Transplant reno-vascular stenoses associated with early erythropoietin use

Anemia after kidney transplantation

Anemia is a frequent complication in pediatric kidney transplant recipients (KTR) with a variable reported prevalence estimated between 20 and 80% depending on how defined. Causes of and risk factors for post-transplantation anemia (PTA) are multifactorial with iron deficiency being the primary cause of early PTA (within the first 6 months after transplantation) and impaired glomerular filtration rate (GFR) commonly responsible for late PTA (after 6 months). Medications, viral infections, chronic inflammation, and comorbidities also play a role. PTA has relevant long-term consequences and is a potential risk factor for allograft dysfunction, cardiovascular morbidity, and mortality. Thus, an anemia evaluation, approximately 3 months post-transplantation, is recommended in order to start early treatment and improve prognosis. Iron status, vitamin B12, folate, markers of hemolysis, and viral PCR should be checked, and medications, in particular combinations of medications, should be carefully evaluated. PTA treatment may be challenging and should be directed to the underlying causes. Iron supplementation and erythropoietin therapy, not extensively used in KTR, may be indicated. Every effort should be made to avoid blood transfusions in the pre-transplant period to avoid allosensitization. Anemia should be corrected to prepare candidates for kidney transplantation in order to reduce the need for perioperative blood transfusions as well.

Outcome of hepatectomy for hepatocellular carcinoma in patients with renal dysfunction

OBJECTIVES

There are few reports on the efficacy of hepatectomy for hepatocellular carcinoma (HCC) in patients with renal dysfunction (RD). This study aimed to clarify the validity of hepatectomy for treating HCC in RD patients, and to compare postoperative courses in RD and non-RD patients.

METHODS

The clinical features of 722 HCC patients who underwent curative hepatectomy between 1986 and 2009 were retrospectively reviewed. Seventeen patients (2.4%) with preoperative serum creatinine levels of >2.0 mg/dl were defined as the RD group, and, of these, seven who did not receive preoperative haemodialysis were defined as borderline patients. Clinicopathological characteristics and postoperative outcomes were compared between the RD group (n= 17) and the non-RD group (n= 705). The postoperative courses of borderline patients were reviewed in detail.

RESULTS

Overall survival (P= 0.177) and disease-free survival (P= 0.942) after hepatectomy did not differ significantly between the groups. Incidences of massive ascites (35.3% vs. 14.3%; P= 0.034) and pleural effusion (52.9% vs. 17.6%; P= 0.001), defined as massive effusion (ME), were significantly higher in the RD group than in the non-RD group. Hypoalbuminaemia (≤2.8 g/dl; P= 0.031), heavy blood loss (≥1000 ml; P= 0.012) and intraoperative blood transfusion (P= 0.007) were risk factors for ME. Among the borderline patients, serum creatinine values were not increased immediately after surgery and four patients underwent haemodialysis.

CONCLUSIONS

Preoperative hypoalbuminaemia, heavy blood loss and blood transfusion are independent risk factors for ME in RD patients. Preoperative improvement of anaemia and reduction of blood loss by meticulous surgical techniques may prevent ME in RD patients who require hepatectomy for HCC.

In praise of arrays

Microarray technologies have both fascinated and frustrated the transplant community since their introduction roughly a decade ago. Fascination arose from the possibility offered by the technology to gain a profound insight into the cellular response to immunogenic injury and the potential that this genomic signature would be indicative of the biological mechanism by which that stress was induced. Frustrations have arisen primarily from technical factors such as data variance, the requirement for the application of advanced statistical and mathematical analyses, and difficulties associated with actually recognizing signature gene-expression patterns and discerning mechanisms. To aid the understanding of this powerful tool, its versatility, and how it is dramatically changing the molecular approach to biomedical and clinical research, this teaching review describes the technology and its applications, as well as the limitations and evolution of microarrays, in the field of organ transplantation. Finally, it calls upon the attention of the transplant community to integrate into multidisciplinary teams, to take advantage of this technology and its expanding applications in unraveling the complex injury circuits that currently limit transplant survival.

Anemia and anemia correction: surrogate markers or causes of morbidity in chronic kidney disease?

Observational studies have shown a strong positive correlation between the severity of anemia and the risk of poor outcomes in patients with chronic kidney disease (CKD). This observation was initially taken to imply that adverse outcomes in CKD are caused by anemia. However, the assumption of causality ignores the possibility that anemia and adverse outcomes might be unrelated and that both are caused by underlying inflammation, oxidative stress and comorbid conditions. Randomized clinical trials of anemia correction have revealed an increased risk of adverse cardiovascular outcomes in patients assigned to normal, rather than subnormal, hemoglobin targets. As a result, correction of anemia is now considered potentially hazardous in patients with CKD. Notably, individuals who did not reach the target hemoglobin level in the clinical trials, despite receiving high doses of erythropoietin and iron, experienced a disproportionately large share of the adverse outcomes. These observations point to overdose of erythropoietin and iron, rather than anemia correction per se, as the likely culprit. This Review explores the reasons for the apparent contradiction between the findings of observational studies and randomized clinical trials of anemia treatment in CKD. I have focused on data from basic and translational studies, which are often overlooked in the design and interpretation of clinical studies and in the formulation of clinical guidelines.