presence of high levels of anti-fibrillin-1 Abs in a significant portion of patients with SSc. (+info)
Autoantibodies in connective tissue diseases: clinical significance and analysis of target autoantigens.
Systemic connective tissue diseases are characterized by the production of a number of autoantibodies directed against various cellular constituents. These autoantibodies are closely associated with certain diseases and clinical manifestations, and are therefore useful for clinical practice such as to diagnose diseases and to predict clinical subsets, disease activity and prognosis. To understand the etiology and pathogenic mechanisms of connective tissue diseases; it is particularly important to elucidate the structure and function of target autoantigens recognized by these disease-specific autoantibodies. In recent years, the nature of many target autoantigens have been identified using molecular biology approaches. Most of them are intracellular enzymes and regulatory factors necessary for important biological function involved in gene replication, transcription, RNA processing and protein translation. Thus, the studies of autoantibodies are useful not only in clinical medicine but also in basic cellular and molecular biology. (+info)
Safety of a home exercise programme in patients with polymyositis and dermatomyositis: a pilot study.
OBJECTIVES: To investigate whether a home exercise programme could safely be performed by patients with stable, inactive polymyositis (PM) and dermatomyositis (DM), regarding disease activity, muscle function, health status and pain. METHODS: Ten patients with reduced muscle function completed the study. A home exercise programme including exercises for strength in the upper and lower limbs, neck and trunk, for mobility in the upper limbs and moderate stretching was developed. The patients exercised for 15 min and took a 15 min walk 5 days a week during a 12 week period. Assessments included clinical evaluation of disease activity, serum creatinine phosphokinase (CPK) levels, magnetic resonance imaging (MRI) of the quadriceps, repeated muscle biopsy of the vastus lateralis, a muscle function index (FI), a walking test and a health status instrument (the SF 36) performed at the start of the study and after 12 weeks. RESULTS: After 12 weeks of exercise, there were no signs of increased disease activity as assessed clinically, by CPK values, MRI or muscle biopsy findings. On an individual basis, all patients improved regarding muscle function according to the FI, in six cases the improvement reached statistical significance (P < 0.05). A significant improvement regarding muscle function in the upper and lower limbs, walking distance and general health status was achieved. CONCLUSIONS: Our results indicate that this home exercise programme can be safely employed in patients with stable, inactive PM and DM, with beneficial effects on muscle function. (+info)