The Role of Cytomegalovirus Infection in Chronic Allograft Nephropathy

Abstract

In the letter “The Role of Cytomegalovirus Infection in Chronic Allograft Nephropathy” in the January 27, 2004 issue of Transplantation (1), Dr. Mahawar makes a few comments about our article published in the June 15, 2003 issue of Transplantation (2). Approximately 150–200 renal transplantations are performed in the Helsinki University Hospital Transplantation Center annually. The patients included in our retrospective study were selected from a population of renal transplant recipients, transplanted between 1994 and 2000, who were at follow-up at the Helsinki University Hospital Division of Nephrology and who had had a suspicion of CMV infection (n=172). The patients are not monitored for the presence of CMV, and samples for the detection of CMV are only taken when infection is suspected. Those 11 patients, with no evidence of CMV infection despite several samples at different time points, were selected as control patients. In addition, only patients with a protocol biopsy taken at 6 months after transplantation were included in the study. Thus, the numbers of positive and control patients in our study do not reflect the incidence of CMV infection in our centre. Dr. Mahawar refers to the definitions of “CMV infection” and “CMV disease” by the International CMV Workshop from 1995 (3). The definitions of CMV-related terminology have been updated during the past years and recently 2 years ago with some changes (4). According to the latest update, CMV end-organ disease in the kidney, “CMV nephritis”, is defined as histologic features of CMV infection in the kidney together with detection of CMV in the kidney biopsy. In addition, the term “CMV syndrome” should be avoided, according to the latest update. Therefore, we believe, that the term “CMV infection” was relevant to describe the patients in our study. It is also in agreement with the updated definitions of CMV infection (4). Ilkka Helanterä Raisa Loginov Irmeli Lautenschlager Transplant Unit Research Laboratory Department of Virology Helsinki University Hospital and University of Helsinki Helsinki, Finland Ilkka Helanterä Petri Koskinen Tom Törnroth Carola Grönhagen-Riska Department of Medicine Division of Nephrology Helsinki University Hospital and University of Helsinki Helsinki, Finland