Weight-based vs fixed dosing of darbepoetin alfa for anemia following kidney transplantation.

PURPOSE: Post-transplantation anemia (PTA) is common in kidney transplant recipients, with patients frequently treated with erythropoietin-stimulating agents such as darbepoetin alfa. The optimal dosing for darbepoetin alfa remains controversial. METHODS: This retrospective cohort study involved kidney transplant recipients who received darbepoetin alfa at 2 clinics. Patients were stratified into 2 groups: those who received a fixed dose of 200 µg and those who received a weight-based dose of 0.45 µg/kg. The dosing interval varied depending on clinical response, clinic visit timing, and frequency allowed by insurance. The primary outcome was achieving a hemoglobin concentration of at least 10 g/dL without blood transfusion by 12 weeks after darbepoetin alfa initiation. RESULTS: Of the 110 patients in the study, 45% received weight-based dosing and 55% received fixed dosing. Darbepoetin alfa was initiated significantly earlier after transplantation in the fixed-dose group (median of 14 vs 20 days; P = 0.003). The weight-based group received more doses of darbepoetin alfa (median of 4 vs 2 doses; P = 0.002) and had a significantly lower cumulative exposure to darbepoetin alfa (125 vs 590 µg; P < 0.001). The median time between doses was 9 days (interquartile range, 7-14 days) in the weight-based group and 12 days (7-32 days) in the fixed-dose group (P = 0.04). Patients in the weight-based group more frequently achieved the primary outcome (67.3% vs 47.5%; P = 0.059). There was no significant difference in secondary or safety outcomes between the groups. CONCLUSION: Weight-based and fixed dosing approaches for darbepoetin alfa were not different in the achievement of a hemoglobin concentration of at least 10 g/dL without blood transfusion at 12 weeks after darbepoetin alfa initiation, with significantly lower cumulative darbepoetin alfa utilization in the weight-based group. Weight-based dosing of darbepoetin alfa in PTA appears to be safe and effective, with the potential for significant patient and health-system cost savings.

Serum sickness induced by alemtuzumab in a kidney-pancreas transplant recipient.

Serum sickness is an immune-complex-mediated hypersensitivity reaction that was first noted in the early 1900s in patients receiving heterologous antisera, such as horse antitetanus or antidiphtheria serum. This condition is primarily self-limited; however, in its acute state, it can cause severe symptoms of fever, rash, polyarthritis, or polyarthralgias. In solid organ transplantation, this condition is frequently reported in association with the use of rabbit anti-thymocyte globulin and chimeric murine monoclonal antibodies such as rituximab. Alemtuzumab, designed as a humanized monoclonal antibody against CD52, is expected to be less immunogenic. Here, we report a case of serum sickness associated with alemtuzumab induction therapy in a kidney-pancreas dual-organ recipient.

Cell-Free DNA and Active Rejection in Kidney Allografts.

Histologic analysis of the allograft biopsy specimen is the standard method used to differentiate rejection from other injury in kidney transplants. Donor-derived cell-free DNA (dd-cfDNA) is a noninvasive test of allograft injury that may enable more frequent, quantitative, and safer assessment of allograft rejection and injury status. To investigate this possibility, we prospectively collected blood specimens at scheduled intervals and at the time of clinically indicated biopsies. In 102 kidney recipients, we measured plasma levels of dd-cfDNA and correlated the levels with allograft rejection status ascertained by histology in 107 biopsy specimens. The dd-cfDNA level discriminated between biopsy specimens showing any rejection (T cell-mediated rejection or antibody-mediated rejection [ABMR]) and controls (no rejection histologically), P<0.001 (receiver operating characteristic area under the curve [AUC], 0.74; 95% confidence interval [95% CI], 0.61 to 0.86). Positive and negative predictive values for active rejection at a cutoff of 1.0% dd-cfDNA were 61% and 84%, respectively. The AUC for discriminating ABMR from samples without ABMR was 0.87 (95% CI, 0.75 to 0.97). Positive and negative predictive values for ABMR at a cutoff of 1.0% dd-cfDNA were 44% and 96%, respectively. Median dd-cfDNA was 2.9% (ABMR), 1.2% (T cell-mediated types ≥IB), 0.2% (T cell-mediated type IA), and 0.3% in controls (P=0.05 for T cell-mediated rejection types ≥IB versus controls). Thus, dd-cfDNA may be used to assess allograft rejection and injury; dd-cfDNA levels <1% reflect the absence of active rejection (T cell-mediated type ≥IB or ABMR) and levels >1% indicate a probability of active rejection.

Routine ultrasonography surveillance of native kidneys for renal cell carcinoma in kidney transplant candidates.

Renal cell carcinoma (RCC) has a high incidence in the kidney transplant population and annual surveillance detects these tumors early in their natural history. Minimal guidelines exist regarding RCC surveillance in ESRD patients awaiting transplant. A retrospective review of our kidney transplant database examined the outcomes of annual ultrasonographic surveillance during initial kidney transplant evaluation and upon annual reassessment. Of 2642 patients listed for transplant, 145 patients were found to have masses during initial kidney transplant evaluation or annual imaging consistent with new complex cystic disease or RCC. A total of 71 patients had RCC identified, with 52 found on initial kidney transplant evaluation and 19 identified on annual surveillance. Male gender and African-American race were independently associated with RCC (P<.05). RCC was detected a median of 2.0 years after listing (two annual ultrasonography studies). Patients with complex cysts were more likely to undergo transplantation (48.7%) compared to patients with RCC (21.1%; P<.001). There was no significant difference in survival between RCC patients and those found to have complex cystic disease, suggesting incidental RCC can be diagnosed early in the natural history and at a curable stage through implementation of a biennial surveillance program.

Late presentation of adenovirus-induced hemorrhagic cystitis and ureteral obstruction in a kidney-pancreas transplant recipient.

We report a late presentation of adenovirus-induced renal allograft and bladder infection causing azotemia and hemorrhagic cystitis in a patient 5 years after simultaneous kidney-pancreas transplantation. Adenovirus has been increasingly recognized as a cause of morbidity and mortality in both solid organ and stem cell transplant recipients. We wish to emphasize the importance of early detection, as treatment options involve reduction of immunosuppression, followed by the addition of antiviral agents and supportive care.

Indications for combined liver and kidney transplantation: propositions after a 23-yr experience.

The frequency of combined liver and kidney transplants (CLKT) persists despite the pronounced scarcity of organs. In this review, we sought to ascertain any factors that would reduce the use of these limited commodities. Seventy-five adult CLKT were performed over a 23-yr period at our center, 29 (39%) of which occurred during the Model for End-stage Liver Disease (MELD) era. Overall, patient survival rates were 82%, 73%, and 62% at one, three, and five yr, respectively. There was no difference in patient survival based either on pre-transplant hemodialysis status or by glomerular filtration rate (GFR) at the time of transplant. Patients undergoing a second CLKT or a liver retransplantation at the time of CLKT had a survival rate of 30% at three months. In the MELD era, patient survival was unchanged (p = NS) despite an older recipient population (p = 0.0029) and a greater number of hepatitis C patients (p = 0.0428). In summary, patients requiring liver retransplantation with concomitant renal failure should be denied CLKT. Renal allografts may also be spared by implementing strict criteria for renal organ allocation (GFR < 30 mL/min at the time of evaluation) and considering the elimination of preemptive kidney transplantation in CLKT.

Use of two expanded-criteria-donor renal allografts in a single patient.

The disparity between the number of available renal donors and the number of patients on the transplant waiting list has prompted the use of expanded-criteria-donor (ECD) renal allografts to expand the donor pool. ECD allografts have shown good results in appropriately selected recipients, yet a number of renal allografts are still discarded. The use of dual renal transplantation may lower the discard rate. Additionally, the use of perfusion systems may improve acute tubular necrosis rates with these allografts. We report a successful case of a dual transplant with ECD allografts using a perfusion system. The biopsy appearance and the pump characteristics were suboptimal for these kidneys, making them unsuitable for single transplantation; however, the pair of transplanted kidneys provided increased nephron mass and functioned well. We recommend that ECD kidneys that are individually nontransplantable be evaluated for potential dual renal transplantation. Biopsy criteria and perfusion data guidelines must be developed to improve the success rates with ECD dual renal allografts. Finally, recipient selection is of utmost importance.

WAGR syndrome: a clinical review of 54 cases.

WAGR syndrome is a rare genetic disorder characterized by a de novo deletion of 11p13 and is clinically associated with Wilms' tumor, aniridia, genitourinary anomalies, and mental retardation (W-A-G-R). Although the genotypic defects in WAGR syndrome have been well established, the large variety of phenotypic manifestations of the syndrome has never been reported. We report on 54 cases of WAGR syndrome to demonstrate both the classical clinical signs and nonclassical manifestations found in a large population of individuals with this disorder. An understanding of WAGR syndrome and its clinical findings can provide important insight regarding the functions of the involved genetic region. Recommendations for diagnosis, evaluation, and surveillance of patients with WAGR syndrome are also presented.