articleSurveillance of active human cytomegalovirus infection in hematopoietic stem cell transplantation ( HLA sibling identical donor ) : search for optimal cutoff value by real-time PCR

Background: Human cytomegalovirus (CMV) infection still causes significant morbidity and mortality after allogeneic hematopoietic stem cell transplantation (HSCT). Therefore, it is extremely important to diagnosis and monitor active CMV infection in HSCT patients, defining the CMV DNA levels of virus replication that warrant intervention with antiviral agents in order to accurately prevent CMV disease and further related complications. Methods: During the first 150 days after allogeneic HSTC, thirty patients were monitored weekly for active CMV infection by pp65 antigenemia, nested-PCR and real-time PCR assays. Receiver operating characteristic (ROC) plot analysis was performed to determine a threshold value of the CMV DNA load by real-time PCR. Results: Using ROC curves, the optimal cutoff value by real-time PCR was 418.4 copies/104 PBL (sensitivity, 71.4%; specificity, 89.7%). Twenty seven (90%) of the 30 analyzed patients had active CMV infection and two (6.7%) developed CMV disease. Eleven (40.7%) of these 27 patients had acute GVHD, 18 (66.7%) had opportunistic infection, 5 (18.5%) had chronic rejection and 11 (40.7%) died one died of CMV disease associated with GVHD and bacterial infection. Conclusions: The low incidence of CMV disease in HSCT recipients in our study attests to the efficacy of CMV surveillance based on clinical routine assay. The quantification of CMV DNA load using real-time PCR appears to be applicable to the clinical practice and an optimal cutoff value for guiding timely preemptive therapy should be clinically validated in future studies. Background Hematopoietic stem cell transplantation (HSCT) is an important therapeutic tool for treating malignant and non-malignant disorders, and the human cytomegalovirus (CMV) reactivation is common in these cases due to the immunocompromised state of patients [1]. Monitoring of its reactivation and preemptive or prophylactic treatment using ganciclovir are critical for HSCT recipients. However, because of the myelotoxicity of ganciclovir and its prolongation of periods of neutropenia, the prognosis in patients at low risk of developing CMV disease is not necessarily improved. Identification of patients at high risk of developing CMV is therefore believed to be important in management of HSCT recipients [2]. Despite major advances in prevention and preemptive treatment, CMV infection still causes significant morbidity and mortality following allogeneic hematopoietic stem cell transplantation (HSCT) [3] and occurs in 50-90% of allogeneic transplant recipients [4]. While detection of CMV pp65 antigenemia is still widely used for monitoring CMV infection and guide preemptive therapy in patients at risk of developing CMV disease [5,6], the quantification of CMV DNA in blood by PCR is emerging as an alternative to the pp65 antigenemia assay and may soon become the standard for the sur* Correspondence: costa@fcm.unicamp. br 1 Department of Clinical Medicine, Faculty of Medical Sciences, University of Campinas Unicamp, P.O. Box 6111, Zipe Code 13083-970, Campinas, SP, Brazil Full list of author information is available at the end of the article Peres et al. BMC Infectious Diseases 2010, 10:147 http://www.biomedcentral. com/1471-2334/10/147 Page 2 of 8 veillance of CMV infection in allogeneic HSCT recipients [7], because it presents several advantages over the pp65 antigenemia assay, including an increased sensitivity for the detection of CMV reactivation, the reliable detection of CMV reactivation during severe neutropenia in the early post-transplant period, the shorter time required for the procedure, and the convenient processing of large numbers of specimens [8]. The aim of this study was to diagnosis and monitor active CMV infection in allogeneic HSCT patients. In addition, we have determined the proper cutoff level of CMV DNA load by real-time PCR for preemptive therapy, in order to switch the monitoring method from the pp65 antigenemia assay to real-time PCR method.