Weight Gain After Living-Related Renal Transplantation Affects Long-Term Graft Function

Nutritional management in renal transplant recipients: A transplant team opportunity to improve graft survival

AIMS

The nutritional management of renal transplant recipients (RTR) represents a complex problem either because the recovery of renal function is not complete and for the appearance of "unavoidable" metabolic side effects of immunosuppressive drugs. Nevertheless, it remains a neglected problem, whereas an appropriate dietary intervention could favorably affect graft survival.

DATA SYNTHESIS

Renal transplantation is associated with steroids and calcineurin inhibitors administration, liberalization of diet after dialysis restrictions, and patients' better quality of life. These factors predispose, from the first months after surgery, to body weight gain, enhanced post transplant diabetes, hyperlipidemia, metabolic syndrome, with negative consequences on graft outcome. Unfortunately, specific guidelines about this topic and nutritional counseling are scarce; moreover, beyond the low adherence of patients to any dietary plan, there is a dangerous underestimation of the problem by physicians, sometimes with inadequate interventions. A prompt and specific nutritional management of RTR can help prevent or minimize these metabolic alterations, mostly when associated with careful and repeated counseling.

CONCLUSIONS

A correct nutritional management, possibly tailored to enhance patients' motivation and adherence, represents the best preventive maneuver to increase patients' life and probably improve graft survival, at no cost and with no side effects.

Early weight changes after liver transplantation significantly impact patient and graft survival

BACKGROUND AND AIM

Associations between pre-liver transplantation (pre-LT) BMI and post-LT survival are well described; however, there are few data assessing the associations between the commonly observed post-LT BMI changes and survival. We investigated the impact of early post-LT BMI change on post-LT patient and graft survival.

METHODS

Using United Network for Organ Sharing data, we identified 2968 adult primary LT recipients who were not overweight pre-LT (BMI >16 to ≤25 kg/m), and who had BMI recorded at 2 years post-LT. Delta BMI was defined as the BMI difference between pre-LT and 2 years post LT. Recipients were grouped into three categories: BMI gain (increase by >1 BMI point), BMI loss (decrease by >1 BMI point), and BMI stable (maintained BMI within 1 point). Associations between delta BMI and patient and graft survival were evaluated using Kaplan-Meier and multivariable Cox regression analyses.

RESULTS

BMI gain was common (54%) and associated with significantly greater 5-year patient and graft survival (90 and 89%, respectively), compared with recipients who had either BMI loss (77 and 74%, respectively, P<0.0001 for both) or were BMI stable (83%, P=0.04 and 82%, P=0.007, respectively). In multivariable analyses, increasing delta BMI was found to be inversely associated with risk for death and graft loss [hazard ratio 0.89 (95% confidence interval 0.86-0.91), P<0.001; and hazard ratio 0.88 (95% confidence interval 0.86-0.91), P<0.001, respectively].

CONCLUSION

This study of a large national liver transplant database demonstrated that post-LT BMI gain was associated with better patient and graft survival, whereas BMI loss was associated with reduced patient and graft survival.

Factors increasing quantitative interstitial fibrosis from 0 hr to 1 year in living kidney transplant patients receiving tacrolimus

BACKGROUND

This study investigated the increase in interstitial fibrosis (IF) from 0 hr to 1 month and 1 year posttransplantation in biopsy sections and assessed the risk of developing IF in 118 living kidney recipients.

METHODS

A quantitative analysis of IF was performed using computer-assisted imaging. The percent IF (%IF) in the cortical region at 0 hr was defined as the baseline, and the increases in %IF at 1 month and 1 year were calculated. Demographics, higher (regimen 1) and lower (regimen 2) target trough concentrations of tacrolimus, and the cytochrome P450 (CYP) 3A5 polymorphism were tested as risk factors.

RESULTS

The mean %IF at 0 hr, 1 month, and 1 year was 10.3%+/-4.2%, 15.0%+/-5.8%, and 19.0%+/-7.7%, respectively. %IF increased 1.7- and 2.2-fold from 0 hr to 1 month and 1 year posttransplantation, respectively. At 1 year, the increase was higher in patients with the CYP3A5*3/*3 genotype (nonexpressers), those treated with regimen 1, and those with a lower estimated glomerular filtration rate and higher body mass index. In a multivariate analysis, CYP3A5 nonexpression correlated with the development of IF (odds ratio 2.63, P=0.018). Tacrolimus blood levels in the early stage posttransplantation were higher in nonexpressers than CYP3A5 expressers in both regimens 1 and 2, despite therapeutic drug monitoring.

CONCLUSIONS

The higher concentrations of tacrolimus, especially in the nonexpressers treated with regimen 1, might influence the development of IF. This study suggested that a new regimen with lower and narrow target trough levels of tacrolimus or a dosing strategy based on the CYP3A5 genotype is needed to reduce the risk of developing IF.

Patterns of chronic injury in pediatric renal allografts

BACKGROUND

In pediatric recipients, the pathophysiology of chronic renal allograft injury is poorly understood.

METHODS

We studied the evolution and determinants of tubulointerstitial, vascular, and glomerular injury in 240 pediatric protocol renal allograft biopsies during the first 5 years posttransplant.

RESULTS

Chronic tubulointerstitial injury (ci, ct) developed predominantly during the first 12 months posttransplant, whereas chronic vascular damage (cv, and arteriolar hyalinosis [ah]) and global glomerulosclerosis (gs) became increasingly prevalent at 25 to 36 months and beyond. Chronic interstitial lesions were associated with acute rejection and borderline histology (odds ratio [OR] 2.3, P<0.04), recipient body surface area less than 1.0 m2 (OR 3.6, P<0.05), and obesity (OR 2.0, P<0.03). Determinants of ct were acute rejection (OR 2.6, P=0.02) and acute tubular necrosis (OR 2.8, P<0.04). Vascular fibrous intimal thickening and ah were associated with donor hypertension (OR 3.6, P=0.001) and recipient body surface area less than 1.0 m (OR 2.6, P=0.02), respectively. The severity of ah correlated with the incidence of gs (r=0.32, P<0.0001), with 7.8% gs for ah0, 14.3% gs for ah1, 60.0% gs for ah2, and 95.5% gs for ah3 (median values). Antibody induction conferred protection from ci (OR 0.31, P=0.008), ct (OR 0.33, P=0.002), and ah (OR 0.12, P<0.001) progression.

CONCLUSIONS

By 5 years posttransplant, pediatric renal allografts manifest a substantial burden of tubulointerstitial and microvascular injury. These lesions are associated with donor hypertension, acute inflammation, renal hypoperfusion, obesity, and calcineurin inhibitor toxicity. The pervasiveness and rapid progression of microvascular lesions at 25 to 36 months suggest that attempts at reducing calcineurin inhibitor exposure should be made before two years posttransplant.

Post-kidney transplant weight change as marker of poor survival outcomes

BACKGROUND

There are few studies on the associations of postkidney transplant weight change on survival. Weight change in different posttransplant periods may have different causes and implications. We used the Australian and New Zealand Dialysis and Transplant Registry data to examine these issues.

METHODS

All adult white primary kidney transplant recipients from April 1991 to December 2004 were included. The associations of first (year 1, n=3899) and second (year 2, n=3419) year weight change with subsequent graft and patient survival were analyzed using multivariable Cox regression.

RESULTS

Weight gain 10% to 19.9% in year 1 and stable weight (0%-4.9% gain) in year 2 were associated with the best outcomes. Weight loss more than 5% was associated with subsequent death (year 1 adjusted hazard ratio [aHR]=1.64 [1.08-2.48], P=0.019; year 2 aHR=2.09 [1.44-3.02], P=0.013) but not death-censored graft loss. Weight gain more than or equal to 20% in year 1 and more than or equal to 10% weight gain in year 2 were also associated with subsequent death (year 1 aHR=1.78 [1.13-2.81], P=0.013; year 2 aHR=1.67 [1.01-2.76], P=0.047). These associations were minimally changed by excluding outcomes within 1 year of the weight change. Deaths were from cardiovascular disease (35%), cancer (35%), infections (15%), and "other" causes (15%). Weight gain more than or equal to 20% in year 1 was associated with infection or "other" deaths, and weight loss more than 5% or weight gain more than or equal to 10% in year 2 with cardiovascular deaths.

CONCLUSIONS

Significant posttransplant weight gain or loss was associated with poorer transplant outcomes. Reasons underlying these associations may differ between year 1 and year 2 weight changes.

Association of cytokine polymorphisms with subclinical progressive chronic allograft nephropathy in Japanese renal transplant recipients: preliminary study

BACKGROUND

The present study calculated the risk of developing subclinical progressive chronic/sclerosing allograft nephropathy (CAN) under tacrolimus-based immunosuppression according to genetic polymorphisms of cytokines and growth factors, and clinical events including delayed graft function (DGF), acute rejection (AR) and cytomegalovirus (CMV) infection.

METHODS

The subjects were 50 recipients with stable graft function more than one year after renal transplantation. The criteria for subclinical progressive CAN were CAN grade 2 or 3 changes on Banff classification and stable serum creatinine (SCr) levels. Ten genetic polymorphisms were assessed.

RESULTS

Eleven patients (22.0%) developed progressive CAN. The mean ages and SCr levels of recipients with and without progressive CAN were 41.2 and 47.1 years, and 1.46 and 1.22 mg/dL, respectively. There were no significant differences in donor age, number of HLA mismatches, DGF or CMV infection. Although the rate of AR episode seemed to be greater in patients with subclinical progressive CAN, the difference did not reach significance (P = 0.093). The frequencies of the interleukin (IL)-2 T-330G TT genotype (P = 0.046) and IL-4 C-590T C allele (P = 0.092) were higher in patients with progressive CAN. In univariate analysis, the presence of IL-2 T-330G TT (OR 4.57, P = 0.044) was associated with CAN development.

CONCLUSION

The presence of IL-2 T-330G TT genotype may be a risk factor for CAN. Further studies with a large number of subjects and analyses of many cytokine polymorphisms would contribute to the ability to make prognostic determinations or tailor immunomodulatory regimens after renal transplantation.

High-risk constellation in living renal transplantation

There is only limited information about recipient risk factors for graft survival in living- donor kidney transplantation. This study aimed to investigate prognostic factors and their impact on living-related and unrelated renal transplant recipients. From October 2000 until October 2004, 81 adult living-related renal transplantations were performed at our institution. Using multivariate analysis, the association of the following variables with kidney graft outcome was studied: ages of donors and recipients, gender and body mass index, cold and warm ischemia, HLA mismatches, identity and compatibility of blood group, duration of dialysis, cytomegalovirus (CMV) status, recipient original disease, surgical and general complications, and status of retransplantation. Multivariate analysis revealed significant reduction of graft function and graft survival in recipients with retransplantation, more than 4 mismatches, and a high body mass index. Thus, living-donor kidney transplantation can be regarded as a safe and standardized operation relating to surgical technique, but further consideration of the recipient body mass index and the number of mismatches are recommended during the preparation for transplantation.