Renal transplantation parenchymal complications: what Doppler ultrasound can and cannot do.

Kidney transplantation is the treatment of choice in end-stage renal disease, given the better quality of life of transplanted patients when compared with patients on maintenance dialysis. In spite of surgical improvements and new immunosuppressive regimens, parts of transplanted grafts still develop chronic dysfunction. Ultrasonography, both in B-mode and with Doppler ultrasound, is an important diagnostic tool in case of clinical conditions which might impair kidney function. Even though ultrasonography is considered fundamental in the diagnosis of vascular and surgical complications of the transplanted kidney, its role is not fully understood in case of parenchymal complications of the graft. The specificity of Doppler is low both in case of acute complications, such as acute tubular necrosis, drugs toxicity and acute rejection, and in case of chronic conditions, such as chronic allograft nephropathy. Single determinations of resistance indices present low diagnostic accuracy, which is higher in case of successive measurements performed during the follow-up of the graft. Modern techniques such as tissue pulsatility index, maximal fractional area and contrast-enhanced ultrasound increase ultrasonography diagnostic power in case of parenchymal complications of the transplanted kidney.

[Oral hypoglycemic drugs in chronic kidney disease: which limitations in the clinical setting]. / Ipoglicemizzanti orali nella malattia renale cronica: quali limiti nell'uso clinico.

A large amount of recent epidemiological studies have shown the worldwide growth on the incidence and prevalence of diabetes mellitus type II (DM2), especially in industrialized countries where DM2 is the most frequent cause of chronic kidney disease. Diabetic nephropathy progression to ESRD (End Stage Renal Disease) may be slowed down only with a tight glycemic control, since no hypoglycemic drugs have been shown to possess renoprotective effects. Treatment with oral hypoglycemic agents should be closely and regularly monitored in patients with diabetic nephropathy since the decline of renal function below 60 ml/min of glomerular filtration rate (GFR) could cause multiple pharmacokinetic alterations. It may expose the patient to serious side effects if cautious dose reduction or even withdrawal of these drugs is not considered. Pharmacological approaches to the treatment of diabetes type 2 include the traditional oral hypoglycemic drugs (insulin sensitizers, insulin secretagogues and drugs inhibiting the absorption of glucose), incretin system drugs (orally or intravenously administered) and insulin therapy, if these drugs are insufficient or are contraindicated. The objective of this review is to evaluate the evidence regarding the use of oral hypoglycemic agents (with particular attention to the DPP-4 inhibitors) in diabetes type 2 with chronic kidney disease stage III- IV and ESRD, while in case of eGFR > 60 ml / min no dosage adjustment is usually required.

[Microbubbles: current state and future prospects]. / Le microbolle: attualita' e prospettive future.

Contrast-enhanced ultrasound (CEUS) represents one of the most interesting applications of traditional medical sonography. Ultrasound contrast agents are classified into first- and second-generation agents depending on the gas (nitrogen, perfluorocarbon or sulfur hexafluoride) in the microbubbles. Both generations are characterized by an excellent safety profile, with low hepatic and renal toxicity and rare central nervous system reactions. The respiratory and hepatic elimination of the gases explains the low nephrotoxicity. CEUS has been successfully employed in drug and gene delivery. Indeed, new molecules such as liposomes, micelles and perfluorocarbon nanoparticles have been recently proposed as ultrasound contrast agents. Possible future applications of liposomes are the treatment of hypertension complications (given the possibility to fill them with nitric oxide), the treatment of cerebral disease with xenon, and the treatment of breast and liver cancer with doxorubicin. Micelles have been demonstrated to be effective in cancer treatment as well. Finally, perfluorocarbon nanoparticles can be used in oncological settings and in pancreatic islet transplantation in patients with type I diabetes.

[Parenchymal complications of the transplanted kidney: the role of color-Doppler imaging]. / Le complicanze parenchimali del rene trapiantato: il ruolo dell'eco-color-Doppler.

Kidney transplantation is the treatment of choice for end-stage renal disease, given the better quality of life of transplanted patients when compared to patients on maintenance dialysis. In spite of surgical improvements and new immunosuppressive regimens, part of the transplanted grafts still develop chronic dysfunction. Ultrasonography, both in B-mode and with Doppler ultrasound, is an important diagnostic tool in case of clinical conditions which might impair kidney function. Even though ultrasonography is considered fundamental in the diagnosis of vascular and surgical complications of the transplanted kidney, its role is not fully understood in case of parenchymal complications of the graft. The specificity of Doppler ultrasound is low both in case of acute complications such as acute tubular necrosis, drug toxicity and acute rejection, and in case of chronic conditions such as chronic allograft nephropathy. Single determinations of resistance indices present low diagnostic accuracy, which is higher in case of successive measurements performed during the follow-up of the graft. Modern techniques including tissue pulsatility index, maximal fractional area and contrast-enhanced ultrasound increase the diagnostic power of ultrasonography in case of parenchymal complications of the transplanted kidney.