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Serum Uric Acid and Renal Transplantation Outcomes: At Least 3-Year Post-transplant Retrospective Multivariate Analysis.

Zhang K, Gao B, Wang Y, Wang G, Wang W, Zhu Y, Yao L, Gu Y, Chen M, Zhou H, Fu Y - PLoS ONE (2015)

Bottom Line: Hyperuricemia was significantly an independent predictor of pure graft failure (hazard ratio=4.01, 95% CI: 1.25-12.91, P=0.02) after adjustment.The results of our study suggest that post-transplant elevated serum uric acid level is an independent predictor of long-term graft survival and graft function.Together with the high TG level impact on poor outcomes, further investigations for therapeutic effect are needed.

View Article: PubMed Central - PubMed

Affiliation: Department of Urology/Transplant Center, First Hospital of Jilin University, Changchun, Jilin, China.

ABSTRACT
Since the association of serum uric acid and kidney transplant graft outcome remains disputable, we sought to evaluate the predictive value of uric acid level for graft survival/function and the factors could affect uric acid as time varies. A consecutive cohort of five hundred and seventy three recipients transplanted during January 2008 to December 2011 were recruited. Data and laboratory values of our interest were collected at 1, 3, 6, 12, 24 and 36 months post-transplant for analysis. Cox proportional hazard model, and multiple regression equation were built to adjust for the possible confounding variables and meet our goals as appropriate. The current cohort study lasts for 41.86 ± 15.49 months. Uric acid level is proven to be negatively associated with eGFR at different time point after adjustment for age, body mass index and male gender (standardized β ranges from -0.15 to -0.30 with all P<0.001).Males with low eGFR but high level of TG were on CSA, diuretics and RAS inhibitors and experienced at least one episode of acute rejection and diabetic issue were associated with a higher mean uric acid level. Hyperuricemia was significantly an independent predictor of pure graft failure (hazard ratio=4.01, 95% CI: 1.25-12.91, P=0.02) after adjustment. But it was no longer an independent risk factor for graft loss after adjustment. Interestingly, higher triglyceride level can make incidence of graft loss (hazard ratio=1.442, for each unit increase millimoles per liter 95% CI: 1.008-2.061, P=0.045) and death (hazard ratio=1.717, 95% CI: 1.105-2.665, P=0.016) more likely. The results of our study suggest that post-transplant elevated serum uric acid level is an independent predictor of long-term graft survival and graft function. Together with the high TG level impact on poor outcomes, further investigations for therapeutic effect are needed.

No MeSH data available.


Related in: MedlinePlus

Kaplan-Meier survival curve estimates for death with functioning graft.No significant difference can be acquired on patient survival rate between these groups.
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pone.0133834.g006: Kaplan-Meier survival curve estimates for death with functioning graft.No significant difference can be acquired on patient survival rate between these groups.

Mentions: To estimate the impact of UA level and hyperuricemia on long-term transplant outcomes, Cox proportional hazard model was used to adjust for confounding factors. In accordance with our expectation, hyperuricemia was found to be a significant predictor for graft loss (defined as allograft failure and death) during the study period(hazard ratio [36] = 2.17, 95% confidential interval[CI]:1.27–3.70, P = 0.004) as illustrated in Fig 4. However, it was not valid(HR = 1.59, 95% CI: 0.73–3.44, P = 0.241) after adjustment for age, gender, BMI, HLA mismatch, introduction regimen, immunosuppressive agent protocol, diabetic mellitus, dialysis type, DGF, infection and acute rejection episode. Further investigation showed that hyperuricemia was significantly an independent predictor of pure graft failure (HR = 4.01, 95% CI: 1.25–12.91, P = 0.02) after adjustment for the same confounding factors as previous. Kaplan-Meier survival curve for allograft failure was depicted in Fig 5. Then we tested UA level as a continuous variable to double confirm our results. Similar analysis showed that UA level was also independently associated with allograft failure (HR = 1.009 for each unit increase in milligram per deciliter, 95% CI: 1.001–1.018, P = 0.026). When tested for graft loss, unlike hyperuricemia, UA level indicated borderline significant independently (HR = 1.005, 95% CI: 1.000–1.011, P = 0.052). Although significant, the HRs were too small to provide a strong evidence that uric acid, as a numeric variable, is associated to overall graft loss (allograft kidney failure and death with functioning graft) or pure graft loss. So we included all qualified recipients (the newly recruited consecutive cohort was made up of kidney transplantation recipients from 2005 to 2008) in our center, in total 1203, to figure out whether uric acid level is an independent risk factor in another Cox proportional hazard model. Due to low data integrity (the degree of low-integrity do not allow us to include these group of patients in other analysis, but it was good enough for us to perform the statistics described below), we had to narrow covariates down to age, gender, BMI, uric acid, DGF, infection and acute rejection episode. The results were encouraging. Uric acid level was independently associated with pure graft failure (HR = 1.121 for each unit increase in milligram per deciliter, 95% CI: 1.076–1.320, P = 0.015) after adjustment for covariates described above. But it was not significantly associated with graft loss (HR = 1.091, 95% CI: 0.898–1.210, P = 0.113) anymore. In contrast, death outcome did not show any correlation with both UA level and hyperuricemia which was obvious as demonstrated in Fig 6. And Table 8 provides all statistical evidences.


Serum Uric Acid and Renal Transplantation Outcomes: At Least 3-Year Post-transplant Retrospective Multivariate Analysis.

Zhang K, Gao B, Wang Y, Wang G, Wang W, Zhu Y, Yao L, Gu Y, Chen M, Zhou H, Fu Y - PLoS ONE (2015)

Kaplan-Meier survival curve estimates for death with functioning graft.No significant difference can be acquired on patient survival rate between these groups.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4514650&req=5

pone.0133834.g006: Kaplan-Meier survival curve estimates for death with functioning graft.No significant difference can be acquired on patient survival rate between these groups.
Mentions: To estimate the impact of UA level and hyperuricemia on long-term transplant outcomes, Cox proportional hazard model was used to adjust for confounding factors. In accordance with our expectation, hyperuricemia was found to be a significant predictor for graft loss (defined as allograft failure and death) during the study period(hazard ratio [36] = 2.17, 95% confidential interval[CI]:1.27–3.70, P = 0.004) as illustrated in Fig 4. However, it was not valid(HR = 1.59, 95% CI: 0.73–3.44, P = 0.241) after adjustment for age, gender, BMI, HLA mismatch, introduction regimen, immunosuppressive agent protocol, diabetic mellitus, dialysis type, DGF, infection and acute rejection episode. Further investigation showed that hyperuricemia was significantly an independent predictor of pure graft failure (HR = 4.01, 95% CI: 1.25–12.91, P = 0.02) after adjustment for the same confounding factors as previous. Kaplan-Meier survival curve for allograft failure was depicted in Fig 5. Then we tested UA level as a continuous variable to double confirm our results. Similar analysis showed that UA level was also independently associated with allograft failure (HR = 1.009 for each unit increase in milligram per deciliter, 95% CI: 1.001–1.018, P = 0.026). When tested for graft loss, unlike hyperuricemia, UA level indicated borderline significant independently (HR = 1.005, 95% CI: 1.000–1.011, P = 0.052). Although significant, the HRs were too small to provide a strong evidence that uric acid, as a numeric variable, is associated to overall graft loss (allograft kidney failure and death with functioning graft) or pure graft loss. So we included all qualified recipients (the newly recruited consecutive cohort was made up of kidney transplantation recipients from 2005 to 2008) in our center, in total 1203, to figure out whether uric acid level is an independent risk factor in another Cox proportional hazard model. Due to low data integrity (the degree of low-integrity do not allow us to include these group of patients in other analysis, but it was good enough for us to perform the statistics described below), we had to narrow covariates down to age, gender, BMI, uric acid, DGF, infection and acute rejection episode. The results were encouraging. Uric acid level was independently associated with pure graft failure (HR = 1.121 for each unit increase in milligram per deciliter, 95% CI: 1.076–1.320, P = 0.015) after adjustment for covariates described above. But it was not significantly associated with graft loss (HR = 1.091, 95% CI: 0.898–1.210, P = 0.113) anymore. In contrast, death outcome did not show any correlation with both UA level and hyperuricemia which was obvious as demonstrated in Fig 6. And Table 8 provides all statistical evidences.

Bottom Line: Hyperuricemia was significantly an independent predictor of pure graft failure (hazard ratio=4.01, 95% CI: 1.25-12.91, P=0.02) after adjustment.The results of our study suggest that post-transplant elevated serum uric acid level is an independent predictor of long-term graft survival and graft function.Together with the high TG level impact on poor outcomes, further investigations for therapeutic effect are needed.

View Article: PubMed Central - PubMed

Affiliation: Department of Urology/Transplant Center, First Hospital of Jilin University, Changchun, Jilin, China.

ABSTRACT
Since the association of serum uric acid and kidney transplant graft outcome remains disputable, we sought to evaluate the predictive value of uric acid level for graft survival/function and the factors could affect uric acid as time varies. A consecutive cohort of five hundred and seventy three recipients transplanted during January 2008 to December 2011 were recruited. Data and laboratory values of our interest were collected at 1, 3, 6, 12, 24 and 36 months post-transplant for analysis. Cox proportional hazard model, and multiple regression equation were built to adjust for the possible confounding variables and meet our goals as appropriate. The current cohort study lasts for 41.86 ± 15.49 months. Uric acid level is proven to be negatively associated with eGFR at different time point after adjustment for age, body mass index and male gender (standardized β ranges from -0.15 to -0.30 with all P<0.001).Males with low eGFR but high level of TG were on CSA, diuretics and RAS inhibitors and experienced at least one episode of acute rejection and diabetic issue were associated with a higher mean uric acid level. Hyperuricemia was significantly an independent predictor of pure graft failure (hazard ratio=4.01, 95% CI: 1.25-12.91, P=0.02) after adjustment. But it was no longer an independent risk factor for graft loss after adjustment. Interestingly, higher triglyceride level can make incidence of graft loss (hazard ratio=1.442, for each unit increase millimoles per liter 95% CI: 1.008-2.061, P=0.045) and death (hazard ratio=1.717, 95% CI: 1.105-2.665, P=0.016) more likely. The results of our study suggest that post-transplant elevated serum uric acid level is an independent predictor of long-term graft survival and graft function. Together with the high TG level impact on poor outcomes, further investigations for therapeutic effect are needed.

No MeSH data available.


Related in: MedlinePlus