Characterizing the risk of human leukocyte antigen-incompatible living donor kidney transplantation in older recipients.

Older compatible living donor kidney transplant (CLDKT) recipients have higher mortality and death-censored graft failure (DCGF) compared to younger recipients. These risks may be amplified in older incompatible living donor kidney transplant (ILDKT) recipients who undergo desensitization and intense immunosuppression. In a 25-center cohort of ILDKT recipients transplanted between September 24, 1997, and December 15, 2016, we compared mortality, DCGF, delayed graft function (DGF), acute rejection (AR), and length of stay (LOS) between 234 older (age ≥60 years) and 1172 younger (age 18-59 years) recipients. To investigate whether the impact of age was different for ILDKT recipients compared to 17 542 CLDKT recipients, we used an interaction term to determine whether the relationship between posttransplant outcomes and transplant type (ILDKT vs CLDKT) was modified by age. Overall, older recipients had higher mortality (hazard ratio: 1.632.072.65, P < .001), lower DCGF (hazard ratio: 0.360.530.77, P = .001), and AR (odds ratio: 0.390.540.74, P < .001), and similar DGF (odds ratio: 0.461.032.33, P = .9) and LOS (incidence rate ratio: 0.880.981.10, P = 0.8) compared to younger recipients. The impact of age on mortality (interaction P = .052), DCGF (interaction P = .7), AR interaction P = .2), DGF (interaction P = .9), and LOS (interaction P = .5) were similar in ILDKT and CLDKT recipients. Age alone should not preclude eligibility for ILDKT.

Securing the future of kidney transplantation by addressing the challenges of transplant nephrology.

Kidney transplant is a life-changing procedure, and transplant nephrologists, as part of a larger transplant team, play an important role in the field by managing the complex medical needs of transplant patients. The subspecialty of transplant nephrology, however, faces structural challenges related to its workforce, reporting structures, compensation, research and innovation, and health care information technology. The position of transplant nephrology at the academic and operational intersection of medicine and surgery may limit its access to critical resources, hinder academic promotion, and contribute to physician burnout. The authors provide an overview of the subspecialty transplant nephrology and propose solutions. Collaborative efforts that fortify the subspecialty of transplant nephrology will ultimately improve the lives of patients suffering from kidney disease.

Delayed graft function and acute rejection following HLA-incompatible living donor kidney transplantation.

Incompatible living donor kidney transplant recipients (ILDKTr) have pre-existing donor-specific antibody (DSA) that, despite desensitization, may persist or reappear with resulting consequences, including delayed graft function (DGF) and acute rejection (AR). To quantify the risk of DGF and AR in ILDKT and downstream effects, we compared 1406 ILDKTr to 17 542 compatible LDKT recipients (CLDKTr) using a 25-center cohort with novel SRTR linkage. We characterized DSA strength as positive Luminex, negative flow crossmatch (PLNF); positive flow, negative cytotoxic crossmatch (PFNC); or positive cytotoxic crossmatch (PCC). DGF occurred in 3.1% of CLDKT, 3.5% of PLNF, 5.7% of PFNC, and 7.6% of PCC recipients, which translated to higher DGF for PCC recipients (aOR = 1.03 1.682.72 ). However, the impact of DGF on mortality and DCGF risk was no higher for ILDKT than CLDKT (p interaction > .1). AR developed in 8.4% of CLDKT, 18.2% of PLNF, 21.3% of PFNC, and 21.7% of PCC recipients, which translated to higher AR (aOR PLNF = 1.45 2.093.02 ; PFNC = 1.67 2.403.46 ; PCC = 1.48 2.243.37 ). Although the impact of AR on mortality was no higher for ILDKT than CLDKT (p interaction = .1), its impact on DCGF risk was less consequential for ILDKT (aHR = 1.34 1.621.95 ) than CLDKT (aHR = 1.96 2.292.67 ) (p interaction = .004). Providers should consider these risks during preoperative counseling, and strategies to mitigate them should be considered.

Efficacy and Safety of Direct Acting Antivirals in Kidney Transplant Recipients with Chronic Hepatitis C Virus Infection.

The prevalence of Hepatitis C Virus (HCV) infection is significantly higher in patients with end-stage renal disease compared to the general population and poses important clinical challenges in patients who undergo kidney transplantation. Historically, interferon-based treatment options have been limited by low rates of efficacy and significant side effects, including risk of precipitating rejection. Limited data exist on the use of all-oral, interferon-free direct-acting antiviral (DAA) therapies in kidney transplant recipients. In this study, we performed a retrospective chart review with prospective clinical follow-up of post-kidney transplant patients treated with DAA therapies at three major hospitals in Boston, MA. A total of 24 kidney recipients with HCV infection received all-oral DAA therapy post-transplant. Patients were predominantly male (79%) with a median age of 60 years (range 34-70 years), median creatinine of 1.2 mg/dL (0.66-1.76), and 42% had advanced fibrosis or cirrhosis. The majority had HCV genotype 1a infection (58%). All patients received full-dose sofosbuvir; it was paired with simeprevir (9 patients without and 3 patients with ribavirin), ledipasvir (7 patients without and 1 patient with ribavirin) or ribavirin alone (4 patients). The overall sustained virologic response (SVR12) was 91% (21 out of 23 patients). One patient achieved SVR4 but demised prior to SVR12 check point due to treatment unrelated cause. Two treatment failures were successfully retreated with alternative DAA regimens and achieved SVR. Both initials failures occurred in patients with advanced fibrosis or cirrhosis, with genotype 1a infection, and prior HCV treatment failure. Adverse events were reported in 11 patients (46%) and were managed clinically without discontinuation of therapy. Calcineurin inhibitor trough levels did not significantly change during therapy. In this multi-center series of patients, all-oral DAA therapy appears to be safe and effective in post-kidney transplant patients with chronic HCV infection.

Association of Sirolimus Use With Risk for Skin Cancer in a Mixed-Organ Cohort of Solid-Organ Transplant Recipients With a History of Cancer.

IMPORTANCE: Solid-organ transplant recipients (OTRs) are at an increased risk for skin cancer. Prior studies have demonstrated a reduced incidence of skin cancer in renal OTRs treated with sirolimus. However, little information exists on the use of sirolimus for the prevention of skin cancer in nonrenal OTRs or those already diagnosed as having a posttransplant cancer. OBJECTIVE: To compare subsequent skin cancer formation in a mixed-organ cohort of OTRs who were or were not treated with sirolimus after developing a posttransplant index cancer of any type. DESIGN, SETTING, AND PARTICIPANTS: A 9-year retrospective cohort study at 2 academic tertiary care centers. Electronic medical records were reviewed for OTRs diagnosed as having a posttransplant cancer of any type to determine the type of organ transplanted, pretransplant and posttransplant cancer, and immunosuppressive medications. Patients underwent transplant from January 1, 2000, to December 31, 2008. Data were collected from July 30, 2011, to December 31, 2012, when follow-up was completed, and analyzed from April 28, 2013, to October 4, 2014. MAIN OUTCOMES AND MEASURES: Factors associated with subsequent skin cancer development were evaluated via multivariate Cox regression analysis. RESULTS: Of 329 OTRs with an index posttransplant cancer (100 women and 229 men; mean [SD] age, 56 [19] years), 177 (53.8%) underwent renal transplant; 58 (17.6%), heart transplant; 54 (16.4%), lung transplant; 34 (10.3%), liver transplant; and 6 (1.8%), mixed-organ transplant. Ninety-seven OTRs (29.5%) underwent conversion to sirolimus therapy after diagnosis. One hundred thirty OTRs (39.5%) developed second posttransplant cancers, of which 115 cases (88.5%) were skin cancers. An 11.6% reduction in skin cancer risk was observed in the sirolimus-treated vs non-sirolimus-treated groups overall (26 of 97 [26.8%] vs 89 of 232 [38.4%]; P = .045) and among nonrenal OTRs only (8 of 34 [23.5%] vs 44 of 112 [39.3%], respectively), although the latter difference was not significant (P = .09). Independent predictors of skin cancer formation after the index posttransplant cancer were history of pretransplant skin cancer (subhazard ratio, 2.1; 95% CI, 1.2-3.7), skin cancer as the index posttransplant cancer (subhazard ratio, 5.5; 95% CI, 2.5-6.4), and sirolimus treatment (subhazard ratio, 0.6; 95% CI, 0.4-0.9). These same risk factors were associated with skin cancer formation when the analysis was limited to nonrenal OTRs. No difference was found in allograft rejection or death between sirolimus-treated and non-sirolimus-treated groups. CONCLUSIONS AND RELEVANCE: In this mixed-organ cohort of OTRs, patients taking sirolimus after developing posttransplant cancer had a lower risk of developing subsequent skin cancer, with no increased risk for overall mortality. Thus, conversion to sirolimus therapy may be considered in OTRs who develop cancer if the risk for skin cancer is of concern. Larger studies are needed to quantify sirolimus-associated risk reduction for other cancer types.

Kidney disease and multiple myeloma.

Kidney injury is a common complication of multiple myeloma and other plasma cell dyscrasias, and it is associated with increased mortality. Multiple pathogenic mechanisms can contribute to kidney injury in the patient with myeloma, some of which are the result of nephrotoxic monoclonal Ig and some of which are independent of paraprotein deposition. The pathogenic mechanisms that underlie paraprotein-related kidney disease are increasingly well understood. A novel assay allowing the quantification of free light chains in the serum has aided the diagnosis of new onset disease and allowed for the earlier detection of relapse. Novel myeloma agents have shown considerable promise in reversing renal failure in some patients and improving outcomes. Stem cell transplantation remains a mainstay of management for younger patients with myeloma who are suitable candidates for intensive therapy, whereas the role of new drugs, plasma exchange, and kidney transplantation continues to evolve.

Eculizumab for dense deposit disease and C3 glomerulonephritis.

BACKGROUND AND OBJECTIVES: The principle defect in dense deposit disease and C3 glomerulonephritis is hyperactivity of the alternative complement pathway. Eculizumab, a monoclonal antibody that binds to C5 to prevent formation of the membrane attack complex, may prove beneficial. DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS: In this open-label, proof of concept efficacy and safety study, six subjects with dense deposit disease or C3 glomerulonephritis were treated with eculizumab every other week for 1 year. All had proteinuria >1 g/d and/or AKI at enrollment. Subjects underwent biopsy before enrollment and repeat biopsy at the 1-year mark. RESULTS: The subjects included three patients with dense deposit disease (including one patient with recurrent dense deposit disease in allograft) and three patients with C3 glomerulonephritis (including two patients with recurrent C3 glomerulonephritis in allograft). Genetic and complement function testing revealed a mutation in CFH and MCP in one subject each, C3 nephritic factor in three subjects, and elevated levels of serum membrane attack complex in three subjects. After 12 months, two subjects showed significantly reduced serum creatinine, one subject achieved marked reduction in proteinuria, and one subject had stable laboratory parameters but histopathologic improvements. Elevated serum membrane attack complex levels normalized on therapy and paralleled improvements in creatinine and proteinuria. CONCLUSIONS: Clinical and histopathologic data suggest a response to eculizumab in some but not all subjects with dense deposit disease and C3 glomerulonephritis. Elevation of serum membrane attack complex before treatment may predict response. Additional research is needed to define the subgroup of dense deposit disease/C3 glomerulonephritis patients in whom eculizumab therapy can be considered.

Hematopoietic stem cell transplantation in patients with chronic kidney disease.

Patients with significant medical comorbidities such as chronic kidney disease (CKD) traditionally have been excluded from hematopoietic stem cell transplantation (HSCT) because of unacceptably high transplant-related morbidity and mortality, an exclusion that can have enormous consequences for patients with CKD from myeloma in particular. Much of the excess HSCT-related morbidity among CKD patients relates to the toxic effects of conditioning regimens, which have a narrow therapeutic index even in patients with normal renal function. Common posttransplant complications are more challenging to prevent and manage in patients with CKD. In selected centers, autologous HSCT is performed with some frequency in patients with advanced CKD and even dialysis-dependent end-stage renal disease (ESRD), with acceptable outcomes, but cure from malignancy rarely is obtained. Allogeneic transplants using reduced-intensity conditioning regimens are being used with increasing frequency in patients with CKD, for both nonmalignant and malignant conditions, relying in the latter case on a graft-versus-malignancy effect to eliminate residual malignancy. In patients with ESRD from myeloma who have suitable donors, simultaneous allogeneic HSCT and kidney transplantation from a human leukocyte antigen-identical sibling provides the opportunity to treat both the malignant condition and the ESRD, avoiding the risks of posttransplant care in a dialysis-dependent patient and freeing the patient of the subsequent burdens of both ongoing dialysis and immunosuppression.

Kidney disease associated with plasma cell dyscrasias.

Plasma cell dyscrasias are frequently encountered malignancies often associated with kidney disease through the production of monoclonal immunoglobulin (Ig). Paraproteins can cause a remarkably diverse set of pathologic patterns in the kidney and recent progress has been made in explaining the molecular mechanisms of paraprotein-mediated kidney injury. Other recent advances in the field include the introduction of an assay for free light chains and the use of novel antiplasma cell agents that can reverse renal failure in some cases. The role of stem cell transplantation, plasma exchange, and kidney transplantation in the management of patients with paraprotein-related kidney disease continues to evolve.

Light chains: heavy burden in kidney transplantation.

Plasma cell dyscrasias are frequently encountered malignancies which are often associated with kidney disease through the production of monoclonal immunoglobulin (Ig). Recent advances in the field include the availability of an assay for free light chains, the introduction of new agents which more effectively target malignant plasma cells, and refinements in the application of stem-cell transplantation. Well-selected patients with plasma cell dyscrasias whose monoclonal Ig is well controlled may be candidates for kidney transplantation. Kidney transplant patients with allograft dysfunction from recurrent or de novo monoclonal Ig deposition can be successfully identified and treated with these new approaches.

Adverse renal and metabolic effects associated with oral sodium phosphate bowel preparation.

Colorectal cancer can be prevented by the removal of adenomatous polyps during screening colonoscopy, but adequate bowel preparation is required. Oral sodium phosphate (OSP), an effective bowel purgative, is available over the counter and requires a substantially lower volume than polyethylene glycol-based preparative agents. Accumulating reports implicate OSP in electrolyte disturbances as well as acute kidney injury (AKI) in a syndrome termed phosphate nephropathy (a form of nephrocalcinosis). Despite published case reports and case series, the actual incidence, risk factors, and natural history of phosphate nephropathy remain largely undefined. Several recent observational studies have provided new information on these important issues while supporting a link between OSP and acute phosphate nephropathy as well as the development of chronic kidney disease in elderly patients, many of whom had a normal serum creatinine at the time of OSP ingestion. This review summarizes current knowledge about the renal complications of OSP, risk factors for its development, and the pathophysiology of acute and chronic kidney damage in nephrocalcinosis.