To develop and test a severity scale for individual organ involvements in systemic sclerosis (SSc, scleroderma).
An international study group completed the following tasks: (1) developed a glossary ...of terms including all pertinent variables for 9 potentially affected organ systems; (2) collected prospective data to determine the feasibility and practicality of each proposed variable; (3) revised the initial list of variables; (4) determined the association of each variable with mortality (a proxy for morbidity) using 579 patients in an existing comprehensive longitudinal scleroderma databank; (5) developed a severity grading scale for each organ system by discussion and consensus; and (6) externally validated the scale using an independent group of 680 patients from the same databank.
Nine organ-specific severity scales were developed from 0 (no documented involvement) to 4 (endstage disease). The data required for scale completion are relatively easy and practical for all physicians to obtain.
This preliminary severity scale will be useful for assessing disease severity status in individual patients both at one point in time and longitudinally. The severity scale will assist in the design and conduct of clinical trials and the comparison of study populations with one another. The scale will serve as a framework for developing a scleroderma disease activity index.
Tenascin (TN), a large extracellular matrix glycoprotein, is transiently expressed during embryonic development, but is absent from most normal adult tissues. TN is reexpressed, however, in healing ...wounds, in the stroma of some tumors, and in fibrotic diseases such as systemic sclerosis (SSc) and rheumatoid arthritis. To clarify the mechanisms regulating TN expression, we studied the effects of selected cytokines (PDGF, bFGF, TGF-β, IL-1, IL-4, IL-6, IFN-γ, and TNF-α) found in fibrotic tissue on TN expression by dermal fibroblasts. IL-4 strongly induced TN protein levels (up to 10-fold over the basal level), whereas PDGF and bFGF were less potent inducers of TN than IL-4. All other cytokines tested, including TGF-β, did not stimulate TN synthesis IL-4 also increased TN mRNA expression, and this effect was blocked by actinomycin D. Cycloheximide increased basal TN mRNA expression and induced TN mRNA in IL-4-treated fibroblasts, suggesting that repressor protein(s) may regulate transcription of the TN gene. Although no differences in constitutive TN expression or effects of cytokines on TN expression were observed between SSc and healthy fibroblasts, these data are consistent with the observations that high levels of both LL-4 and TN are present in the affected skin of patients with SSc. These results suggest that the high level of TN found in the affected tissue of patients with SSc results from the high level of IL-4 present.
Objective. To determine the frequency, clinical associations, and any major histocompatibility complex correlations of antifibrillarin antibodies in patients with systemic sclerosis (SSc).
Methods. ...Antifibrillarin antibodies were determined by indirect immunofluorescence, immunoblotting, and immunoprecipitation, and HLA class II alleles by DNA oligotyping, in a large cohort of SSc patients.
Results. Antifibrillarin was found in 8% of 335 SSc sera and was significantly more common in blacks (16%) than whites (5%), in males (33%) than females (14%), and in patients with cardiac, renal, or gut involvement. The HLA class II haplotype DRB1*1302, DQB1*0604 was found significantly more frequently in SSc patients with antifibrillarin compared with racematched normal controls and 260 SSc patients without antifibrillarin. In addition, 1 or more of the HLA–DQB1 alleles *0604, *0301, *0602, and/or *0302 was found in all antifibrillarin‐positive patients, and 62% of the antifibrillarin‐positive patients had 2 of these HLA–DQB1 alleles, a highly significant difference from both race‐matched normal controls and antifibrillarin‐negative SSc patients.
Conclusion. Antifibrillarin, although an infrequent nucleolar autoantibody, is a marker for severe SSc, especially in blacks and males, and is strongly associated with a unique HLA haplotype, as well as with combinations of certain HLA–DQB1 alleles.
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 Sjögren'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.
Latent human cytomegalovirus (HCMV) infection has been implicated in diseases characterized by tissue remodeling. Because of recent evidence indicating the possibility of a partial HCMV reactivation, ...the purpose of this study was to examine the role of the HCMV immediate early (IE) genes in the regulation of extracellular matrix (ECM) related host genes. Adenoviral vector expressing IE1 was generated to allow efficient gene delivery into human fibroblasts. IE1 stimulated the prolonged expression of connective tissue growth factor (CTGF) and TIMP1. IE1-dependent stimulation of CTGF was partially mediated by TGF-beta. Moreover, whereas collagenous proteins and collagen type 1 mRNA were only transiently induced by IE1 in the majority of fibroblasts, in selected fibroblast strains IE1 induced persistent ECM upregulation for up to 120 hours. This study suggests that transient or limited HCMV reactivation may play a direct role in abnormal matrix remodeling in GVHD, scleroderma, atherosclerosis and other HCMV-linked diseases.
We describe the detection and the growth of fibroblasts with human smooth muscle cell differentiation features from bronchoalveolar lavage (BAL) fluid of 53% of patients with scleroderma, but not ...from healthy controls. The binding of alpha-actin, vimentin and desmin antibodies by scleroderma lung fibroblasts exceeded that of normal adult lung fibroblasts, indicating that scleroderma lung fibroblasts express some markers of human smooth muscle cell differentiation (myofibroblasts), which may account for differences in biological behavior. A mesenchymal cell phenotype was documented by mRNA analysis, showing high expression of collagen type I and fibronectin in these cells. Fibronectin is also released in significantly higher amounts by scleroderma alveolar macrophages than by macrophages from healthy donors.
In this study, we have used the mRNA differential display technique to investigate the changes in gene expression that occur in the process of cellular aging. A number of cDNAs whose corresponding ...mRNAs are either increasingly or decreasingly expressed in senescent cells were thereby isolated. Through DNA sequencing, one of these differentially displayed mRNAs was identified as mitochondrial ADP/ATP translocase. The altered expression of ADP/ATP translocase in different stages of senescent fibroblasts was futher confirmed by Northern blots and semiquantitative RT-PCR. Our results demonstrate that expression of ADP/ATP translocase is progressively decreased during the process of in vitro cellular senescence. Further analyses with MTT assays indicate that the decreased expression of ADP/ATP translocase in senescent cells is in parallel with the decline of mitochondrial functions, suggesting that altered expression of this important mitochondrial enzyme might play an active role in the process of cellular senescence.
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