Prediction of cytomegalovirus (CMV) plasma load from evaluation of CMV whole-blood load in samples from renal transplant recipients.
In a prospective cohort of 82 renal transplant recipients, we evaluated the capacity of the cytomegalovirus (CMV) load in whole blood (WB) to predict the plasma CMV load, aiming to identify active CMV infections by using WB samples only and to deduce a WB threshold. Using quantitative real-time PCR, a total of 1,474 WB samples were assayed, of which 279 were positive for CMV, and 140 out of the 276 paired plasma samples tested positive. Thirty (36.6%) patients presented with at least one positive plasma PCR result, and 21 infection episodes (19 patients) required curative treatment (median follow-up time, 12 months). When the plasma CMV load was >500 copies/ml (n = 70), more than 94% (95% confidence interval, 86.0%, 98.4%) of WB samples had >500 copies/ml. Two prediction models were built: log(10) plasma viral load (VL) was calculated as -0.3777 + 0.9342 x log(10) WB VL and as -0.3777 + 0.8563 x log(10) WB VL for patients with and without treatment, respectively. In the validation sample (578 routine samples), 77.2% of the observed and expected plasma viral loads were concordant (95% confidence intervals, 73.5 and 80.5%). According to the model, the plasma viral load was >500 copies/ml when the WB load was >3,170 or >4,000 copies/ml in patients with or without treatment, respectively. WB seems to be an appropriate candidate for routine CMV monitoring of transplant recipients by using a single assay.
Université Victor Segalen Bordeaux 2, Laboratoire de Virologie EA2968, 146 rue Léo Saignat, 33 076 Bordeaux Cédex, France. isabelle.garrigue@chu-bordeaux.fr
Isabelle
I
Garrigue
Adélaïde
A
Doussau
Julien
J
Asselineau
Hélène
H
Bricout
Lionel
L
Couzi
Catherine
C
Rio
Pierre
P
Merville
Hervé
H
Fleury
Marie-Edith
ME
Lafon
Rodolphe
R
Thiébaut
D000328:Adult; D001769:Blood / Q000821:virology*; D015331:Cohort Studies; D003587:Cytomegalovirus / Q000302:isolation & purification; D003586:Cytomegalovirus Infections / Q000821:virology*; D005260:Female; D006801:Humans; D007166:Immunosuppressive Agents / Q000627:therapeutic use; D016030:Kidney Transplantation; D008297:Male; D008875:Middle Aged; D010949:Plasma / Q000821:virology*; D016133:Polymerase Chain Reaction / Q000379:methods*; D011446:Prospective Studies; D019562:Viral Load / Q000379:methods*
D007166:Immunosuppressive Agents