EMC - Néphrologie最新文献

Apart from the graft rejection risk, renal transplantation may be complicated by various non immune complications that can affect the graft's vital prognosis. During the early phase, acute renal failure or delayed functional recovery is often linked to an ischemic nephropathy due to the transplantation conditions. Delayed complications may affect many organs. Therefore, the quality of long term follow up is critical for post-transplantation outcome. The nephrotoxicity of immunosuppressive drugs or renal lesions caused by chronic rejection may worsen the chronic allograft nephropathy. Bone loss must be prevented or compensated. Late metabolic and cardiovascular complications are today the first cause of post-transplantation mortality. Therefore, cardiovascular risk factors (diabetes, dyslipidaemia and high blood pressure) must be carefully monitored. In this article, we also review complications that may affect other organs or systems.

Imaging is indicated prior to transplantation in order to evaluate the graft and assess its vascular anatomy in potential living donors. After the transplantation, the main role of imaging is to detect vascular and urological complications, which do not require biopsy and can lead to reconstructive surgery or percutaneous management. In most cases, the first line imaging modality is the colour doppler ultrasonography. Compared to iodinated contrast-enhanced CT, contrast-enhanced MRI provides accurate, noninvasive and nonnephrotoxic evaluation of the arterial pedicle and perfusion disorders.

Acute renal failure (ARF) is defined in general terms as an abrupt decrease in renal function sufficient enough to result in retention of nitrogenous waste and disrupt fluid and electrolyte homeostasis. There is no consensus regarding a quantifiable definition of ARF. Prompt evaluation of ARF is vital because ARF can be the end result of diverse processes which can often be reversed or attenuated through therapy directed at the underlying condition. Evaluation begins with careful review of the patient's history, previous medical records, physical examination, urinanalysis, and available laboratory data. Routine urine chemical indices, calculation of the fractional excretion of sodium, and examination of the urine sediment are valuable in characterizing the cause of ARF. When this evaluation fails to yield a diagnosis, further testing may be required to evaluate intravascular volume status or diagnose a systemic disorder or glomerular cause of ARF. Response to therapeutic trials may provide a diagnosis. When a diagnosis cannot be made with reasonable certainty through this evaluation renal biopsy should be considered.

The pediatric IgA nephropathies are IgA nephrothapy (Berger’s Disease) and Henoch-Schönlein purpura nephritis. Both conditions are reviewed in detail with respect to epidemiology, clinical features, outcome, prognostic markers, and therapeutic approaches. For both conditions variable disease severity and outcome along with the lack of conclusive evidence for efficacy of treatment based on randomized clinical trials makes it difficult to make strong recommendations regarding therapy.

The hepatorenal syndrome (HRS) is the final manifestation of the circulatory failure syndrome in decompensated cirrhotic patients. The syndrome consists of an acute functional renal failure due to renal arterial vasoconstriction as the result of a hypovolaemia following diffuse arteriole vasodilatation. There are two types of HRS, which can be differentiated according to the course and the stage of the renal failure; they have a different prognosis. Liver transplantation remains the standard treatment. Maintenance medical therapy is mainly based on vasopressin analogues. The interest of both dialysis and portosystemic intrahepatic shunt techniques remains to be determined. The prognosis of HRS is poor and in the absence of treatment, onset is usually followed by rapid fatal outcome.

The most serious among the multiple renal complications of HIV infection is acute renal failure (ARF). ARF usually occurs in the late stages of the disease (AIDS). ARF has several causes, of which the most specific are HIV nephropathy and thrombotic microangiopathy. ARF can also be caused by the intake of drugs that are toxic to the kidney, which is common in such patients, or by a state of shock. Thus, given the wide range of possible causes of ARF, needle biopsy of the kidney is of vital help in choosing the appropriate treatment for each disease entity. Triple antiretroviral therapy and enzyme conversion inhibitors are effective in establishing the prognosis of HIV-related ARF.

Drug-induced acute renal failure (ARF) is common. Many therapeutic agents may induce ARF and there are numerous mechanisms that cause drug-induced ARF. The mechanisms may act at the vascular, glomerular or tubular levels. Drug toxicity may be related to the effects of the treatment itself or caused by hypovolaemia or disturbances of intrarenal haemodynamics. During the course of ARF, diagnosis should systematically include consideration of drug-related precipitating or predisposing factors. Drug-induced ARF is an undesirable iatrogenic occurrence that is largely avoidable and which has a more favourable prognosis than ARF of different pathogenesis. Treatment of this type of ARF is based on prevention. Any drug that is potentially toxic to the kidney should be prescribed in strict accordance with the indications and contraindications of the therapy. Prescription must take into account drug interactions and constitutional susceptibility (pre-exciting chronic renal failure, cirrhosis, old age). Dosage must be adapted to the glomerular filtration rate as estimated by the formula of Cockcroft-Gault. Hypovolaemia must be prevented or corrected.

Renal cystic disease can be developmental, acquired or inherited and is the most common genetic cause for end-stage renal insufficiency in children. The recent increase in the pre-natal detection rate poses a challenge to the paediatrician in achieving a diagnosis and deciding appropriate management. This article reviews the causes of renal cystic disease in childhood with an up-to-date overview of the features and management of the most common causes.