Leflunomide therapy for BK virus allograft nephropathy in pediatric and young adult kidney transplant recipients
ABSTRACT BKVAN affects about 5% of kidney transplant recipients and may lead to graft failure. Treatment for BKVAN is challenging. Leflunomide, an immunosuppressant with antiviral activity in vitro was used successfully in some adult patients but there are no reports of its use in pediatric patients. We present our experience with three kidney transplant recipients with BKVAN who received leflunomide. Three male patients aged 9, 12, and 20 yr developed BKVAN at 9, 12, and 2 months after a kidney transplant. Immunosuppression was reduced and cidofovir was administered in all patients 2-3 wk apart. Due to inability to travel to receive cidofovir in one, lack of reduction in BK viral load in the second, and rising serum creatinine despite cidofovir in the third patient, we discontinued cidofovir and initiated leflunomide. Teriflunomide target trough levels were 30-60 microg/mL. The patients received leflunomide for 27, 26, and 24 months, respectively. BK viral load decreased below 1000 DNA copies/mL in one and was undetectable in two patients after beginning leflunomide. All patients tolerated leflunomide without side effects. Leflunomide use in a select group of patients is well tolerated and may provide an alternative for treatment of BKVAN in pediatric patients.
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ABSTRACT: A simple and reliable method for controlling the relative orientation between the two magnetic fields of a permanent magnet synchronous motor is presented. Finding the initial (at motor powering-up time) value of this relative location is essential for the proper operation of the motor. The feedback control loop used finds this initial relative orientation quickly. Further, using the proposed method allows considerable cost saving, as a transducer that is usually used for this purpose can be eliminated. The cost saving is most obvious in the case of linear motors and angle motors with large diameters. The way the problem is posed is an essential part of this work and it is the reason behind the apparent simplicity of the solution. The method relied upon a single sensor, and it has been tested when a relative encoder was usedSystems, Man, and Cybernetics, 2001 IEEE International Conference on; 02/2001
Article: Emerging viruses in transplantation[Show abstract] [Hide abstract]
ABSTRACT: Several viruses have recently gained importance for the transplant recipient. The purpose of this review is to give an update on emerging viruses in transplantation. BK virus-associated nephropathy (BKVAN) causes graft loss after kidney transplantation. Immunosuppression lowering strategies have now been shown to have benefit in decreasing the incidence of BKVAN. Guidelines for screening, prevention, and therapy have also been developed. Another polyomavirus, JC virus, is a cause of progressive multifocal leukoencephalopathy and has also gained prominence due to the increasing use of monoclonal antibodies in transplant recipients. The significance of human herpesvirus-6 and -7 continues to be debated in the literature, and new data is available on their association with clinical disease. Finally, newly discovered respiratory viruses, such as human metapneumovirus, bocavirus, KI and WU viruses, have also been described in transplant recipients. Human metapneumovirus appears to cause significant respiratory disease whereas the significance of bocavirus, KI and WU viruses in transplant recipients remains uncertain. Viral infections, such as polyomaviruses, human herpesvirus-6 and -7 and respiratory viruses, are emerging as causes of significant disease in transplantation. Antiviral options for these viruses are limited, and decreasing immunosuppression is the cornerstone of therapy.Current Opinion in Infectious Diseases 08/2010; 23(4):374-8. DOI:10.1097/QCO.0b013e32833bc19d
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ABSTRACT: The BK virus, a DNA virus from the Polyomavirus group, represents an opportunistic infection of immunosuppressed transplant recipients. Though the virus was discovered approximately 40 years ago, the emergence of BK virus nephropathy since 1995 onwards, with associated high graft loss rates, has revolutionized renal transplantation medicine. Kidney transplant professionals realized that the consequences of over-immunosuppression were as severe as the consequences of under-immunosuppression and we entered the era of immunosuppressive minimization. Despite this recognition, the optimal testing type for BK virus infections and frequency of testing are hotly debated. Similarly, optimal treatment strategies remain sources of intense controversy. The authors review the current strategies of screening, diagnosis, and possible treatment, and also review the amount and quality of evidence in favor or against. Similarities and differences between cytomegalovirus, Epstein-Barr virus, and BV virus, the three major viral infections in kidney transplantation, are highlighted.Pediatric Nephrology 12/2010; 26(10):1763-74. DOI:10.1007/s00467-010-1716-6