The causes and treatment of kidney disease in scleroderma

This project examines the pathogenic processes that lead to kidney disease in scleroderma and tests a novel therapy for scleroderma kidney disease in a clinical trial. I describe three programmes of experiment to identify possible pathogenic targets and new treatment strategies in scleroderma kidney disease. The first divides a large cohort of patients according to their immunological and renal phenotypes, uses genome wide association to identify possible risk genes and then interrogates candidate genes further by staining renal disease tissue for the relevant gene products. In the second stream of investigation, I describe a project to develop novel biomarkers of renal disease activity by measuring concentrations of candidate proteins in urine and serum of scleroderma patients and compare the measurements from matched control groups. The final set of investigations is a randomised control clinical trial, testing the safety and efficacy of the highly selective endothelin antagonist zibotentan in renal outcomes for patients with scleroderma-associated chronic kidney disease and scleroderma renal crisis. Outcomes are assessed by traditional clinical measures of renal function as well as deploying novel disease activity biomarkers developed in parallel in my earlier experiments. In a parallel study I assess the pharmacokinetics of zibotentan in patients on haemodialysis

Fresolimumab Treatment Decreases Biomarkers and Improves Clinical Symptoms in Systemic Sclerosis Patients

BACKGROUND. TGF-β has potent profibrotic activity in vitro and has long been implicated in systemic sclerosis (SSc), as expression of TGF-β–regulated genes is increased in the skin and lungs of patients with SSc. Therefore, inhibition of TGF-β may benefit these patients. METHODS. Patients with early, diffuse cutaneous SSc were enrolled in an open-label trial of fresolimumab, a high-affinity neutralizing antibody that targets all 3 TGF-β isoforms. Seven patients received two 1 mg/kg doses of fresolimumab, and eight patients received one 5 mg/kg dose of fresolimumab. Serial mid-forearm skin biopsies, performed before and after treatment, were analyzed for expression of the TGF-β–regulated biomarker genes thrombospondin-1 (THBS1) and cartilage oligomeric protein (COMP) and stained for myofibroblasts. Clinical skin disease was assessed using the modified Rodnan skin score (MRSS). RESULTS. In patient skin, THBS1 expression rapidly declined after fresolimumab treatment in both groups (P = 0.0313 at 7 weeks and P = 0.0156 at 3 weeks), and skin expression of COMP exhibited a strong downward trend in both groups. Clinical skin disease dramatically and rapidly decreased (P \u3c 0.001 at all time points). Expression levels of other TGF-β–regulated genes, including SERPINE1 and CTGF, declined (P = 0.049 and P = 0.012, respectively), and a 2-gene, longitudinal pharmacodynamic biomarker of SSc skin disease decreased after fresolimumab treatment (P = 0.0067). Dermal myofibroblast infiltration also declined in patient skin after fresolimumab (P \u3c 0.05). Baseline levels of THBS1 were predictive of reduced THBS1 expression and improved MRSS after fresolimumab treatment. CONCLUSION. The rapid inhibition of TGF-β–regulated gene expression in response to fresolimumab strongly implicates TGF-β in the pathogenesis of fibrosis in SSc. Parallel improvement in the MRSS indicates that fresolimumab rapidly reverses markers of skin fibrosis

Biomarkers in systemic scelrosis

Systemic sclerosis (SSc; scleroderma) is a chronic multisystem autoimmune disease that includes prominent skin involvement in all patients and is characterized by fibrosis, inflammation, and microvascular injury of the skin and internal organs. Clinical trial design for patients with systemic sclerosis (SSc) has been confounded by the heterogeneity of disease progression and lack of objective outcome measures. This has hampered identification of therapies for patients who have frequently fatal fibrotic complications. Direct pulmonary complications are the leading cause of death in SSc. For clinical trials in patients with diffuse cutaneous SSc, identification of a pharmacodynamic biomarker associated with clinical improvement would allow for alternative approaches to trial design. Furthermore, identification of a diagnostic biomarker for SSc complicated by pulmonary arterial hypertension (SSc-PAH) would provide a reliable non-invasive method for diagnosis of pulmonary arterial hypertension. Through the combination of high throughput technologies and clinical information we have identified three preliminary biomarkers for SSc: i) Two pharmacodynamic biomarkers for diffuse skin disease (dcSSc), one in using mRNA from skin biopsies and one using proteomic profiles from sera; ii) a serum based proteomic classifier for the screening and diagnostic evaluation of pulmonary arterial hypertension in systemic sclerosis. We show these biomarkers can be applied to assess changes in skin disease in dSSc patients over time and with further development could be used to supplement or replace the physical examination assessment (Modified Rodnan Skin Score, MRSS) as an outcome measure in clinical trials for dcSSc patients. Routine use of these biomarkers in SSc clinical trial design could expand treatment options for a patient population that currently has few if any treatment options that slow progression of disease. Furthermore we identified a serum biomarker for the major SSc pulmonary complication, SSc-PAH. This diagnostic SSc-PAH biomarker has the potential to be used as a screening tool in order to reduce the need for unnecessary invasive diagnostic procedures. This non-invasive screening method could lead to early diagnosis thus improving patient survival and aid in clinical management of a complication for which there are several treatments but which is still frequently fatal.2018-06-15T00:00:00

Novel approaches to identify biomechanisms in systemic sclerosis

Systemic sclerosis is a severe connective tissue disease in which inflammation and autoimmunity are associated with progressive tissue remodeling and fibrosis of the skin and internal organs. Complex genetic backgrounds contribute to susceptibility and the disease can be triggered by environmental factors. It is proposed that based on the genetic susceptibility an immune inflammatory disease microenvironment is initiated leading to overexpression of cytokines and growth factors and the development of a fibrotic disease process. Analysis of copy number variation in candidate genes was performed using DNA from patients and controls. This identified a possible association between disease susceptibility and one candidate factor, LEPREL1, a prolyl 3- hydroxylase involved in collagen alignment in the endoplasmic reticulum. Deletion of the LEPREL1 gene led to resistance to dermal fibrosis in mice, whereas levels of the encoded enzyme were increased in disease fibroblasts, all consistent with an important role in the fibrotic process. Furthermore, profiling of tissue fluid from the dermal lesions revealed the presence of an inflammatory, pro-fibrotic microenvironment. When candidate factors present in the tissue fluid (e.g. PDGF), were applied to fibroblasts on aligned collagen matrices, fibroblast orientation and migration was enhanced, modeling the effect on spread of the disease. In contrast, the use of inhibitors (e.g. heparin, imatinib), particularly in combination, attenuated fibroblast alignment and migration. Finally, since this disease has proved resistant to current non-specific therapies, a novel anti-inflammatory peptide was evaluated using a mouse model of systemic sclerosis-like inflammation and fibrosis. Treatment with the peptide suppressed the pattern of inflammatory changes seen in this model of systemic sclerosis, and significantly reduced tissue fibrosis and the replacement of the normal tissue architecture with scar tissue. This approach using antiinflammatory peptides could be potentially relevant for the treatment of individuals with systemic sclerosis in order to attenuate the pathological inflammatory fibrotic process

Multiplex cytokine analysis of dermal interstitial blister fluid defines local disease mechanisms in systemic sclerosis.

Clinical diversity in systemic sclerosis (SSc) reflects multifaceted pathogenesis and the effect of key growth factors or cytokines operating within a disease-specific microenvironment. Dermal interstitial fluid sampling offers the potential to examine local mechanisms and identify proteins expressed within lesional tissue. We used multiplex cytokine analysis to profile the inflammatory and immune activity in the lesions of SSc patients