A PD-1highCD4+ T Cell Population With a Cytotoxic Phenotype is Associated With Interstitial Lung Disease in Systemic Sclerosis

OBJECTIVE

T cells contribute to tissue injury in systemic sclerosis (SSc), yet the specific T cell subsets expanded in patients with SSc remain incompletely defined. Here we evaluated specific phenotypes and functions of peripheral helper T (Tph) and follicular helper T (Tfh) cells, which have been implicated in autoantibody production, and assessed their associations with clinical features in a well-characterized cohort of patients with SSc.

METHODS

Mass cytometry of T cells from peripheral blood mononuclear cells of patients with SSc and controls were evaluated using t-distributed stochastic neighbor embedding visualization, biaxial gating, and marker expression levels. Findings were validated with flow cytometry and in vitro assays.

RESULTS

The frequencies of PD-1highCXCR5+ Tfh cells and PD-1highCXCR5- Tph cells were similar in patients with SSc and controls. t-distributed stochastic neighbor embedding visualization (tSNE) revealed distinct populations within the PD-1highCXCR5- cells distinguished by expression of HLA-DR and inducible costimulator (ICOS). Among PD-1highCXCR5- cells, only the HLA-DR+ICOS- cell population was expanded in patients with SSc. Cytometric and RNA sequencing analyses indicated that these cells expressed cytotoxic rather than B cell helper features. HLA-DR+ICOS- PD-1highCXCR5- cells were less potent in inducing B cell plasmablast differentiation and antibody production than comparator T helper cell populations. HLA-DR+ICOS-PD-1highCXCR5- cells were significantly associated with the presence and severity of interstitial lung disease among patients with SSc.

CONCLUSION

Among PD-1highCXCR5- T cells, a subset of HLA-DR+ICOS- cells with cytotoxic features is specifically expanded in patients with SSc and is significantly associated with interstitial lung disease severity. This potential cytotoxicity appearing in the CD4 T cell population can be evaluated as a prognostic disease biomarker in patients with SSc.

Protein biomarkers of disease progression in patients with systemic sclerosis associated interstitial lung disease

Systemic sclerosis is a rare connective tissue disease; and interstitial lung disease (SSc-ILD) is associated with significant morbidity and mortality. There are no clinical, radiologic features, nor biomarkers that identify the specific time when patients are at risk for progression at which the benefits from treatment outweigh the risks. Our study aimed to identify blood protein biomarkers associated with progression of interstitial lung disease in patients with SSc-ILD using an unbiased, high-throughput approach. We classified SSc-ILD as progressive or stable based on change in forced vital capacity over 12 months or less. We profiled serum proteins by quantitative mass spectrometry and analyzed the association between protein levels and progression of SSc-ILD via logistic regression. The proteins associated with at a p value of < 0.1 were queried in the ingenuity pathway analysis (IPA) software to identify interaction networks, signaling, and metabolic pathways. Through principal component analysis, the relationship between the top 10 principal components and progression was evaluated. Unsupervised hierarchical clustering with heatmapping was done to define unique groups. The cohort consisted of 72 patients, 32 with progressive SSc-ILD and 40 with stable disease with similar baseline characteristics. Of a total of 794 proteins, 29 were associated with disease progression. After adjusting for multiple testing, these associations did not remain significant. IPA identified five upstream regulators that targeted proteins associated with progression, as well as a canonical pathway with a higher signal in the progression group. Principal component analysis showed that the ten components with the highest Eigenvalues represented 41% of the variability of the sample. Unsupervised clustering analysis revealed no significant heterogeneity between the subjects. We identified 29 proteins associated with progressive SSc-ILD. While these associations did not remain significant after accounting for multiple testing, some of these proteins are part of pathways relevant to autoimmunity and fibrogenesis. Limitations included a small sample size and a proportion of immunosuppressant use in the cohort, which could have altered the expression of inflammatory and immunologic proteins. Future directions include a targeted evaluation of these proteins in another SSc-ILD cohort or application of this study design to a treatment naïve population.

Oxidative stress promotes fibrosis in systemic sclerosis through stabilization of a kinase-phosphatase complex

Systemic sclerosis (SSc) is a fibrotic autoimmune disease characterized by pathogenic activation of fibroblasts enhanced by local oxidative stress. The tyrosine phosphatase PTP4A1 was identified as a critical promoter of TGF-β signaling in SSc. Oxidative stress is known to functionally inactivate tyrosine phosphatases. Here, we assessed whether oxidation of PTP4A1 modulates its profibrotic action and found that PTP4A1 forms a complex with the kinase SRC in scleroderma fibroblasts, but surprisingly, oxidative stress enhanced rather than reduced PTP4A1’s association with SRC and its profibrotic action. Through structural assessment of the oxo-PTP4A1-SRC complex, we unraveled an unexpected mechanism whereby oxidation of a tyrosine phosphatase promotes its function through modification of its protein complex. Considering the importance of oxidative stress in the pathogenesis of SSc and fibrosis, our findings suggest routes for leveraging PTP4A1 oxidation as a potential strategy for developing antifibrotic agents.

Peripheral blood leucocyte telomere length is associated with progression of interstitial lung disease in systemic sclerosis

BACKGROUND

Peripheral blood leucocyte telomere length (PBL-TL) is associated with outcomes in patients with idiopathic pulmonary fibrosis. Whether PBL-TL is associated with progression of systemic sclerosis-associated interstitial lung disease (SSc-ILD) is unknown.

METHODS

A retrospective observational cohort study was performed using prospectively collected data from 213 patients with SSc followed at the University of California San Francisco (UCSF) Scleroderma Center. PBL-TL was measured by quantitative PCR of DNA isolated from peripheral blood. Associations between PBL-TL and pulmonary function test trends in patients with SSc-ILD were assessed by longitudinal analysis using Generalised Linear Mixed Models. Findings were validated in a cohort of 61 patients with SSc-ILD enrolled in the Stanford University Scleroderma Center database.

RESULTS

Patients with UCSF SSc with ILD were found to have shorter PBL-TL compared with those without ILD (6554±671 base pairs (bp) vs 6782±698 bp, p=0.01). Shorter PBL-TL was associated with the presence of ILD (adjusted OR 2.1 per 1000 bp TL decrease, 95% CI [1.25 to 3.70], p=0.006). PBL-TL was shorter in patients with SSc-ILD lacking SSc-specific autoantibodies compared with seropositive subjects (6237±647 bp vs 6651±653 bp, p=0.004). Shorter PBL-TL was associated with increased risk for lung function deterioration with an average of 67 mL greater loss in per year for every 1000 bp decrease in PBL-TL in the combined SSc-ILD cohorts (longitudinal analysis, adjusted model: 95% CI -104 mL to -33 mL, p<0.001).

CONCLUSIONS

These findings suggest that telomere dysfunction may be associated with SSc-ILD progression and that PBL-TL measurement may be useful for stratifying risk for SSc-ILD progression.

Autoantibodies targeting telomere-associated proteins in systemic sclerosis

OBJECTIVES

Systemic sclerosis (SSc) is an autoimmune fibrotic disease affecting multiple tissues including the lung. A subset of patients with SSc with lung disease exhibit short telomeres in circulating lymphocytes, but the mechanisms underlying this observation are unclear.

METHODS

Sera from the Johns Hopkins and University of California, San Francisco (UCSF) Scleroderma Centers were screened for autoantibodies targeting telomerase and the shelterin proteins using immunoprecipitation and ELISA. We determined the relationship between autoantibodies targeting the shelterin protein TERF1 and telomere length in peripheral leucocytes measured by qPCR and flow cytometry and fluorescent in situ hybridisation (Flow-FISH). We also explored clinical associations of these autoantibodies.

RESULTS

In a subset of patients with SSc, we identified autoantibodies targeting telomerase and the shelterin proteins that were rarely present in rheumatoid arthritis, myositis and healthy controls. TERF1 autoantibodies were present in 40/442 (9.0%) patients with SSc and were associated with severe lung disease (OR 2.4, p=0.04, Fisher's exact test) and short lymphocyte telomere length. 6/6 (100%) patients with TERF1 autoantibodies in the Hopkins cohort and 14/18 (78%) patients in the UCSF cohort had a shorter telomere length in lymphocytes or leukocytes, respectively, relative to the expected age-adjusted telomere length. TERF1 autoantibodies were present in 11/152 (7.2%) patients with idiopathic pulmonary fibrosis (IPF), a fibrotic lung disease believed to be mediated by telomere dysfunction.

CONCLUSIONS

Autoantibodies targeting telomere-associated proteins in a subset of patients with SSc are associated with short lymphocyte telomere length and lung disease. The specificity of these autoantibodies for SSc and IPF suggests that telomere dysfunction may have a distinct role in the pathogenesis of SSc and pulmonary fibrosis.

Longitudinal assessment of interstitial lung disease in single lung transplant recipients with scleroderma

OBJECTIVE

To investigate the natural history of fibrotic lung disease in recipients of a single lung transplant for scleroderma-associated interstitial lung disease (ILD).

METHODS

Global ILD (including ground glass, nodular opacities and fibrosis) was categorized into severity quintiles on first and last post-transplant CT scans, and percent fibrosis by manual contouring was also determined, in nine single lung transplant recipients. Quantitative mean lung densities and volumes for the native and allograft lungs were also acquired.

RESULTS

In the native lung, global ILD severity quintile worsened in two cases and percent fibrosis worsened in four cases (range 5-28%). In the lung allograft, one case each developed mild, moderate and severe ILD; of these, new fibrotic ILD (involving <10% of lung) occurred in two cases and acute cellular rejection occurred in one. The average change in native lung density over time was +2.2 Hounsfield Units per year and lung volume +1.4 ml per year, whereas the allograft lung density changed by -5.5 Hounsfield Units per year and total volume +27 ml per year (P = 0.011 and P = 0.039 for native vs allograft density and volume comparisons, respectively).

CONCLUSIONS

While the course of ILD in the native and transplanted lungs varied in this series, these cases illustrate that disease progression is common in the native lung, suggesting that either the immune process continues to target autoantigens or ongoing fibrotic pathways are active in the native lung. Mild lung disease may occur in the allograft after several years due to either allograft rejection or recurrent mild ILD.

Definition of Naturally Processed Peptides Reveals Convergent Presentation of Autoantigenic Topoisomerase I Epitopes in Scleroderma

OBJECTIVE

Autoimmune responses to DNA topoisomerase I (topo I) are found in a subset of scleroderma patients who are at high risk for interstitial lung disease (ILD) and mortality. Anti-topo I antibodies (ATAs) are associated with specific HLA-DRB1 alleles, and the frequency of HLA-DR-restricted topo I-specific CD4+ T cells is associated with the presence, severity, and progression of ILD. Although this strongly implicates the presentation of topo I peptides by HLA-DR in scleroderma pathogenesis, the processing and presentation of topo I has not been studied.

METHODS

We developed a natural antigen processing assay (NAPA) to identify putative CD4+ T cell epitopes of topo I presented by monocyte-derived dendritic cells (mo-DCs) from 6 ATA-positive patients with scleroderma. Mo-DCs were pulsed with topo I protein, HLA-DR-peptide complexes were isolated, and eluted peptides were analyzed by mass spectrometry. We then examined the ability of these naturally presented peptides to induce CD4+ T cell activation in 11 ATA-positive and 11 ATA-negative scleroderma patients.

RESULTS

We found that a common set of 10 topo I epitopes was presented by Mo-DCs from scleroderma patients with diverse HLA-DR variants. Sequence analysis revealed shared peptide-binding motifs within the HLA-DRβ chains of ATA-positive patients and a subset of topo I epitopes with distinct sets of anchor residues capable of binding to multiple different HLA-DR variants. The NAPA-derived epitopes elicited robust CD4+ T cell responses in 73% of ATA-positive patients (8 of 11), and the number of epitopes recognized correlated with ILD severity (P = 0.025).

CONCLUSION

These findings mechanistically implicate the presentation of a convergent set of topo I epitopes in the development of scleroderma.

The Utility of Plasma Vascular Biomarkers in Systemic Sclerosis: A Prospective Longitudinal Analysis

OBJECTIVE

In cross-sectional studies, pulmonary hypertension (PH) and ischemic digital lesions are 2 scleroderma vascular outcomes associated with abnormalities in biomarkers of angiogenesis. The clinical usefulness of these biomarkers is unknown, in part due to lack of data on longitudinal measurement. This prospective longitudinal study was undertaken to evaluate vascular biomarker measurements in patients with systemic sclerosis (SSc) over time.

METHODS

We conducted a prospective cohort study of 300 patients with SSc who were followed up for at least a 5-year period and lacked evidence of PH and/or active ischemic digital lesions at enrollment. Levels of hepatocyte growth factor (HGF), soluble Flt-1 (sFlt-1), soluble endoglin, endostatin, and placental growth factor (PLGF) were obtained at multiple time points and assessed for their ability to predict the development of PH/ischemic digital lesions. Hazard ratios (HRs) with 95% confidence intervals (95% CIs) were calculated.

RESULTS

Forty-six patients (15%) developed PH and 69 patients (23%) developed an ischemic digital lesion. In time-to-event analyses, the following 3 biomarkers measured at cohort entry were found to be significantly associated with the development of PH: HGF (HR 1.99 [95% CI 1.24-3.17], P = 0.004), sFlt-1 (HR 3.04 [95% CI 1.29-7.14], P = 0.011), and PLGF (HR 2.74 [95% CI 1.32-5.69], P = 0.007). As time approaching PH diagnosis decreased, there was no corresponding increase in any biomarker level. Upon converting each continuous vascular biomarker into a binary variable, a dose-response relationship was observed for the number of elevated biomarkers at cohort entry and the risk of developing PH. With each additional elevated biomarker at cohort entry, there was a 78% increase in the risk of developing PH (HR 1.78 [95% CI 1.2-2.6], P = 0.004).

CONCLUSION

These data suggest that molecules involved in angiogenesis reflect vascular perturbation, and that elevations in these biomarkers at first encounter can indicate patients who are at risk of PH development.

Regulatory T cells in skin are uniquely poised to suppress profibrotic immune responses

At the center of fibrosing diseases is the aberrant activation of tissue fibroblasts. The cellular and molecular mechanisms of how the immune system augments fibroblast activation have been described; however, little is known about how the immune system controls fibroblast function in tissues. Here, we identify regulatory T cells (T_regs) as important regulators of fibroblast activation in skin. Bulk cell and single-cell analysis of T_regs in murine skin and lungs revealed that T_regs in skin are transcriptionally distinct and skewed toward T helper 2 (T_H2) differentiation. When compared with T_regs in lung, skin T_regs preferentially expressed high levels of GATA3, the master T_H2 transcription factor. Genes regulated by GATA3 were highly enriched in skin "T_H2 T_reg" subsets. In functional experiments, T_reg depletion resulted in a preferential increase in T_H2 cytokine production in skin. Both acute depletion and chronic reduction of T_regs resulted in spontaneous skin fibroblast activation, profibrotic gene expression, and dermal fibrosis, all of which were exacerbated in a bleomycin-induced murine model of skin sclerosis. Lineage-specific deletion of Gata3 in T_regs resulted in an exacerbation of T_H2 cytokine secretion that was preferential to skin, resulting in enhanced fibroblast activation and dermal fibrosis. Together, we demonstrate that T_regs play a critical role in regulating fibroblast activation in skin and do so by expressing a unique tissue-restricted transcriptional program that is mediated, at least in part, by GATA3.

Clinical and Molecular Phenotyping in Scleromyxedema Pretreatment and Posttreatment With Intravenous Immunoglobulin

OBJECTIVE

Scleromyxedema (SMX) is a rare systemic sclerosis mimic that often responds to intravenous immunoglobulin (IVIG) therapy, yet the resulting clinical and biochemical changes have not been well characterized. To better understand the pathogenesis of the disease and the efficacy of IVIG, we sought to explore whether IVIG would introduce a measurable biologic effect corresponding with clinical improvement.

METHODS

Fifteen patients with SMX were recruited for the study. Clinical information and peripheral blood mononuclear cells for flow cytometry were obtained immediately before and again 1-2 weeks after patients received IVIG therapy. Ten patients also underwent skin biopsies for gene expression analysis both before and after IVIG therapy. Clinical data included measures of skin involvement (modification of the modified Rodnan skin thickness score [MMRSS] and percentage of body surface area) and several patient-reported outcome measures assessing patients' skin.

RESULTS

Posttreatment, the average MMRSS score decreased from mean ± SD 13.6 ± 2.6 to 10.3 ± 1.9; P = 0.003. There were also significant improvements in skin flexibility (mean ± SD 5.4 ± 0.8 to 3.2 ± 0.7; P = 0.003) and softening (mean ± SD 4.9 ± 0.9 to 2.6 ± 0.6; P = 0.022). Baseline levels of Tc17 cells (CD8+CCR6+CXCR3+CCR4-) correlated with the extent of skin involvement as measured by MMRSS pretreatment (r = 0.69, P = 0.012) and decreased after IVIG therapy (mean ± SD 3.4% ± 3.2% to 1.3% ± 1.7%; P = 0.008). Posttreatment analysis of RNA in skin tissue revealed a decrease in gene expression of transforming growth factor β (TGFβ) cytokines as well as several interferon-inducible proteins.

CONCLUSION

This open-label study further supports the evidence that patients with SMX respond both objectively and subjectively to IVIG therapy. Biologic studies suggest a role for T lymphocytes in the pathogenesis of the disease and reveal the potential significance of TGFβ and interferon pathways.

Digital ulcers: should debridement be a standard of care in systemic sclerosis?

Digital ulcers are a serious, recurrent complication in patients with systemic sclerosis. They are often slow to heal and exquisitely painful. Local wound care, such as debridement of the wound bed, is an essential component in the management of digital ulcers in systemic sclerosis. However, digital ulcer debridement is not a standard of care, and there is substantial international variation in the use of this approach. In this Viewpoint, we discuss the assessment of the wound bed and different methods of debridement using the model of tissue management, infection and inflammation, moisture control, and wound edge or epidermal advancement, known as TIME. We highlight the challenges in standard practice and the need for research into local wound care for this type of ulceration, before suggesting a potential roadmap to develop a standardised approach to support ulcer debridement in systemic sclerosis. Debridement might be the missing component in optimising the management of digital ulcers and we propose that the approach should be rigorously investigated as a standard of care in this common complication of systemic sclerosis.

Heart-lung transplantation: A viable option for connective tissue diseases

BACKGROUND

While lung transplantation (LTx) has been effective for connective tissue disease (CTD) patients with pulmonary involvement, outcomes for heart-lung transplantation (HLTx) are less defined. The aim of this study is to evaluate HLTx in CTD patients utilizing the UNOS database.

METHODS

HLTx patients with CTD (HLTx-CTD) were compared to both LTx patients with CTD (LTx-CTD) and HLTx patients with all other indications (HLTx-OI) from 1999 to 2018. Primary outcome was 1- and 5-year graft survival. Secondary outcomes included freedom from first-year rejection and outcomes prior to transplant discharge.

RESULTS

1143/29 323 adults received first-time HLTx or LTx for CTD. Seventeen were HLTx-CTD (3.3% of total HLTx) and 1126 were LTx-CTD (3.9% of total LTx). There were 492 HLTx-OI. Transplant hemodynamic values including cardiac output, pulmonary capillary wedge pressure, and calculated pulmonary vascular resistance were significantly worse for HLTx-CTD vs LTx-CTD (4.2 vs 5.4 L/min, P = .005; 14 vs 10 mm Hg, P = .009; 439 vs 267 dynes, P = .007, respectively). Cardiac status 1 was more common for HLTx-CTD vs HLTx-OI (94% vs 56%, P < .001). HLTx-CTD 1 and 5-year graft survival was similar compared to LTx-CTD and HLTx-OI.

CONCLUSION

HLTx-CTD is a valid option for carefully selected patients with CTD cardiac and pulmonary involvement with similar morbidity and mortality compared to LTx-CTD and HLTx-OI.

Brief Report: Whole-Exome Sequencing to Identify Rare Variants and Gene Networks That Increase Susceptibility to Scleroderma in African Americans

OBJECTIVE

Whole-exome sequencing (WES) studies in systemic sclerosis (SSc) patients of European American (EA) ancestry have identified variants in the ATP8B4 gene and enrichment of variants in genes in the extracellular matrix (ECM)-related pathway that increase SSc susceptibility. This study was undertaken to evaluate the association of the ATP8B4 gene and the ECM-related pathway with SSc in a cohort of African American (AA) patients.

METHODS

SSc patients of AA ancestry were enrolled from 23 academic centers across the US under the Genome Research in African American Scleroderma Patients consortium. Unrelated AA individuals without serologic evidence of autoimmunity who were enrolled in the Howard University Family Study were used as unaffected controls. Functional variants in genes reported in the 2 WES studies in EA patients with SSc were selected for gene association testing using the optimized sequence kernel association test (SKAT-O) and pathway analysis by Ingenuity Pathway Analysis in 379 patients and 411 controls.

RESULTS

Principal components analysis demonstrated that the patients and controls had similar ancestral backgrounds, with roughly equal proportions of mean European admixture. Using SKAT-O, we examined the association of individual genes that were previously reported in EA patients and none remained significant, including ATP8B4 (P = 0.98). However, we confirmed the previously reported association of the ECM-related pathway with enrichment of variants within the COL13A1, COL18A1, COL22A1, COL4A3, COL4A4, COL5A2, PROK1, and SERPINE1 genes (corrected P = 1.95 × 10^-4 ).

CONCLUSION

In the largest genetic study in AA patients with SSc to date, our findings corroborate the role of functional variants that aggregate in a fibrotic pathway and increase SSc susceptibility.

Vascular complications in systemic sclerosis: a prospective cohort study

Two major complications in scleroderma patients that cause substantial morbidity and mortality are ischemic digital lesions (DL) and pulmonary hypertension (PH). The clinician's ability to predict which patients will develop these complications is imperfect. We conducted a prospective observational cohort study of 300 patients with scleroderma who were followed for at least a 5-year period. At baseline, patients lacked evidence of PH and were without a current DL. At each 6-month visit, the patient was examined for signs/symptoms of PH and/or a DL. The primary outcomes were (1) PH defined as a mean pulmonary artery pressure ≥ 25 mmHg by right heart catheterization and (2) ≥ 1 DL defined as new onset of severe vascular compromise. Thirty patients (10%) developed PH (11 group 1/PAH, 4 group II, 15 group III) and 69 developed DL. The average time from enrollment until diagnosis of PH was 3.2 ± 2 years. In multivariable analyses, patients who developed PH were more likely to have diffuse disease (HR 3.2, p = 0.004), a forced vital capacity (FVC)/diffusing capacity of the lungs for carbon monoxide (DLCO) ratio > 1.6 (HR 1.7, p = 0.008), and elevated RVSP (HR = 1.07, p = 0.007). Patients who developed PAH were more likely to have a FVC/DLCO ratio > 1.6 (HR = 5.8, p = 0.014), and patients who developed group III PH were less likely to have an elevated FVC (HR = 0.92, p = 0.001). Patients were more likely to develop a DL if they had a history of prior DL (HR = 7.0, p < 0.001), or were men (HR = 2.3, p = 0.007). In a prevalent cohort of scleroderma patients, individuals who develop PH or DL have simple to measure clinical features that can predict these complications years before they occur.

Patient-reported outcome instruments for assessing Raynaud's phenomenon in systemic sclerosis: A SCTC Vascular Working Group Report

The episodic nature of Raynaud's phenomenon (RP) in systemic sclerosis (SSc) has led to a reliance on patient-reported outcome (PRO) instruments such as the Raynaud's Condition Score (RCS) diary. Little is known about the utilisation in routine clinical practice and health professional attitudes towards existing PRO instruments for assessing SSc-RP. Members of the Scleroderma Clinical Trials Consortium Vascular Working Group (SCTC-VWG, n=28) were invited to participate in a survey gauging attitudes towards the RCS diary and the perceived need for novel PRO instruments for assessing SSc-RP. Nineteen SCTC-VWG members (68% response rate) from academic units based in North America (n=9), Europe (n=8), South America (n=1) and Australasia (n=1) took part in the survey. There was broad consensus that RCS diary returns could be influenced by factors including seasonal variation in weather, efforts made by patients to avoid or ameliorate attacks of RP, habituation to RP symptoms, evolution of RP symptom characteristics with progressive obliterative microangiopathy, patient coping strategies, respondent burden and placebo effect. There was consensus that limitations of the RCS diary might be a barrier to drug development (79% of respondents agree/strongly agree) and that a novel PRO instrument for assessing SSc-RP should be developed with the input of both clinicians and patients (84% agree/strongly agree). Perceived potential limitations of the RCS diary have been identified along with concerns that such factors might impede drug development programs for SSc-RP. There is support within the systemic sclerosis community for the development of a novel PRO instrument for assessing SSc-RP.

Clinical and serological features of systemic sclerosis in a multicenter African American cohort: Analysis of the genome research in African American scleroderma patients clinical database

Racial differences exist in the severity of systemic sclerosis (SSc). To enhance our knowledge about SSc in African Americans, we established a comprehensive clinical database from the largest multicenter cohort of African American SSc patients assembled to date (the Genome Research in African American Scleroderma Patients (GRASP) cohort).African American SSc patients were enrolled retrospectively and prospectively over a 30-year period (1987-2016), from 18 academic centers throughout the United States. The cross-sectional prevalence of sociodemographic, clinical, and serological features was evaluated. Factors associated with clinically significant manifestations of SSc were assessed using multivariate logistic regression analyses.The study population included a total of 1009 African American SSc patients, comprised of 84% women. In total, 945 (94%) patients met the 2013 American College of Rheumatology/European League Against Rheumatism (ACR/EULAR) classification criteria for SSc, with the remaining 64 (6%) meeting the 1980 ACR or CREST (calcinosis, Raynaud's phenomenon, esophageal dysmotility, sclerodactyly, telangiectasia) criteria. While 43% were actively employed, 33% required disability support. The majority (57%) had the more severe diffuse subtype and a young age at symptom onset (39.1 ± 13.7 years), in marked contrast to that reported in cohorts of predominantly European ancestry. Also, 1 in 10 patients had a severe Medsger cardiac score of 4. Pulmonary fibrosis evident on computed tomography (CT) chest was present in 43% of patients and was significantly associated with anti-topoisomerase I positivity. 38% of patients with CT evidence of pulmonary fibrosis had a severe restrictive ventilator defect, forced vital capacity (FVC) ≤50% predicted. A significant association was noted between longer disease duration and higher odds of pulmonary hypertension, telangiectasia, and calcinosis. The prevalence of potentially fatal scleroderma renal crisis was 7%, 3.5 times higher than the 2% prevalence reported in the European League Against Rheumatism Scleroderma Trials and Research (EUSTAR) cohort.Our study emphasizes the unique and severe disease burden of SSc in African Americans compared to those of European ancestry.

Flow cytometric discrimination of seven lineage markers by using two fluorochromes

Flow cytometry is the primary immunological technique used to analyze multiple parameters on complex cell populations. We present a staining method that identifies major human mononuclear lymphoid and myeloid populations (CD4⁺ and CD8⁺ T cells, γδ T cells, B cells, NK cells and monocytes), using only two fluorochromes and a minimal number of cells. Our approach increases the number of markers recordable on most flow cytometers allowing for a deeper and more comprehensive immunophenotyping.

Integrated, multicohort analysis of systemic sclerosis identifies robust transcriptional signature of disease severity

Systemic sclerosis (SSc) is a rare autoimmune disease with the highest case-fatality rate of all connective tissue diseases. Current efforts to determine patient response to a given treatment using the modified Rodnan skin score (mRSS) are complicated by interclinician variability, confounding, and the time required between sequential mRSS measurements to observe meaningful change. There is an unmet critical need for an objective metric of SSc disease severity. Here, we performed an integrated, multicohort analysis of SSc transcriptome data across 7 datasets from 6 centers composed of 515 samples. Using 158 skin samples from SSc patients and healthy controls recruited at 2 centers as a discovery cohort, we identified a 415-gene expression signature specific for SSc, and validated its ability to distinguish SSc patients from healthy controls in an additional 357 skin samples from 5 independent cohorts. Next, we defined the SSc skin severity score (4S). In every SSc cohort of skin biopsy samples analyzed in our study, 4S correlated significantly with mRSS, allowing objective quantification of SSc disease severity. Using transcriptome data from the largest longitudinal trial of SSc patients to date, we showed that 4S allowed us to objectively monitor individual SSc patients over time, as (a) the change in 4S of a patient is significantly correlated with change in the mRSS, and (b) the change in 4S at 12 months of treatment could predict the change in mRSS at 24 months. Our results suggest that 4S could be used to distinguish treatment responders from nonresponders prior to mRSS change. Our results demonstrate the potential clinical utility of a novel robust molecular signature and a computational approach to SSc disease severity quantification.

Frequency of circulating topoisomerase-I-specific CD4 T cells predicts presence and progression of interstitial lung disease in scleroderma

Background

Scleroderma is an antigen-driven T cell-mediated autoimmune disease. Presence of anti-topoisomerase-I antibodies is associated with pulmonary fibrosis and predicts increased mortality. Characterization of autoreactive T lymphocytes may shed light on disease pathogenesis and serve as a biomarker for disease activity. Here, we aimed to quantify and functionally characterize circulating topoisomerase I (topo-I)-specific CD4+ T cells and to define their association with presence and progression of interstitial lung disease (ILD) in patients with scleroderma.

Methods

Using flow cytometry, circulating topo-I-reactive CD4+ T cells were identified by the expression of specific activation markers (CD154 and CD69) upon stimulation with purified topo-I and quantified in 27 SSc patients and 4 healthy donors (HD). Polarization of autoreactive T cells (Th1, Th2, Th17, Th1–17) was defined using surface expression of specific chemokine receptors. Presence and progression of ILD were determined using high-resolution chest CT and pulmonary function tests.

Results

Topo-I-reactive CD4+ T cells were found in all topo-I-positive patients compared to one topo-I-negative subject and no HD. Topo-I-specific CD4+ T cells exhibited a distinct Th17 polarized phenotype. Autoreactive T cells were significantly increased in subjects with evidence of ILD and were quantitatively associated with the decline of lung volumes.

Conclusions

Topo-I-specific T cells can be reliably quantified in the peripheral blood of patients with scleroderma, exhibit a pro-inflammatory Th17 phenotype, and predict progression of ILD.

Electronic supplementary material

The online version of this article (doi:10.1186/s13075-016-0993-2) contains supplementary material, which is available to authorized users.

Association of Acroosteolysis With Enhanced Osteoclastogenesis and Higher Blood Levels of Vascular Endothelial Growth Factor in Systemic Sclerosis

OBJECTIVE

Bone resorption of distal phalanges, or acroosteolysis (AO), can develop in patients with systemic sclerosis (SSc), causing pain and functional limitation. This study was undertaken to investigate whether AO may be associated with abnormal osteoclastogenesis in SSc patients and whether hypoxia may be involved in this process.

METHODS

Peripheral blood mononuclear cells (PBMCs) obtained from 26 SSc patients (11 with AO and 15 without AO) and 14 healthy controls were cultured in the presence of RANKL and macrophage colony-stimulating factor for 9 days. Tartrate-resistant acid phosphatase-positive multinucleated giant cells (MGCs) containing 3 or more nuclei were counted as osteoclasts. Plasma levels and effects of vascular endothelial growth factor (VEGF) on osteoclast formation were evaluated.

RESULTS

SSc patients with AO formed significantly more osteoclasts after 9 days than did patients without AO (mean ± SD 142.4 ± 67.0 versus 27.2 ± 17.6 MGCs/well; P < 0.001) or healthy controls (mean ± SD 18.7 ± 27.0 MGCs/well; P < 0.001). No significant difference in osteoclast formation was noted between the patients without AO and healthy controls. Plasma levels of VEGF were higher in SSc patients with AO compared to those without (mean ± SD 142.4 ± 69.6 pg/ml versus 88.1 ± 38.2 pg/ml; P < 0.005) or healthy controls (54.2 ± 24.6 pg/ml; P = 0.018). Priming with VEGF-A for 24 hours significantly increased osteoclast generation by 5.3 ± 1.9 fold (P = 0.0018). The radiographic extent of AO was associated with increased osteoclast formation (Spearman's ρ = 0.741, P = 0.01).

CONCLUSION

Our findings indicate that increased osteoclast formation and higher VEGF levels may contribute to AO in SSc patients. Further studies are needed to elucidate whether targeting osteoclastogenesis may provide a specific therapeutic option for SSc-associated AO.

Spectrum of Muscle Histopathologic Findings in Forty-Two Scleroderma Patients With Weakness

OBJECTIVE

To determine if distinct muscle pathologic features exist in scleroderma subjects with weakness.

METHODS

This retrospective study included weak scleroderma subjects with muscle biopsies available for review. Biopsies were systematically assessed for individual pathologic features, including inflammation, necrosis, fibrosis, and acute neurogenic atrophy. Based on the aggregate individual features, biopsies were assigned a histopathologic category of polymyositis, dermatomyositis, necrotizing myopathy, nonspecific myositis, "acute denervation," "fibrosis only," or "other." Clinical data analyzed included autoantibody profiles, scleroderma subtype and disease duration, Medsger muscle severity scores, creatine kinase, electromyography, and muscle magnetic resonance imaging.

RESULTS

A total of 42 subjects (79% female and 64% diffuse scleroderma) were included in this study. Necrosis (67%), inflammation (48%), acute neurogenic atrophy (48%), and fibrosis (33%) were the most prevalent pathologic features. The presence of fibrosis was strongly associated with anti-PM-Scl antibodies. Histopathologic categories included nonspecific myositis (36%), necrotizing myopathy (21%), dermatomyositis (7%), "acute denervation" (7%), "fibrosis only" (7%), and polymyositis (5%). Disease duration of scleroderma at the time of muscle biopsy was shorter in polymyositis than other histopathologic categories. Patients with anti-PM-Scl and Scl-70 antibodies also had a shorter disease duration than those with other autoantibody profiles.

CONCLUSION

Nonspecific myositis and necrotizing myopathy were the most common histopathologic categories in weak scleroderma subjects. Surprisingly, nearly half of the subjects studied had histologic evidence of acute motor denervation (acute neurogenic atrophy); this has not been previously reported. Taken together, these observations suggest that a variety of pathologic mechanisms may underlie the development of myopathy in scleroderma.

A methodology for exploring biomarker--phenotype associations: application to flow cytometry data and systemic sclerosis clinical manifestations

Background

This work seeks to develop a methodology for identifying reliable biomarkers of disease activity, progression and outcome through the identification of significant associations between high-throughput flow cytometry (FC) data and interstitial lung disease (ILD) - a systemic sclerosis (SSc, or scleroderma) clinical phenotype which is the leading cause of morbidity and mortality in SSc. A specific aim of the work involves developing a clinically useful screening tool that could yield accurate assessments of disease state such as the risk or presence of SSc-ILD, the activity of lung involvement and the likelihood to respond to therapeutic intervention. Ultimately this instrument could facilitate a refined stratification of SSc patients into clinically relevant subsets at the time of diagnosis and subsequently during the course of the disease and thus help in preventing bad outcomes from disease progression or unnecessary treatment side effects.

The methods utilized in the work involve: (1) clinical and peripheral blood flow cytometry data (Immune Response In Scleroderma, IRIS) from consented patients followed at the Johns Hopkins Scleroderma Center. (2) machine learning (Conditional Random Forests - CRF) coupled with Gene Set Enrichment Analysis (GSEA) to identify subsets of FC variables that are highly effective in classifying ILD patients; and (3) stochastic simulation to design, train and validate ILD risk screening tools.

Results

Our hybrid analysis approach (CRF-GSEA) proved successful in predicting SSc patient ILD status with a high degree of success (>82 % correct classification in validation; 79 patients in the training data set, 40 patients in the validation data set).

Conclusions

IRIS flow cytometry data provides useful information in assessing the ILD status of SSc patients. Our new approach combining Conditional Random Forests and Gene Set Enrichment Analysis was successful in identifying a subset of flow cytometry variables to create a screening tool that proved effective in correctly identifying ILD patients in the training and validation data sets. From a somewhat broader perspective, the identification of subsets of flow cytometry variables that exhibit coordinated movement (i.e., multi-variable up or down regulation) may lead to insights into possible effector pathways and thereby improve the state of knowledge of systemic sclerosis pathogenesis.

Electronic supplementary material

The online version of this article (doi:10.1186/s12859-015-0722-x) contains supplementary material, which is available to authorized users.

Intravenous immunoglobulin may be an effective therapy for refractory, active diffuse cutaneous systemic sclerosis

OBJECTIVE

We sought to retrospectively review a single-center experience using intravenous immunoglobulin (IVIG) for the treatment of refractory, active diffuse cutaneous systemic sclerosis (dcSSc).

METHODS

The mean modified Rodnan Skin score (mRSS) at baseline was compared to the mRSS at 6, 12, 18, and 24 months post-IVIG initiation by the paired Student t test. Changes in mRSS at 6 and 12 months were also compared to data from historical controls of 3 large, negative, multicenter, randomized clinical trials of other medications [D-penicillamine (D-pen), recombinant human relaxin (relaxin), and oral bovine type I collagen (collagen)] and to patients treated with mycophenolate mofetil (MMF) alone using the Student t test.

RESULTS

Thirty patients were treated with adjunctive IVIG (2 g/kg/mo) for refractory, active dcSSc. The mean baseline mRSS of our cohort was 29.6 ± 7.2, and this significantly decreased to 24.1 ± 9.6 (n = 29, p = 0.0011) at 6 months, 22.5 ± 10.0 (n = 25, p = 0.0001) at 12 months, 20.6 ± 11.8 (n = 23, p = 0.0001) at 18 months, and 15.3 ± 6.4 (n = 15, p < 0.0001) at 24 months. The mean change in mRSS at 6 months was not significantly different in the IVIG group (-5.3 ± 7.9) compared to the relaxin trial (-4.8 ± 6.99, p = 0.74) or MMF group (-3.4 ± 7.4, p = 0.26); however, at 12 months, the mean change in mRSS was significantly better in the IVIG group (-8 ± 8.3) than in the D-pen (-2.47 ± 8.6, p = 0.005) and collagen (-3.4 ± 7.12, p = 0.005) groups, and was comparable to the group of primary MMF responders (-7.1 ± 9, p = 0.67).

CONCLUSION

Our observational study suggests that IVIG may be an effective adjunctive therapy for active dcSSc in patients failing other therapies.

Oxidative stress-dependent activation of collagen synthesis is induced in human pulmonary smooth muscle cells by sera from patients with scleroderma-associated pulmonary hypertension

Pulmonary arterial hypertension is a major complication of systemic sclerosis. Although oxidative stress, intima hyperplasia and a progressive vessel occlusion appear to be clearly involved, the fine molecular mechanisms underpinning the onset and progression of systemic sclerosis-associated pulmonary arterial hypertension remain largely unknown. Here we shows for the first time that an increase of NADPH-derived reactive oxygen species production induced by sera from systemic sclerosis patients with pulmonary arterial hypertension drives collagen type I promoter activity in primary human pulmonary artery smooth muscle cells, suggesting that antioxidant-based therapies should be considered in the treatment of systemic sclerosis-associated vascular diseases.

Association of the autoimmune disease scleroderma with an immunologic response to cancer

Autoimmune diseases are thought to be initiated by exposures to foreign antigens that cross-react with endogenous molecules. Scleroderma is an autoimmune connective tissue disease in which patients make antibodies to a limited group of autoantigens, including RPC1, encoded by the POLR3A gene. As patients with scleroderma and antibodies against RPC1 are at increased risk for cancer, we hypothesized that the "foreign" antigens in this autoimmune disease are encoded by somatically mutated genes in the patients' incipient cancers. Studying cancers from scleroderma patients, we found genetic alterations of the POLR3A locus in six of eight patients with antibodies to RPC1 but not in eight patients without antibodies to RPC1. Analyses of peripheral blood lymphocytes and serum suggested that POLR3A mutations triggered cellular immunity and cross-reactive humoral immune responses. These results offer insight into the pathogenesis of scleroderma and provide support for the idea that acquired immunity helps to control naturally occurring cancers.

Race and association with disease manifestations and mortality in scleroderma: a 20-year experience at the Johns Hopkins Scleroderma Center and review of the literature

Experience suggests that African Americans may express autoimmune disease differently than other racial groups. In the context of systemic sclerosis (scleroderma), we sought to determine whether race was related to a more adverse expression of disease. Between January 1, 1990, and December 31, 2009, a total of 409 African American and 1808 white patients with scleroderma were evaluated at a single university medical center. While the distribution by sex was virtually identical in both groups, at 82% female, African American patients presented to the center at a younger mean age than white patients (47 vs. 53 yr; p < 0.001). Two-thirds of white patients manifested the limited cutaneous subset of disease, whereas the majority of African American patients manifested the diffuse cutaneous subset (p < 0.001). The proportion seropositive for anticentromere antibody was nearly 3-fold greater among white patients, at 34%, compared to African American patients (12%; p < 0.001). Nearly a third of African American (31%) patients had autoantibodies to topoisomerase, compared to 19% of white patients (p = 0.001). Notably, African American patients experienced an increase in prevalence of cardiac (adjusted odds ratio [OR], 1.6; 95% confidence interval [CI], 1.3-2.2), renal (OR, 1.6; 95% CI, 1.2-2.1), digital ischemia (OR, 1.5; 95% CI, 1.4-2.2), muscle (OR, 1.7; 95% CI, 1.3-2.3), and restrictive lung (OR, 6.9; 95% CI, 5.1-9.4) disease. Overall, 700 (32%) patients died (159 African American; 541 white). The cumulative incidence of mortality at 10 years was 43% among African American patients compared to 35% among white patients (log-rank p = 0.0011). Compared to white patients, African American patients experienced an 80% increase in risk of mortality (relative risk [RR], 1.8; 95% CI, 1.4-2.2), after adjustment for age at disease onset and disease duration. Further adjustment by sex, disease subtype, and scleroderma-specific autoantibody status, and for the socioeconomic measures of educational attainment and health insurance status, diminished these risk estimates (RR, 1.3; 95% CI, 1.0-1.6). The heightened risk of mortality persisted in strata defined by age at disease onset, diffuse cutaneous disease, anticentromere seropositivity, decade of care at the center, and among women. These findings support the notion that race is related to a distinct phenotypic profile in scleroderma, and a more unfavorable prognosis among African Americans, warranting heightened diagnostic evaluation and vigilant care of these patients. Further, we provide a chronologic review of the literature regarding race, organ system involvement, and mortality in scleroderma; we furnish synopses of relevant reports, and summarize findings.

The degree of skin involvement identifies distinct lung disease outcomes and survival in systemic sclerosis

OBJECTIVE

To determine whether the pattern of skin involvement can predict clinical features, risk of restrictive lung disease (RLD) and survival in a large scleroderma (SSc) cohort.

METHODS

Demographic and clinical data collected over 30 years from 2205 patients with SSc were retrospectively analysed after subdividing subjects into four subtypes based on pattern of skin fibrosis: type 0 (no skin involvement), type 1 (limited to metacarpophalangeal joints), type 2 (distal to elbows/knees) and type 3 (proximal to elbows/knees). Clinical features associated with skin subsets were identified by regression analyses. Kaplan-Meier and Cox proportional hazards models were used to compare time to RLD and survival across subtypes.

RESULTS

The presence and severity of RLD were positively associated with skin subtype (p<0.001). RLD prevalence incrementally ranged from 51.9% in type 0 to 76.7% in type 3 (p<0.001). Type 2 SSc exhibited a distinct phenotype with intermediate risk for RLD relative to type 1 (higher, p<0.001) and type 3 (lower, p<0.001) and a unique autoantibody profile, with a prevalence of anticentromere antibodies lower than type 1 (28.9% vs 44.1%, p=0.001) and of anti-topoisomerase I antibodies similar to type 3 (32.8% vs 28.7%, p=0.38). These autoantibodies were also found to be significant negative (OR=0.33, p<0.001) and positive (OR=1.6, p=0.01) predictors of RLD risk, respectively. Mortality was also intermediate in type 2 patients relative to type 3 (p=0.0003) and type 1 (p=0.066).

CONCLUSIONS

These data suggest that the current classification subdividing SSc into limited and diffuse cutaneous subtypes misclassifies an intermediate group of patients exhibiting unique autoantibody profile, disease course and clinical outcomes.

Open label study of escalating doses of oral treprostinil diethanolamine in patients with systemic sclerosis and digital ischemia: pharmacokinetics and correlation with digital perfusion

Introduction

Treprostinil diethanolamine is an innovative salt form of the prostacyclin analogue, treprostinil sodium, developed as an oral sustained release (SR) osmotic tablet. The availability of a formulation permitting convenient systemic delivery might have applicability to scleroderma vascular complications. We evaluated pharmacokinetics and perfusion in scleroderma patients with digital ischemia following escalating twice-daily doses of treprostinil diethanolamine SR.

Methods

Scleroderma patients with digital ulcers were enrolled in this dual-center, open-label, phase I pharmacokinetic study. Drug concentrations and perfusion, quantified by laser Doppler imaging, were measured over 12 hours at the 2 mg and 4 mg (or maximally tolerated) doses. Pharmacokinetic parameters were determined from individual plasma concentration versus time profiles using non-compartmental analysis methods. Digital perfusion and skin temperature were modeled as a function of log-transformed drug concentration and other covariates by performing repeated measures analyses using random effects models.

Results

Nineteen scleroderma patients (84% female, 53% limited scleroderma) received treprostinil diethanolamine SR with dose titration up to 4 mg twice daily as tolerated. Peak concentrations (mean maximum plasma concentration (C_max) = 1,176 and 2,107 pg/mL) occurred approximately 3.6 hours after dose administration, and overall exposure (under the plasma concentration-time curve from time 0 to 12 hours post dose (AUC_0-12) = 7,187 and 12,992 hr*pg/mL) was linear between the 2 mg and 4 mg doses. Perfusion and digital skin temperature were positively associated with log-transformed plasma concentration at the 4 mg dose (P = 0.015 and P = 0.013, respectively). The most frequent adverse events were similar to those seen with prostacyclin analogues.

Conclusions

Oral treprostinil diethanolamine was effectively absorbed in patients with scleroderma. Drug administration was temporally associated with improved cutaneous perfusion and temperature. Treprostinil diethanolamine may provide a new therapeutic option for Raynaud's phenomenon and the peripheral vascular disease of scleroderma.

Trial Registration

ClinicalTrials.gov NCT00848939.

Electronic supplementary material

The online version of this article (doi:10.1186/ar4216) contains supplementary material, which is available to authorized users.

Efficacy of Rho kinase inhibitor fasudil in secondary Raynaud's phenomenon

OBJECTIVE

The RhoA/Rho kinase pathway plays a pivotal role in cold-induced vasoconstriction, vascular smooth muscle cells function, and vascular homeostasis. This study evaluates the efficacy of fasudil, a RhoA/Rho kinase inhibitor, to reverse cold-induced vasospasm in patients with Raynaud's phenomenon (RP) secondary to systemic sclerosis (SSc; scleroderma).

METHODS

This is a single-center, double-blind, placebo-controlled, randomized, 3-period crossover study of oral fasudil (40 mg or 80 mg) or placebo administered 2 hours before a standardized cold challenge. The fall in skin temperature after the cold challenge and time to recover 50% and 70% of prechallenge digital skin temperature were used as primary outcomes. Digital blood flow assessed by laser Doppler, time to minimum skin temperature, and rate of skin cooling were also measured.

RESULTS

A total of 17 patients with SSc and RP completed the study. After the cold challenge, skin temperatures and the average time (minutes) to recover 50% (7.9 minutes for placebo, 7.5 minutes for fasudil 40 mg, and 8.2 minutes for fasudil 80 mg; P = 0.791) and 70% (18.2 minutes for placebo, 15.0 minutes for fasudil 40 mg, and 17.1 minutes for fasudil 80 mg; P = 0.654) of prechallenge skin temperature were not significantly different across the 3 groups. The digital blood flow measurements were higher in fasudil-treated groups than placebo, but differences were not significant (P = 0.693).

CONCLUSION

Fasudil administered at a single oral dose of 40 mg or 80 mg was not associated with significant benefit in terms of the skin temperature recovery time and the digital blood flow after the cold challenge.

Antibodies recognising sulfated carbohydrates are prevalent in systemic sclerosis and associated with pulmonary vascular disease

BACKGROUND

Glycosylation represents an important modification that regulates biological processes in tissues relevant for disease pathogenesis in systemic sclerosis (SSc), including the endothelium and extracellular matrix. Whether patients with SSc develop antibodies to carbohydrates is not known.

OBJECTIVES

To determine the prevalence and clinical phenotype associated with serum IgG antibodies recognising distinct glycans in patients with SSc.

METHODS

Pooled serum samples from patients with SSc and controls were screened for the presence of specific anticarbohydrate antibodies using a novel array containing over 300 glycans. Antibody titres to 4-sulfated N-acetyl-lactosamine (4S-LacNAc, (4OSO3)Galβ1-4GlcNAc) were determined in 181 individual serum samples from patients with SSc by ELISA and associated with disease phenotype.

RESULTS

4S-LacNAc was identified as a target in pooled SSc serum. Anti-4S-LAcNAc antibodies were detected in 27/181 patients with SSc (14.9%) compared with 1/40 healthy controls (2.5%). Sulfation at position C4 of galactose (4S-LacNAc) was found to be critical for immunogenicity. Anti-4S-LacNAc antibody-positive patients with SSc had a higher prevalence of pulmonary hypertension by echocardiography than anti-4S-LacNAc-negative patients (15/27 (55.7%) vs 49/154 (31.8%), p=0.02) with an OR of 2.6 (95% CI 1.1 to 6.3). Anti-4S-LacNAc-positive patients accounted for 23.4% of all patients with pulmonary hypertension.

CONCLUSION

Serum from patients with SSc contains IgG antibodies targeting distinct sulfated carbohydrates. The presence of anti-4S-LacNAc antibodies is associated with a high prevalence of pulmonary hypertension. These results suggest that specific post-translational carbohydrate modifications may act as important immunogens in SSc and may contribute to disease pathogenesis.

Long-term experience of mycophenolate mofetil for treatment of diffuse cutaneous systemic sclerosis

BACKGROUND

Immunosuppressive therapy may potentially alter the natural disease course of scleroderma. There have been reports of using mycophenolate mofetil (MMF) for the treatment of scleroderma skin disease.

OBJECTIVE

To analyse the experience of using MMF for the treatment of active diffuse cutaneous scleroderma.

METHODS

The authors compared the change in mean modified Rodnan skin scores (mRSS) in an MMF cohort at baseline with scores at 3, 6, 9 and 12 months and with those of historical controls from a pooled analysis of three multicentre randomised clinical trials of recombinant human relaxin, d-penicillamine and oral bovine type I collagen.

RESULTS

Improvement in mRSS after treatment with MMF compared with baseline was seen as early as 3 months and continued through the 12-month follow-up. The mRSS of the MMF cohort was not different from that of the historical controls at 6 months (MMF -3.05 ± 7.4 vs relaxin -4.83 ± 6.99, p=0.059), but was significantly lower at 12 months (MMF -7.59 ± 10.1 vs d-penicillamine -2.47 ± 8.6, p<0.001; collagen -3.4 ± 7.12, p=0.002). General and muscle severity scores and quality of life measures also improved compared with baseline. Pulmonary function remained stable.

CONCLUSIONS

MMF may benefit skin disease in patients with diffuse scleroderma, but prospective studies are required to determine its role.

Immunotherapy of systemic sclerosis

Scleroderma is a multisystem autoimmune disease characterized by an abnormal immune activation associated with the development of underlying vascular and fibrotic disease manifestations. This article highlights the current use of drugs targeting the immune system in scleroderma. Nonselective immunosuppression, and in particular cyclophosphamide, remains the main treatment for progressing skin involvement and active interstitial lung disease. Mycophenolate mofetil is a promising alternative to cyclophosphamide. The use of cyclosporine has been limited by modest efficacy and serious renal toxicity. Newer T-cell (sirolimus and alefacept) and B-cell (rituximab)-targeted therapies have provided some encouraging results in small pilot studies. Hematopoietic stem cell transplantation can be effective for severe fibrotic skin disease, but toxicity remains a concern. Clinical efficacy and safety of antifibrotic treatments (e.g., imatinib) await confirmation. Newer biological agents targeting key molecular or cellular effectors in scleroderma pathogenesis are now available for clinical testing.

Independent association of anti-beta(2)-glycoprotein I antibodies with macrovascular disease and mortality in scleroderma patients

OBJECTIVE

Systemic sclerosis (SSc; scleroderma) is characterized by a unique widespread vascular involvement that can lead to severe digital ischemia, pulmonary arterial hypertension (PAH), or other organ dysfunction. Microthrombotic events and procoagulation factors such as anti-beta2-glycoprotein I (anti-beta2GPI) or anticardiolipin antibodies (aCL) may be implicated in the development of these manifestations. This study was undertaken to investigate whether anti-beta2GPI and aCL are correlated with macrovascular disease, including ischemic digital loss and PAH, in SSc patients.

METHODS

Seventy-five SSc patients with a history of ischemic digital loss and 75 matched SSc controls were evaluated. Anticentromere antibodies (ACAs), anti-beta2GPI, and aCL were measured, and clinical associations were determined using conditional and simple logistic regression models.

RESULTS

Positivity for anti-beta2GPI was significantly more frequent in SSc patients with digital loss than in patients without digital loss (P=0.017), with the IgA isotype of anti-beta2GPI showing the strongest association (odds ratio [OR] 4.0). There was no significant difference in aCL frequency between patients with digital loss and control patients. After adjustment for demographic characteristics, disease type, smoking, and ACA, anti-beta2GPI positivity was significantly associated with active digital ischemia (OR 9.4), echocardiographically evident PAH (OR 4.8), and mortality (OR 2.9). ACA positivity was associated with history of digital loss (OR 3.28), but not with PAH or mortality. History of digital loss was strongly associated with increased mortality (OR 12.5).

CONCLUSION

Anti-beta2GPI is significantly associated with macrovascular disease in SSc and independently predicts mortality. It is unclear whether it has a pathogenetic role or simply reveals the presence of underlying endothelial injury. The use of anti-beta2GPI as a biomarker of vascular disease in SSc should be further explored.

Lack of detection of agonist activity by antibodies to platelet-derived growth factor receptor alpha in a subset of normal and systemic sclerosis patient sera

OBJECTIVE

To investigate whether agonist anti-platelet-derived growth factor receptor alpha (anti-PDGFRalpha) antibodies are present in the serum of patients with systemic sclerosis (SSc; scleroderma).

METHODS

Sera were obtained from healthy subjects and scleroderma patients. An electrochemiluminescence binding assay was performed for detection of serum autoantibodies to PDGFRalpha, PDGFRbeta, epidermal growth factor receptor (EGFR), and colony-stimulating factor receptor 1 (CSFR1). Serum immunoglobulin was purified by protein A/G chromatography. To assess Ig agonist activity, PDGFRalpha-expressing cells were incubated with pure Ig and the level of receptor phosphorylation determined in an enzyme-linked immunoassay, as well as by Western blotting. Ig agonist activity was also assessed in a mitogenic assay and by MAP kinase activation in a PDGFRalpha-expressing cell line.

RESULTS

Sera from 34.3% of the healthy subjects and 32.7% of the SSc patients contained detectable autoantibodies to PDGFRalpha and PDGFRbeta, but not EGFR or CSFR1. Purified Ig from these sera was shown to retain PDGFR binding activity and, at 200-1,000 microg/ml, exhibited no agonist activity in a cell-based PDGFRalpha phosphorylation assay and did not stimulate a mitogenic response or MAP kinase activation in a PDGFRalpha-expressing cell line. Two purified Ig samples that were unable to bind PDGFRalpha did exhibit binding activity to a nonglycosylated form of PDGFRalpha.

CONCLUSION

Although approximately one-third of sera from scleroderma patients contained detectable autoantibodies to PDGFR, these antibodies were not specific to scleroderma, since they were also detected in a similar percentage of samples from normal subjects. PDGFRalpha agonist activity was not demonstrated when purified Ig from these sera was tested in cell-based assays.

T cell polarization identifies distinct clinical phenotypes in scleroderma lung disease

OBJECTIVE

Lung involvement is the leading cause of morbidity and mortality in systemic sclerosis (SSc; scleroderma), and interstitial lung disease (ILD) is the most common pulmonary manifestation. An abnormal profibrotic Th2/Tc2-polarized T cell response is postulated to mediate tissue damage and fibrosis. The aim of this study was to investigate whether a polarized T cell phenotype in SSc is associated with lung disease or other clinical manifestations of SSc.

METHODS

Circulating T cells were characterized by flow cytometry in 62 patients with SSc and 36 healthy control subjects, using antibodies against CD3, CD4, CD8, chemokine receptor CCR5 (Th1/Tc1-specific), and prostaglandin D2 receptor CRTH2 (Th2/Tc2-specific). The ratio between CCR5 and CRTH2 T cell frequencies was used to quantify type 1 (high-ratio) or type 2 (low-ratio) immune polarization.

RESULTS

Patients with SSc exhibited lower CCR5/CRTH2 T cell ratios than those exhibited by control subjects (P<0.0001), indicating a Th2/Tc2-polarized phenotype. Markedly reduced CCR5/CRTH2 T cell ratios were observed in SSc patients with ILD compared with SSc patients without ILD (P<0.0001), particularly in patients with active ILD (P<0.0001) compared with those with stable lung function. Lower CCR5/CRTH2 ratios were strongly associated with a lower value for the percent predicted forced vital capacity (P<0.0001). In patients with an estimated right ventricular systolic pressure>35 mm Hg, suggestive of pulmonary vascular disease, a lower value for the percent predicted diffusing capacity (DLCO) was associated with higher CCR5/CRTH2 T cell ratios (Th1/Tc1) (P=0.009), while in those with right ventricular systolic pressure<35 mm Hg, a lower value for the percent predicted DLCO correlated with lower ratios (Th2/Tc2) (P<0.0001), as observed for ILD.

CONCLUSION

T cell polarization in SSc is strongly associated with specific manifestations of lung disease. Measurement of T cell polarization may represent a valuable tool to monitor disease activity and predict clinical outcomes in SSc patients with lung disease.

Scleroderma-like fibrosing disorders

Many conditions presenting with clinical hard skin and tissue fibrosis can be confused with systemic sclerosis (scleroderma). These disorders have very diverse etiologies and often an unclear pathogenetic mechanism. Distinct clinical characteristics, skin histology, and disease associations may allow one to distinguish these conditions from scleroderma and from each other. A prompt diagnosis is important to spare patients from ineffective treatments and inadequate management. This article highlights nephrogenic systemic fibrosis (nephrogenic fibrosing dermopathy), eosinophilic fasciitis (Shulman's syndrome), scleromyxedema, and scleredema. These often are detected in the primary care setting and referred to rheumatologists for further evaluation. Rheumatologists must be able to promptly recognize them to provide valuable prognostic information and appropriate treatment options for affected patients.

Autoimmunity in systemic sclerosis: current concepts

Systemic sclerosis (SSc) is characterized by tissue fibrosis, obliterative microangiopathy, and immune abnormalities. The role of autoimmunity in generating the clinical and pathologic phenotype in SSc remains uncertain. Distinct subsets of antinuclear antibodies are selectively associated with unique disease manifestations but do not have a proven pathogenic role. A new class of autoantibodies recognizing cellular or extracellular matrix antigens has been recognized in SSc patients. They seem to directly activate pathways that may contribute to SSc-specific tissue and vascular damage. Data confirms that activation and polarization of T cells can contribute to a profibrotic environment. Also, activated immune effector cells can promote vascular obliterative damage through direct cytotoxic pathways targeting the endothelium or by inducing proinflammatory molecules. Technologies are emerging to accurately measure the autoantigen-specific T-cell response in SSc patients. Perturbed B-cell homeostasis has been reported in SSc. If confirmed in-vivo, these advances could lead to new disease-modifying therapeutic strategies directed at SSc-specific immune effector pathways.

Evaluation of topoisomerase-1-specific CD8+ T-cell response in systemic sclerosis

Measurement of disease activity in systemic autoimmune disorders is often unreliable, and immunosuppressive therapy is often titrated to crude clinical response and/or onset of complications. Systemic sclerosis (SSc) presents a distinct clinical phenotype associated with specific autoantibodies. Anti-topoisomerase-1 (SCL-70) is selectively detected in 30-60% of subjects with diffuse skin and interstitial lung involvement. Such patients offer an ideal clinical model to characterize and quantify the autoantigen-specific T-cell response and its correlation with disease phenotype and activity. Human leukocyte antigen A2 (HLA-A2)-restricted topo-1 peptides were selected based on an epitope prediction algorithm. For initial studies, the best binder topo-1(262-270) KMLDHEYTT (#262) was used alone or loaded onto an artificial antigen-presenting platform generated by coupling a dimeric major histocompatibility complex-immunoglobulin G fusion protein (HLA-A2-Ig) and anti-CD28 antibodies onto magnetic beads (artificial antigen-presenting cells). Blood samples (100 microL) from HLA-A2+ SSc patients and cytomegalovirus (CMV) seropositive healthy control subjects were tested in an intracellular cytokine staining assay. Gamma interferon production by CD8+ T cells was measured after stimulation with peptide #262, CMVpp65, or MART-1 (irrelevant peptide). In two of five SCL-70+ patients, peptide #262-loaded aAPCs induced a specific CD8+ T-cell response (0.45% +/- 0.23% of total CD8+ cells). This response was not observed in the seven SCL-70- (five SSc and two CMV+) control subjects studied (0.03% +/- 0.02%). Interestingly, bronchoalveolar lavage fluid obtained from one topo-1-responsive SSc patient who had worsening respiratory function and active alveolitis showed striking enrichment of topo-1-specific CD8+ T cells (3.94%). This small-volume ex vivo assay may prove to be a sensitive and specific tool to assess disease activity and to monitor response to therapy in patients with scleroderma.

Understanding, assessing and treating Raynaud's phenomenon

PURPOSE OF REVIEW

New insights in the pathophysiology and molecular mechanisms implicated in cutaneous vasomotor response to cooling are emerging from recent literature. These advances are introducing significant changes in the management of Raynaud's phenomenon. In this review, we outline how these new findings are leading to novel methods of assessment and new opportunities for specific targeted therapy.

RECENT FINDINGS

New potential targets for treatment of Raynaud's phenomenon derive from experimental observations. Increased protein tyrosine kinase activity and tyrosine phosphorylation have been described in vascular smooth muscle cells in response to cooling and are linked to excessive alpha2-adrenergic response. Activation of Rho/Rho kinase pathway is triggered by increase of reactive oxygen species and up-regulates alpha2c-adrenergic receptors on the surface of vascular smooth muscle cells, thus determining an excessive vasoconstrictive response to cooling. This observation generated pilot trials testing rho-kinase inhibitors and alpha2c-adrenergic receptors antagonists in vasospastic conditions with encouraging results. Therapies already in use for pulmonary hypertension are also showing an effect in Raynaud's phenomenon. Studies evaluating anti-endothelin-1 (bosentan), phosphodiesterases inhibitors (sildenafil), and prostanoids (given for critical digital ischemia) in the treatment of Raynaud's phenomenon all determined improvement of symptoms and/or digital ischemic lesions. Novel techniques for better visualization and quantification of cutaneous microvascular defects are under development. The hope is that these new tools will allow earlier discrimination between primary and secondary Raynaud's phenomenon as well as a better way to predict outcome and response to therapy.

SUMMARY

Remarkable progress towards a rational approach to the management and treatment of Raynaud's phenomenon is emerging.

Role of CREB transcription factor in c-fos activation in natural killer cells

In natural killer (NK) cells, interleukin-2 (IL-2) differentially regulates the expression of several transcription factors, including JunB and c-fos. The cAMP response element binding protein, CREB, is a key transcriptional regulator of a large number of genes containing the octanucleotide CRE consensus sequence in their upstream regulatory regions. We studied here the functional role of CREB in the IL-2-mediated transcriptional regulation of c-fos in human NK cells. Our results show that IL-2 activates CREB in human NK cells and that CREB activation hasa prominent regulatory role on the IL-2-induced expression of functional c-fos and AP-1 in NK cells. We identify two domains of the c-fos promoter, containing three CRE sites, which are critical for the transcriptional activity induced by IL-2. The first domain is located within the first 220 nucleotides of the c-fos promoter, while the second encompasses the nucleotides - 440 and - 220. Our results show that CREB has a relevant role in the cytokine-mediated activation of NK cells, and are particularly remarkable in the light of the several genes that are positively regulated by c-fos and AP-1, such as IFN-gamma, IL-2 and GM-CSF genes.

Increased serum interleukin-8 and interleukin-10 in schizophrenic patients resistant to treatment with neuroleptics and the stimulatory effects of clozapine on serum leukemia inhibitory factor receptor

There is now evidence that schizophrenia may be accompanied by an activation of the monocytic and T-helper-2 (Th-2) arms of cell-mediated immunity (CMI) and by various alterations in the Th-1 arm of CMI. There is also evidence that repeated administration of typical and atypical antipsychotics may result in negative immunomodulatory effects. This study was carried out to examine (1) the serum concentrations of interleukin-8 (IL-8), IL-10, the soluble CD8 (sCD8) and the leukemia inhibitory factor receptor (LIF-R) in nonresponders to treatment with typical neuroleptics as compared with normal volunteers and responders to treatment; and (2) the effects of atypical antipsychotics on the above immune variables. The latter were determined in 17 nonresponders to treatment with neuroleptics and in seven normal volunteers and 14 schizophrenic patients who had a good response to treatment with antipsychotic agents. The nonresponders had repeated measurements of the immune variables before, and 2 and 4 months after treatment with clozapine or risperidone. Serum IL-8 and IL-10 were significantly higher in schizophrenic patients than in normal controls. The serum concentrations of the sCD8 were significantly increased 2 months, but not 4 months, after starting treatment with atypical antipsychotics. Serum LIF-R concentrations were significantly increased 2 and 4 months after starting treatment with atypical antipsychotics. It is concluded that: (1) schizophrenia is characterized by an activation of both pro-inflammatory and anti-inflammatory aspects of cell-mediated immunity; (2) prolonged treatment with atypical antipsychotics may increase the anti-inflammatory capacity of the serum in schizophrenic patients by increasing serum LIF-R concentrations; and (3) short-term treatment with clozapine may induce signs of immune activation which disappear upon prolonged treatment.

Association between promoter polymorphic haplotypes of interleukin-10 gene and schizophrenia

BACKGROUND

Schizophrenia is one of the most severe psychiatric disorders, with a worldwide incidence of 1%. Several reports show abnormal cytokine levels in psychotic patients and indicate a possible role of the immune response system in the pathogenesis of schizophrenia. Increased concentrations of interleukin 10 (IL-10) have been found in plasma of schizophrenic patients, suggesting its potential role as a candidate gene for susceptibility to schizophrenia. IL-10 gene maps on chromosome 1 (q31-q32), a locus associated with genetic susceptibility to schizophrenia. Three functional haplotypes of the gene (GCC, ACC, ATA) have been described, derived from different combinations of three "single nucleotide polymorphisms" and directly related to the expression levels of the protein.

METHODS

We analyzed allele, genotype, and haplotype distributions in an association case-control study involving 106 schizophrenic patients and 143 unrelated healthy volunteers using polymerase chain reaction (PCR)-Single Strand Conformation Polymorphism and PCR Restriction Fragment Length Polymorphism methods.

RESULTS

Our results show a significant increase of GCC homozygotes (the high IL-10-producing haplotype) in schizophrenic patients compared to control subjects (chi(2) = 13, p =.023; odds ratio = 3.03; 95% confidence interval, 1.274-7.355).

CONCLUSIONS

These data could partly explain the abnormal secretion of IL-10 occurring in schizophrenic patients in response to infections or different stressors and suggest a potential role of IL-10 as a candidate gene for susceptibility to schizophrenia.

Association between -G308A tumor necrosis factor alpha gene polymorphism and schizophrenia

Dysregulation of the inflammatory response system has been linked to pathophysiology of schizophrenia. Evidence of immune activation has derived from the detection of abnormal levels of proinflammatory cytokines and their receptors in peripheral blood and cerebrospinal fluid from schizophrenic patients. Cytokines are involved in normal CNS development as well as in the pathogenesis of many neuro-psychiatric disorders, acting directly on neural cells or modulating neurotransmitter and neuropeptide systems. In particular tumor necrosis factor alpha (TNFalpha), depending on its concentration, can exert both neurotrophic and neurotoxic effects and influence neural cell growth and proliferation. Moreover, TNFalpha gene is located on the small arm of chromosome 6 (6p21.1-21.3), a locus associated with genetic susceptibility to schizophrenia. We studied the distribution of -G308A TNFalpha gene polymorphism in 84 schizophrenic patients and in 138 healthy volunteers. This biallelic base exchange polymorphism directly affects TNFalpha plasma levels. Frequency of the TNF2(A) allele is significantly increased in schizophrenic patients as compared to controls (P = 0.0042). Genotype distribution is also significantly different (P = 0.0024). TNF2 homozygotes are represented only in the patient group (P = 0.002). These data suggest a potential role of TNFalpha as a candidate gene for susceptibility to schizophrenia and suggest that immune dysregulation in schizophrenic patients could also have a genetic component.

Effects of atypical antipsychotics on the inflammatory response system in schizophrenic patients resistant to treatment with typical neuroleptics

There is now some evidence that schizophrenia may be accompanied by an activation of the inflammatory response system (IRS) and that typical antipsychotics may suppress some signs of IRS activation in that illness. This study was carried out to examine (i) the serum concentrations of interleukin-6 (IL-6), IL-6 receptor (IL-6R), IL-1R antagonist (IL-1RA) and Clara Cell protein (CC16), an endogenous anticytokine, in nonresponders to treatment with typical neuroleptics and (ii) the effects of atypical antipsychotics on the above IRS variables. The above parameters were determined in 17 patients with treatment-resistant schizophrenia (TRS) to treatment with neuroleptics and in seven normal volunteers and 14 schizophrenic patients who had a good response to treatment with antipsychotic agents. Patients with TRS had repeated measurements of the IRS variables before and 2 and 4 months after treatment with atypical antipsychotics. Serum IL-6 was significantly higher in schizophrenic patients, irrespective of their response to typical antipsychotics, than in normal controls. Serum IL-1RA was significantly higher in the TRS patients than in controls, whereas responders took up an intermediate position. The serum concentrations of CC16 were significantly lower after treatment with atypical antipsychotics during 4 months than before treatment. It is concluded that (i) schizophrenia and, in particular, TRS is characterized by an activation of the monocytic arm of cell-mediated immunity and (ii) atypical antipsychotics may decrease the anti-inflammatory capacity of the serum in TRS patients.