Posttransplant recurrence of calcium oxalate crystals in patients with primary hyperoxaluria: Incidence, risk factors, and effect on renal allograft function.

Primary hyperoxaluria (PH) is a metabolic defect that results in oxalate overproduction by the liver and leads to kidney failure due to oxalate nephropathy. As oxalate tissue stores are mobilized after transplantation, the transplanted kidney is at risk of recurrent disease. We evaluated surveillance kidney transplant biopsies for recurrent calcium oxalate (CaOx) deposits in 37 kidney transplants (29 simultaneous kidney and liver [K/L] transplants and eight kidney alone [K]) in 36 PH patients and 62 comparison transplants. Median follow-up posttransplant was 9.2 years (IQR: [5.3, 15.1]). The recurrence of CaOx crystals in surveillance biopsies in PH at any time posttransplant was 46% overall (41% in K/L, 62% in K). Higher CaOx crystal index (which accounted for biopsy sample size) was associated with higher plasma and urine oxalate following transplant (p < .01 and p < .02, respectively). There was a trend toward higher graft failure among PH patients with CaOx crystals on surveillance biopsies compared with those without (HR 4.43 [0.88, 22.35], p = .07). CaOx crystal deposition is frequent in kidney transplants in PH patients. The avoidance of high plasma oxalate and reduction of CaOx crystallization may decrease the risk of recurrent oxalate nephropathy following kidney transplantation in patients with PH. This study was approved by the IRB at Mayo Clinic.

Kidney Transplantation in Patients With Monoclonal Gammopathy of Renal Significance (MGRS)-Associated Lesions: A Case Series.

RATIONALE & OBJECTIVE: Data on kidney transplantation outcomes among patients with monoclonal gammopathy of renal significance (MGRS) are lacking. STUDY DESIGN: Case series of patients with MGRS, some of whom received clone-directed therapies before kidney transplantation. SETTING & PARTICIPANTS: 28 patients who underwent kidney transplantation from 1987 through 2016 after diagnosis with MGRS-associated lesions including light-chain deposition disease (LCDD), C3 glomerulopathy with monoclonal gammopathy (C3G-MG), and light-chain proximal tubulopathy (LCPT). FINDINGS: Of the 19 patients with LCDD, 10 were treated before kidney transplantation and 9 were treatment-naive. Among the treated patients with LCDD, 3 (30%) experienced histologic recurrence, 2 (20%) grafts failed, and 2 (20%) died during a median follow-up of 70 (range, 3-162) months after transplant. In the treatment-naive LCDD group, 8 (89%) had histologic recurrence, 6 (67%) grafts failed, and 4 (44%) patients died during a median follow-up of 60 (range, 35-117) months. Of the 5 patients who had a complete response before transplant, none died, and only 1 experienced graft failure, 162 months after transplant. Of 5 patients with C3G-MG, 3 were treatment-naive before transplant. Both patients who were treated before transplant had histologic recurrence, and 1 experienced graft failure and died. Among the 3 patients with treatment-naive C3G-MG, histologic recurrence occurred in all, and graft loss and death were observed in 2 and 1, respectively. In the LCPT group (n=4), histologic recurrence was observed in all 3 patients who did not receive clone-directed therapies before transplant, and 2 of these patients died, 1 with a functioning kidney. The 1 patient with LCPT who received therapy before transplant did not have histologic recurrence or graft loss and survived. LIMITATIONS: Small sample size, nonstandardized clinical management, retrospective design. CONCLUSIONS: Recurrence is very common in all MGRS-associated lesions after kidney transplant. Achieving a complete hematologic response may reduce the risks of recurrence, graft loss, and death. More studies are needed to determine the effects of hematologic response on outcomes for each MGRS-associated lesion.

Development and Validation of a Kidney-Transplant Specific Measure of Treatment Burden.

BACKGROUND: Treatment burden refers to the work involved in managing one's health and its impact on well-being and has been associated with nonadherence in patients with chronic illnesses. No kidney transplant (KT)-specific measure of treatment burden exists. The aim of this study was to develop a KT-specific supplement to the Patient Experience with Treatment and Self-Management (PETS), a general measure of treatment burden. METHODS: After drafting and pretesting KT-specific survey items, we conducted a cross-sectional survey study involving KT recipients from Mayo Clinic in Minnesota, Arizona, and Florida. Exploratory factor analysis (EFA) was used to identify domains for scaling the KT-specific supplement. Construct and known-groups validity were determined. RESULTS: Survey respondents (n = 167) had a mean age of 61 years (range 22-86) and received a KT on average 4.0 years ago. Three KT-specific scales were identified (transplant function, self-management, adverse effects). Higher scores on the KT-specific scales were correlated with higher PETS treatment burden, worse physical and mental health, and lower self-efficacy (p < 0.0001). Patients taking more medications reported higher transplant self-management burden. CONCLUSIONS: We developed a KT-specific supplement to the PETS general measure of treatment burden. Scores may help providers identify recipients at risk for nonadherence.

A study from The Mayo Clinic evaluated long-term outcomes of kidney transplantation in patients with immunoglobulin light chain amyloidosis.

Longer survival using modern therapies has increased the number of patients with immunoglobulin light-chain amyloidosis receiving kidney transplantation. We evaluated 60 patients with immunoglobulin light chain amyloidosis who underwent kidney transplantation based on their hematologic response for outcomes of death, graft failure, and complications. Patient hematologic responses (light-chain in blood or urine) prior to kidney transplantation were three patients had no response, five had a partial response, six had a very good partial response, 37 had a complete response, and nine were treatment-naive patients (never treated for this disorder). After transplantation, seven of nine treatment-naive patients achieved a complete response. The median follow-up for the entire transplant cohort was 61 months. The estimated median overall survival from the time of kidney transplantation was 123 months for the entire group. Median overall survival was not reached for the very good partial response plus complete response groups, it was 47 months for no response plus partial response groups, and 117 months for the treatment-naive group (all significantly different). Median overall survival of very good partial response was 81 months, while the median was not reached in the complete response group (no significant difference). The time to amyloid recurrence was significantly longer in complete response compared to very good partial response (median 181 vs 81 months). Death-censored graft survival at one- and five-years was 98.3%, and 95.8%, respectively for all groups. Of the 60 patients, three had allograft failure, 19 died with a functioning graft, and 13 had an amyloid recurrence. Thus, outcomes after kidney transplant in patients with immunoglobulin light-chain amyloidosis seem acceptable if a very good partial response or complete response is achieved either before or after transplantation.

Chronic graft-versus-host disease in pancreas after kidney transplant recipients - An unrecognized entity.

Graft-versus-host disease (GVHD), a common complication after peripheral blood stem cell or bone marrow transplantation, rarely occurs in kidney and pancreas transplant recipients. The true incidence may be confounded by the rarity of the disorder, with a resultant lack of appreciation of the diagnosis as a potential cause of common clinical manifestations such as cytopenias and immune dysfunction. Reports of GVHD in kidney and pancreas transplant recipients almost uniformly describe patients in the early posttransplant period (days to months) with the typical manifestations of acute GVHD involving the skin, liver, and intestines. In contrast, reports of solid organ transplant recipients with clinical features more consistent with chronic GVHD (cGVHD) are lacking, raising concern of underrecognition of this severe complication. Occurrence later after transplant may be even more likely to result in lack of recognition. We report 2 cases of possible cGVHD occurring in recipients of pancreas after kidney transplantation, which were diagnosed at 5.5 and 42 months after pancreas transplant. Both patients presented with severe pancytopenia, multiple opportunistic infections, and features suggestive of cGVHD. Transplant professionals should be aware of the possibility of acute and cGVHD in pancreas after kidney transplant recipients and be able to recognize the clinical manifestations.

Recovery From Dialysis in Patients With Primary Hyperoxaluria Type 1 Treated With Pyridoxine: A Report of 3 Cases.

Primary hyperoxaluria type 1 (PH1) is a genetic disorder characterized by overproduction of oxalate and eventual kidney failure. Kidney failure is usually irreversible in PH1. However, in patients with PH1 homozygous for the G170R mutation (in which the glycine at amino acid 170 is replaced by an arginine), pyridoxine is an enzyme cofactor and decreases urinary oxalate excretion by reducing hepatic oxalate production. We report recovery from dialysis in 3 patients with PH1 homozygous for the G170R mutation in response to pharmacologic-dose pyridoxine treatment. Median age at initiation or resumption of pyridoxine treatment was 37 (range, 20-53) years, and median daily pyridoxine dose was 8.8 (range, 6.8-14.0) mg per kilogram of body weight. Duration of hemodialysis before recovery of kidney function was 10 (range, 5-19) months. Plasma oxalate concentration improved after recovery of kidney function. At a median of 3 (range, 2-46) months following discontinuation of hemodialysis, estimated glomerular filtration rate was 34 (range, 23-52) mL/min/1.73m2, plasma oxalate concentration was 8.8 (range, 4.6-11.3) µmol/L, and urinary oxalate excretion was 0.93 (range, 0.47-1.03) mmol/d. Kidney function was maintained during a median of 3.2 (range, 1.3-3.8) years of follow-up. These observations suggest that kidney failure may be reversible in a subset of patients with PH1 homozygous for the G170R mutation treated with pharmacologic-dose pyridoxine.

Protocolized exercise improves frailty parameters and lower extremity impairment: A promising prehabilitation strategy for kidney transplant candidates.

BACKGROUND: Frailty and decreased functional status are risk factors for adverse kidney transplant (KT) outcomes. Our objective was to examine the efficacy of an exercise intervention on frailty and decreased functional status in a cohort of patients with advanced chronic kidney disease (CKD). METHODS: We conducted a prospective study involving 21 adults with ≥stage 4 CKD who were (a) frail or pre-frail by Fried phenotype and/or (b) had lower extremity impairment [short physical performance battery score ≤10]. The intervention consisted of two supervised outpatient exercise sessions per week for 8 weeks. RESULTS: Among our cohort, median participant age was 62 years (interquartile range, 53-67) and 85.7% had been evaluated for KT. Following the study, participants reported satisfaction with the intervention and multiple frailty parameters improved significantly, including fatigue, physical activity, walking time, and grip strength. Lower extremity impairment also improved (90.5%-61.9%, P = .03). No study-related adverse events occurred. CONCLUSIONS: Preliminary data from this study suggest that a supervised, outpatient exercise intervention is safe, acceptable, feasible, and associated with improved frailty parameters, and lower extremity function, in patients with advanced CKD. Further studies are needed to confirm these findings and determine whether this prehabilitation strategy improves KT outcomes.

Relationship between pre-transplant physical function and outcomes after kidney transplant.

BACKGROUND: Performance-based measures of physical function predict morbidity following non-transplant surgery. Study objectives were to determine whether physical function predicts outcomes after kidney transplant and assess how physical function changes post-transplant. METHODS: We conducted a prospective study involving living donor kidney transplants recipients at our center from May 2012 to February 2014. Physical function was measured using the Short Physical Performance Battery (SPPB [balance, chair stands, gait speed]) and grip strength testing. Initial length of stay (LOS), 30- day rehospitalizations, allograft function, and quality of life (QOL) were assessed. RESULTS: The majority of the 140 patients in our cohort had excellent pre-transplant physical function. In general, balance scores were more predictive of post-transplant outcomes than the SPPB. Decreased pre-transplant balance was independently associated with longer LOS and increased rehospitalizations but not with post-transplant QOL; 35% of patients experienced a clinically meaningful (≥ 1.0 m/s) improvement in gait speed 4 months post-transplant. CONCLUSIONS: Decreased physical function may be associated with longer LOS and rehospitalizations following kidney transplant. Further studies are needed to confirm this association. The lack of relationship between pre-transplant gait speed and outcomes in our cohort may represent a ceiling effect. More comprehensive measures, including balance testing, may be required for risk stratification.

Outcomes of patients with renal monoclonal immunoglobulin deposition disease.

Recent reports suggest that deep hematologic responses to chemotherapy are associated with improved renal outcomes in monoclonal immunoglobulin deposition disease (MIDD). Here we describe the long term outcomes and identify prognostic factors after first line treatment of the largest reported series of patients with MIDD. Between March 1992 and December 2014, 88 patients with MIDD were seen at Mayo Clinic, MN. Renal responses were defined using criteria used for light chain amyloidosis (AL) or those used by the IMWG. Sixty-one (69%) patients had a GFR < 30 mL/min/1.73 m2 and 16 (18%) were on renal replacement therapy at diagnosis. The interval between albuminuria or elevation in creatinine and MIDD diagnosis was 12 months suggesting a delay in diagnosis. Thirty-seven patients (42%) had at least a hematologic CR/VGPR. Fifty-three (60%) received an autologous stem cell transplant (ASCT) or proteasome inhibitor (PI)-based treatments. Patients receiving ASCT or PI-based therapies were more likely to achieve at least a hematologic CR/VGPR compared to those receiving other therapies: 66% vs 2%, p < 0.0001. Patients that achieved a hematologic CR were more likely to achieve a renal response (53% vs 24%, p = 0.001). Five year overall and renal survival for the entire cohort was 67% and 57%, respectively. In multivariate analyses, a baseline GFR < 20 mL/min/1.73 m2 and a renal response (using AL or IMWG criteria) were independently predictive of progression to dialysis. This study confirms that deep hematologic responses, best achieved with ASCT or PI-based therapies, are a prerequisite to achieving renal responses. Am. J. Hematol. 91:1123-1128, 2016. © 2016 Wiley Periodicals, Inc.

Progressive polyradiculoneuropathy due to intraneural oxalate deposition in type 1 primary hyperoxaluria.

INTRODUCTION: A 24-year-old man with primary hyperoxaluria type 1 (PH1) presented with a rapidly progressive axonal and demyelinating sensorimotor polyradiculoneuropathy shortly after the onset of end-stage renal disease. His plasma oxalate level was markedly elevated at 107 µmol/L (normal<1.8 µmol/L). METHODS: A sural nerve biopsy was performed. Teased fiber and paraffin and epoxy sections were done and morphometric procedures were performed on this sample and on an archived sample from a 22-year-old man as an age- and gender-matched control. Embedded teased fiber electron microscopy was also performed. RESULTS: The biopsy revealed secondary demyelination and axonal degeneration. Under polarized light, multiple bright hexagonal, rectangular, and starburst inclusions, typical of calcium oxalate monohydrate crystals, were seen. CONCLUSIONS: The proposed mechanisms of nerve damage include disruption of axonal transport due to crystal deposition, toxic effect of oxalate, or nerve ischemia related to vessel occlusion from oxalate crystal deposition.

Adherence to a pedometer-based physical activity intervention following kidney transplant and impact on metabolic parameters.

The majority of kidney transplant recipients die from cardiovascular events. Physical activity may be a modifiable risk factor for cardiovascular disease following transplant. The goal of our study was to examine adherence to a physical activity intervention following kidney transplant and its impact on metabolic parameters. All patients who received a kidney transplant at our center between 12/2010 and 12/2011 received usual care (n = 162), while patients transplanted between 12/2011 and 1/2013 received a 90-day pedometer-based physical activity intervention (n = 145). Metabolic parameters were assessed at four and 12 months post-transplant. Baseline demographics and clinical management were similar between cohorts. Adherence to the prescription was 36.5%. Patients in the physical activity cohort had lower systolic and diastolic blood pressure four months post-transplant compared to the usual care cohort (122 ± 18 vs. 126 ± 16 mmHg, p = 0.049 and 73 ± 10 vs. 77 ± 9, p = 0.004) and less impaired fasting glucose (20.7% vs. 30.9%, p = 0.04). Twelve-month outcomes were not different between cohorts. Over one-third of our cohort adhered to a pedometer-based physical activity intervention following kidney transplant, and the intervention was associated with improved metabolic parameters. Further study of post-transplant exercise interventions and methods to optimize long-term adherence are needed.

Clinical findings, pathology, and outcomes of C3GN after kidney transplantation.

C3 glomerulonephritis (C3GN) results from abnormalities in the alternative pathway of complement, and it is characterized by deposition of C3 with absent or scant Ig deposition. In many patients, C3GN progresses to ESRD. The clinical features, pathology, and outcomes of patients with C3GN receiving kidney transplantation are unknown. Between 1996 and 2010, we identified 21 patients at our institution who received a kidney transplant because of ESRD from C3GN. The median age at the time of initial diagnosis of C3GN at kidney biopsy was 20.8 years. The median time from native kidney biopsy to dialysis or transplantation was 42.3 months. Of 21 patients, 14 (66.7%) patients developed recurrent C3GN in the allograft. The median time to recurrence of disease was 28 months. Graft failure occurred in 50% of patients with recurrent C3GN, with a median time of 77 months to graft failure post-transplantation. The remaining 50% of patients had functioning grafts, with a median follow-up of 73.9 months. The majority of patients had hematuria and proteinuria at time of recurrence. Three (21%) patients were positive for monoclonal gammopathy and had a faster rate of recurrence and graft loss. Kidney biopsy at the time of recurrence showed mesangial proliferative GN in eight patients and membranoproliferative GN in six patients. All allograft kidney biopsies showed bright C3 staining (2-3+), with six biopsies also showing trace/1+ staining for IgM and/or IgG. To summarize, C3GN recurs in 66.7% of patients, and one half of the patients experience graft failure caused by recurrence.

Enhanced posttransplant management of patients with diabetes improves patient outcomes.

The survival of patients with diabetes mellitus in the general population has improved in recent years. Here we assessed whether similar trends have occurred in 1688 kidney recipients, including 413 with diabetes prior to transplant between 1996 and 2007. Compared to patients without diabetes, the 5-year mortality was significantly increased (hazard ratio (HR) 2.68 (1.95-3.69)) due to higher cardiovascular-, infection-, and malignancy-related deaths in those with diabetes. However, 5-year mortality in patients with diabetes significantly declined over time (HR 0.883 (0.817-0.954)), narrowing the mortality difference between patients with and those without diabetes and in more recent years largely eliminating it. Post transplant, patients with diabetes experienced a significant decline in major fatal/nonfatal cardiac events (HR 0.853 (0.782-0.930)) and infectious deaths over time. In contrast, neither cardiac events nor overall mortality declined in recipients without diabetes. The decline in mortality due to diabetes did not relate to a reduced pretransplant risk profile and was independent of posttransplant variables. The use of cardioprotective medications and glycemic control improved over time post transplant. Furthermore, graft function and serum albumin significantly improved over time and these parameters related to better survival (albumin, HR 0.365 (0.223-0.599); eGFR, HR 0.803 (0.756-0.852)). Thus, survival of kidney recipients with diabetes mellitus has improved markedly since 1996 likely reflecting, at least in part, enhanced posttransplant management and outcomes.

Increased Pretransplant Inflammatory Biomarkers Predict Death With Function After Kidney Transplantation.

BACKGROUND: Chronic systemic inflammation is associated with mortality in patients with chronic kidney disease, cardiovascular disease, and diabetes. The goal of this study was to examine the relationship between pretransplant inflammatory biomarkers (growth differentiation factor-15 [GDF-15], interleukin-6 [IL-6], soluble tumor necrosis factor receptor-1, monokine induced by gamma interferon/chemokine [C-X-C motif] ligand 9 [MIG/CXCL9], monocyte chemoattractant protein-1, soluble FAS, tumor necrosis factor-α, interleukin-15, and interleukin-1ß) and death with function (DWF) after kidney transplantation (KT). METHODS: We retrospectively measured inflammatory biomarker levels in serum collected up to 1 y before KT (time from blood draw to KT was 130 ±â€…110 d) in recipients transplanted between January 2006 and December 2018. Kaplan-Meier estimation, Cox regression, and Gradient Boosting Machine modeling were used to examine the relationship between inflammatory biomarkers and DWF. RESULTS: Our cohort consisted of 1595 KT recipients, of whom 62.9% were male and 83.2% were non-Hispanic White. Over a mean follow-up of 7.4 ±â€…3.9 y, 21.2% of patients (n = 338) experienced DWF. Patients with the highest quartile levels of GDF-15 (>4766 pg/mL), IL-6 (>6.11 pg/mL), and MIG/CXCL9 (> 5835 pg/mL) had increased rates of DWF, and each predicted mortality independently of the others. When adjusted for clinical factors (age, diabetes, etc), the highest quartile levels of GDF-15 and IL-6 remained independently associated with DWF. Adding inflammatory markers to a clinical Cox model improved the C-statistic for DWF from 0.727 to 0.762 using a Gradient Boosting Machine modeling approach. CONCLUSIONS: These findings suggest that pre-KT serum concentrations of GDF-15, IL-6, and MIG/CXCL9 may help to risk stratify and manage patients undergoing KT and suggests that chronic inflammation may play a role in mortality in KT recipients.

Update on oxalate crystal disease.

Oxalate arthropathy is a rare cause of arthritis characterized by deposition of calcium oxalate crystals within synovial fluid. This condition typically occurs in patients with underlying primary or secondary hyperoxaluria. Primary hyperoxaluria constitutes a group of genetic disorders resulting in endogenous overproduction of oxalate, whereas secondary hyperoxaluria results from gastrointestinal disorders associated with fat malabsorption and increased absorption of dietary oxalate. In both conditions, oxalate crystals can deposit in the kidney leading to renal failure. Since oxalate is primarily renally eliminated, it accumulates throughout the body in renal failure, a state termed oxalosis. Affected organs can include bones, joints, heart, eyes, and skin. Since patients can present with renal failure and oxalosis before the underlying diagnosis of hyperoxaluria has been made, it is important to consider hyperoxaluria in patients who present with unexplained soft tissue crystal deposition. The best treatment of oxalosis is prevention. If patients present with advanced disease, treatment of oxalate arthritis consists of symptom management and control of the underlying disease process.

Examining the safety and effectiveness of a 4-week supervised exercise intervention in the treatment of frailty in patients with chronic kidney disease.

Background: The optimal duration of antifrailty interventions and how best to deliver them to patients with chronic kidney disease (CKD) is unknown. The aim of this study was to examine the safety, feasibility and preliminary efficacy of a 4-week supervised exercise intervention on frailty in patients with CKD. Methods: We conducted a prospective feasibility study involving patients with ≥stage 3 CKD (1 patient with stage 3 CKD, 7 patients with stage 4 CKD and 17 patients with stage 5 CKD) who were either frail or prefrail according to the physical frailty phenotype and/or had a Short Physical Performance Battery (SPPB) score ≤10. The exercise intervention consisted of two supervised outpatient sessions per week for 4 weeks (eight total sessions). Frailty and other study measures were assessed at baseline and after 4 weeks of exercise. Results: Of the 34 participants who completed the baseline assessment and were included in the analyses, 25 (73.5%) completed the 4-week assessment. Overall, 64.0% of patients were on dialysis and 64.0% had diabetes mellitus. After 4 weeks of exercise, frailty prevalence, total SPPB scores and energy/fatigue scores improved. No adverse study-related outcomes were reported. Conclusions: The 4 weeks of supervised exercise was safe, was associated with an excellent completion rate and improved frailty parameters in CKD patients with CKD. This study provides important preliminary data for a future larger prospective randomized study. Clinical Trialgov: registration: NCT03535584.

Cellular Senescence and Frailty in Transplantation.

Purpose of review: To summarizes the literature on cellular senescence and frailty in solid-organ transplantation and highlight the emerging role of senotherapeutics as a treatment for cellular senescence. Recent findings: Solid-organ transplant patients are aging. Many factors contribute to aging acceleration in this population, including cellular senescence. Senescent cells accumulate in tissues and secrete proinflammatory and profibrotic proteins which result in tissue damage. Cellular senescence contributes to age-related diseases and frailty. Our understanding of the role cellular senescence plays in transplant-specific complications such as allograft immunogenicity and infections is expanding. Promising treatments, including senolytics, senomorphics, cell-based regenerative therapies, and behavioral interventions, may reduce cellular senescence abundance and frailty in patients with solid-organ transplants. Summary: Cellular senescence and frailty contribute to adverse outcomes in solid-organ transplantation. Continued pursuit of understanding the role cellular senescence plays in transplantation may lead to improved senotherapeutic approaches and better graft and patient outcomes.