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

Hyperuricemia is common in cyclosporine-treated renal allograft recipients. An increased incidence of gout in patients receiving both diuretics and cyclosporine has been reported, but the effect of hyperuricemia on renal allograft function has not been studied. In a prospective, randomized trial of cyclosporine and prednisone versus azathioprine, prednisone, and antilymphocyte globulin for immunosuppression in renal allograft recipients, 105 of 131 cyclosporine and prednisone-treated patients (80 percent) experienced hyperuricemia (serum uric acid level above 8 mg/dl) and 13 of 131 (10 percent) were severely hyperuricemic (serum uric acid level above 14 mg/dl). In contrast, hyperuricemia developed in 63 of 115 patients (55 percent) treated with azathioprine, prednisone, and antilymphocyte globulin (p less than 0.002). Despite the frequent occurrence of hyperuricemia, gout was rare. Clinical gout developed in six patients in the cyclosporine and prednisone group and in 0 patients in the azathioprine, prednisone, and antilymphocyte globulin group between 1 and 43 months (median 22.5 months) after transplantation. Neither severe hyperuricemia nor diuretic therapy were associated with a significantly increased incidence of gout. The mean serum creatinine concentration of severely hyperuricemic patients (all on cyclosporine and prednisone) was similar to that of normouricemic cyclosporine and prednisone patients (1.8 mg/dl versus 1.6 mg/dl, p greater than 0.2), and the severely hyperuricemic patients had a 4-year graft survival rate of 90 percent. Asymptomatic hyperuricemia after renal transplantation does not adversely affect allograft function, requires no specific therapy, and is not a contraindication to use of diuretics.     

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.     

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.     

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.     

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.     

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.     

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.     

Opportunistic infections after renal transplantation

Opportunistic infection is a serious clinical complication in patients receiving immunosuppressive therapy after kidney transplantation. This article deals with some of the possible infectious agents that were recently encountered at our transplantation centre in Düsseldorf, Germany. Opportunistic organsims such as human herpesviruses 6-8, polyomavirus, parvovirus B19, varicella zoster virus, Nocardia and Listeria monocytogenes are rare but severe complications that are presented in this overview. As a result of the use of new immunosuppresive drugs like tacrolimus and mycophenolate mofetil these infections are now seen more frequently, so they should always be included in differential diagnostic considerations. New diagnostic procedures and new treatment strategies should allow early detection and successful treatment of opportunistic infections in the majority of kidney transplant recipients.