Therapeutic Efficacy and Cost Effectiveness of High Cut-Off Dialyzers Compared to Conventional Dialysis in Patients with Cast Nephropathy.

BACKGROUND: High Cut-Off (HCO) dialysis membranes efficiently reduce serum free light chain (FLC) concentrations and may improve renal recovery and survival from multiple myeloma (MM) associated renal failure with cast nephropathy. However, clinical trials comparing dialysis with HCO versus conventional filters are lacking. The aim of this study was to assess clinical outcomes and economic impact of HCO dialyzers compared to conventional hemodialysis membranes in cast nephropathy. METHODS: Multicenter retrospective analysis of 19 patients treated for renal failure from FLC associated cast nephropathy with standard induction chemotherapy (bortezomib/dexamethasone). We compared hemodialysis treatment with High Cut-Off (n = 12) versus conventional dialyzers (n = 7). Primary endpoint was survival; secondary endpoints were renal recovery, renal function and treatment costs. RESULTS: At 12 months, patient survival was 25% in the HCO group versus 0% in controls (p = NS). A tendency towards faster renal recovery (p = 0.066) and better renal function at 3, 6 and 12 months (p = 0.109) after diagnosis of MM was noted in the HCO group. Complete renal response rate was achieved in 10.5 and 0% of HCO and control patients, respectively, partial renal response in 15.8 and 5.3%, and minor renal response in 26.3 and 15.8%, respectively. Both patient survival and renal recovery were significantly correlated with the extent of free light chain (FLC) reduction in serum. Median treatment costs were CHF 230'000 and 223'000 (p = NS) in the HCO and control group, respectively. CONCLUSIONS: Hemodialysis treatment with HCO membranes for cast nephropathy tended towards better survival as well as faster and better recovery of renal function versus conventional dialyzers. Moreover, total medical costs were comparable between groups. In the absence of results from randomized prospective trials on this topic, the use of HCO dialyzers in patients with renal failure from cast nephropathy may be recommended. Prospective randomized trials are required.

Quantification of excretory renal function and urinary protein excretion by determination of body cell mass using bioimpedance analysis.

BACKGROUND: Creatinine clearance (CrCl) based on 24 h urine collection is an established method to determine glomerular filtration rate (GFR). However, its measurement is cumbersome and the results are frequently inaccurate. The aim of this study was to develop an alternative method to predict CrCl and urinary protein excretion based on plasma creatinine and the quantification of muscle mass through bioimpedance analysis (BIA). METHODS: In 91 individuals with normal and impaired renal function CrCl was measured from 24 h urine excretion and plasma creatinine concentration. A model to predict 24 h-creatininuria was developed from various measurements assessing muscle mass such as body cell mass (BCM) and fat free mass (FFM) obtained by BIA, skinfold caliper and other techniques (training group, N = 60). Multivariate regression analysis was performed to predict 24 h-creatininuria and to calculate CrCl. A validation group (N = 31) served to compare predicted and measured CrCl. RESULTS: Overall (accuracy, bias, precision, correlation) the new BIA based prediction model performed substantially better compared with measured CrCl (P15 = 87 %, bias = 0, IQR of differences = 7.9 mL/min/1.73 m(2), R = 0.972) versus established estimation formulas such as the 4vMDRD (P15 = 6 %, bias = -8.3 mL/min/1.73 m(2), IQR = 13.7 mL/min/1.73 m(2), R = 0.935), CKD-EPI (P15 = 29 %, bias = -7.0 mL/min/1.73 m(2), IQR = 12.1 mL/min/1.73 m(2), R = 0.932, Cockcroft-Gault equations (P15 = 55 %, bias = -4.4 mL/min/1.73 m(2), IQR = 9.0 mL/min/1.73 m(2), R = 0.920). The superiority of the new method over established prediction formulas was most obvious in a subgroup of individuals with BMI > 30 kg/m(2) and in a subgroup with CrCl > 60 mL/min/1.73 m(2). Moreover, 24 h urinary protein excretion could be estimated accurately by normalization with 24 h-creatininuria derived from BIA based BCM. CONCLUSION: Prediction of CrCl based on estimated urinary creatinine excretion determined from measurement of BCM by BIA technique is both accurate and convenient to quantify renal function in normal and diseased states. This new method may become particularly helpful for the evaluation of patients with borderline renal insufficiency and/or with abnormal body composition.

Basal cell carcinoma in a series of renal transplant recipients: epidemiology and clinicopathologic features.

BACKGROUND: Basal cell carcinoma (BCC) is the most common malignancy among Caucasians worldwide. The risk of BCC is 10-16 times higher among immunosuppressed transplant recipients compared with the general population. OBJECTIVE: To analyze the incidence, clinical presentation, histologic features, treatment and recurrence rate of BCC in a cohort of 69 renal transplant recipients (RTRs; 53 male). METHODS: Retrospective population-based cohort study of immunosuppressed RTRs. RESULTS: Ten of 69 patients (14.5%, five male) developed a total of 17 BCCs, mostly on the head. Mean age at first diagnosis of BCC was 65.5 +/- 8.5 years, and latency between kidney transplantation and diagnosis of the first BCC was 11.1 +/- 6.3 years (mean +/- SD). The risk of female RTRs to develop BCCs appeared to be three times higher than the risk of male RTRs, and female RTRs developed BCCs earlier after transplantation. Nodular BCC was the most common histologic subtype. Most BCCs in these RTRs were treated by complete surgical excision. Recurrence after surgical excision was observed in one of the 10 patients (10%). CONCLUSION: Our results suggest female RTRs to be at higher risk to develop cutaneous BCCs than male RTRs. There are no differences in localization and clinicopathologic presentation of BCCs developing in RTRs compared with immunocompetent patients. Therefore, BCCs in RTRs do not require different treatment than in other patient groups. As patients tend to develop a second BCC, close follow-up is mandatory.

Dialysis-related amyloidosis revisited.

OBJECTIVE: Dialysis-related amyloidosis occurs secondarily to the deposition of beta(2)-microglobulin. Dialysis-related amyloidosis predominantly involves the osteoarticular system and is clinically manifested by erosive and destructive osteoarthropathies, destructive spondyloarthropathy, and carpal tunnel syndrome. This article illustrates the radiographic, sonographic, CT, and MRI findings of dialysis-related amyloid arthropathies. CONCLUSION: Dialysis-related amyloidosis is characterized by various imaging appearances. In evaluating amyloidosis, MRI provides considerably more information than that obtained from conventional radiographic, CT, and sonographic studies.

Successful treatment of hypercalcemia with cinacalcet in renal transplant recipients with persistent hyperparathyroidism.

BACKGROUND: Cinacalcet lowers plasma parathyroid hormone (PTH) levels in primary and secondary hyperparathyroidism. The efficacy and safety of cinacalcet have not been examined in renal transplant patients with persistent hyperparathyroidism. The aim of this study was to evaluate the effect of cinacalcet as a novel therapy for the management of such patients. METHODS: Eleven renal allograft recipients with persistent hyperparathyroidism were treated with cinacalcet. The total study time was 10 weeks. Individual cinacalcet doses were adjusted to obtain a serum calcium in the predefined normal target range of 2.10-2.60 mmol/l. RESULTS: Serum calcium decreased significantly from 2.73+/-0.05 mmol/l to 2.44+/-0.05 and 2.42+/- 0.04 mmol/l after 2 and 10 weeks of treatment, respectively. All patients reached the target range rapidly and remained normocalcaemic throughout the study. Serum PTH significantly decreased 16.1 and 21.8% at study weeks 2 and 10, respectively, compared with week 0. Serum phosphate increased. Renal function remained stable and no allograft rejection was observed. From weeks 2 to 10, daily cinacalcet doses administered were 30 mg (n = 8), 15 mg (n = 1) and 60 mg (n = 1), respectively. CONCLUSION: Cinacalcet was effective in correcting the hypercalcaemia associated with persistent hyperparathyroidism after renal transplantation. It appears to be safe. Thus, cinacalcet represents a promising alternative for parathyroidectomy in these patients.