title: Evaluation of diagnostic tests for cytomegalovirus active infection in renal transplant recipients.
abstract: BACKGROUND
  Cytomegalovirus (CMV) infection is a main viral infection after kidney transplantation. The diagnostic methods currently employed are pp65 antigenemia and nucleic acid amplification by polymerase chain reaction (PCR) and aim at detecting viral replication.
  
  
  OBJECTIVE
  The goal of this study was to evaluate and compare by both methods the incidence of CMV active infection in kidney transplant patients and to establishthe best clinical-laboratory correlation.
  
  
  METHODS
  Thirty sequential kidney transplant recipients were enrolled in a single center prospective cohort study. Peripheral blood samples were drawn from day 15 until the 6th month after transplantation and tested for CMV replication by pp65 antigenemia and quantitative PCR assays (qPCR).
  
  
  RESULTS
  Two hundred forty samples were analyzed and the incidence of active infection was similar by both methods. Time elapsed to the first positive test was almost identical but more samples tested positive by qPCR than by antigenemia in a behavior that was almost evenly distributed overtime. Agreement between tests was observed in 217 samples (90.4%; kappa = 0.529; p < 0.001) and in 25 patients the tests were concordant (83.3%; kappa = 0.667; p < 0.001). The evaluation of the diagnostic parameters for CMV replication revealed higher sensitivity for the qPCR test (82.1%) against antigenemia (59.0%). Quantitative PCR was also slightly more accurate than antigenemia.
  
  
  CONCLUSIONS
  Our data demonstrate that both methods are suitable and have almost equivalent accuracy for the detection of post-transplant cytomegalovirus replication. The choice for either test must take in consideration the demand, execution capability and cost-effectiveness at each institution.
authors.affiliation: Hospital de Clínicas de Porto Alegre, Brazil.
authors.forename: Rodrigo Fontanive
authors.initials: RF
authors.lastname: Franco
authors.affiliation: Hospital de Clínicas de Porto Alegre, Brazil.
authors.forename: Rosangela Munhoz
authors.initials: RM
authors.lastname: Montenegro
authors.affiliation: Hospital de Clínicas de Porto Alegre, Brazil.
authors.forename: Alice Beatriz Mombach Pinheiro
authors.initials: AB
authors.lastname: Machado
authors.affiliation: Hospital de Clínicas de Porto Alegre, Brazil.
authors.forename: Fernanda de
authors.initials: F
authors.lastname: Paris
authors.affiliation: Hospital de Clínicas de Porto Alegre, Brazil.
authors.forename: Denise Silva
authors.initials: DS
authors.lastname: Menezes
authors.affiliation: Hospital de Clínicas de Porto Alegre, Brazil.
authors.forename: Roberto Ceratti
authors.initials: RC
authors.lastname: Manfro
mesh_terms: D000293:Adolescent; D000328:Adult; D003586:Cytomegalovirus Infections / Q000097:blood / Q000175:diagnosis*; D006403:Hematologic Tests; D006801:Humans; D016030:Kidney Transplantation; D008137:Longitudinal Studies; D008875:Middle Aged; D011183:Postoperative Complications / Q000097:blood / Q000175:diagnosis* / Q000821:virology*; D015203:Reproducibility of Results; D055815:Young Adult