Humoral autoimmunity after solid organ transplantation: Germinal ideas may not be natural

Non-HLA antibody responses following solid organ transplantation have become increasingly emphasised, with several large clinical series suggesting that such responses contribute to late graft failure. Many of the responses described recognise both recipient and donor moieties of the target antigen and thus represent auto-, rather than allo-immunity. Within this rapidly evolving field, many questions remain unanswered: what triggers the response; how innate and adaptive humoral autoimmunity integrate; and most pressingly, how autoimmunity contributes to graft damage and its relationship to other effector mechanisms of graft rejection. This review summarises recent clinical and experimental studies of humoral autoimmunity in transplant rejection, and considers some of the answers to these questions

Kidney Transplantation

Renal transplantation remains the optimal treatment for end stage renal disease. Compared with dialysis, it is associated with increased patient survival and better quality of life, and is cost effective. Kidney transplantation requires a multi-disciplinary approach in the pre-operative assessment and work-up of donors and recipients, and subsequent post-operative care. The classical surgical procedure for renal transplantation has changed little from the original pelvic operation originally described in 1951, but the surgical complexity however has been magnified by the increasing age of recipients, frequently with other comorbidities, and impetus to utilise kidneys from extended criteria donors, either as single or dual transplants. There have also been tremendous advances in the technical aspects of live-donation. This chapter details the surgical aspects of kidney donation and transplantation, including preparation of the graft, vessel reconstruction, urinary drainage and identification and management of post-donation and transplantation complications. It is hoped the reader is provided with a comprehensive account of the technical aspects of renal transplantation, with a description of variation in procedure based on anatomical aberrations. An overview of current practise with a look to the future is provided

Germinal center humoral autoimmunity independently mediates progression of allograft vasculopathy

The development of humoral autoimmunity following organ transplantation is increasingly recognised, but of uncertain significance. We examine whether autoimmunity contributes independently to allograft rejection. In a MHC class II-mismatched murine model of chronic humoral rejection, we report that effector antinuclear autoantibody responses were initiated upon graft-versus-host allorecognition of recipient B cells by donor CD4 T-cells transferred within heart allografts. Consequently, grafts were rejected more rapidly, and with markedly augmented autoantibody responses, upon transplantation of hearts from donors previously primed against recipient. Nevertheless, rejection was dependent upon recipient T follicular helper (TFH) cell differentiation and provision of cognate (peptide-specific) help for maintenance as long-lived GC reactions, which diversified to encompass responses against vimentin autoantigen. Heart grafts transplanted into stable donor/recipient mixed haematopoietic chimeras, or from parental strain donors into F1 recipients (neither of which can trigger host adaptive alloimmune responses), nevertheless provoked GC autoimmunity and were rejected chronically, with rejection similarly dependent upon host TFH cell differentiation. Thus, autoantibody responses contribute independently of host adaptive alloimmunity to graft rejection, but require host TFH cell differentiation to maintain long-lived GC responses. The demonstration that one population of helper CD4 T-cells initiates humoral autoimmunity, but that a second population of TFH cells is required for its maintenance as a GC reaction, has important implications for how autoimmune-related phenomena manifest

Renal Transplant Outcomes in Amyloidosis

Background: Outcomes after renal transplantation have traditionally been poor in systemic amyloid A (AA) amyloidosis and systemic light chain (AL) amyloidosis, with high mortality and frequent recurrent disease. We sought to compare outcomes with matched transplant recipients with autosomal dominant polycystic kidney disease (ADPKD) and diabetic nephropathy (DN), and identify factors predictive of outcomes. Methods: We performed a retrospective cohort study of 51 systemic AL and 48 systemic AA amyloidosis patients undergoing renal transplantation. Matched groups were generated by propensity score matching. Patient and death-censored allograft survival were compared via Kaplan–Meier survival analyses, and assessment of clinicopathological features predicting outcomes via Cox proportional hazard analyses. Results: One-, 5- and 10-year death-censored unadjusted graft survival was, respectively, 94, 91 and 78% for AA amyloidosis, and 98, 93 and 93% for AL amyloidosis; median patient survival was 13.1 and 7.9 years, respectively. Patient survival in AL and AA amyloidosis was comparable to DN, but poorer than ADPKD [hazard ratio (HR) = 3.12 and 3.09, respectively; P 12 mm (HR = 26.58; P = 0.03), while survival was predicted by haematologic response (very good partial or complete response; HR = 0.07; P = 0.018). In AA amyloidosis, recurrent amyloid was associated with elevated serum amyloid A concentration but not with outcomes. Conclusions: Renal transplantation outcomes for selected patients with AA and AL amyloidosis are comparable to those with DN. In AL amyloidosis, IVSd thickness and achievement of deep haematologic response pre-transplant profoundly impact patient survival

Control of human cytomegalovirus replication by liver resident natural killer cells

Natural killer cells are considered to be important for control of human cytomegalovirus– a major pathogen in immune suppressed transplant patients. Viral infection promotes the development of an adaptive phenotype in circulating natural killer cells that changes their anti-viral function. In contrast, less is understood how natural killer cells that reside in tissue respond to viral infection. Here we show natural killer cells resident in the liver have an altered phenotype in cytomegalovirus infected individuals and display increased anti-viral activity against multiple viruses in vitro and identify and characterise a subset of natural killer cells responsible for control. Crucially, livers containing natural killer cells with better capacity to control cytomegalovirus replication in vitro are less likely to experience viraemia post-transplant. Taken together, these data suggest that virally induced expansion of tissue resident natural killer cells in the donor organ can reduce the chance of viraemia post-transplant