Family recurrence and oligo-anuria predict uremic restless legs syndrome

OBJECTIVES

To determine clinical and laboratory predictors of restless legs syndrome (RLS) in patients with end-stage kidney disease (ESKD) undergoing long-term hemodialysis (HD).

MATERIALS AND METHODS

One hundred and sixty-two consecutive patients were assessed. History of sleep disturbances, neurological examination, clinical, and laboratory data were collected. Patients with and without RLS were compared, and a logistic regression model described the relations between independent predictors and RLS.

RESULTS

Fifty-one patients (32%) currently had RLS (RLS+). RLS+ vs RLS- patients were more frequently women (49% vs 29%, P = 0.012), had first-degree relative with RLS (22% vs 6%, P = 0.004), insomnia (59% vs 36%, P = 0.007), peripheral neuropathy (41% vs 21%, P = 0.006), and low residual diuresis (92% vs 68% with below 500 ml/24 h, P = 0.001). Low (OR = 8.71, CI = 2.27-33.41; P = 0.002) and absent (OR = 4.96, CI = 1.52-16.20; P = 0.008) residual diuresis, peripheral neuropathy (OR = 4.00, CI = 1.44-11.14; P = 0.008), and first-degree relative with RLS (OR = 3.82, CI = 1.21-12.13; P = 0.023) significantly predicted RLS in ESKD patients undergoing HD.

CONCLUSION

Positive family history for RLS together with reduced/absent residual renal function and peripheral neuropathy predicts the risk for RLS in ESKD patients undergoing HD. Longitudinal studies are warranted to correlate RLS occurrence with genetic and environmental factors.

Incidence of cancer in kidney transplantation waiting list patients: a single center experience

INTRODUCTION

It is widely accepted that the risk of malignancies is significantly increased among patients with end-stage kidney disease (ESKD) and after kidney transplantation compared with the general population. Only a few data are available on kidney transplantation waiting list patients. The aim of this study was to investigate solid organ cancer incidence among subjects on the waiting list at a single center.

MATERIALS AND METHODS

We retrospectively reviewed the records of all patients enrolled on our kidney transplantation waiting list between August 1, 2008 and July 31, 2010, seeking to evaluate the causes of withdrawal from the list, incidence of cancer, type of neoplasm, and its correlation with clinical features. We estimated the ratio of observed to expected numbers of cancers, the standardized incidence ratio (SIR).

RESULTS

Among 1184 patients, we excluded 569 patients from the waiting list including 26 (4.56%) who displayed malignancies. The overall incidence of cancer was 0.11 events/person-months and the overall prevalence of cancer was 2.2%. In 97% of patients, the malignant disease was confined to the primitive organ of origin without secondary dissemination. We observed a prevalence of cancers related to ESKD (17; 65.38%). The SIR for all cancer types in our population compared with the general population was 2.22. The SIR for native kidney and thyroid cancers among our population compared with the general population was >10.

CONCLUSION

The incidence of cancer was significantly increased among kidney transplantation waiting list patients compared with the general population. Our study highlighted the importance of a careful, targeted neoplastic screening. It could be particularly important for ESKD-related malignancies like native kidney tumors or thyroid cancers.

Alpine skiing and anaerobic performance in solid organ transplant recipients

Limited information has been published about sporting activities in solid organ transplant recipients. The aim of this study was to assess "in the field" performance capacities of a group of transplant recipients involved in an alpine skiing competition. We studied 16 transplant recipients (13 men and 3 women) who had undergone transplantations (11 kidney, 4 liver, and 1 heart) at 89 +/- 68 months prior while participating in an alpine skiing race. The patients performed a countermovement jumping test to measure the explosive power of the lower limbs. In all patients blood lactate concentrations (La) were measured at the end of a giant slalom race. The maximum displacement of the center of mass during the jumping test was 22.4 +/- 9.3 cm; the time to complete the giant slalom was 75.5 +/- 16.5 seconds and La was 3.5 +/- 0.8 mmol/L. We observed significant linear relationships between race time and La (R(2) = 0.4733; P < .01) and between race time and performance in the jumping test (R(2) = 0.3655; P < .05). This study indicated that recovery of anaerobic and technical sporting activities is possible in organ transplant recipients. Muscular power and anaerobic performances among a selected group of solid organ transplant recipients were similar to those of the general untrained population.

Native kidney function after renal transplantation combined with other solid organs in preemptive patients

Kidney transplantations combined with other solid organs are progressively increasing in number. There are no guidelines regarding the nephrologic indications for combined transplantations, namely liver-kidney (LKT), or heart-kidney (HKT), in preemptive patients with chronic kidney failure who are not on regular dialysis therapy. The objective of this study was to assess the functional contribution of the native kidneys after preemptive kidney transplantation combined with other solid organs. From 2004, 9 patients (aged 50.3 +/- 8.5 years) with chronic kidney failure (creatinine 2.5 +/- 1.0 mg/dL) caused by polycystic kidney disease (n = 4), vascular nephropathy (n = 2), interstitial nephropathy (n = 1), glomerulonephritis (n = 1), or end-stage kidney disease (n = 1), underwent combined transplantations (8 LKT, 1 HKT). A scintigraphic functional study (Tc-99DMSA or Tc-99mMAG3), was performed at 4 +/- 3 months after transplantation to evaluate the functional contribution of both the native kidneys and the graft. All patients were given immunosuppressive drugs, including a calcineurin inhibitor (tacrolimus/or cyclosporine). At the time of scintigraphy, renal function in all patients was 1.3 +/- 0.3 mg/dL. The functional contribution of the transplanted kidneys was on average 77 +/- 18%. Only in 1 patient was the contribution of the graft <50%. At follow-up after 36 months, patient and kidney survivals were 100%. The study confirmed a high risk of loss of native kidney function in the presence of organic nephropathy. In light of our experience, a creatinine clearance <30 mL/min in an appropriate cutoff for a combined transplantation. Close clinical and instrumental assessment pretransplant is essential before proceeding with a combined transplant program to exclude functional forms and to optimize the use of organs.

[Factors determining cardiovascular disease progression after kidney transplant]

Cardiovascular disease is the leading cause of mortality and morbidity in renal transplant recipients as well as the leading cause of death with a functioning graft. The high cardiovascular risk is attributable to the prolonged exposure to multiple traditional and nontraditional risk factors in the pretransplant and posttransplant period. Particular attention must be paid to cardiovascular screening of candidates for kidney transplantation. After a transplant, treatment and prevention strategies should be focused on the modifiable risk factors including smoking, dietary habits, physical activity, weight control, hypertension, and dyslipidemia. Further studies on these factors are needed to better define the pharmacological approaches (hypotensive or hypolipemic drugs) and therapeutic targets. In view of the role of immunosuppressive therapy in the onset or worsening of several risk factors, it is important to tailor the treatment approach and dosage to the cardiovascular risk profile of the individual patient.

[Low-toxicity immunosuppressive therapy in renal transplant]

INTRODUCTION

Renal allograft loss in the long term may be due to the death of a patient with a functioning graft or to chronic allograft nephropathy. One of the most important factors in the development of chronic allograft nephropathy is drug nephrotoxicity. The term nephrotoxicity comprises two distinct forms of renal injury: acute and chronic. Immunosuppressive drugs, and in particular calcineurin inhibitors, have a variety of side effects including nephrotoxicity. The nephrotoxicity associated with calcineurin inhibitors is well known; this association has also been described for the newer agents.

METHODS

We reviewed a large number of recent studies that attempted to reduce the toxicity of immunosuppressive regimens.

RESULTS

A number of low-toxicity protocols have been developed. Encouraging results have been obtained with regimens that reduce or eliminate nephrotoxicity-inducing calcineurin inhibitors and with regimens that reduce or eliminate steroids, which are responsible for many diseases that may lead to the death of the patient, even with a functioning graft.

CONCLUSION

All immunosuppressive drugs may be nephrotoxic, even if they act through different mechanisms. Combining different drugs at low dosage would therefore seem the best solution. It is not yet clear which regimens will be the most effective from the point of view of maximizing patient and graft survival, minimizing rejection, and minimizing adverse events.

Predictive Factors in Chronic Allograft Nephropathy

Chronic allograft nephropathy (CAN) is characterized by progressive renal dysfunction leading in many cases to graft loss. The pathogenesis of CAN involves both immune and nonimmune factors. Concerning immune factors, one of the most remarkable predictors of CAN is acute rejection, which is associated with a worse prognosis if there are multiple episodes or when late onset occurs. Delayed graft function is also a major risk factor for CAN because of a correlation between late restoration of renal function after transplantation and long-term decreased graft survival. High creatinine levels at 6 months and 1 year after transplantation, proteinuria, viral infections, and cardiovascular risk factors are additional significant parameters for the development of CAN. Recent findings suggest that a high renal segmental arterial resistance index measured by Doppler ultrasonography in intrarenal vessels is associated with poor allograft function. Moreover, the study of patient genetic profile represents a new approach to identify predictive factors for CAN.