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)
Myasthenia gravis and polymyositis as manifestations of chronic graft-versus-host-disease.
Myasthenia gravis and polymyositis are each a rare manifestation of immune dysregulation in chronic graft-versus-host disease (cGVHD). We report a 4-year-old boy with idiopathic acquired aplastic anemia who developed myasthenia gravis 22 months and polymyositis 69 months after an allogeneic BMT (5/6 matched, MLC-nonreactive). The occurrence of both syndromes in one patient is unique. Autoimmune dysfunction may be associated with the development of cGVHD as demonstrated by the high incidence of prior aplastic anemia in BMT patients presenting with myasthenia gravis and polymyositis. Recognition of these neurologic manifestations is important in the diagnosis and treatment of cGVHD. (+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)
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)
HLA-DRB1 genes in 5 rheumatic disease multi-case families.
OBJECTIVE: To detect HLA-DRB1 (DR1-10) alleles in 5 families with multi-case rheumatic diseases, and to study the possible influence of DRB1 genes in the pathogenesis of rheumatic diseases. METHODS: Sequence-Specific Primer PCR (PCR-SSP) method was used to examine HLA-DRB1 alleles. Totally 36 members of 5 families and 166 healthy people were involved in this study. The results were assessed by Chi-square test. RESULTS: The HLA-DRB1 allele frequency in the patients and their relatives was similar. No significant difference was found. But DR4 allele frequency in the patients (90.9%) and their relatives (68%) was much higher than that in normal controls (16.8%) and the difference was statistically significant (P < 0.0001). In family 4, two RA patients have different DRB1 alleles, while in family 5, two patients have the same DRB1 alleles, one developed SLE and the other developed RA. CONCLUSIONS: DR4 is closely related to rheumatoid arthritis. The nelatives of RA patients may be at greater risk to develop RA than individuals without family history. Some patients had the same DRB1 allele but developed different rheumatic diseases. This suggested that there might be some common pathways in genetic predisposing of rheumatic diseases. On the other hand, only a few patients with the same DRB1 allele developed rheumatic diseases during their life, so other factors besides DRB1 gene might also be involved in the pathogenesis of rheumatic diseases. (+info)
Expression of the costimulatory molecule BB-1, the ligands CTLA-4 and CD28, and their mRNA in inflammatory myopathies.
To examine if the muscle fibers in patients with inflammatory myopathies have the potential to behave as antigen presenting cells (APCs), we investigated the expression of costimulatory molecules BB-1, B7-1 (CD80), and B7-2 (CD86), and their counterreceptors, CD28 or CTLA-4 (CD152), in the muscle biopsies of patients with polymyositis (PM), PM associated with human immunodeficiency virus infection (HIV-PM), sporadic inclusion body myositis (s-IBM), dermatomyositis (DM), and normal or disease controls. The expression of the B7 family of molecules on the muscle fibers was limited to BB-1. In PM, HIV-PM, and s-IBM, but not the disease controls, the nonnecrotic, MHC-class I-expressing muscle fibers, invaded or not by CD8+ T cells, had prominent membrane expression of BB-1. Several of the BB-1-positive fibers bound strongly in a cell-to-cell contact with their CD28 or CTLA-4 ligands on the autoinvasive CD8+ T cells, as confirmed by confocal microscopy. By reverse transcription-polymerase chain reaction, the expression of CD28 and CTLA-4 was up-regulated in PM, HIV-PM, and s-IBM, but not the controls. Because the BB-1-positive fibers expressed MHC-class I antigen and bound to up-regulated counterreceptors CD28 and CTLA-4 on the autoinvasive CD8+ T cells only in PM, HIV-PM, and s-IBM, the BB-1 molecule in these diseases should have a functional role in antigen presentation and T cell differentiation. These findings complement recent studies and suggest that in PM, HIV-PM, and s-IBM the muscle fibers are not only targets of CD8+ cytotoxic T cells but may also behave as "professional" APC. (+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)