Background: Kidney disease (lupus nephritis [LN]) constitutes a feature of systemic lupus erythematosus (SLE) in up to 50 - 70% of patients with the disease. Although most LN patients are suitable for renal transplantation when they develop end stage renal disease (ESRD), the risk of recurrence of LN post-transplantation can be as high as 30%. Since the outcomes of renal transplantation in ESRD-LN patients has not been adequately studied in South Africa, the present study aims to retrospectively explore the aforementioned objective in a single centre. Methodology: The study was designed as a retrospective descriptive study of patients with LN transplanted in the renal unit of Groote Schuur Hospital, Cape Town from 1st January 2004 to 31st December 2013. Results: There were 454 patients who were transplanted in the study period of which 15/454 (3.3%) had LN. The M:F ratio of LN patients was 1:14, mean age was 25±10 years, all were known with class- IV LN and 10/15 (66.7%) received graft from a cadaveric donor. Immunosuppression was initiated in 7/15 (46.7%) with combination of cyclosporine and azathioprine; in 2/15 (13.3%) with tacrolimus and azathioprine and in 6/15 (40.0%) with Tacrolimus and MMF. All patients received corticosteroids. Recurrence of LN was seen in one patient (6.7%) who developed class V LN. Graft rejection was diagnosed in 10/15 cases (66.7%) with types of rejection noted to be acute cellular rejection in 6/15 (40%), antibody mediated rejection 1/15 (6.7%) and chronic rejection in 3/15 (20%). ESRD occurred in 3 patients (20%) with causes from antibody mediated rejection (6.7%), chronic allograft nephropathy (6.7%) and renal artery thrombosis (6.7%). Mean time to ESRD was 16.0 months. Five deaths (33.3%) occurred from sepsis in 3/15 (20%), pulmonary embolism; 1/15 (6.7%) and progressive ESRD after non-acceptance to the chronic dialysis program; 1/15 (6.7%). Mean time to death was 44.1 months. Conclusion: This study shows that recurrence of LN in the graft kidney is uncommon in South Africa. However, effort to reduce high rates of rejection and improve graft and patient survival still needs to be studied.

Lu, Jianxin. / Thesis (Ph.D.)--Chinese University of Hong Kong, 2011. / Includes bibliographical references (leaves 218-241). / Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Abstract also in Chinese.

Thesis (Ph. D.)--University of Hong Kong, 2009. / Includes bibliographical references (leaves 238-276). Also available online.

Thesis (Ph. D.)--University of Hong Kong, 2009. / Includes bibliographical references (leaves 238-276). Also available in print.

This study compared the effect of various immunosuppressive therapies on the development of lupus nephritis using a murine model of SLE, the MRL lpr/lpr mouse. The agents investigated were cyclosporin A (CsA), FK506, rapamycin and mycophenolate mofetil (MM). Female MRL lpr/lpr mice at 12 weeks old were treated with CsA (40mg/kg/day p.o.), FK506 (2.5mg/kg/3 times/week or/day s.c.), rapamycin (1.5mg/kg.day s.c.), MM (50mg/kg/2 times daily p.o.) or vehicle controls. These groups were compared with untreated MRL lpr/lpr and also untreated MRL +/+ mice which do not develop this autoimmune disease. Disease progression was assessed using various markers for SLE and glomerular dysfunction. The results obtained showed CsA and rapamycin to both inhibit glomerular proliferation and reduce glomerular macrophage infiltrate. In addition, rapamycin also reduced chronic inflammatory cell infiltrate, lymphadenopathy and splenomegaly. Rapamycin treated animals did not develop skin lesions and alopecia which became apparent on mice from other groups. In contrast neither low or high dose FK506 treatments prevented the development of the autoimmune pathological features, including renal disease. Likewise, mycophenolate mofetil had no beneficial effects in disease prevention. In conclusion, it appears that both rapamycin and CsA but not FK506 or mycophenolate mofetil reduce macrophage infiltration, glomerular proliferation and, in the case of rapamycin chronic inflammatory cell infiltrate and lymphadenopathy, in the MRL lpr/lpr mouse.

Lupus nephritis is a severe organ manifestation of systemic lupus erythematosus (SLE), and is characterized by the production of anti-dsDNA antibodies. It is an important cause of renal failure. The mechanism through which anti-dsDNA antibodies bind to tissues and mediate kidney injury remains to be fully elucidated. Emerging evidence suggests that anti-dsDNA antibodies can bind to cells and extracellular antigens directly through cross-reactivity, independent of bridging chromatin material. Mesangial cells play an important role in normal kidney structure and functions, and its pathophysiology. Mesangial abnormalities in lupus nephritis precede more severe injuries such as lesions in the glomerular capillary loop. We previously demonstrated that the binding of human anti-dsDNA antibodies to mesangial cells (HMC) correlated with disease activity and induced inflammatory as well as fibrotic pathways. The aim of this project is to identify the cross-reactive antigen(s) on the mesangial cell surface that mediates anti-dsDNA antibody binding and the alterations in cell functions that result from this interaction. HMC plasma membrane proteins were purified. Using proteomic and biochemical approaches, we identified annexin II as the predominant cross-reactive antigen on the HMC surface that mediated human polyclonal anti-dsDNA antibody binding. Following this interaction, anti-dsDNA antibodies were internalized in a time- and temperature-dependent manner, and translocated to both the cytoplasm and nucleus within 30 min. This resulted in induction of annexin II synthesis, IL-6 secretion and cell proliferation, which was mediated through the activation of p38 MAPK, JNK and AKT. The binding activity to annexin II in the serum immunoglobulin fraction correlated with the titre of anti-dsDNA antibody. Binding activity of anti-dsDNA antibodies to annexin II correlated with clinical disease activity and circulating anti-dsDNA antibody levels. These correlations were more prominent in male patients with lupus nephritis. Glomerular annexin II expression was increased in patients with active lupus nephritis and co-localized with IgG and C3 deposition. Gene silencing of annexin II in HMC reduced anti-dsDNA antibody binding, which was accompanied by reduced IL-6 secretion and cell proliferation. Using female NZB/W F1 mice, an established murine model of lupus nephritis, we demonstrated that intra-glomerular annexin II expression increased with disease progression and was accompanied by an increase in the expression of p11, its cellular protein ligand. Our data suggest that annexin II may exist in the kidney as a heterotetramer and is involved in disease pathogenesis. At the ultrastructural level, annexin II was detected in the mesangial matrix, amongst electron dense deposits in the glomerular basement membrane, on the foot processes in podocytes and within the Bowman’s capsule. In conclusion, our data demonstrated that annexin II is the major cell surface antigen on HMC that mediates the cross-reactive binding of human anti-DNA antibodies. Through this interaction, cellular processes are triggered that contribute to the pathogenesis of lupus nephritis. / published_or_final_version / Medicine / Doctoral / Doctor of Philosophy

Lupus nephritis (LN)is an important clinical manifestation of systemic lupus erythematosus (SLE)and contributes significantly to patient morbidity and mortality. In the era of effective immunosuppressive treatments, the clinical outcomes of LN patients have substantially improved, and the10-year patient and renal survival rates were98.2% and 98.0% respectively. With prolonged patient survival, infection (50.0%), cardiovascular disease (20.8%) and malignancy(12.5%)but not uncontrolled disease, have emerged as the leading causes of death in LN patients. The strongest predictor of mortalityin LN patients, however, was endstage renal disease (ESRD)as indicated by a high standardized mortality ratio of 26.1which doubled that of cardiovascular disease and history of malignancy. Despite the improved patient outcomes, conventional treatment such as cyclosphosphamide (CTX) was associated with significant toxicities and suboptimal long-term renal prognosis and hence alternative immunosuppressive agents with anti-fibrotic properties such as mycophenolate mofetil (MMF) and proliferation signal inhibitors (PSI)warrants further investigation. In Chinese patients with proliferative LN, corticosteroids and MMF as initial therapy conferred favorable long-term outcomes, with 10-year patient and renal survival of91% and 86% respectively. This regimen, when used as continuous induction-maintenance treatment, is Efficacious and well-tolerated, and the continuation of MMF treatment for at least 24 months was associated with significantly lower risk of relapse when compared to treatment for shorter duration. As the severity of tubulointerstitial fibrosis can be attenuated by growth factors with anti-fibrotic properties such as bone morphogenetic protein 7 (BMP7), hepatocyte growth factor (HGF) and vascular endothelial growth factor (VEGF), studies were conducted in NZB/W F1 mice to investigate the impact of treatment on intra-renal expression of growth factors pertinent to fibrosis. Methylprednisolone (MP) combined with either MMF or CTX have resulted in increased BMP7 and reduced HGF and VEGF in the renal parenchyma, reduced fibrosis, and improved clinical parameters, compared with MP alone. The data also suggested that the increase in BMP7, a potentially anti-fibrotic cytokine, was observed earlier in the mice treated with MMF compared with those treated with CTX. Our preliminary clinical experience also suggested that PSI combined with corticosteroids may serve as an efficacious and well-tolerated immunosuppressive regimen in human LN, especially in patients with MMF intolerance or history of malignancy. These observations have important implications on the choice of therapy for the treatment of proliferative LN. As for membranous LN, our pilot results suggested that corticosteroids combined with either MMF or tacrolimus can be effective treatment options for patients with significant proteinuria, while each regimen exhibits distinct efficacy and tolerability profiles. In conclusion, the results from the studies included in this thesis show the magnitude of benefit conferred by novel immunosuppressive treatment regimens for LN on renal and patient survival, and on the associated intra-renal mechanisms pertaining to fibrosis. / published_or_final_version / Medicine / Master / Doctor of Medicine

published_or_final_version / Medicine / Doctoral / Doctor of Philosophy

Lupus nephritis is a severe organ manifestation of systemic lupus erythematosus, characterized by the production of autoantibodies and immune-mediated injury to the kidney. Hyaluronan (HA) is a major component of the extracellular matrix, which is involved in immune-mediated renal injury. We have previously demonstrated that HA expression is increased in the glomerulus of patients with severe lupus nephritis, attributed in part to anti-dsDNA antibody-mediated induction of low molecular weight (LMW) HA and high molecular weight (HMW) HA synthesis in mesangial cells. The causal role of HA and its fragments in the pathogenesis of lupus nephritis has not been explored. In this project, two separate in vivo studies were undertaken to delineate the role of HA in disease progression in NZBWF1/J mice. In the first study, we determined the effect of 4-methylumbelliferone (MU), a specific inhibitor of HA synthesis, on renal function and histology in NZBWF1/J mice with active disease, with particular emphasis on inflammatory and fibrotic processes. In the second study, we investigated whether exogenous HA could exacerbate disease manifestations in pre-disease NZBWF1/J mice. The mechanisms underlying the effects of MU and exogenous LMW HA and HMW HA were investigated in mesangial cells isolated from NZBWF1/J mice. Female NZBWF1/J mice with established nephritis were randomized into 3 groups and treated with (1) PBS, (2) Arabic gum (Gum) or (3) MU (3g/kg/day) for 2, 4, 8 and 12 weeks. Treatment of mice with MU for 12 weeks reduced serum HA levels and abrogated intra-renal expression of HA compared to PBS and Gum treated mice. Inhibition of HA synthesis in the kidney resulted in decreased IgG and C3 deposition, reduced B cell, T cell and macrophage infiltration, matrix accumulation and TNF-, IL-6 and MCP-1 expression, which was associated with improved renal functions. To confirm that HA influenced pathogenesis of lupus nephritis, pre-disease NZBWF1/J mice were randomized to receive (1) PBS, (2) LMW HA or (3) HMW HA for periods up to 24 weeks. Administration of LMW HA and HMW HA into NZBWF1/J mice by tail-vein injection induced intra-glomerular deposition of IgG and C3, B cell infiltration, glomerular hypercellularity and tubular atrophy, which was accompanied by induction of MAPK signaling pathways, enhanced MCP-1 expression, and increased matrix deposition in the glomerular and tubular basement membranes. In vitro studies showed that exogenous IL-6, IL-1, TGF-1 and TNF- induced HA synthesis in murine mesangial cells (MMC), with over 80% secreted into the conditioned medium. This was accompanied by an increase in pro-inflammatory cytokine secretion and synthesis of fibronectin and laminin. Inhibition of HA synthesis with MU significantly decreased cytokine secretion and fibronectin synthesis. The ability of HA to induce inflammatory and fibrotic processes in mesangial cells was confirmed in separate studies in which MMC were incubated with exogenous LMW HA and HMW HA. In summary, these original findings provide evidence of a direct effect of HA on intra-renal inflammation and fibrosis in lupus nephritis. Approaches to inhibit HA synthesis may offer novel therapeutic strategies to delay disease progression. / published_or_final_version / Medicine / Doctoral / Doctor of Philosophy

published_or_final_version / Medicine / Doctoral / Doctor of Philosophy