Recurrent cytomegalovirus infection: prevalence and risk factors.

Cytomegalovirus (CMV) is a beta herpes virus that can infect several organs. It is transmitted through infected body secretions, blood, and organ allografts,1 and is considered as the leading infectious reason of mortality and morbidity in organ transplantation.2 It is also the most important cause of infectious disease after kidney transplantation.3 Cytomegalovirus infection is defined according to the American Society of Transplantation’s recommendations for use in clinical trials as evidence of CMV replication without any symptoms.4 The existence of CMV symptoms, which can be characterized as a viral syndrome (fever, malaise, leukopenia, and thrombocytopenia) or as a tissue invasive disease confirmed the diagnosis of CMV disease.4 In addition, recurrent CMV infection is defined as new detection of CMV infection in a patients that has had previously documented CMV infection.5 Several studies have evaluated the impact of CMV infection and disease on kidney transplantation outcomes.6-8 Reisching and colleagues9 showed that CMV disease was an important risk factor for acute rejection, particularly in the first 12 months after kidney transplantation. Basri and coworkers10 stated a possible relationship between CMV infection and graft failure in kidney transplant recipients. Indirect effect of CMV on outcomes of transplantation is enhanced systemic immuno suppression (ie, effect favoring opportunistic infections), increasing risk of posttransplant malignancies (ie, posttransplantation lymphoproliferative diseases),3,8 CMV-induced vasculopathy and thrombosis,11 the potential role in allograft rejection (either cellular or antibody mediated),8 urologic and gastrointestinal complications, etc.11 It has also shown that CMV infection is an independent risk factor for a high incidence of hyperglycemia12 and developing newonset diabetes mellitus, which is an important cause for mortality and morbidity after transplantation.13 In the current issue of the Iranian Journal of Kidney Diseases, Nafar and colleagues14 have evaluated the prevalence and risk factors of CMV and its recurrent infection in a sample of 427 kidney transplant recipients. They reported 16% and 4.4% prevalence of CMV infection and recurrent CMV infection, respectively. It means that recurrent CMV infection occurred in 26% of patients after treatment of primary CMV infection. It is similar to the results of a multi-center study of 3065 kidney transplant recipients in Iran.7 In this study, the authors showed the incidence of CMV infection 27. Shooshtarizadeh T, Mohammadali A, Ossareh S, Ataipour Y. Relation between pretransplant serum levels of soluble CD30 and acute rejection during the first 6 months after a kidney transplant. Exp Clin Transplant. 2013;11:229-33.