Donor-recipient size matching influences early but not late graft function after pediatric en-bloc kidney transplantation.

BACKGROUND: Pediatric en-bloc kidney transplantation into adult recipients is an accepted technique to expand the donor pool. Concerns about adequate "nephron dosing" have traditionally favored placing these kidneys into smaller recipients. METHODS: We reviewed 20 pediatric en-bloc transplants performed at our institution between 2002 and 2008. We examined the impact of donor age, donor weight, recipient sex, combined kidney length, recipient weight, recipient-to-donor weight ratio, and recipient weight gain on serum creatinine over time using regression analysis. RESULTS: Patient survival was 100%. Two grafts were lost early from vascular thrombosis. Of the remaining 18 recipients, all had immediate and excellent long-term function with average creatinine of 0.91+/-0.38 mg/dL at a mean follow-up of 1257+/-656 days. For 17 patients with 1 year follow-up, recipient weight, recipient-to-donor weight ratio, and recipient male sex negatively influenced renal function at 1 month. However, this relationship was lost by 1 year with increasing function in the smallest donors and largest size mismatches. Between 1 month and 1 year posttransplant, estimated creatinine clearance improved from 59+/-13 mL/min at 1 month posttransplant to 88+/-41 mL/min (P<0.015). Weight gain after transplant was associated with improved creatinine clearance, suggesting continued adaptation over time. CONCLUSIONS: We conclude that donor or recipient size matching up to a recipient-to-donor weight ratio of 7.5 does not significantly impact later renal function after pediatric en-bloc kidney transplantation into adults.

Higher levels of leflunomide are associated with hemolysis and are not superior to lower levels for BK virus clearance in renal transplant patients.

BACKGROUND AND OBJECTIVES: Leflunomide use in renal transplantation has been increasing. Outcome correlation and safety data are still to be refined. The goals of this study were to report one center's experience with leflunomide, specifically the correlation of leflunomide levels with the outcomes of BK nephropathy and the observed toxic effects during the treatment with leflunomide. DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS: Leflunomide was used in 21 patients with BK nephropathy. These patients were divided into two groups on the basis of the leflunomide levels achieved: Low-level group (<40 microg/ml) and high-level group (>40 microg/ml). RESULTS: During 13 mo of follow-up, there was no difference in the rate of serum BK viral clearance between the groups. There were three graft losses in the low-level group and one in the high-level group; however, creatinine levels were higher at the time of starting leflunomide in the low-level group. Leflunomide was also used in six patients with chronic allograft injury. No graft loss was observed during the follow-up period of 16 mo. Treatment with leflunomide seemed to be associated with a new toxicity, hemolysis, seen in four of the 27 patients so treated. Patients with hemolysis had high leflunomide levels (81.4 +/- 14 microg/ml) and worsening allograft function. Two patients had histologic evidence of thrombotic microangiopathy, which led to graft loss in one patient. CONCLUSIONS: The clinical correlation between leflunomide levels and outcomes needs to be further refined. This study described a possible association of leflunomide with thrombotic microangiopathy, especially at higher levels.

Managing the failing allograft.

Managing the failing allograft juxtaposes immunosuppressive management and routine chronic kidney disease care. The complications of immunosuppression can be more pronounced in those with renal failure (infection, anemia, bone disease). The withdrawal of immunosuppression may be associated with acute allograft rejection, arthralgias, and the development of antidonor antibodies. Likewise depression is prevalent. Improving well-being and overall survival necessitates proper titration of immunosuppressive medications and control of blood pressure, anemia, lipids, and glucose along with attention to treatment of depression.

Sirolimus-associated pulmonary toxicity.

BACKGROUND: Pulmonary toxicity has recently been recognized as a potentially serious complication associated with sirolimus therapy. We further detail this condition on the basis of our own cases and those reported in the literature. METHODS: We report three cases of suspected sirolimus-induced pulmonary toxicity that occurred in three renal transplant recipients and searched PubMed for all previously reported cases. RESULTS: Including our current cases, 43 patients with sirolimus-induced pulmonary toxicity have now been reported. Clinical data were incomplete in 28 cases. Analysis of available data for 15 patients revealed that the most commonly presenting symptoms were dyspnea on exertion and dry cough followed by fatigue and fever. Chest radiographs and high-resolution computed tomography scans commonly revealed bilateral patchy or diffuse alveolo-interstitial infiltrates. Bronchoalveolar fluid analysis and lung biopsy in selected case reports revealed several distinct histologic features, including lymphocytic alveolitis, lymphocytic interstitial pneumonitis, bronchoalveolar obliterans organizing pneumonia, focal fibrosis, pulmonary alveolar hemorrhage, or a combination thereof. The diagnosis of sirolimus-associated pulmonary toxicity was made after an exhaustive work-up to exclude infectious causes and other pulmonary disease. Sirolimus discontinuation or dose reduction resulted in clinical and radiologic improvement in all 15 patients within 3 weeks. CONCLUSION: The temporal relationship between sirolimus exposure and onset of pulmonary symptoms in the absence of infectious causes and other alternative pulmonary disease and the associated clinical and radiologic improvement after its cessation suggests a causal relationship. Because the use of sirolimus in organ transplantation has become more widespread, clinicians must remain vigilant to its potential pulmonary complication.