Soluble interleukin-2 receptor, interleukin-2 and interleukin-4 in sera and supernatants from patients with progressive systemic sclerosis

Identification of immune- and autophagy-related genes and effective diagnostic biomarkers in endometriosis: a bioinformatics analysis

Background

To identify autophagy- and immune-related hub genes affecting the diagnosis and treatment of endometriosis.

Methods

Gene expression data were downloaded from the Gene Expression Omnibus (GEO) (GSE11691 and GSE120103 for training, and GSE7305 for validation). By overlapping the differentially expressed genes (DEGs), Weighted gene co-expression network analysis (WGCNA) module genes, and autophagy-related genes (ARGs), and immune-related genes (IRGs) separately, hub genes were identified using the least absolute shrinkage and selection operator (LASSO)and support vector machine recursive feature elimination (SVM-RFE). The hub genes were analyzed by Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analyses. A hub gene-prediction model was constructed and assessed using five-fold cross-validation via five supervised machine-learning algorithms: random forest, the sequential minimal optimization (SMO), K-nearest neighbours (IBK), C4.5 decision tree (J48), and logistics regression. The area under the receiver operating characteristic curve (AUC) was adopted to assess the identification ability of characteristic genes.

Results

1,116 DEGs were obtained from the training cohort, and 22 endometriosis-related IRGs were identified by overlapping the 1,116 DEGs, 3,222 module genes, and 1,793 IRGs. Meanwhile, 45 endometriosis-related ARGs were obtained (1,928 ARGs). Subsequently, nine IRG hub genes (BST2, CCL13, CD86, CSF1, FAM3C, GREM1, ISG20, PSMB8, and S100A11) and nine ARG hub genes (GSK3A, HTR2B, RAB3GAP1, ARFIP2, BNIP3, CSF1, MAOA, PPP1R13L, and SH3GLB2) were obtained by LASSO and SVM-RFE. GO analysis indicated that the ARG hub genes responded to the regulation of autophagy and mitochondrial outer membrane permeabilization, and KEGG enrichment analysis involved serotonergic and dopaminergic synapses. GO analysis also indicated that the IRG hub genes responded to the regulation of leukocyte proliferation and mononuclear cell migration, and KEGG analysis showed enrichment involved in viral protein interaction with cytokines and cytokine receptors. The AUC of the random-forest algorithm of ARGs was 0.975 in the training cohort and 0.940 in the validation cohort, and the AUC of the SMO algorithm of IRGs was 0.907 in the training cohort and 0.8 in the validation cohort.

Conclusions

Seventeen hub genes are closely associated with endometriosis. These genes are potential autophagy- and immune-related biomarkers for diagnosis and treatment of endometriosis.

Dendritic cells drive profibrotic inflammation and aberrant T cell polarization in systemic sclerosis

OBJECTIVES

Systemic sclerosis (SSc) is a devastating autoimmune disease characterized by fibrosis and obliterative vasculopathy affecting the skin and visceral organs. While the processes mediating excessive extracellular matrix (EM) deposition and fibroblast proliferation are clear, the exact link between autoimmunity and fibrosis remains elusive. Th17 cells have been proposed as critical drivers of profibrotic inflammation during SSc, but little is known about the immune components supporting their pathogenic role.

METHODS

Dendritic cells (DCs) activate and shape T cell differentiation by producing polarizing cytokines. Hence, we investigated the cytokine responses of monocyte-derived DCs (Mo-DCs) from patients with limited cutaneous SSc (lcSSc), diffuse cutaneous SSc (dcSSc), and healthy controls (HC) after stimulation with toll-like receptor (TLR) agonists. Also, using co-culture assays, we analyzed T cell subpopulations after contact with autologous TLR-activated Mo-DCs.

RESULTS

In general, we observed an increased production of Th17 related cytokines like IL-1β, IL-17F, IL-21, IL-22 by SSc compared with HC Mo-DCs, with variations between lcSSc vs. dcSSc and early- vs. late-stage subgroups. Noticeably, we found a significant increment in IL-33 production by Mo-DCs in all SSc cases regardless of their clinical phenotype. Strikingly, T cells displayed Th2, Th17, and dual Th2/Th17 phenotypes after exposure to autologous TLR-stimulated Mo-DCs from SSc patients but not HC. These changes were pronounced in individuals with early-stage dcSSc and less significant in the late-stage lcSSc subgroup.

CONCLUSIONS

Our findings suggest that functional alterations of DCs subsidize the immune mechanisms favoring the aberrant T cell polarization and profibrotic inflammation behind the clinical SSc heterogeneity.

Cytokines Involved in the Pathogenesis of SSc and Problems in the Development of Anti-Cytokine Therapy

Systemic sclerosis (SSc) is a connective tissue disease of unknown etiology. SSc causes damage to the skin and various organs including the lungs, heart, and digestive tract, but the extent of the damage varies from patient to patient. The pathology of SSc includes ischemia, inflammation, and fibrosis, but the degree of progression varies from case to case. Many cytokines have been reported to be involved in the pathogenesis of SSc: interleukin-6 is associated with inflammation and transforming growth factor-β and interleukin-13 are associated with fibrosis. Therapeutic methods to control these cytokines have been proposed; however, which cytokines have a dominant role in SSc might differ depending on the extent of visceral lesions and the stage of disease progression. Therefore, it is necessary to consider the disease state of the patient to be targeted and the type of evaluation method when an anti-cytokine therapy is conducted. Here, we review the pathology of SSc and potential cytokine targets, especially interleukin-6, as well as the use of anti-cytokine therapy for SSc.

Cytomegalovirus aggravates the autoimmune phenomenon in systemic autoimmune diseases

BACKGROUND

Human Cytomegalovirus (CMV), because of its ability to extensively manipulate host immunity during active infection, has been suggested to be involved in autoimmunity. However, its influence on T-cells and cytokines in systemic autoimmune diseases like systemic lupus erythematosus (SLE) and systemic sclerosis (SSc) is indistinct.

METHODS

We investigated the in-vitro response of T lymphocytes from SLE and SSc patients to CMV antigen. Functional activity of T lymphocytes was determined by estimating Th1 (IL-2 and IFN-γ) and Th2 (IL-4 and IL-10) cytokines.

RESULTS

We observed that CMV antigen stimulation in-vitro resulted in significant increase in CD4:CD8 T-cell ratio in peripheral blood mononuclear cells (PBMCs) from SLE and SSc patients; response dominated by CD4⁺ than CD8⁺ memory T-cells. SSc T-cell response was differentiated by aberrant increase in CD4⁺CD25⁺ T-cells. CMV antigen caused elevation in IL-4 and IFN-γ production in both patient PBMCs, whereas IL-2 was also raised in SLE PBMCs. The development of large pool of memory T-cells and overproduction of IFN-γ may result in flare-up of autoimmunity in these patients.

CONCLUSION

Our study provides an insight into the immunopathological potential of CMV-reactive immune cells to develop new potential strategies for targeted therapeutic intervention.

Deregulated PSGL-1 Expression in B Cells and Dendritic Cells May Be Implicated in Human Systemic Sclerosis Development

Systemic sclerosis (SSc) is an autoimmune disorder with high morbidity and mortality, is difficult to diagnose early, and has no curative treatment. PSGL-1 is a leukocyte receptor whose deficiency in mice promotes an SSc-like disease. ADAM8, a metalloprotease that cleaves PSGL-1, is implicated in inflammatory processes. Our goal was to evaluate whether PSGL-1 and ADAM8 contribute to the pathogenesis of human SSc. We found that patients with SSc presented increased PSGL-1 expression on monocytes, dendritic cells, and T cells and decreased expression of PSGL-1 on B cells. PSGL-1 on monocytes from SSc patients failed to induce Syk phosphorylation or IL-10 production after interaction with P-selectin. Up to 60% of the IL-10-producing B cells expressed PSGL-1, pointing to a regulatory role for PSGL-1 in B cells, and PSGL-1⁺ B cells from SSc patients had decreased IL-10 production. ADAM8 expression was increased on antigen-presenting cells and T lymphocytes of SSc patients. Patients treated with calcium antagonists had lower levels of ADAM8 on APCs and T lymphocytes. Multivariate analysis indicated that the high percentage of ADAM8-expressing plasmacytoid dendritic cells discriminated patients from healthy donors. High PSGL-1 expression on dendritic cells was associated with the presence of interstitial lung disease.

The role of endothelial cells in the vasculopathy of systemic sclerosis: A systematic review

INTRODUCTION

Systemic sclerosis (SSc) is an autoimmune connective tissue disorder characterized by fibroproliferative vasculopathy, immunological abnormalities and progressive fibrosis of multiple organs including the skin. In this study, all English speaking articles concerning the role of endothelial cells (ECs) in SSc vasculopathy and representing biomarkers are systematically reviewed and categorized according to endothelial cell (EC) (dys)function in SSc.

METHODS

A sensitive search on behalf of the EULAR study group on microcirculation in Rheumatic Diseases was developed in Pubmed, The Cochrane Library and Web of Science to identify articles on SSc vasculopathy and the role of ECs using the following Mesh terms: (systemic sclerosis OR scleroderma) AND pathogenesis AND (endothelial cells OR marker). All selected papers were read and discussed by two independent reviewers. The selection process was based on title, abstract and full text level. Additionally, both reviewers further searched the reference lists of the articles selected for reading on full text level for supplementary papers. These additional articles went through the same selection process.

RESULTS

In total 193 resulting articles were selected and the identified biomarkers were categorized according to description of EC (dys)function in SSc. The most representing and reliable biomarkers described by the selected articles were adhesion molecules for EC activation, anti-endothelial cell antibodies for EC apoptosis, vascular endothelial growth factor (VEGF), its receptor VEGFR-2 and endostatin for disturbed angiogenesis, endothelial progenitors cells for defective vasculogenesis, endothelin-1 for disturbed vascular tone control, Von Willebrand factor for coagulopathy and interleukin (IL)-33 for EC-immune system communication. Emerging, relatively new discovered biomarkers described in the selected articles, are VEGF₁₆₅b, IL-17A and the adipocytokines. Finally, myofibroblasts involved in tissue fibrosis in SSc can derive from ECs or epithelial cells through a process known as endothelial-to-mesenchymal transition.

CONCLUSION

This systematic review emphasizes the growing evidence that SSc is primarily a vascular disease where EC dysfunction is present and prominent in different aspects of cell survival (activation and apoptosis), angiogenesis and vasculogenesis and where disturbed interactions between ECs and various other cells contribute to SSc vasculopathy.

Strategy for treatment of fibrosis in systemic sclerosis: Present and future

Systemic sclerosis (SSc) is a generalized connective tissue disorder characterized by microvascular damage, autoimmunity, and excessive fibrosis of the skin and various internal organs. Regardless of the recent progress in medicine, no radical therapy for SSc has been developed, and the risk of mortality remains high. Therefore, diagnosis in the early disease stage, risk stratification for the development of serious organ involvement and therapeutic intervention with disease-modifying drugs can reduce the maximum degree of fibrosis, leading to improved long-term survival. Recently, new criteria for very early diagnosis of SSc have been proposed, which are expected to be useful for regularly following up patients with very early SSc, regardless of the absence of skin sclerosis, and for detecting the development of internal organ involvement as early as possible. At present, several immunosuppressants, including methotrexate, corticosteroids and cyclophosphamide, are being used for the treatment of fibrosis. Furthermore, mycophenolate mofetil, i.v. immunoglobulins, B-cell depletion, anti-interleukin-6 receptor antibody, autologous hematopoietic stem cell transplantation, rapamycin, pirfenidone and imatinib mesylate are potential candidates for the treatment of SSc, although their efficacy has not been validated. Moreover, targeting transforming growth factor-1 and its signaling pathway or modulating the imbalance between T-helper 1 and 2 immune responses are also attractive therapeutic options. This review describes recent advances in the strategy for treatment of fibrosis in SSc and future perspectives.

Increased circulating fibrinogen-like protein 2 in patients with systemic sclerosis

Fibrinogen-like protein 2 (FGL2), a member of the fibrinogen-related superfamily of proteins, is expressed on the surface of macrophages, T cells, and endothelial cells and directly cleaves prothrombin to thrombin. The aim of this study is to determine the serum FGL2 level and its association with clinical parameters in patients with systemic sclerosis (SSc). Serum FGL2 level was examined by enzyme-linked immunosorbent assay in 61 patients with SSc, 24 patients with systemic lupus erythematosus, and 24 healthy individuals. In a retrospective longitudinal study, sera from 13 patients with SSc were analyzed. The serum FGL2 level was increased in patients with SSc compared with healthy individuals (P < 0.001) and patients with systemic lupus erythematosus (P < 0.01). Among patients with SSc, there were no differences in serum FGL2 level between limited cutaneous SSc and diffuse cutaneous SSc. In the longitudinal study, the FGL2 level was generally unchanged at follow-up. The results show that the serum FGL2 level was increased in patients with SSc but not in patients with systemic lupus erythematosus or healthy individuals. Therefore, FGL2 possibly contribute to the development of SSc.

Biological significance of soluble IL-2 receptor

A NUMBER of receptors for growth factors and differentiation antigens have been found to be secreted or released by cells. Following mononuclear cell (MNC) activation and interleukin-2 receptor (IL-2R) expression, a soluble form of the Alpha;-chain of IL-2R (sIL-2R) is released. The sIL-2R has been shown to be present in the culture supernatants of activated MNCs as well as in normal sera and, in higher amounts, in sera from subjects affected by several diseases including neoplastic, infectious and autoimmune ones, and in sera from transplanted patients suffering allograft rejection. The blood sIL-2R levels depend on the number of producing cells and the number of molecules per cell, so that sIL-2R blood values may represent an index of the number and the functional state of producing cells, both normal and neoplastic. Thus, monitoring of the immune system, mostly T-cells and haematological malignancies might be targets for the measurement of sIL-2R. Since many conditions may influence sIL-2R production, little diagnostic use may result from these measurements. However, since blood sIL-2R levels may correlate with disease progression and/or response to therapy, their measurement may be a useful index of activity and extent of disease. The precise biological role of the soluble form of the IL-2R is still a matter of debate. However, we know that increased sIL-2R levels may be observed in association with several immunological abnormalities and that sIL-2R is able to bind IL-2. It is conceivable then that in these conditions the excess sIL-2R released in vivo by activated lymphoid cells or by neoplastic cells may somehow regulate IL-2-dependent processes. On the other hand, it cannot exclude that sIL-2R is a by-product without biological significance. Finally, it is puzzling that in many conditions in which an increase of blood sIL-2R values has been observed, MNCs display a decreased in vitro capacity to produce sIL-2R. These seemingly contrasting findings are discussed in the light of the data showing that sIL-2R production correlates with IL-2 production.

Augmented production of soluble CD93 in patients with systemic sclerosis and clinical association with severity of skin sclerosis

BACKGROUND

The cell surface protein CD93, expressed on endothelial and myeloid cells, mediates phagocytosis, inflammation and cell adhesion. A soluble form of CD93 (sCD93) is released during inflammation.

OBJECTIVES

To determine the serum sCD93 level and its association with clinical parameters in patients with systemic sclerosis (SSc).

METHODS

Serum sCD93 levels were examined by enzyme-linked immunosorbent assay in 59 patients with SSc, 24 patients with systemic lupus erythematosus and 47 healthy individuals. The expression of CD93 in skin tissues was examined immunohistochemically. In a retrospective longitudinal study, sera from 11 patients with SSc were analysed.

RESULTS

Serum sCD93 levels were increased in patients with SSc compared with healthy individuals (P<0·001). Patients with diffuse cutaneous SSc showed greater levels of sCD93 than those with limited cutaneous SSc (P<0·01) or systemic lupus erythematosus (P<0·01). Serum sCD93 levels correlated positively with the severity of skin sclerosis. Strong CD93 immunostaining was observed on endothelial cells in lesional skin tissues. In the longitudinal study, sCD93 levels decreased in parallel with improvement in skin sclerosis.

CONCLUSIONS

Serum sCD93 levels are increased in patients with SSc and correlate with the severity and activity of skin sclerosis. CD93 may contribute to the development of skin fibrosis in SSc.

Serum interleukin 9 levels are increased in patients with systemic sclerosis: association with lower frequency and severity of pulmonary fibrosis

OBJECTIVE

To determine serum interleukin 9 (IL-9) levels and their clinical associations in patients with systemic sclerosis (SSc).

METHODS

Serum IL-9 levels were examined by ELISA in 71 patients with SSc, 15 with systemic lupus erythematosus (SLE), 15 with dermatomyositis (DM), 39 with atopic dermatitis, and 28 healthy individuals.

RESULTS

Serum IL-9 levels were significantly elevated in SSc patients (84.6 ± 76.0 pg/ml) compared with healthy individuals (40.4 ± 41.7 pg/ml; p < 0.001), and patients with SLE (50.7 ± 52.0 pg/ml; p < 0.05) or DM (50.6 ± 55.8 pg/ml; p < 0.05) or atopic dermatitis (41.8 ± 38.8 pg/ml; p < 0.001). Among SSc patients, there were no differences in serum IL-9 levels between those with limited cutaneous SSc and those with diffuse cutaneous SSc. Patients with SSc and raised IL-9 levels less often had pulmonary fibrosis and decreased percentage vital capacity than those with normal IL-9 levels. IL-9 levels were positively correlated with percentage vital capacity in patients with SSc.

CONCLUSION

Serum IL-9 level was increased in patients with SSc, and was associated with lower frequency and severity of pulmonary fibrosis in SSc. IL-9 could be a protective factor against the development of pulmonary fibrosis in this disease, and as such would be a possible therapeutic target.

Serum IL-33 levels are raised in patients with systemic sclerosis: association with extent of skin sclerosis and severity of pulmonary fibrosis

To determine serum interleukin-33 (IL-33) levels and their associations with clinical parameters in patients with systemic sclerosis (SSc). Serum IL-33 levels were examined by enzyme-linked immunosorbent assay in 69 patients with SSc and 30 healthy individuals. In a retrospective longitudinal study, sera from 14 patients with SSc were analyzed (follow-up, 1-7 years). Serum IL-33 levels were elevated in SSc patients (261.7 ± 141.9 pg/ml) compared with healthy individuals (174.9 ± 72.4 pg/ml; P < 0.001). Patients with diffuse cutaneous SSc had higher levels of IL-33 (287.5 ± 146.6 pg/ml) than those with limited cutaneous SSc (221.5 ± 126.5 pg/ml; P < 0.05). Pulmonary fibrosis and decreased forced vital capacity were more commonly found in patients with elevated IL-33 levels than in those with normal IL-33 levels. IL-33 levels correlated positively with the extent of skin sclerosis, and inversely with percent predicted forced vital capacity. IL-33 levels were increased in SSc patients and correlated with the extent of skin sclerosis and the severity of pulmonary fibrosis. Therefore, IL-33 possibly plays a role in cutaneous and pulmonary fibrosis in SSc patients.

[Cytokines and T cell differentiation in systemic sclerosis]

The physiopathology of systemic sclerosis remains unclear within a complex interaction between vasculopathy, perivascular inflammatory infiltrate, extensive tissue fibrosis and auto-immune manifestations. Chronology between vascular disease and adjacent inflammatory cell infiltration is still not yet clarified. There is growing evidence that T cell activation and its cytokine expression play a key role in vascular impairment occurrence and collagen dysregulation. Nevertheless, cytokine descriptions are mainly limited to blood and tissue measurement and the T cells differentiation analysis restricted to the Th1/Th2 balance. The purpose of this review is to establish an exhaustive cartography of cytokines involved in T cell differentiation, regarding the recent advance in T lymphocyte differentiation, including Th9, Th17, Th22 and regulatory T cells (Treg) pathways. This review will focus on Th17, Th22 and Treg differentiation, corresponding to the equilibrium between inflammation and tolerance. Finally, regarding published results in systemic sclerosis, T cells participation appears to be more a Th1/Th2 co-expression than an exclusive Th1 or Th2 polarization. Also, a possible Th22/Treg imbalance is suggested, leading to a Th22 overexpression and likely to tissue inflammation genesis.

Serum CCL23 levels are increased in patients with systemic sclerosis

The aim of this study is to determine serum CCL23 levels and their clinical associations in patients with systemic sclerosis (SSc). Serum CCL23 levels were examined by ELISA in 66 patients with SSc, 20 patients with systemic lupus erythematosus, 20 patients with dermatomyositis, and 33 healthy individuals. Serum CCL23 levels were elevated in SSc patients (389.1 ± 199.2 pg/mL) compared with healthy individuals (94.1 ± 85.6 pg/mL; P < 0.001) and patients with systemic lupus erythematosus (43.4 ± 39.3 pg/mL; P < 0.001) or dermatomyositis (132.1 ± 104.5 pg/mL; P < 0.001). Among SSc patients, there were no differences in serum CCL23 levels between those with limited cutaneous SSc and those with diffuse cutaneous SSc. SSc patients with elevated CCL23 levels were found to have shorter disease duration than those with normal CCL23 levels (P < 0.001). Furthermore, raised CCL23 levels were associated with a higher frequency of pulmonary arterial hypertension (P < 0.05). The results show that serum CCL23 level was increased in the early phase of SSc. CCL23 could be associated with induction of SSc and as such would be a serologically useful marker for disease activity.

Resistin-like molecule-beta in scleroderma-associated pulmonary hypertension

Scleroderma is a systemic, mixed connective tissue disease that can impact the lungs through pulmonary fibrosis, vascular remodeling, and the development of pulmonary hypertension and right heart failure. Currently, little is known about the molecular mechanisms that drive this condition, but we have recently identified a novel gene product that is up-regulated in a murine model of hypoxia-induced pulmonary hypertension. This molecule, known as hypoxia-induced mitogenic factor (HIMF), is a member of the newly described resistin gene family. We have demonstrated that HIMF has mitogenic, angiogenic, vasoconstrictive, inflammatory, and chemokine-like properties, all of which are associated with vascular remodeling in the lung. Here, we demonstrate that the human homolog of HIMF, resistin-like molecule (RELM)-beta, is expressed in the lung tissue of patients with scleroderma-associated pulmonary hypertension and is up-regulated compared with normal control subjects. Immunofluorescence colocalization revealed that RELM-beta is expressed in the endothelium and vascular smooth muscle of remodeled vessels, as well as in plexiform lesions, macrophages, T cells, and myofibroblast-like cells. We also show that addition of recombinant RELM-beta induces proliferation and activation of ERK1/2 in primary cultured human pulmonary endothelial and smooth muscle cells. These results suggest that RELM-beta may be involved in the development of scleroderma-associated pulmonary hypertension.

T cells, B cells, and polarized immune response in the pathogenesis of fibrosis and systemic sclerosis

PURPOSE OF REVIEW

A better comprehension of the interactions between cells of the adaptive immune system with fibroblasts and endothelial cells is required to understand abnormal extracellular matrix deposition, development of pathologic fibrosis, and vasculopathy.

RECENT FINDINGS

Skin T cells with high IL-4 production potential and peripheral blood T cells preferentially expressing chemokine receptors associated with Th2 functions are found in individuals with active systemic sclerosis. Animal models indicate that Th2 cells and IL-13 can induce muscular hypertrophy in pulmonary arterial vasculature. In bleomycin-induced fibrosis, B cells produce fibrogenic cytokines upon interaction of an endogenous ligand (hyaluronan) with toll-like receptor-4. In the sclerodermatous graft versus host model, the lack of tumor necrosis factor-production by CD4+ T cells is permissive for fibrosis development. Dermal fibrosis and capillary loss typical of systemic sclerosis can be reversible after high-dose immunosuppression and hematopoietic stem cell transplantation.

SUMMARY

Although immunosuppressive strategies to treat patients with systemic sclerosis and allied conditions are largely disappointing, thus indicating a permissive rather than causative role of immunoinflammatory events characteristic of the disease, new findings stress that cells of the adaptive immune system play important roles in assisting fibrogenesis and vascular abnormalities. This may help in identifying efficacious strategies aimed at their control.

Physiopathologie de la sclérodermie systémique: état des lieux sur une affection aux multiples facettes

Systemic sclerosis is a rare disease characterized by vascular hyperreactivity and collagen deposition. Endothelial cell, fibroblast and lymphocyte abnormalities have been reported in systemic sclerosis. Fibroblast dysfunction is characterized by uncontrolled activation of the transforming growth factor-beta (TGF-beta) pathway and excess synthesis of both connective tissue growth factor (CTGF) and free radicals. These promote the accumulation of extracellular matrix. Endothelial cells produce excess quantities of endothelin 1 and inducible NO synthase. They also undergo early apoptosis. Oxidative stress appears to play a major role in disease progression. Increased levels of interleukin 4, a profibrotic cytokine, have been detected in plasma and skin of systemic sclerosis patients. Autoantibodies are detectable in the serum of almost all systemic sclerosis patients. Some are directed against well-identified ubiquitous nuclear proteins and have no demonstrated pathogenic role. Other autoantibodies bind to endothelial cells or fibroblasts and may have a pathogenic role.

Differential expression of stromal cell-derived factor 1 and its receptor CXCR4 in the skin and endothelial cells of systemic sclerosis patients: Pathogenetic implications

OBJECTIVE

Systemic sclerosis (SSc) is characterized by early endothelial damage evolving to vascular desertification. Stromal cell-derived factor 1 (SDF-1) and its receptor CXCR4 regulate specific steps in new vessel formation. We undertook this study to determine whether an alteration of the SDF-1/CXCR4 axis might be involved in the pathogenetic mechanisms following ischemic damage during SSc.

METHODS

We enrolled 36 SSc patients and 15 controls. Skin biopsy samples were obtained from each subject, and the expression of SDF-1 and CXCR4 was assessed by immunohistochemistry, reverse transcription-polymerase chain reaction (RT-PCR), and Western blot analyses. Furthermore, isolated microvascular endothelial cells (MVECs) from 4 patients with diffuse cutaneous SSc (dcSSc) and 3 controls were analyzed for SDF-1 and CXCR4 by confocal laser scanning microscopy, RT-PCR, and Western blotting.

RESULTS

SDF-1 and CXCR4 were up-regulated in the skin of patients with early (edematous) SSc, both in the diffuse and limited cutaneous forms, and progressively decreased, with the lowest expression in the latest phases of both SSc subsets. MVECs from patients with dcSSc expressed significantly higher amounts of both isoforms of SDF-1 in the early stage of disease, with a progressive reduction of SDF-1 and CXCR4 in later stages. On the surface of cultured MVECs from patients with dcSSc, SDF-1 and CXCR4 colocalized in polarized areas, suggesting that they are activated in vivo and that they are under strict genetic control to retain capping function.

CONCLUSION

Due to its transient expression, SDF-1 could be considered a future therapeutic target to induce new vessel formation in SSc.

Alveolar macrophages from systemic sclerosis patients: evidence for IL-4-mediated phenotype changes

The mechanism of chronic lung inflammation leading to lung fibrosis is unknown and does not have a characteristic inflammatory macrophage phenotype. This study was undertaken to determine whether a change in macrophage phenotype could account for chronic lung inflammation. In this study, human alveolar macrophages (AM) from subjects with systemic sclerosis (SSc) were obtained from bronchoalveolar lavage (BAL) and characterized on the basis of function (response to LPS), phenotype, and relative cell-surface B7 expression. AM from the subjects' disease-involved and noninvolved lung lobes were compared with each other and to AM from normal volunteer BAL. AM from involved SSc lobes produced significantly more interleukin (IL)-1β and PGE2than AM from uninvolved lobes in response to LPS, but there was no spontaneous production of either mediator. The activator AM phenotype designated by RFD1+ surface epitope was significantly elevated in SSc BAL samples compared with normal BAL, although there were no differences comparing involved vs. noninvolved lobes within SSc subjects. The major histocompatibility complex II costimulatory molecule B7.2 was also significantly elevated in SSc AM compared with normal AM, again with no differences between involved and noninvolved lobes. In an attempt to determine environmental influences on AM phenotypes, normal AM were cultured in vitro with IFN-γ, IL-3, IL-4, IL-10, IL-12, or dexamethasone for 6 days. Of the cytokines examined, only IL-4 induced significant increases in both the activator phenotype RFD1+ and B7.2 expression. Taken together, these results indicate that IL-4 could account for proinflammatory AM phenotype changes and B7 surface-marker shifts, as seen in subjects with SSc.

Die Extrakorporale Photopherese bei Progressiver Systemischer Sklerodermie: Unterscheidung von Respondern und Non-Respondern. Extracorporeal photopheresis in progressive systemic sclerosis: discrimination of responders and non-responders

BACKGROUND

The benefit of extracorporeal photopheresis (ExP) in progressive systemic sclerosis (PSS) is controversial. There is limited experience with the long-term use of ExP in PSS. The purpose of the present study was to distinguish between responders and non-responders by using ExP in PSS and to evaluate activation markers for PSS.

PATIENTS AND METHODS

20 subjects with PSS were treated for 12 months with ExP (interval: 1x/month) as an immunomodulating monotherapy (11/20) or combination therapy (9/20). The course of PSS was assessed by both specially designed clinical score and serological parameters (CRP, ANA, beta-galactosidase, P-III-P, CD4/CD8-ratio, TNF-alpha, 11-2-R, 11-6).

RESULTS

After 12 cycles of ExP, 30% of the subjects showed a partial remission and 25%, stable disease (55% responders) while 45% had a progression (non-responders). Although there was no correlation between the clinical course and the serological parameters, an increase of beta-galactosidase during therapy marked a progression of PSS in non-responders. Responders with a short PSS-course before ExP, moderate ANA titres, normal TNF-alpha levels and lack of Scl-70 had a good prognosis.

CONCLUSIONS

About the half of the subjects with PSS profited by the long-term use of ExP. Thereby the mild immunomodulating effect of ExP seems to be insufficient to control markedly progressive courses of PSS.

Autoimmune aspects of cytokine and anticytokine therapies

Cytokines and anticytokines are used increasingly in the treatment of immune, autoimmune, inflammatory, infectious, and malignant disorders. Commonly used treatments include the anti-tumor necrosis factor agents interferon alpha, interferon beta, interferon gamma, and interleukin 2. Several autoimmune phenomena have been reported in patients treated with these substances. This review summarizes the published data on the autoimmune manifestations associated with cytokine and anticytokine therapies, as well as describes possible mechanisms of these phenomena.

Abnormal expression of intracellular cytokines and chemokine receptors in peripheral blood T lymphocytes from patients with systemic sclerosis

In patients with systemic sclerosis (SSc), there are conflicting findings regarding which is predominant between type 1 and type 2 immune responses. To determine the balance between type 1 and type 2 T lymphocytes in peripheral blood from SSc patients, we investigated the expression of intracellular cytokines, such as interferon-gamma (IFN-gamma), interleukin-2 (IL-2), IL-4, and IL-13, and chemokine receptors such as CXCR3 and CCR4 by flow cytometry. The frequency of IFN-gamma-producing cells among CD8+ cells was significantly increased in patients with diffuse cutaneous SSc (n = 11, P < 0.0001) and limited cutaneous SSc (lSSc; n= 16, P < 0.0001) compared with normal controls (n = 17) while there was no significant difference in the frequency of IL-4- or IL-13-producing cells. In contrast, the frequency of IFN-gamma- or IL-4-producing cells among CD4+ cells was similar between the three groups. Similar results were obtained when absolute numbers were assessed. The frequency of IFN-gamma-producing cells among CD8+ cells inversely correlated with percentage DLco in SSc patients (r = - 0.650, P < 0.005). CXCR3+ CD8+ cells selectively produced IFN-gamma, and the frequency of CXCR3+ CD45RO+ cells among CD8+ cells was higher in lSSc patients (n = 14, P < 0.01) than in normal controls (n = 22). In contrast, there was no significant difference in the frequencies of CXCR3- or CCR4-expressing CD45RO+ cells among CD4+ cells. These results demonstrate the predominance of type 1 cytokine-producing cells (Tc1 cells) in peripheral blood CD8+ T cells from SSc patients, but no definite Th1/Th2 imbalance in CD4+ T cells. Tc1 cells may be associated with pulmonary vascular damage in SSc.

Circulating gamma/delta T lymphocytes from systemic sclerosis (SSc) patients display a T helper (Th) 1 polarization

Systemic sclerosis (SSc) is a connective tissue disease in which immune system activation is evidenced by high levels of different cytokines in the sera and/or in the supernatants of cultured peripheral blood mononuclear cells (PBMC) and by the presence of specific autoantibodies. gamma/delta T cells accumulate in the lung and the skin of SSc patients suggesting their potential role in the development and maintenance of the disease. The aim of this study was to assess cytokine production and cytotoxic activity of circulating gamma/delta T lymphocytes obtained from SSc patients and to evaluate their potential role during this disorder. Our results showed that both the proportion and the absolute number of IFN-gamma gamma/delta-producing cells (i.e. displaying a Th1 polarization) in SSc was significantly higher than either the proportion and the absolute number of IL-4 gamma/delta-producing cells in SSc or the proportion and the absolute number of IFN-gamma gamma/delta-producing cells in healthy controls (P < 0.05 for both groups). Furthermore, the cytotoxic activity of enriched gamma/delta T cells was significantly increased in SSc patients compared with controls. The results concerning the Vdelta1+ T cell subset paralleled those of total gamma/delta T lymphocytes. In contrast, alpha/beta T cells from SSc and control subjects displayed Th2 cytokine production. All these findings were independent of both disease subset and clinical status. Our data demonstrate that, although SSc is generally considered a Th2 autoimmune disease, Th1 polarization of gamma/delta T cells and an increase in their cytotoxic activity is observed in SSc, suggesting that gamma/delta T cells could have a relatively autonomous role in the pathogenesis in this disease.

Long-term therapy with plasma exchange in systemic sclerosis: effects on laboratory markers reflecting disease activity

Plasma exchange (PEX) is a technique that has been applied to the treatment of many immunological disorders, including connective tissue diseases. The crucial role of some humoral factors in the pathogenesis of systemic sclerosis (SSc) could explain the good clinical results obtained in terms of slowing down the disease progression, but the efficacy of PEX in the treatment of SSc is not yet well defined, owing to the lack of controlled studies and validated parameters of disease activity. To demonstrate the long-term efficacy of PEX in the treatment of SSc we treated a group of 28 SSc patients affected with recent onset and/or rapidly progressive disease. Most of these had a diffuse form of SSc, with anti-Sc170 antibody as a disease marker. Before and after long-term PEX treatment we evaluated disease activity parameters including the serum levels of interleukin 2 soluble receptor (sIL-2R) and aminoterminal type III procollagen peptide (PIIINP), plus the percentage of DR+ T cells in the peripheral blood. We also assessed clinical parameters of total skin score and total visceral score. The same parameters were evaluated in 25 SSc patients who did not satisfy the admission criteria for PEX, treated long-term with drugs only. At baseline, serum PIIINP and sIL-2R levels and the percentage of DR+ T cells were significantly increased in PEX patients as compared to others. Following long-term PEX treatment, all the laboratory parameters significantly decreased and the clinical scores showed a slight but not significant improvement. Conversely, in the other group of SSc patients treated for the same period with drugs only, no significant change of laboratory parameters was detected and the clinical scores slightly worsened. Our data suggest that long-term PEX therapy seems to be effective in slowing down the clinical course of patients with severe and rapidly progressive SSc.

Peripheral blood T lymphocytes from systemic sclerosis patients show both Th1 and Th2 activation

Our objective was to investigate the phenotype of helper T cells in the peripheral blood of patients with systemic sclerosis (SSc). PBMC from 15 patients with SSc and 15 sex- and age-matched controls were investigated for lymphocyte subpopulations (CD3, CD4, CD8, CD19, CD16/CD56, CD3-DR); IL-2, IL-4, and IFN-gamma mRNAs; and the relative cytokines in their cytoplasm. The last assay was carried out both in unstimulated and in PMA-activated PBMC. SSc patients presented a higher percentage of activated T cells, CD3+ DR+ (19.7 +/- 9.9 vs 5.1 +/- 2.5%; P < 0.0001); 12 of them presented IFN-gamma mRNA-positive cells; and none IL-2 or IL-4 mRNAs. Under basal conditions, PBMC from six SSc patients contained IL-2, IL-4, and IFN-gamma (i.e., they showed both Th1 and Th2 activation), and 1 IFN-gamma only. PMA-stimulated PBMC of patients differed from those of controls only in the increased percentage of IFN-gamma positive cells (52 +/- 12 vs 37 +/- 11%; P < 0.01). Our study demonstrates that Thl activation occurs in the peripheral blood of SSc patients. This evidence must be faced with from both a pathogenetic and a therapeutical point of view.

Derangement of apoptosis-related lymphocyte homeostasis in systemic sclerosis

OBJECTIVES

Both increased and decreased apoptosis may be involved in generating autoimmunity. This study addressed the question of whether apoptosis and apoptosis-regulating proteins are altered in systemic sclerosis (SSc). Patients and methods. Peripheral lymphocytes of 39 SSc patients and 47 healthy control persons were studied for apoptosis, Bcl-2 and Bax levels, expression of Fas (CD95) and activation markers (CD25, HLA-DR) as determined by fluorocytometry. Serum Fas and Fas ligand were measured by ELISA.

RESULTS

SSc lymphocytes (mainly CD4(+)) expressed increased amounts of Bcl-2, while Bax was not elevated. Apoptosis rates of SSc lymphocytes were increased in unsupplemented medium, but returned to normal in the presence of autologous plasma. SSc patients had increased percentages of activated and CD95(+) lymphocytes and elevated soluble Fas and soluble FasL levels in serum. Activating anti-CD95 antibodies further increased the apoptosis rate.

CONCLUSIONS

Increased in vitro apoptosis, elevated lymphocytic Bcl-2 content and the increased number of Fas-positive T cells are not specific for peripheral blood from SSc patients, but indicate deregulation of lymphocyte homeostasis in this disease.

Immune stimulation in scleroderma patients treated with thalidomide

Scleroderma (SSc) is a fibrosing connective tissue disease that is poorly responsive to any treatment, including immune suppression. SSc shares many characteristics with chronic graft-versus-host disease (GVHD). Because the immunomodulatory drug thalidomide has proven beneficial in chronic GVHD, we studied the immune response and clinical effects of thalidomide in SSc patients. We treated 11 SSc patients with thalidomide in an open label, dose escalating, 12 week study. Histologic comparison of skin biopsies showed changes in skin fibrosis and an increase in epidermal and dermal infiltrating CD8(+) T cells with thalidomide treatment. In thalidomide-treated SSc patients, plasma levels of IL-12 and TNF-alpha increased, while plasma IL-5 and IL-10 levels remained unchanged. These changes were associated with clinical effects, including dry skin, dermal edema, transient rashes, decreased gastroesophageal reflux symptoms, and healing of digital ulcers. When SSc PBMCs activated by anti-CD3 mAb were exposed to thalidomide, increases in both production of IL-2, IL-3, GM-CSF, and IFN-gamma and T cell expression of CD40L were observed. Thalidomide therefore appears to induce immune stimulation in SSc patients in association with clinical changes. However, it remains to be shown whether long-term enhancement of immune responses in SSc patients is clinically beneficial.

Inhibition of type I collagen production by dermal fibroblasts upon contact with activated T cells: different sensitivity to inhibition between systemic sclerosis and control fibroblasts

OBJECTIVE

To assess the role of T lymphocyte-fibroblast contact in type I collagen production by cultured dermal fibroblasts from normal individuals and from patients with diffuse systemic sclerosis (SSc).

METHODS

Cell membranes were prepared from activated CD4+ and CD8+ T cells, or type 1 T helper (Th1) clones, and added to confluent fibroblast monolayers. Type I collagen production was measured in culture supernatants, and messenger RNA (mRNA) levels of type I procollagen alpha1 (pro alpha1[I]) and matrix metalloproteinase 1 (MMP-1) were evaluated by Northern hybridization analysis.

RESULTS

Dose-dependent inhibition of type I collagen production was observed with CD4+ and CD8+ T cells from both SSc patients and controls. Inhibition of type I collagen was significantly less pronounced in fibroblasts from SSc patients than in fibroblasts from controls (P < 0.02). Inhibition was not reversed by the addition of exogenous transforming growth factor beta, interleukin-4, interleukin-1 receptor antagonist, anti-tumor necrosis factor, anti-CD40, or indomethacin, whereas anti-interferon-gamma (IFNgamma) reversed Th1-mediated inhibition. This inhibitory activity was specific for type I collagen, since mRNA levels of pro alpha1(I) were decreased, whereas mRNA levels of MMP-1 were strongly increased.

CONCLUSION

The production of type I collagen by skin fibroblasts is specifically down-regulated by membranes from activated T cells. The contact-dependent regulatory activity exerted by T cells on fibroblasts depends, at least in part, on the presence of membrane-associated IFNgamma. However, SSc fibroblasts are more resistant to inhibition than are fibroblasts from normal individuals.

The concept of type-1 and type-2 helper T cells and their cytokines in humans

In both mice and humans, functionally distinct helper T (Th)-cell subsets, known as Th1 and Th2 cells, are characterized by the patterns of cytokines they produce. These two polarized forms of the specific cellular immune response provide a useful model for explaining not only the different types of protection, but also the pathogenic mechanisms of several immunopathological disorders. The development of polarized Th1 or Th2 responses depends on either environmental factors, including dose of antigen, nature of immunogen and cytokines (IL-12 and interferons or IL-4) at the time of antigen presentation, or other undefined factors in the individual genetic background, mainly at level of the so-called "natural immunity". Th1-dominated responses are potentially effective in eradicating infectious agents, including those hidden within the host cells. When the Th1 response is poorly effective or exhaustively prolonged, it may result in host damage. In contrast, Th2 responses are apparently insufficient to protect against the majority of infectious agents, but can provide some protection against parasites. Th2 cells are able to make unpleasant the life of parasites in the host and tend to limit potentially harmful Th1-mediated responses. Thus, Th2 cells may be regarded as a part of down regulatory (or suppressor) mechanism for exaggerated and/ or inappropriate Th1 responses. The Th1/Th2 paradigm applied to the study of chronic inflammatory disorders or autoimmune diseases allowed to understand that a number of diseases are mediated by Th1 cells, the two clearest examples being multiple sclerosis and thyroid autoimmunity. In other disorders, Th1/Th2 polarization is less prominent, or rather Th2 responses tend to predominate, such as in systemic lupus erythematosus, progressive systemic sclerosis or allergic diseases. It is of note that in experimental models in animals, a number of diseases can be prevented by switching immune responses from Th1 to Th2 or from Th2 to Th1. Moreover, the Th1/Th2 concept suggests that modulation of the relative contribution of Th1- or Th2-type cytokines makes possible to regulate the balance between protection and immunopathology, as well as the development and/or the severity of some immunologic disorders.

Circulating Vdelta1+ T cells are activated and accumulate in the skin of systemic sclerosis patients

OBJECTIVE

An increased percentage of Vdelta1+/gamma/delta T cells has been detected both in the peripheral blood and bronchoalveolar lavage fluid of patients with systemic sclerosis (SSc). This study evaluated the subset distribution, activation status, and expression of cellular adhesion molecules, such as intercellular adhesion molecule 1 (CD54), very late activation antigen alpha4 (CD49d), and lymphocyte function-associated antigen 1alpha (CD11a), on circulating gamma/delta T cells, as well as their presence in the skin of SSc patients.

METHODS

We studied 12 patients with SSc and 16 healthy volunteer donors. The distribution, activation status, and expression of cellular adhesion molecules were studied by flow cytometry; their presence in SSc patient skin was evaluated by immunohistochemistry.

RESULTS

We found that the percentages and absolute numbers of peripheral blood gamma/delta T cells, CD16, CD8, CD45RO, CD25, HLA-DR, CD54, and CD11a coexpression did not differ significantly from those of the controls. CD49d gamma/delta T cells were significantly increased in SSc patients (2.3%) compared with controls (0.5%). A marked increase in the ratio of Vdelta1+ cells to gamma/delta cells was observed in the patients (72%) compared with the controls (31%). The Vdelta1+ subset showed a significant expression of both HLA-DR (83% of total Vdelta1+ cells) and CD49d (90% of total Vdelta1+ cells) compared with the controls (20.5% and 60%, respectively). In the skin, the absolute numbers of gamma/delta T cells were found in striking amounts in perivascular areas, particularly in the early edematous phase of SSc (22.58 in patients and 0 in controls); the majority of gamma/delta T cells were Vdelta1+ (19 in patients and 0 in controls). In the advanced phase of SSc, Vdelta1+ T cells were also increased compared with controls (3.5 versus 0).

CONCLUSION

Our results show that Vdelta1+ T cells express both adhesion molecules and activation markers, and strongly support gamma/delta T cell homing to sites of inflammation. The increase in the Vdelta1 subset suggests a selective V gene subset expansion.

Type 2 helper T-cell predominance and high CD30 expression in systemic sclerosis

The pattern of cytokine production of skin-infiltrating T cells from patients with progressive systemic sclerosis was investigated. Most CD4+ T-cell clones generated from skin biopsy specimens showed a type 2 helper (Th2) cytokine profile (production of interleukin-4, but no interferon (IFN)-gamma). High interleukin-4 but little or no IFN-gamma mRNA expression was found by in situ hybridization in skin perivascular mononuclear cell infiltrates. The immunohistochemical analysis revealed CD30 expression by high numbers of CD4+ T cells in the same specimens. Finally, the great majority of patients with diffuse disease had elevated levels of soluble CD30 in their sera. These data suggest the existence in patients with progressive systemic sclerosis of a predominant activation of Th2-like T cells, which may account for the major alterations (endothelial cell injury, fibrosis, and autoantibody production) occurring in this disease.

Analysis of proteins that interact with the IL-2 regulatory region in patients with rheumatic diseases

In order to investigate transcriptional regulation of lymphokine genes in rheumatic diseases, peripheral blood mononuclear cells from patients with systemic lupus erythematosus (SLE), rheumatoid arthritis (RA), and systemic sclerosis (SSc) were analysed for expression of DNA-binding proteins. Nuclear extracts prepared from unstimulated and mitogen-activated cells were studied for their ability to bind to 32P-labelled oligonucleotides containing the AP-1, NF-AT, NF-B and CD28RC sites of the IL-2 promoter. Using gel mobility-shift assay, detection of protein binding to the AP-1 site was reduced in SLE compared with controls. NF-AT binding activity was enhanced in all groups of patients, and was associated with measures of disease activity in RA. In addition, SSc patients showed increased NF-kappa B binding activity. Altered patterns of DNA-binding proteins suggest disturbed intracellular signalling which may contribute to abnormal lymphokine production in rheumatic diseases.

Demonstration of interleukin-2, interleukin-4 and interleukin-6 in sera from patients with localized scleroderma

Localized scleroderma has been reported to be accompanied by immunological abnormalities related to B cells, but little is known about T-cell activation in this disease. In this study, serum levels of interleukin-2 (IL-2), interleukin-4 (IL-4) and interleukin-6 (IL-6), which are known to be released by activated T cells, were determined using a sensitive enzyme-linked immunosorbent assay in 48 patients with localized scleroderma and 20 with systemic sclerosis, and in 20 healthy control subjects. IL-2, IL-4 and IL-6 were detected in serum from patients with localized scleroderma but not in that from healthy controls. The presence of antihistone antibodies correlated significantly with elevated IL-4 and IL-6 levels. Decreased serum levels of IL-2, IL-4 and IL-6 paralleled improvement in cutaneous sclerosis. Frequent detection of these lymphokines in serum from patients with localized scleroderma reflects T-cell activation in this disorder.

Role of T cells and cytokines in effecting fibrosis

A number of humoral and cellular immune abnormalities are present in patients with early scleroderma (systemic sclerosis). Most of these abnormalities reflect ongoing autoimmune reactions of the cellular and humoral types, resulting in a variety of autoantibodies to cellular and tissue constituents. Evidence exists for a defect(s) in immunoregulation favoring excessive helper T cell activity. The presence of circulating cytokines and shed interleukin-2 receptors suggest ongoing cellular immune reactions are occurring, generating cytokines and lymphokines that are capable of effecting the vascular and fibrotic lesions that are hallmarks of the disease. Future directions for research are suggested that would focus on determining if, and at what point, fibroblasts might function autonomously to generate excessive matrix components and on determining the nature of the original antigenic stimulus that starts the scleroderma process.

Serum levels of soluble interleukin-2 receptor. A marker of disease activity in localized scleroderma

OBJECTIVE

To determine whether circulating serum levels of soluble interleukin-2 receptor (sIL-2R) are elevated in patients with localized scleroderma, and if levels of sIL-2R can differentiate between active and inactive disease.

METHODS

Seventeen patients with localized scleroderma were categorized by overall physician assessment into active, inactive, and indeterminate groups, according to disease activity. Serum sIL-2R levels were analyzed and correlated with disease activity.

RESULTS

The mean sIL-2R level was significantly higher (P = 0.005) in those with active disease (1,675 +/- 823 units/ml) than in those with inactive disease (722 +/- 218 units/ml).

CONCLUSION

Serum sIL-2R levels are elevated in patients with localized scleroderma. When present, elevated sIL-2R levels appear to be able to differentiate active from inactive disease. This fact also suggests cell-mediated immune activation in this condition. Further serial studies are required to assess the value and sensitivity of sIL-2R levels in measuring changes in disease activity.

CD4+ and CD8+ subsets: naive and memory cells in the peripheral blood of patients with systemic sclerosis

Systemic Sclerosis (SSc; scleroderma) is associated with several immunological abnormalities, including altered proportion between lymphocyte subsets. Peripheral blood lymphocyte subsets from 25 patients with SSc were studied by two-colour flow cytometry using monoclonal antibodies against CD45RA and CD29 markers, which allow a dissection of CD4+ and CD8+ populations into 'naive' and 'memory' subsets. A decrease of the percentage of CD8+ (p < 0.05) and of CD8+CD29+ (p < 0.001) cells was observed compared to that in 20 age and sex-matched controls. These abnormalities were not significantly associated with the extension of cutaneous disease or other clinical features of SSc nor with treatment, pattern of autoantibodies or HLA phenotype.

Immunologic parameters in systemic sclerosis

BACKGROUND

Immunologic abnormalities seem to play an important role in important role in systemic sclerosis (SSc).

METHODS

We studied the following immune parameters to get more insight into SSc: autoantibodies (antinuclear antibodies (ANA), anti-Scl-70, anticentromere antibodies (ACA) subsets of lymphocyte subpopulations and markers of their activation, as well as serum levels of IL-2, the soluble IL-2 receptor (SIL-2R), IL-6 and its correlation to N-terminal procollagen-III propeptide (P III P), and finally, the IL-6 production by SSc and normal dermal fibroblasts.

RESULTS

In patients with active SSc, we found a reduced number of CD2+ T-lymphocytes and an increase in the expression of T-lymphocyte activation markers such as CD25+ and CD71+, HLA-DR Ia, as well as elevated serum levels of SIL-2LR and IL-6. SSc fibroblasts did not produce more IL-6 than normal fibroblasts in monolayer cultures.

CONCLUSIONS

Our data show that a wide range of immunologic parameters are altered in SSc. In general, T-helper (TH) lymphocytes are activated possibly because of reduced T-suppressor (TS) and natural killer (NK)-cell levels. TH may polyclonally stimulate B cells, which in turn produce higher amounts of autoantibodies. Our findings support the concept that TH cell-derived cytokines/growth factors stimulate matrix protein synthesis by fibroblasts, resulting in generalized fibrosis.

Lymphokines and soluble interleukin-2 receptors in juvenile chronic arthritis. Clinical and laboratory correlations

Serum levels of interleukin (IL)-2, interferon gamma (IFNg) and soluble IL-2 receptors (sIL-2R) were determined in sera from 34 patients with poly- or pauciarticular juvenile chronic arthritis (JCA) by use of enzyme-linked immunosorbent assays (ELISAs). Levels of sIL-2R were elevated in the group of patients compared with those of healthy children and correlated significantly with several parameters of clinical activity, including the functional capacity, joint score, visual-analogue score and erythrocyte sedimentation rate (ESR). Serum IL-2 levels were also elevated in the JCA patients, correlating with the patients functional capacity. Serum levels of IFNg were below the detection limit of the assay. Our data supported the notion that T-cell activation plays a role in the immunopathologic processes leading to clinical JCA.