Mycophenolate Mofetil Is Associated with Altered Expression of Chronic Renal Transplant Histology

Mycophenolate mofetil (MMF) reduces acute rejection in controlled trials of kidney transplantation and is associated with better registry graft survival. Recent experimental studies have demonstrated additional antifibrotic properties of MMF, however, human histological data are lacking. We evaluated sequential prospective protocol kidney biopsies from two historical cohorts treated with cyclosporine (CSA)-based triple therapy including prednisolone and either MMF (n = 25) or azathioprine (AZA, n = 25). Biopsies (n = 360) were taken from euglycemic kidney-pancreas transplant recipients. Histology was independently assessed by the Banff schema and electron microscopic morphometry. MMF reduced acute rejection and OKT3 use (p < 0.05) compared with AZA. MMF therapy was associated with limited chronic interstitial fibrosis, striped fibrosis and periglomerular fibrosis (p < 0.05-0.001), mesangial matrix accumulation (p < 0.01), chronic glomerulopathy scores (p < 0.05) and glomerulosclerosis (p < 0.05). MMF was associated with delayed expression of CSA nephrotoxicity, reduced arteriolar hyalinosis, striped fibrosis and tubular microcalcification (p < 0.05-0.001). The beneficial effects of MMF remained in recipients without acute rejection. Retrospective analysis shows that MMF therapy was associated with substantially reduced fibrosis in the glomerular, microvascular and interstitial compartments, and a delayed expression of CSA nephrotoxicity. These outcomes may be due to a limitation of immune-mediated injury and suggest a direct effect of reduced fibrogenesis.     

Health-related quality of life,uncertainty and coping strategies in solid organ transplant recipients during shielding for the COVID-19 pandemic

Strict isolation of vulnerable individuals has been a strategy implemented by authorities to protect people from COVID-19. Our objective was to investigate health-related quality of life (HRQoL), uncertainty and coping behaviours in solid organ transplant (SOT) recipients during the COVID-19 pandemic. A cross-sectional survey of adult SOT recipients undergoing follow-up at our institution was performed. Perceived health status, uncertainty and coping strategies were assessed using the EQ-5D-5L, Short-form Mishel Uncertainty in Illness Scale (SF-MUIS) and Brief Cope, respectively. Interactions with COVID-19 risk perception, access to health care, demographic and clinical variables were assessed. The survey was completed by 826 of 3839 (21.5%) invited participants. Overall, low levels of uncertainty in illness were reported, and acceptance was the major coping strategy (92%). Coping by acceptance, feeling protected, self-perceived susceptibility to COVID-19 were associated with lower levels of uncertainty. Health status index scores were significantly lower for those with mental health illness, compromised access to health care, a perceived high risk of severe COVID-19 infection and higher levels of uncertainty. A history of mental health illness, risk perceptions, restricted healthcare access, uncertainty and coping strategies was associated with poorer HRQoL in SOT recipients during strict isolation. These findings may allow identification of strategies to improve HRQoL in SOT recipients during the pandemic.     

HLA incompatible combined liver–kidney transplantation: Dynamics of antibody modulation revealed by a novel approach to HLA antibody characterisation

This case report confirms the utility of simultaneous liver transplantation in allowing successful kidney transplantation in the face of preformed, high levels of DSA, which would under normal circumstances be associated with hyperacute rejection and kidney graft failure. Antibody characterisation in terms of epitope specificity is more accurate and informative than antibodies described as “antigen-specific” and we suggest a method for identifying and tracking these antibodies; i.e. follow the epitope reaction not the antigen reactions. We consider that this will give a better insight into the behaviour and pathogenicity of HLA-specific sera. In the case presented here this approach has revealed some novel features of the post transplant antibody response in a sensitised recipient. These illustrate three phenomena which challenge current dogmas; an early resynthesis of DSA does not necessarily cause AMR, high levels of DSA can spontaneously modulate, and measurement of antibodies in terms of antigen specificity can give misleading results.     

Evolution and pathophysiology of renal-transplant glomerulosclerosis

BACKGROUND: Glomerulosclerosis (GS) is characteristic of chronic allograft nephropathy and graft failure; however, its natural history and pathophysiology are poorly defined. METHODS: We evaluated 959 prospective protocol kidney-transplant biopsies from 120 recipients taken regularly up to 10 years after transplantation for evidence of glomerular injury. RESULTS: GS exhibited a nonlinear triphasic time course. An intense but limited peak of damage in the first month was associated with cold ischemia (P<0.05) and calcineurin nephrotoxicity (P<0.001). GS then occurred as a late consequence of earlier immune-mediated tubular damage (9.3+/-6.6%, P<0.01 vs. no damage), suggesting delayed sclerosis of atubular glomeruli. Subsequent progressive GS occurred beyond 4 years, associated with increasing arteriolar hyalinosis from calcineurin inhibitor nephrotoxicity (r=0.33, P<0.001). From 5 years after transplantation, 32.4+/-22.2% of glomeruli were globally sclerosed, and segmental GS and periglomerular fibrosis increased by 4.0+/-9.3% and 8.4+/-14.2% per year, respectively. Severe arteriolar hyalinosis resulted in greater GS on sequential biopsies (P<0.001), consistent with vascular narrowing causing glomerular ischemia. Chronic glomerulopathy scores were relatively mild. Glomerular loss was patchy, with a high coefficient of variation of 633%. Isotopic glomerular filtration rate correlated best with Banff chronic interstitial fibrosis (r=-0.30, P<0.001) and chronic glomerulopathy scores (r=-0.23, P<0.001) rather than the percentage of sclerosed glomeruli (r=-0.12, P<0.05). Renal function gradually fell with time, and the hyperfiltration index increased from 1.14+/-0.42 at 3 months to 1.83+/-1.40 by 7 to 10 years after transplantation. CONCLUSIONS: In summary, GS is a time-dependent response to glomerular injury from early ischemia, immune-mediated tubular loss, and late calcineurin nephrotoxicity.