title: Peripheral blood leukocytes and serum nested polymerase chain reaction are complementary methods for monitoring active cytomegalovirus infection in transplant patients.
abstract: BACKGROUND
  Human cytomegalovirus is an important cause of morbidity and mortality in immunocompromised patients. Qualitative polymerase chain reaction (PCR) has proven to be a sensitive and effective technique in defining active cytomegalovirus infection, in addition to having low cost and being a useful test for situations in which there is no need for quantification. Real-time PCR has the advantage of quantification; however, the high cost of this methodology makes it impractical for routine use.
  
  
  OBJECTIVE
  To apply a nested PCR assay to serum (sPCR) and to evaluate its efficiency to diagnose active cytomegalovirus infection compared with PCR of peripheral blood leukocytes (L-PCR).
  
  
  METHODS
  Samples of 37 patients were prospectively evaluated. An internal control was created and applied to sPCR to exclude false-negative results.
  
  
  RESULTS
  In total, 21 patients (57%) developed active cytomegalovirus infection. After analyzing the two methods for the diagnosis of active infection, higher sensitivity and negative predictive value of the L-PCR versus sPCR (100% versus 62%), and higher specificity and positive predictive value of sPCR versus L-PCR (81% versus 50% and 72%, respectively) were observed. Discordant results were observed in 11 patients who were L-PCR-positive but sPCR-negative for active cytomegalovirus infection, five of whom developed clinical symptoms of cytomegalovirus. Clinical symptoms were observed in 14 patients, 12 of whom were diagnosed with active infection by nested L-PCR (P=0.007) and seven by nested sPCR (P=0.02). Higher specificity and a positive predictive value for sPCR were observed.
  
  
  CONCLUSIONS
  Nested L-PCR and sPCR were considered to be complementary methods for the diagnosis and management of symptomatic cytomegalovirus infection.
authors.affiliation: Department of Internal Medicine, Faculty of Medical Sciences, State University of Campinas (Unicamp), Campinas, São Paulo, Brazil.
authors.forename: Pd
authors.initials: P
authors.lastname: Andrade
authors.affiliation: Department of Internal Medicine, Faculty of Medical Sciences, State University of Campinas (Unicamp), Campinas, São Paulo, Brazil.
authors.forename: Mt
authors.initials: M
authors.lastname: Fioravanti
authors.affiliation: Department of Internal Medicine, Faculty of Medical Sciences, State University of Campinas (Unicamp), Campinas, São Paulo, Brazil.
authors.forename: Ebv
authors.initials: E
authors.lastname: Anjos
authors.affiliation: Department of Internal Medicine, Faculty of Medical Sciences, State University of Campinas (Unicamp), Campinas, São Paulo, Brazil.
authors.forename: C
authors.initials: C
authors.lastname: De Oliveira
authors.affiliation: Department of Internal Medicine, Faculty of Medical Sciences, State University of Campinas (Unicamp), Campinas, São Paulo, Brazil.
authors.forename: Dm
authors.initials: D
authors.lastname: Albuquerque
authors.affiliation: Department of Internal Medicine, Faculty of Medical Sciences, State University of Campinas (Unicamp), Campinas, São Paulo, Brazil.
authors.forename: Scb
authors.initials: S
authors.lastname: Costa
keywords: CMV; Nested PCR; Serum nested PCR; Transplant