The beneficial effects of calcium channel blockers on long-term kidney transplant survival are independent of blood-pressure reduction

Unique Considerations When Managing Hypertension in the Transplant Patient

For the select fortunate recipients of organ transplants, transplantation affords the rare opportunity for a new life. Given the scarcity of organs for transplantation, it is imperative that the health of transplant recipients be optimized in order to fully benefit from this gift of life. Unfortunately, hypertension is highly prevalent in the transplant population and it is considered a major cardiovascular risk factor contributing to mortality and morbidity in this population. In this chapter, we expound on the epidemiology, unique pathophysiology, evaluation, and management of hypertension as it pertains to the solid organ transplant recipient. In addition, a brief commentary is made on the subject of hypertension following living kidney donation, and practical aspects of management of hypertension in the solid organ recipient are summarized at the end of the chapter.

Serum free sulfhydryl status is associated with patient and graft survival in renal transplant recipients

Oxidative stress contributes significantly to graft failure, morbidity and mortality in renal transplant recipients (RTR). In cells, free sulfhydryl groups (reduced thiols, R-SH) are the transducers of redox-regulated events; their oxidation status is modulated by interaction with reactive oxygen and nitrogen oxide species and thought to be in equilibrium with the circulating pool. We hypothesized that high levels of serum free thiols are a reflection of a favorable redox status and therefore positively associated with cardiovascular risk parameters, patient and graft survival in RTR. To test this, reactive free thiol groups (R-SH; corrected for total protein) were quantified in serum of 695 RTR (57% male, 53±13yr, functioning graft ≥1yr) using Ellman's Reagent, and R-SH determinants were evaluated with multivariable linear regression models. Associations between R-SH and mortality or graft failure were assessed using multivariable Cox regression analyses. In multivariable models, male gender, estimated glomerular filtration rate and serum thiosulfate positively associated with R-SH while BMI, HbA1c, corrected calcium and NT-pro-BNP inversely associated with R-SH (model R²=0.26). During follow-up (3.1 [2.7-3.9] yrs), 79 (11%) patients died and 45 (7%) patients developed graft failure. R-SH correlated inversely with all-cause mortality (HR 0.58 [95% CI 0.45-0.75] per SD increase) and graft failure (HR 0.42 [0.30-0.59]; both P<0.001), independent of parameters with which R-SH significantly associated in the multivariable regression analyses, except for NT-pro-BNP. Serum R-SH are associated with a beneficial cardiovascular risk profile and better patient and graft survival in RTR, suggesting potential usefulness as low-cost, high-throughput screening tool for whole-body redox status in translational studies. Whether R-SH modification improves long-term outcome of RTR warrants further exploration.

Hypertension: The Neglected Complication of Transplantation

Arterial hypertension and transplantation are closely linked, and its association may promote impaired graft and overall survival. Since the introduction of calcineurin inhibitors, it is observed in 50–80% of transplanted patients. However, many pathophysiological mechanisms are involved in its genesis. In this review, we intend to provide an updated overview of these mechanisms, dealing with the causes common to all kinds of transplantation and emphasizing special cases with distinct features, and to give a perspective on the pharmacological approach, in order to help clinicians in the management of this frequent complication.

Reducing the risks of cardiovascular disease in liver allograft recipients

Liver allograft recipients are at increased risk of death from cerebrovascular and cardiovascular disease. We propose the following strategy of risk-reduction, based on currently available literature. Lifestyle: standard advice should be given (avoidance of smoking, excess alcohol and obesity, adequate exercise, reduction of excess sodium intake). Hypertension: target blood pressure should be 140/90 mmHg or lower, but for those with diabetes or renal disease, 130/80 mmHg or lower. For patients without proteinuria, antihypertensive therapy should be initiated with a calcium channel blocker and for those with proteinuria, an angiotensin-converting enzyme (ACE) inhibitor or angiotensin II receptor blocker. If monotherapy fails to achieve adequate response, calcium channel blockers and ACE-inhibitors or angiotensin II receptor blockers should be combined. If hypertension remains uncontrolled, an alpha-blocker may be added. Consideration should be given to changing immunosuppression and avoiding use of calcineurin inhibitors. Diabetes: recipients should be regularly screened for diabetes. For patients with new-onset diabetes after transplant, stepwise therapy should be guided by HbA1c concentrations, as with type II diabetes mellitus. Hyperlipidemia: annual screening of lipid profile should be undertaken, with treatment thresholds and targets based on those advocated for the high risk general population. Dietary intervention is appropriate for all patients. A statin should be considered as the first line treatment to achieve specified targets. In patients receiving a calcineurin inhibitor, Pravastatin should be commenced at a dose of 10 mg/day. In patients receiving other forms of immunosuppression, pravastatin may be commenced at a dose of 20 mg/day. Liver tests should be monitored and patients warned to report myalgia. If monotherapy is inadequate, ezetimibe or a fibrate may be added. Consideration may be given to change in immunosuppression if combination lipid-lowering therapy proves inadequate.

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.

Comparison between swallowing and chewing of garlic on levels of serum lipids, cyclosporine, creatinine and lipid peroxidation in renal transplant recipients

Hyperlipidemia and increased degree of oxidative stress are among the important risk factors for Atherosclerosis in renal transplant recipients (RTR). The Medical treatment of hyperlipidemia in RTR because of drugs side effects has been problematic, therefore alternative methods such as using of Garlic as an effective material in cholesterol lowering and inhibition of LDL Oxidation has been noted. For evaluation of garlic effect on RTR, 50 renal transplant patients with stable renal function were selected and divided into 2 groups. They took one clove of garlic (1 gr) by chewing or swallowing for two months, after one month wash-out period, they took garlic by the other route. Results indicated that although lipid profile, BUN, Cr, serum levels of cyclosporine and diastolic blood pressure did not change, Systolic blood pressure decreased from 138.2 to 132.8 mmHg (p=0.001) and Malondialdehyde (MDA) decreased from 2.4 to 1.7 nmol/ml (p=0.009) by swallowing route, Cholesterol decreased from 205.1 to 195.3 mg/dl (p=0.03), triglyceride decreased from 195.7 to 174.8 mg/dl (p=0.008), MDA decreased from 2.5 to 1.6 nmol/ml (p=0.001), systolic blood pressure decreased from 137.5 to 129.8 mmHg (p=0.001), diastolic blood pressure decreased from 84.6 to 77.6 mmHg (p=0.001) and Cr decreased from 1.51 to 1.44 mg/dl (p=0.03) by chewing route too. However HDL, LDL and cyclosporine serum levels had no significant differences by both of swallowing and chewing routes. We conclude that undamaged garlic (swallowed) had no lowering effect on lipid level of serum. But Crushed garlic (chewed) reduces cholesterol, triglyceride, MDA and blood pressure. Additionally creatinine reduced without notable decrease in cyclosporine serum levels may be due to cyclosporine nephrotoxicity ameliorating effect of garlic.

Post-transplant nephrotic syndrome: A comprehensive clinicopathologic study

BACKGROUND

Post-transplant (Tx) nephrotic syndrome (NS) is not well defined.

METHODS

Seventy-four renal transplant recipients with NS were studied.

RESULTS

Biopsies showed chronic allograft nephropathy (CAN) in 31 patients; recurrent glomerular disease (GN) in 15, de novo GN in 18, and undetermined GN in 9. NS developed 0.25 to 384 months post-Tx and was treated with angiotensin-converting enzyme inhibitors (ACEI) or angiotensin receptor blockers (ARB) in 18 patients; calcium channel blockers in 25; or both drugs in 31. NS remitted in 24% of cases 2 to 28 months after onset, and this persisted in all except 3 patients. The remission rate was lowest (9%) for CAN and highest (47%) for de novo GN. Compared with persistent NS, those with remission showed higher prevalence of de novo GN (53% vs. 17%), lower prevalence of CAN (18% vs. 50%), earlier onset of NS (39 vs. 59 months), lower serum SCr at onset (2.3 vs. 2.9 mg/dL), and higher incidence of treatment with ACE or ARB. The 5-year graft loss rates for CAN, recurrent and de novo GN were 57%, 36%, and 23%, respectively. Compared with the functioning grafts, the failed grafts showed higher prevalence of CAN (60% vs. 16%), lower prevalence of de novo GN (12% vs. 46%), earlier onset of NS (47 vs 65 months post-Tx), higher serum SCr at onset (3.3 vs. 2.0 mg/dL), lower prevalence of remission of NS (5% vs. 48%), and higher proteinuria at follow-up (5.1 vs. 2.5 g/day). Graft survival improved with NS remission (88% vs. 18%).

CONCLUSION

Post-Tx NS displays distinctive clinicopathologic features with pathogenetic and therapeutic implications.

The remission of post-transplant nephrotic syndrome clinicopathologic characterization

Among 67 renal transplant recipients with nephrotic syndrome (NS), nine episodes were reversible in eight patients. Biopsies showed minimal-change disease, focal segmental membranous glomerulonephritis and acute glomerulitis, IgA nephropathy and acute glomerulitis or thrombotic microangiopathy, and chronic transplant nephropathy with or without acute glomerulitis. NS developed 1-4 months post transplant in the four patients with minimal-change disease, but later (33-151 months) in the others. At onset, serum creatinine was normal or elevated. Treatment included calcium-channel blockers, angiotensin-converting enzyme inhibitors, or both, together with routine antirejection therapy. Remission was achieved 4-12 months after onset, when renal function remained normal in four, improved in four, and worsened in one. At last follow-up, six patients still had remission and functional grafts. One lost graft to chronic transplant nephropathy while NS remained in remission. In the remaining patient, proteinuria, which was due to chronic transplant glomerulopathy unrelated to the initial minimal-change disease-associated NS, recurred 50 months post transplant. Remission of post-transplant NS is possible. It is often associated with minimal-change diseases and less frequently with other glomerular lesions, including acute glomerulitis. Reversible post-transplant NS does not have an adverse effect on the renal allografts.