肾移植术后发生高尿酸血症的机制

目的：探讨肾移植术后发生高尿酸血症的机制及防治策略。方法：分析480例肾移植术后患者的临床资料。结果：肾移植术后移植肾功能正常而血尿酸增高者43例(9％)，其中痛风7例，移植肾肾盂或输尿管结石3例。随访1～5年，1例痛风患者血尿酸及症状控制不理想，余血尿酸均控制在正常水平，未见并发症的发生。结论：高尿酸血症是肾移植术后较常见的问题，发生原因较多，但主要与环孢素A的作用有关；长期降尿酸及碱化尿液治疗安全、有效。     

Hyperuricemia after renal transplantation

Background

Hyperuricemia is a common complication after kidney transplantation, and may adversely affect graft survival.

Objective

To assess the prevalence of and predictors for development of hyperuricemia after renal transplantation.

Materials and Methods

Hyperuricemia was defined as a serum uric acid concentration of at least 7.0 mg/dL in men and 6.0 mg/dL in women. From March 2008 to May 2010, uric acid concentration was measured in 12,767 blood samples from 2961 adult renal transplant recipients (64% male and 36% female patients).

Results

Hyperuricemia was observed in 1553 patients (52.4%). The disorder frequently occurred in women (P = .003) and in patients with impaired renal graft function (P = .00). After adjustment for sex, serum creatinine concentration, diabetes mellitus, cyclosporine concentration, and dyslipidemia, only female sex (P = .03) and renal allograft dysfunction (P = .05) were associated with hyperuricemia after kidney transplantation.

Conclusion

Hyperuricemia is a common complication after kidney transplantation, and renal allograft insufficiency predisposes to higher uric acid concentration.     

Hyperuricemia, gout, and renal function after liver transplantation.

BACKGROUND: Hyperuricemia is a recognized complication of renal and cardiac transplantation, but the development of hyperuricemia and gout following liver transplantation have received less attention. We have retrospectively assessed the prevalence of hyperuricemia in 134 consecutive liver transplant recipients. RESULTS: Forty-seven percent of the liver transplant recipients studied had hyperuricemia. Serum creatinine was higher in hyperuricemic than in nonhyperuricemic patients. Peak uric acid correlated significantly with corresponding serum creatinine (rs=0.694). Only 6% developed gout. All the patients with gout and 10 hyperuricemic patients with renal impairment but without gout were treated with allopurinol. Over a median period of 3 months, mean serum creatinine fell from 177 micromol/l to 160 micromol/l (P=0.01), without change in type or dose of immuno-suppression. CONCLUSIONS: There is an important association between liver transplantation and hyperuricemia. Treatment with allopurinol results in a significant reduction in serum creatinine in patients with gout and in those with hyperuricemia and renal impairment.     

Hyperuricemia and gout following pediatric renal transplantation

Hyperuricemia and gout are common complications in adult renal transplant recipients. In pediatric recipients, however, hyperuricemia seems to be rare, but data are scarce. Thirty-two children (21 males, 11 females) were investigated for a median time of 4.8 years (range: 0.4–11.2 years) following renal transplantation. The median age of this pediatric study group was 13.9 years (range: 5.7–20.3 years), and the calculated glomerular filtration rate (GFR) was 61 ml/min per 1.73 m² (range:12–88 ml/min per 1.73 m²). All patients were given calcineurin inhibitors, with 22 and ten children receiving cyclosporine A (CSA) and tacrolimus (TAC), respectively. The median plasma uric acid was 385 μmol/l (range: 62–929 μmol/l); 15 children (47%) were above the age-related normal range. Only one patient experienced gouty arthritis. There was a significant correlation between plasma uric acid concentration and both time span after transplantation and plasma creatinine, and an inverse correlation to GFR (p<0.05). No significant correlation was found between plasma uric acid and body mass index (BMI). Plasma uric acid concentrations were neither different among CSA- and TAC-treated children, nor did they correlate with drug exposure or blood trough levels of CSA or TAC. Plasma uric acid concentration was not different when compared to children with chronic renal failure (CRF) of a similar degree in native kidneys. We conclude that hyperuricemia is common among pediatric renal transplant recipients and rather a consequence of chronic renal transplant dysfunction than the use of calcineurin inhibitors. Gout, however, is rare.     

高尿酸血症与肾损害

随着高尿酸血症发病率的逐年增高,其所引起的肾脏损害越来越受到重视,本文就原发性高尿酸血症的研究现状及其所致肾损害的机制及治疗等相关方面作一综述.     

Pancreatitis after renal transplantation

Five cases of fatal pancreatitis in a series of eighty-six renal allotransplants illustrate the difficulties of diagnosis and treatment of this complication. Pancreatitis after renal transplantation may be caused by steroid medication, hyperparathyroidism, surgical trauma to the pancreas, autorejection, or viral pancreatitis. We suggest alert early detection, appropriate standard treatment, and reduction of steroids as the best steps now available to improve survival of the patient.     

Hypertension after renal transplantation

Hypertension is a common and serious complication after renal transplantation. It is an important risk factor for graft loss and morbidity and mortality of transplanted children. The etiology of posttransplant hypertension is multifactorial: native kidneys, immunosuppressive therapy, renal-graft artery stenosis, and chronic allograft nephropathy are the most common causes. Blood pressure (BP) in transplanted children should be measured not only by casual BP (CBP) measurement but also regularly by ambulatory BP monitoring (ABPM). The prevalence of posttransplant hypertension ranges between 60% and 90% depending on the method of BP measurement and definition. Left ventricular hypertrophy is a frequent type of end-organ damage in hypertensive children after transplantation (50–80%). All classes of antihypertensive drugs can be used in the treatment of posttransplant hypertension. Hypertension control in transplanted children is poor; only 20–50% of treated children reach normal BP. The reason for this poor control seems to be inadequate antihypertensive therapy, which can be improved by increasing the number of antihypertensive drugs. Improved hypertension control leads to improved long-term graft and patient survival in adults. In children, there is a great potential for antihypertensive treatment that could also result in improved graft and patient survival.     

Cancers after renal transplantation

For patients with end-stage kidney failure, kidney transplantation improves both their quality of life and overall life expectancy compared with dialysis, but it is not without adverse effects. Cancer is second to cardiovascular disease as one of the major causes of morbidity and mortality in renal transplant recipients. Prolonged use of modern immunosuppression, which leads to alteration of immune function and immune surveillance, is associated with increased cancer risk. There is now convincing evidence from observational studies and registry data to confirm a 3- to 5-fold increase in overall cancer incidence, with viral-related neoplasia incurring the greatest risk when compare with the general population. Despite the increased risk, little is known about the overall cancer prognosis, screening, treatment strategies, and effectiveness in this population. Cancers can recur, occur de novo, and be transmitted from donor organs posttransplantation. Uncertainties exist as to how modern immunosuppressive agents impact on cancer management and outcomes in these patients, with some agents such as calcineurin inhibitors and azathioprine, being more carcinogenic than others. The newer agents, proliferation signal/mammalian target of rapamycin inhibitors and mycophenolate mofitil, may have some antiproliferative and antitumor activities demonstrated in preclinical and clinical studies, but long-term well-powered trial data are needed to determine whether they are either protective or curative for cancers in renal transplant recipients. In this review, the incidence, etiology, prognosis, and potential approaches to cancer screening and management post–renal transplantation are discussed.     

Exercise after renal transplantation

Renal transplant recipients experience troublesome side effects of the immunosuppression medication, many of which may be attenuated or ameliorated with regular physical activity. Preliminary data show that exercise training after transplantation increases exercise capacity and muscle strength and may contribute to higher quality of life after transplantation.     

Sarcoidosis after renal transplantation

This is the case of a 41-year-old renal transplant recipient taking tacrolimus immunosuppressive therapy, who had a large pleural effusion, found on a chest radiograph during the work-up of digital clubbing. The patient had undergone a renal transplant 17 months earlier for end-stage renal disease secondary to immunoglobulin A nephropathy. Analysis of the effusion fluid demonstrated a lymphocytic exudate. Biopsy specimens of pleural and lung tissues showed noncaseating granulomas. Fluid and tissue cultures were negative for viral, fungal, and bacterial pathogens. Diagnosis of sarcoidosis was established by identification of noncaseating granulomas in pleural and lung tissue, the exclusion of other conditions, and rapid resolution of the effusion after the institution of corticosteroid therapy. The patient has remained free of pulmonary symptoms and had normal chest radiographs during the 20-month follow-up period.     

Growth after renal transplantation

Growth may be severely impaired in children with chronic renal insufficiency. Since short stature can have major consequences on quality of life and self-esteem, achieving a ‘normal’ height is a crucial issue for renal transplant recipients. However, despite successful renal transplantation, the final height attained by most recipients is not the calculated target height. Catch-up growth spurts post-transplantation are usually insufficient to compensate for the retardation in growth that has occurred during the pre-transplant period. Longitudinal growth post-transplantation is therefore influenced by the age at transplantation but also by subsequent allograft function and steroid exposure, both of which interfere with the growth hormone/insulin-like growth factor axis. The management of growth retardation in renal transplant recipients includes adequate nutritional intake, correction of metabolic acidosis, prevention of bone disease, steroid-sparing strategies and a supraphysiological dose of recombinant human growth hormone in selected cases.     

Cancer after renal transplantation

PURPOSE OF REVIEW: Prolonged waiting times for renal transplantation, an increase in the average age of recipients, decreased acute rejection rates due to use of newer potent immunosuppressives and improving long-term transplant survival have raised concerns in the transplant community regarding posttransplant cancer. In view of the fact that transplant recipients are living longer, it is of paramount importance that we continue to translate discoveries at the bench to the bedside and document cancers in the posttransplant recipient registries. Analysis of data will help in optimizing patient management. RECENT FINDINGS: Recent evidence indicates that sirolimus is associated with a decreased incidence of posttransplant de-novo cancer and remission of Kaposi's sarcoma and nonmelanoma skin cancer. Mycophenolate mofetil has been shown to have an antiproliferative activity against leukemia and lymphoma and an anti-tumor effect against colon and prostate cancer. Clinically it has been shown to be associated with a reduced incidence of cancers like posttransplant lymphoproliferative disorder. SUMMARY: Appropriate selection of transplant candidates, pretransplant and posttransplant cancer surveillance and judicious evidence-based use of newer immunosuppressants may help reduce the incidence and improve the outcome of posttransplant cancer.     

Anemia after renal transplantation

The study aimed the estimation of posttransplantant anemia (PTA) frequency between the recepients of allogenic kidneys and testing the influence of different factors on the anemia development. The study was ased on the analysis of 129 patients with ERSD, to whom 129 donor kidneys were grafted. An actuarial survival of patients and allografts were calculated. The analysis demonstrated that a duration of the pretranplant hemodialysis influences the dynamics of hemoglobin level and the red blood cells count. The shorter were the dialysis terms, the easier was the anemia to correct. Shorter terms of the pretransplant dialysis also correlated with the higher rates of the overall survival after the transplantation.     

Tuberculosis after renal transplantation

Tuberculosis (TB) remains a major public health problem in our country. Its diagnosis in immunodeficient patients is difficult. In this retrospective study, we analyzed the prevalence, clinical presentation, and outcome of TB after renal transplantation (RT) in our Tunisian team's experience. Among 359 renal transplant recipients, 9 (2.5%) developed TB at 49.6 months (range, 3-156 months) after RT. There were 7 men and 2 women of mean age 37.8 years (range, 15-53 years). The organs involved included lymph nodes in 1 case; lung in 5 cases; genitourinary system in 1 case; rachis in 1 case; pleural in 1 case; and both pulmonary and urinary systems in 1 case. The diagnosis was bacteriologic in 6 cases; histologic in 1 case; and 2 patients had a high index of suspicion. All patients were treated with a combination of rifampicin, isoniazide, pyrazinamide, and ethambutal. Recurrence of TB infection was noted in 3 cases with multiple localizations: lymph node, muscle abscess, meningitis, genitourinary system, rachis, and lung. Two patients died. In conclusion, among renal transplant patients, extrapulmonary involvement and recurrence of TB were frequent.