M. Kari Connolly

Systemic and cell type-specific gene expression patterns in scleroderma skin

We used DNA microarrays representing >12,000 human genes to characterize gene expression patterns in skin biopsies from individuals with a diagnosis of systemic sclerosis with diffuse scleroderma. We found consistent differences in the patterns of gene expression between skin biopsies from individuals with scleroderma and those from normal, unaffected individuals. The biopsies from affected individuals showed nearly indistinguishable patterns of gene expression in clinically affected and clinically unaffected tissue, even though these were clearly distinguishable from the patterns found in similar tissue from unaffected individuals. Genes characteristically expressed in endothelial cells, B lymphocytes, and fibroblasts showed differential expression between scleroderma and normal biopsies. Analysis of lymphocyte populations in scleroderma skin biopsies by immunohistochemistry suggest the B lymphocyte signature observed on our arrays is from CD20+ B cells. These results provide evidence that scleroderma has systemic manifestations that affect multiple cell types and suggests genes that could be used as potential markers for the disease.

Molecular Subsets in the Gene Expression Signatures of Scleroderma Skin

Background Scleroderma is a clinically heterogeneous disease with a complex phenotype. The disease is characterized by vascular dysfunction, tissue fibrosis, internal organ dysfunction, and immune dysfunction resulting in autoantibody production. Methodology and Findings We analyzed the genome-wide patterns of gene expression with DNA microarrays in skin biopsies from distinct scleroderma subsets including 17 patients with systemic sclerosis (SSc) with diffuse scleroderma (dSSc), 7 patients with SSc with limited scleroderma (lSSc), 3 patients with morphea, and 6 healthy controls. 61 skin biopsies were analyzed in a total of 75 microarray hybridizations. Analysis by hierarchical clustering demonstrates nearly identical patterns of gene expression in 17 out of 22 of the forearm and back skin pairs of SSc patients. Using this property of the gene expression, we selected a set of ‘intrinsic’ genes and analyzed the inherent data-driven groupings. Distinct patterns of gene expression separate patients with dSSc from those with lSSc and both are easily distinguished from normal controls. Our data show three distinct patient groups among the patients with dSSc and two groups among patients with lSSc. Each group can be distinguished by unique gene expression signatures indicative of proliferating cells, immune infiltrates and a fibrotic program. The intrinsic groups are statistically significant (p<0.001) and each has been mapped to clinical covariates of modified Rodnan skin score, interstitial lung disease, gastrointestinal involvement, digital ulcers, Raynauds phenomenon and disease duration. We report a 177-gene signature that is associated with severity of skin disease in dSSc. Conclusions and Significance Genome-wide gene expression profiling of skin biopsies demonstrates that the heterogeneity in scleroderma can be measured quantitatively with DNA microarrays. The diversity in gene expression demonstrates multiple distinct gene expression programs in the skin of patients with scleroderma.

Pathologic alterations of cutaneous innervation and vasculature in affected limbs from patients with complex regional pain syndrome.

Abstract Complex regional pain syndromes (CRPS, type I and type II) are devastating conditions that can occur following soft tissue (CRPS type I) or nerve (CRPS type II) injury. CRPS type I, also known as reflex sympathetic dystrophy, presents in patients lacking a well‐defined nerve lesion, and has been questioned as to whether or not it is a true neuropathic condition with an organic basis. As described here, glabrous and hairy skin samples from the amputated upper and lower extremity from two CRPS type I diagnosed patients were processed for double‐label immunofluorescence using a battery of antibodies directed against neural‐related proteins and mediators of nociceptive sensory function. In CRPS affected skin, several neuropathologic alterations were detected, including: (1) the presence of numerous abnormal thin caliber NF‐positive/MBP‐negative axons innervating hair follicles; (2) a decrease in epidermal, sweat gland, and vascular innervation; (3) a loss of CGRP expression on remaining innervation to vasculature and sweat glands; (4) an inappropriate expression of NPY on innervation to superficial arterioles and sweat glands; and (5) a loss of vascular endothelial integrity and extraordinary vascular hypertrophy. The results are evidence of widespread cutaneous neuropathologic changes. Importantly, in these CRPS type I patients, the myriad of clinical symptoms observed had detectable neuropathologic correlates.

The Pathogenesis of Systemic Sclerosis

Systemic sclerosis (SSc), also known as scleroderma, is a rare connective tissue disease characterized by vascular and immune dysfunction, leading to fibrosis that can damage multiple organs. Its pathogenesis is complex and poorly understood. Two major clinical subtypes are the limited and diffuse forms. Research into SSc has been hampered by its rarity, its clinical heterogeneity, and the lack of mouse models that accurately recapitulate the disease. Clinical and basic studies have yielded some mechanistic clues regarding pathogenesis. Recent insights gained through the use of microarrays have revealed distinctive subsets of SSc within and beyond the limited and diffuse subsets. In this review, we discuss potential mechanisms underlying the vascular, autoimmune, and fibrotic points of dysregulation. Proper categorization of SSc patients for research studies by use of microarrays or other biomarkers is critical, as disease heterogeneity may explain some of the inconsistencies of prior studies.

Capillary Regeneration in Scleroderma: Stem Cell Therapy Reverses Phenotype?

Background Scleroderma is an autoimmune disease with a characteristic vascular pathology. The vasculopathy associated with scleroderma is one of the major contributors to the clinical manifestations of the disease. Methodology/Principal Findings We used immunohistochemical and mRNA in situ hybridization techniques to characterize this vasculopathy and showed with morphometry that scleroderma has true capillary rarefaction. We compared skin biopsies from 23 scleroderma patients and 24 normal controls and 7 scleroderma patients who had undergone high dose immunosuppressive therapy followed by autologous hematopoietic cell transplant. Along with the loss of capillaries there was a dramatic change in endothelial phenotype in the residual vessels. The molecules defining this phenotype are: vascular endothelial cadherin, a supposedly universal endothelial marker required for tube formation (lost in the scleroderma tissue), antiangiogenic interferon α (overexpressed in the scleroderma dermis) and RGS5, a signaling molecule whose expression coincides with the end of branching morphogenesis during development and tumor angiogenesis (also overexpressed in scleroderma skin. Following high dose immunosuppressive therapy, patients experienced clinical improvement and 5 of the 7 patients with scleroderma had increased capillary counts. It was also observed in the same 5 patients, that the interferon α and vascular endothelial cadherin had returned to normal as other clinical signs in the skin regressed, and in all 7 patients, RGS5 had returned to normal. Conclusion/Significance These data provide the first objective evidence for loss of vessels in scleroderma and show that this phenomenon is reversible. Coordinate changes in expression of three molecules already implicated in angiogenesis or anti-angiogenesis suggest that control of expression of these three molecules may be the underlying mechanism for at least the vascular component of this disease. Since rarefaction has been little studied, these data may have implications for other diseases characterized by loss of capillaries including hypertension, congestive heart failure and scar formation.

Mycophenolate mofetil versus oral cyclophosphamide in scleroderma-related interstitial lung disease (SLS II): a randomised controlled, double-blind, parallel group trial

Summary BACKGROUND Twelve months of oral cyclophosphamide (CYC) has been shown to alter the progression of scleroderma-related interstitial lung disease (SSc-ILD) when compared to placebo. However, toxicity was a concern and without continued treatment the efficacy disappeared by 24 months. We hypothesized that a two-year course of mycophenolate mofetil (MMF) would be safer, better tolerated and produce longer lasting improvements than CYC. METHODS Patients with SSc-ILD meeting defined dyspnea, pulmonary function and high-resolution computed tomography (HRCT) criteria were randomized in a double-blind, two-arm trial at 14 medical centers. MMF (target dose 1500 mg twice daily) was administered for 24 months in one arm and oral CYC (target dose 2·0 mg/kg/day) administered for 12 months followed by placebo for 12 months in the other arm. The primary endpoint, change in forced vital capacity as a percent of the predicted normal value (FVC %) over the course of 24 months, was assessed in a modified intention-to-treat analysis using an inferential joint model combining a mixed effects model for longitudinal outcomes and a survival model to handle non-ignorable missing data. The study was registered with ClinicalTrials.gov, number NCT00883129, and is closed. RESULTS Between November, 2009, and January, 2013, 142 patients were randomized. 126 patients (63 MMF; 63 CYC) with acceptable baseline HRCT studies and at least one outcome measure were included in the analysis. The adjusted FVC % (primary endpoint) improved from baseline to 24 months by 2.17 in the MMF arm (95% CI, 0.53–3.84) and 2·86 in the CYC arm (95% confidence interval 1·19–4·58) with no significant between-treatment difference (p=0·24), indicating that the trial was negative for the primary endpoint. However, in a post-hoc analysis of the primary endpoint, within-treatment improvements from baseline to 24 months were noted in both the CYC and MMF arms. A greater number of patients on CYC than on MMF prematurely withdrew from study drug (32 vs 20) and failed treatment (2 vs 0), and the time to stopping treatment was significantly shorter in the CYC arm (p=0·019). Sixteen deaths occurred (11 CYC; 5 MMF) with most due to progressive ILD. Leukopenia (30 vs 4 patients) and thrombocytopenia (4 vs 0 patients) occurred more often in patients treated with CYC. In post-hoc analyses, within- (but not between-) treatment improvements were also noted in defined secondary outcomes including skin score, dyspnea and whole-lung HRCT scores. INTERPRETATION Treatment of SSc-ILD with MMF for two years or CYC for one year both resulted in significant improvements in pre-specified measures of lung function, dyspnea, lung imaging, and skin disease over the 2-year course of the study. While MMF was better tolerated and associated with less toxicity, the hypothesis that it would have greater efficacy at 24 months than CYC was not confirmed. These findings support the potential clinical impact of both CYC and MMF for progressive SSc-ILD, as well as the current preference for MMF due to its better tolerability and toxicity profile. FUNDING National Heart, Lung and Blood Institute/National Institutes of Health with drug supply provided by Hoffmann-La Roche/Genentech.

Molecular Framework for Response to Imatinib Mesylate in Systemic Sclerosis

Systemic sclerosis (SSc) is an autoimmune disease in which the tyrosine kinases platelet-derived growth factor receptor (PDGFR) and Abl are hypothesized to contribute to the fibrosis and vasculopathy of the skin and internal organs. Herein we describe 2 patients with early diffuse cutaneous SSc (dcSSc) who experienced reductions in cutaneous sclerosis in response to therapy with the tyrosine kinase inhibitor imatinib mesylate. Immunohistochemical analyses of skin biopsy specimens demonstrated reductions of phosphorylated PDGFRbeta and Abl with imatinib therapy. By gene expression profiling, an imatinib-responsive signature specific to dcSSc was identified (P < 10(-8)). The response of these patients and the findings of the analyses suggest that PDGFRbeta and Abl play critical, synergistic roles in the pathogenesis of SSc, and that imatinib targets a gene expression program that is frequently dysregulated in dcSSc.

The Stiff Skin Syndrome Case Series, Differential Diagnosis of the Stiff Skin Phenotype, and Review of the Literature

BACKGROUND Stiff skin syndrome is a sclerodermalike disorder that presents in infancy or early childhood with rock-hard skin, limited joint mobility, and mild hypertrichosis in the absence of visceral or muscle involvement, immunologic abnormalities, or vascular hyperreactivity. OBSERVATIONS We describe 6 children who fit criteria for stiff skin syndrome. A review of the clinical range of this disorder and discussion of the differential diagnosis is presented. The age at onset in our cases ranged from infancy to 6 years of age. Stony-hard skin was noted mostly on the thighs, buttocks, and lower back with shoulder and arm involvement in 2 cases. There was associated hypertrichosis in 3 of 6 cases. Extracutaneous manifestations consisted primarily of joint restriction, and several patients had resulting postural and thoracic wall irregularities. Histopathologically, our cases showed areas of fascial sclerosis or showed increased fibroblast cellularity with thickened, sclerotic, horizontally oriented collagen bundles in the deep reticular dermis and/or subcutaneous septa without associated inflammation. CONCLUSIONS Stiff skin syndrome is characterized by an early, insidious onset of stony-hard skin, often with associated contracturelike joint restriction, hypertrichosis, and postural and thoracic wall abnormalities. Supportive histopathologic findings consisting of either fascial sclerosis or increased fibroblast cellularity with sclerotic collagen bundles in the deep reticular dermis and/or subcutaneous septa may help to confirm this diagnosis.

Peripheral neuropathy in scleroderma.

Because patients with scleroderma report neuropathic symptoms including numbness, paresthesias, and dysesthesias, we assessed peripheral nerve function in such patients. Fourteen scleroderma patients underwent complete neurologic examination, nerve conduction studies (NCS) and quantitative sensory testing (QST). Neurologic examination revealed reduced vibration (7) or pinprick (4) sensation in the upper or lower extremities, focal atrophy or proximal weakness (2), and decreased deep tendon reflexes (2). NCS showed reduced sensory nerve action potentials (1) and carpal tunnel syndrome (1). QST of the upper and lower extremity revealed increased cold or vibration detection thresholds in 8 of 14 patients. Our findings suggest that peripheral neuropathy occurs in patients with scleroderma at a higher frequency than previously appreciated. These findings cannot be ascribed to compression neuropathies, but rather involve large and small fibers in a non–length‐dependent fashion. Larger, prospective studies using the more sensitive QST as well as pathologic studies of nerve, including cutaneous innervation, are needed to further assess the characteristics and etiology of the neuropathy. Muscle Nerve 28: 330–335, 2003

Updates in adult-onset Still disease: Atypical cutaneous manifestations and associations with delayed malignancy

Adult-onset Still disease (AOSD) is a systemic inflammatory disorder that is clinically characterized by a heterogeneous constellation of symptoms and signs. Though an evanescent eruption is the classic cutaneous finding, recent literature has highlighted atypical rashes associated with Still disease. A second emerging concept in presentations of AOSD is its association with malignancy. This review focuses on these concepts: the clinical spectrum of atypical skin manifestations and AOSD as a paraneoplastic phenomenon. PubMed-MEDLINE was screened for peer-reviewed articles describing atypical presentations of AOSD and cases associated with malignancy. Erythematous, brown or violaceous, persistent papules and plaques were the most common cutaneous finding (28/30 [93%]). Linear configurations were also rarely described. Of these patients, 81% concurrently had the typical evanescent skin eruption. There were 31 patients with associated malignancies, most commonly breast cancer and lymphoma. The diagnosis of malignancy did not precede or immediately follow a clinical presentation otherwise consistent with AOSD in a considerable subset of patients (42%). Understanding the cutaneous spectrum of AOSD and heightened awareness for its delayed association with malignancy may lead to improved recognition of cutaneous variants and reinforce the need for diagnostic evaluation and long-term follow-up for malignancy in patients with this clinical presentation.