Comparison of efficacy and safety between febuxostat and allopurinol in early post-renal transplant recipients with new onset of hyperuricemia

Controversies and practical management of patients with gout and chronic kidney disease

Uric acid is a toxin retained with advancing kidney disease. Clinical manifestations of hyperuricemia include gout and systemic inflammation that are associated with increased risk of cardiovascular mortality. As many as one-third of all patients with chronic kidney disease have a history of gout, yet <25% of these patients are effectively treated to target serum urate levels of ≤6 mg/dl. A major reason for ineffective management of gout and hyperuricemia is the complexity in managing these patients, with some medications contraindicated and others requiring special dosing, potential drug interactions, and other factors. Consequently, many nephrologists do not primarily manage gout despite it being a common complication of chronic kidney disease, leaving management to the primary physician or rheumatologist. We believe that kidney specialists should consider gout as a major complication of chronic kidney disease and actively manage it in their patients. Here, we present insights from nephrologists and rheumatologists into a team approach to gout management that includes the nephrologist.

Cardiovascular Risk after Kidney Transplantation: Causes and Current Approaches to a Relevant Burden

Background. Cardiovascular disease is a frequent complication after kidney transplantation and represents the leading cause of mortality in this population. Material and Methods. We searched for the relevant articles in the National Institutes of Health library of medicine, transplant, cardiologic and nephrological journals. Results. The pathogenesis of cardiovascular disease in kidney transplant is multifactorial. Apart from non-modifiable risk factors, such as age, gender, genetic predisposition and ethnicity, several traditional and non-traditional modifiable risk factors contribute to its development. Traditional factors, such as diabetes, hypertension and dyslipidemia, may be present before and may worsen after transplantation. Immunosuppressants and impaired graft function may strongly influence the exacerbation of these comorbidities. However, in the last years, several studies showed that many other cardiovascular risk factors may be involved in kidney transplantation, including hyperuricemia, inflammation, low klotho and elevated Fibroblast Growth Factor 23 levels, deficient levels of vitamin D, vascular calcifications, anemia and poor physical activity and quality of life. Conclusions. The timely and effective treatment of time-honored and recently discovered modifiable risk factors represent the basis of the prevention of cardiovascular complications in kidney transplantation. Reduction of cardiovascular risk can improve the life expectancy, the quality of life and the allograft function and survival.

Creation of an adequate animal model of hyperuricemia (acute and chronic hyperuricemia); study of its reversibility and its maintenance

AIM

Hyperuricemia is defined by the European Rheumatology Society as a uric acid level greater than 6 mg/dl (60 mg/l or 360 μmol/l). Our goal was to evaluate the hypouricemic effect of nettle. For this reason, we have first of all try to create an hyperuricemic animal model which is very suitable because at the level of literature there is not an exact model, there are many models and our objective is to set an adequate model.

MATERIALS AND METHODS

An attempt has been made to test acute and chronic hyperuricemia by varying the duration and method of induction of potassium oxonate. Similarly, attempts have been made to induce chronic hyperuricemia through an animal and vegetable diet. The reversibility of hyperuricemia was tested with a maintenance protocol.

KEY FINDINGS

For the creation of the hyperuricemia model, it has been shown that acute hyperuricemia cannot be induced by short administration of potassium oxonate and persistent chronic hyperuricemia can be induced only after daily administration of oxonate of potassium by intraperitoneal injection for 15 days. Indeed, hyperuricemia was reversible after stopping the administration of potassium oxonate. The high-purine diet is also capable of inducing chronic hyperuricemia but to a less extent.

SIGNIFICANCE

After creating an adequate model of hyperuricemia while setting the dose of potassium oxonate, route of administration and duration. A maintenance protocol was followed which subsequently made it possible to deduce that the daily administration of potassium oxonate must be continued to maintain the hyperuricemia.

Management of Hyperuricemia in Patients with Chronic Kidney Disease: a Focus on Renal Protection

PURPOSE OF REVIEW

In chronic kidney disease (CKD), plasma uric acid levels are increased because of the decrease in glomerular filtration rate. However, in addition to CKD, hyperuricemia is frequently associated with a number of other conditions such as hypertension, type 2 diabetes, obesity, and heart failure, overweight, and cardiovascular disease.

RECENT FINDINGS

It is now becoming increasingly clear that, in many clinical conditions, elevated levels of uric acid have a much greater role beyond just causing gout. The present review will summarize current knowledge on the relation between hyperuricemia, CKD, and existing comorbidities, as well as the mechanisms of uric acid-related renal damage. In addition, the role and evidence for urate-lowering therapy in prevention and cardiovascular protection in CKD patients is discussed with a focus on allopurinol and febuxostat. To date, several clinical studies have provided evidence that urate-lowering therapy may help to prevent and delay the decline of renal function in patients with CKD. Use of a xanthine oxidase inhibitor should be considered in patients who are at high renal risk and/or with declining renal function in the presence of hyperuricemia with and without deposition, although additional studies are warranted to define treatment targets. Notwithstanding, the possibility to delay deterioration of renal function in patients with CKD merits consideration.

Management of asymptomatic hyperuricemia: Integrated Diabetes & Endocrine Academy (IDEA) consensus statement

AIM

The definition and management of asymptomatic hyperuricemia has been an area of controversy for many decades. Debate persists regarding the benefit of treating all cases of asymptomatic hyperuricemia and hence, unsurprisingly there are no clear clinical practice guidelines from our country.

PARTICIPANTS

Ten members consisting of eminent physicians, endocrinologists, nephrologist and a rheumatologist were selected by the Integrated Diabetes & Endocrine Academy (IDEA) for a closed meeting with the aim to come to a consensus.

EVIDENCE

A literature search was performed using PubMed and Cochrane library following which published articles in indexed peer review journals were selected.

CONSENSUS PROCESS

Each participant voiced their opinion after reviewing the available data and a consensus was reached after three meetings by voting.

CONCLUSION

Recommendations were made on important areas such as definition, investigation and management of asymptomatic hyperuricemia.

Comparison of efficacy and safety between febuxostat and allopurinol in early post-renal transplant recipients with new onset of hyperuricemia

What is known and objective

Febuxostat and allopurinol are xanthine oxidase inhibitors for urate‐lowering therapy. The efficacy and safety of febuxostat and allopurinol have been mostly reported in hyperuricemia patients with normal renal function. Here, we aimed to compare the effects of these two drugs in early post‐renal transplant recipients, focusing on evaluating the urate‐lowering effect and recovery of allograft renal function.

Methods

A retrospective cohort study was performed in early post‐renal transplant recipients with new onset of hyperuricemia receiving febuxostat or allopurinol therapy. Serum uric acid (UA) and estimated glomerular filtration rate (eGFR) were detected on days 3, 7 and 15 and months 1, 3 and 6 after therapy initiation. Liver and blood functions were monitored and other adverse events were recorded.

Results and discussion

A total of 48 and 33 patients were enrolled in the febuxostat and allopurinol groups, respectively. Significant UA‐lowering effects were observed on day 3 in both groups. Febuxostat caused a more rapid UA decline, starting on day 3 and lasting for 1 month. The most apparent contrast was found in UA level (267.25 ± 93.66 vs 334.18 ± 96.56 μmol/L, P = 0.003) on day 7; 62.5% and 30.3% of patients achieved target UA level in febuxostat and allopurinol groups respectively on day 3 (P = 0.004), but there was no significant difference between two groups from days 15 to months 6. The median times to achieve target UA level were 3 and 5 days in febuxostat and allopurinol groups respectively (P = 0.002). The eGFR levels and recovering rates were gradually upregulated but no significant differences were found between two groups. No abnormities related to febuxostat or allopurinol were observed.

What is new and conclusion

This is the first comprehensive evaluation of UA‐lowering effects of febuxostat and allopurinol in early post‐renal transplant recipients. Febuxostat caused a marginally quicker serum UA‐lowering effect than allopurinol, but there was no advantage for long‐term use of febuxostat. The drugs had no significant differences in impacting renal allograft function recovery, and both were well tolerated.