Primary Membranous Nephropathy as a Model of Autoimmune Disease

Membranous nephropathy is the most common cause of adult nephrotic syndrome worldwide with a significant health care burden. There has been a leap in our understanding of the disease mechanism over the last decade with a remarkably strong genetic component to the development of the disease and its strong association with high affinity antibody—in the form of anti-PLA2R autoantibody in the majority of cases, with a smaller proportion associated with anti-THSD7A autoantibody. New evidence is now providing confirmation of specific elements in the development of the disease pathogenesis, such as involvement of loss of peripheral tolerance. There is a striking correlation between disease activity and anti-PLA2R antibody levels, along with response to treatment; evidence points strongly to these antibodies being pathogenic. The development of membranous nephropathy therefore follows the well appreciated multi-hit step-wise path to autoimmune clinical disease. Given its strong genetic basis and putative pathogenic antibody the disease provides an invaluable model for understanding of autoimmunity. This chapter focuses on the most up to date knowledge of autoimmune membranous nephropathy and provides a paradigm for understanding the underlying disease mechanisms in autoimmunity

A Study to Inform the Design of a National Multicentre Randomised Controlled Trial to Evaluate If Reducing Serum Phosphate to Normal Levels Improves Clinical Outcomes including Mortality, Cardiovascular Events, Bone Pain, or Fracture in Patients on Dialysis

Background. Retrospective, observational studies link high phosphate with mortality in dialysis patients. This generates research hypotheses but does not establish “cause-and-effect.” A large randomised controlled trial (RCT) of about 3000 patients randomised 50 : 50 to lower or higher phosphate ranges is required to answer the key question: does reducing phosphate levels improve clinical outcomes? Whether such a trial is technically possible is unknown; therefore, a study is necessary to inform the design and conduct of a future, definitive trial. Methodology. Dual centre prospective parallel group study: 100 dialysis patients randomized to lower (phosphate target 0.8 to 1.4 mmol/L) or higher range group (1.8 to 2.4 mmol/L). Non-calcium-containing phosphate binders and questionnaires will be used to achieve target phosphate. Primary endpoint: percentage successfully titrated to required range and percentage maintained in these groups over the maintenance period. Secondary endpoints: consent rate, drop-out rates, and cardiovascular events. Discussion. This study will inform design of a large definitive trial of the effect of phosphate on mortality and cardiovascular events in dialysis patients. If phosphate lowering improves outcomes, we would be reassured of the validity of this clinical practice. If, on the other hand, there is no improvement, a reassessment of resource allocation to therapies proven to improve outcomes will result. Trial Registration Number. This trial is registered with ISRCTN registration number ISRCTN24741445

Molecular, genetic, patient and surgical factors involved in the development and outcome of central nervous system tumours

Prognostic factors come in a variety of forms and may be patient, tumour or environmental related. This thesis examines the interaction of prognostic factors for a variety of tumour types. It particularly focuses on single nucleotide polymorphisms (SNPs) of the vascular endothelial growth factor (VEGF) gene. The first section on meningiomas describes the frequency of sex steroid receptors in meningiomas. In this study, absence of progesterone receptors is associated with high tumour grade and male gender. Tumours that are progesterone receptor negative have an odds ratio for recurrence of 5.Choroid plexus carcinomas are aggressive malignant tumours generally occurring in young children. Gross total surgical resection has been shown to be a highly significant factor in tumour recurrence and survival. This study describes a treatment paradigm of neoadjuvant ICE chemotherapy in these children which decreases the vascularity and increase the chance of a complete removal. The operative blood loss with this regimen is reduced to 0.22 blood volumes from 1.11 blood volumes without neoadjuvant chemotherapy. The VEGF gene is highly polymorphic and SNPs of the region have previously been shown to influence VEGF protein expression. This study looks at cohorts of both adult gliomas and a variety of paediatric brain tumours; comparing them to controls. There are several associations described between the development of certain tumours and specific SNP genotypes. In addition to this, certain genotypes and haplotypes have an influence on survival of adult grade 2 astrocytomas and paediatric medulloblastomas and ependymomas. There are consistent themes to the prognostic genotypes throughout both the adult and the paediatric tumours.Prognostic factors come in a variety forms as described in this thesis. It is vital to understand the complex interaction between factors to best utilise them for the benefit of patients.EThOS - Electronic Theses Online ServiceGBUnited Kingdo

Molecular, genetic, patient and surgical factors involved in the development and outcome of central nervous system tumours

Prognostic factors come in a variety of forms and may be patient, tumour or environmental related. This thesis examines the interaction of prognostic factors for a variety of tumour types. It particularly focuses on single nucleotide polymorphisms (SNPs) of the vascular endothelial growth factor (VEGF) gene. The first section on meningiomas describes the frequency of sex steroid receptors in meningiomas. In this study, absence of progesterone receptors is associated with high tumour grade and male gender. Tumours that are progesterone receptor negative have an odds ratio for recurrence of 5.Choroid plexus carcinomas are aggressive malignant tumours generally occurring in young children. Gross total surgical resection has been shown to be a highly significant factor in tumour recurrence and survival. This study describes a treatment paradigm of neoadjuvant ICE chemotherapy in these children which decreases the vascularity and increase the chance of a complete removal. The operative blood loss with this regimen is reduced to 0.22 blood volumes from 1.11 blood volumes without neoadjuvant chemotherapy. The VEGF gene is highly polymorphic and SNPs of the region have previously been shown to influence VEGF protein expression. This study looks at cohorts of both adult gliomas and a variety of paediatric brain tumours; comparing them to controls. There are several associations described between the development of certain tumours and specific SNP genotypes. In addition to this, certain genotypes and haplotypes have an influence on survival of adult grade 2 astrocytomas and paediatric medulloblastomas and ependymomas. There are consistent themes to the prognostic genotypes throughout both the adult and the paediatric tumours.Prognostic factors come in a variety forms as described in this thesis. It is vital to understand the complex interaction between factors to best utilise them for the benefit of patients.EThOS - Electronic Theses Online ServiceGBUnited Kingdo

Activation of transforming growth factor-β(1 )and early atherosclerosis in systemic lupus erythematosus

The efficiency of activating latent transforming growth factor (TGF)-β(1 )in systemic lupus erythematosus (SLE) may control the balance between inflammation and fibrosis, modulating the disease phenotype. To test this hypothesis we studied the ability to activate TGF-β(1 )in SLE patients and control individuals within the context of inflammatory disease activity, cumulative organ damage and early atherosclerosis. An Activation Index (AI) for TGF-β(1 )was determined for 32 patients with SLE and 33 age-matched and sex-matched control individuals by quantifying the increase in active TGF-β(1 )under controlled standard conditions. Apoptosis in peripheral blood mononuclear cells was determined by fluorescence-activated cell sorting. Carotid artery intima-media thickness was measured using standard Doppler ultrasound. These measures were compared between patients and control individuals. In an analysis conducted in patients, we assessed the associations of these measures with SLE phenotype, including early atherosclerosis. Both intima-media thickness and TGF-β(1 )AI for SLE patients were within the normal range. There was a significant inverse association between TGF-β(1 )AI and levels of apoptosis in peripheral blood mononuclear cells after 24 hours in culture for both SLE patients and control individuals. Only in SLE patients was there a significant negative correlation between TGF-β(1 )AI and low-density lipoprotein cholesterol (r = -0.404; P = 0.022) and between TGF-β(1 )AI and carotid artery intima-media thickness (r = -0.587; P = 0.0004). A low AI was associated with irreversible damage (SLICC [Systemic Lupus International Collaborating Clinics] Damage Index ≥1) and was inversely correlated with disease duration. Intima-media thickness was significantly linked to total cholesterol (r = 0.371; P = 0.037). To conclude, in SLE low normal TGF-β(1 )activation was linked with increased lymphocyte apoptosis, irreversible organ damage, disease duration, calculated low-density lipoprotein levels and increased carotid IMT, and may contribute to the development of early atherosclerosis

An investigation of EPO as a tissue protective agent in human kidney transplantation

Ischaemia-reperfusion injury (IRI) has been identified as a major contributor to both short and long term kidney transplant failure. Experimental evidence from the literature suggests that Erythropoietin (EPO) is tissue protective, reducing both inflammation and apoptosis following IRI. We performed a randomised, double blind, placebo controlled trial examining the tissue protective effect of high dose EPO (100,000iu over 3 days) in 39 recipients of an extended criteria donor kidney or a non-heart-beating donor kidney. The primary endpoints of the study were difference in plasma and urinary biomarker levels (NGAL, IL-18 and KIM-1) in addition to changes in gene expression. Secondary endpoints included safety, clinical data and differences in metabolomics profiles. There was no difference detected between the treatment groups in terms of biomarkers, gene expression, metabolomics profiling or clinical parameters. No adverse events related to EPO therapy were recorded. In addition, we developed a cell model of kidney transplantation using primary tubulo-epithelial cells and HMEC-1 cells, with which to confirm the protective effects of EPO. Treatment with 50U/ml one hour prior to undergoing cold hypoxia resulted in the maximum degree of tissue protection, as measured using an MTT and an LDH assay. No evidence of EPO toxicity was demonstrated. Tubulo-epithelial cells expressed EPOR mRNA and protein. No CD131 receptor could be demonstrated. In summary, EPO confers tissue protection in a cell model of kidney transplantation but this has not been shown to occur in a clinical trial using high dose EPO in recipients of marginal donor kidneys.EThOS - Electronic Theses Online ServiceDepartment of Renal Medicine, Manchester Royal InfirmaryGBUnited Kingdo

Mesangial IgA1 in IgA nephropathy exhibits aberrant O-glycosylation: Observations in three patients

Mesangial IgA1 in IgA nephropathy exhibits aberrant O-glycosylation: Observations in three patients.BackgroundIn IgA nephropathy (IgAN), circulating IgA1 molecules display an abnormal pattern of O-glycosylation. This abnormality may potentially contribute to mesangial IgA1 deposition, but this is unproven because the O-glycosylation of mesangial IgA1 has not been analyzed.MethodsIgA1 was eluted from glomeruli isolated from the kidneys of three IgAN patients obtained after nephrectomy or at postmortem. Serum from these patients, other patients with IgAN, and controls was subjected to the same treatment as the glomerular eluates. The O-glycosylation of eluted and serum IgA1 was measured by lectin binding using an enzyme-linked immunosorbent assay-based system.ResultsIn all three cases, the lectin binding of IgA1 eluted from the glomeruli of IgAN patients was markedly higher than that of the serum IgA1 of the same individual, and also all but one of a series of serum IgA1 samples from other patients and controls.ConclusionsThe higher lectin binding of glomerular compared with serum IgA1 suggests that O-glycosylated IgA1 molecules abnormally and selectively deposit in the kidney. These results provide the first evidence that mesangial IgA1 is abnormally O-glycosylated, and support a direct role for abnormal IgA1 O-glycosylation in the mechanism of mesangial IgA deposition in IgAN

Healthcare decision-making in end stage renal disease-patient preferences and clinical correlates

Background: Medical decision-making is critical to patient survival and well-being. Patients with end stage renal disease (ESRD) are faced with incrementally complex decision-making throughout their treatment journey. The extent to which patients seek involvement in the decision-making process and factors which influence these in ESRD need to be understood. Methods: 535 ESRD patients were enrolled into the cross-sectional study arm and 30 patients who started dialysis were prospectively evaluated. Patients were enrolled into 3 groups-'predialysis' (group A), 'in-centre' haemodialysis (HD) (group B) and self-care HD (93 % at home-group C) from across five tertiary UK renal centres. The Autonomy Preference Index (API) has been employed to study patient preferences for information-seeking (IS) and decision-making (DM). Demographic, psychosocial and neuropsychometric assessments are considered for analyses. Results: 458 complete responses were available. API items have high internal consistency in the study population (Cronbach's alpha > 0.70). Overall and across individual study groups, the scores for information-seeking and decision-making are significantly different indicating that although patients had a strong preference to be well informed, they were more neutral in their preference to participate in DM (p 70: and low DM ( Conclusion: ESRD patients prefer to receive information, but this does not always imply active involvement in decision-making. By understanding modifiable and non-modifiable factors which affect patient preferences for involvement in healthcare decision-making, health professionals may acknowledge the need to accommodate individual patient preferences to the extent determined by the individual patient factors.Peer reviewe

Global analysis reveals the complexity of the human glomerular extracellular matrix.

The glomerulus contains unique cellular and extracellular matrix (ECM) components, which are required for intact barrier function. Studies of the cellular components have helped to build understanding of glomerular disease; however, the full composition and regulation of glomerular ECM remains poorly understood. We used mass spectrometry-based proteomics of enriched ECM extracts for a global analysis of human glomerular ECM in vivo and identified a tissue-specific proteome of 144 structural and regulatory ECM proteins. This catalog includes all previously identified glomerular components plus many new and abundant components. Relative protein quantification showed a dominance of collagen IV, collagen I, and laminin isoforms in the glomerular ECM together with abundant collagen VI and TINAGL1. Protein network analysis enabled the creation of a glomerular ECM interactome, which revealed a core of highly connected structural components. More than one half of the glomerular ECM proteome was validated using colocalization studies and data from the Human Protein Atlas. This study yields the greatest number of ECM proteins relative to previous investigations of whole glomerular extracts, highlighting the importance of sample enrichment. It also shows that the composition of glomerular ECM is far more complex than previously appreciated and suggests that many more ECM components may contribute to glomerular development and disease processes. The mass spectrometry proteomics data have been deposited to the ProteomeXchange Consortium with the dataset identifier PXD000456