Transplant Onconephrology in Patients With Kidney Transplants

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Our Timing to Remove Peritoneal Catheter Dialysis After Kidney Transplant

Background

Patients on peritoneal dialysis treatment represent 15% of the global dialysis population. The major complication of peritoneal dialysis is catheter and peritoneal infection. Peritoneal dialysis patients who receive kidney transplants are at increased risk of infection because of immunosuppressive therapy.

Endothelial Dysfunction in Peritoneal Dialysis Patients With and Without Failed Renal Transplants

Background

Endothelial dysfunction (ED) is a common, early abnormality that predisposes patients to develop atherosclerosis and cardiovascular events; inflammation is associated with atherosclerosis and malnutrition. Patients with failed transplants are usually complicated by inflammation; however, ED in this group of patients has not been well defined. In this cross-sectional study, we sought to investigate ED among naïve peritoneal dialysis (nPD) patients who were never transplanted as well as patients with failed renal transplants who were re-starting peritoneal dialysis (fTxPD).

Methods

Twenty-five nPD patients (15 female/10 males; mean age, 44 ± 11 years), and 12 fTxPD patients (4 males; mean age, 37 ± 10 years) were included in the study. Coronary flow reserve (CFR) measurements were used to evaluate ED. Serum creatinine, calcium, phosphorus, total cholesterol, albumin, hemoglobin, and intact parathyroid hormone (iPTH) were measured. Also, highly sensitive C-reactive protein (hs-CRP) levels and weekly Kt/V were determined as possible confounding factors. Results were compared between the 2 groups.

Results

There were no significant differences regarding age, gender, mean systolic and diastolic blood pressures, or smoking status. Mean duration on PD, peritoneal transport characteristics, PD modality and doses, frequency of peritonitis episodes, as well as serum creatinine, calcium, phosphorus, total cholesterol, albumin, hemoglobin and iPTH levels were similar between the 2 groups. Weekly Kt/V of both groups were similar as well. However, hs-CRP levels were significantly higher (34 ± 52 vs 6.7 ± 7.5 mg/L; P = .017) and CFR significantly lower among patients with fTxPD compared with nPD patients (1.52 ± 0.20 vs 1.91 ± 0.53; P = .022).

Conclusion

ED was more prominent among patients with failed transplants than nPD cases, suggesting that the failed allograft may be responsible for this abnormality.     

Development of Charcot Neuroarthropathy in Diabetic Patients who Received Kidney or Kidney-Pancreas Transplants

Only a small percentage of the general diabetic population develops Charcot neuroarthropathy. Charcot arthropathy greatly increases the risk of foot complications. At our academic institution, there appeared to be an increased incidence of Charcot arthropathy in transplant patients. We hypothesized that Charcot neuroarthropathy incidence is higher in the diabetic patients who had received kidney or kidney-pancreas transplants. The charts of 1000 patients were reviewed from January 2000 to January 2011. Four hundred and eighty-seven patients were included in the study. Of these diabetic patients, 249 had received a kidney transplant and 238 a kidney-pancreas transplant. The data were analyzed for the incidence of Charcot in each group. Other risk factors and sequelae were also evaluated and analyzed. The incidence of Charcot development in the diabetic patients who had a kidney-pancreas transplant was 18.4%, 44 of 238 patients. This was significantly higher than the incidence in kidney transplant patients, which was 11.2%, 28 of 249 patients (p < .05). Peripheral arterial disease was a statistically significant independent risk factor for developing ulceration, osteomyelitis, and subsequent amputation. Type 1 diabetic patients developed Charcot at a higher rate that was also statistically significant compared with type 2 diabetic patients. In our study, diabetic patients who had undergone kidney-pancreas transplants were associated with higher risk for development of Charcot neuroarthropathy than kidney transplants alone. The incidence of Charcot development in both these transplant groups was also much higher than in the general diabetic population. This is of particular interest to clinicians and surgeons as both transplant groups were found to be high risk for subsequent foot ulceration, infection, and amputation.     

Dietary Protein Intake in Patients with Advanced Chronic Kidney Disease and on Dialysis

Many patients with chronic kidney disease (CKD), particularly those with stage 5 CKD, have protein wasting. The degree to which increased morbidity and mortality seen in these patients is due to protein depletion rather than to the often accompanying comorbidity is not clear. High protein diets lead to the accumulation of metabolites of protein that are potentially toxic. The MDRD Study, which investigated the effects of three levels of dietary protein and phosphorus intakes and two blood pressure goals on the progression of CKD, has several limitations. Several meta‐analyses have examined the effects of low protein diets (LPD) on the progression of CKD. It is possible that the lower SUN levels or lesser degree of uremic symptoms may have contributed to the positive findings of LPD in the meta‐analyses of Fouque and Pedrini et al., when compared with the study of Kasiske et al. A number of published reports indicate that LPD provide adequate protein for almost all clinically stable CKD patients and do not adversely affect body composition. In general, there are no large differences in the protein intake recommended by different expert groups for a given stage of CKD.     

Encapsulating Peritoneal Sclerosis in Peritoneal Dialysis Patients After Kidney Transplantation

Objective

Encapsulating peritoneal sclerosis (EPS) is a serious complication for patients with chronic kidney disease (CKD) who were treated with long-term peritoneal dialysis (PD). The risk of EPS was increased after kidney transplantation. In our study we evaluated risk factors for EPS patients after kidney transplantation who were treated before with PD.

Tolerance and Withdrawal of Immunosuppressive Drugs in Patients Given Kidney and Hematopoietic Cell Transplants

Sixteen patients conditioned with total lymphoid irradiation (TLI) and antithymocyte globulin (ATG) were given kidney transplants and an injection of CD34+ hematopoietic progenitor cells and T cells from HLA‐matched donors in a tolerance induction protocol. Blood cell monitoring included changes in chimerism, balance of T‐cell subsets and responses to donor alloantigens. Fifteen patients developed multilineage chimerism without graft‐versus‐host disease (GVHD), and eight with chimerism for at least 6 months were withdrawn from antirejection medications for 1–3 years (mean, 28 months) without subsequent rejection episodes. Four chimeric patients have just completed or are in the midst of drug withdrawal, and four patients were not withdrawn due to return of underlying disease or rejection episodes. Blood cells from all patients showed early high ratios of CD4+CD25+ regulatory T cells and NKT cells versus conventional naive CD4+ T cells, and those off drugs showed specific unresponsiveness to donor alloantigens. In conclusion, TLI and ATG promoted the development of persistent chimerism and tolerance in a cohort of patients given kidney transplants and hematopoietic donor cell infusions. All 16 patients had excellent graft function at the last observation point with or without maintenance drugs.