Expertise of laboratories in viral load quantification, genotyping, and precore mutant determination for hepatitis B virus in a multicenter study.
A national evaluation study was performed in 14 specialized laboratories with the objective of assessing their capacities to provide (i) hepatitis B virus (HBV) viral loads (VL), (ii) HBV genotypes, and(iii) identification of precore/core mutants. The panel consisted of 12 HBV DNA-positive samples with VLs from 2.8 to 9.1 log(10) copies/ml, different HBV genotypes (A to F), and 3 mutant and 9 wild-type samples at nucleotide 1896. The coefficients of variation of the mean VLs ranged from 2.4% to 10.4% with the Cobas HBV Monitor assay, from 1.8% to 5.5% with the Cobas TaqMan 48, from 1.5 to 26.2% with RealArt HBV PCR, and from 0 to 7% with branched DNA (bDNA). The Cobas Monitor assay underestimated the VLs of genotype F samples, with differences ranging from 1.4 to 2.4 log(10) copies/ml. The accuracies of genotype determinations ranged from 33% to 100%, and those of precore mutant determinations ranged from 25 to 100%. This study showed some drawbacks of two widely used assays: (i) Cobas Monitor has a narrow dynamic range and underestimates genotype F sample VLs and (ii) bDNA shows poor sensitivity and may fail to identify patients with low VLs. With higher performance in terms of analytical sensitivity combined with a larger dynamic range and an ability to quantify the main genotypes equally, real-time PCR methods appear more appropriate for accurate monitoring of HBV DNA quantification. Furthermore, the clinical implications of HBV genotyping and the determination of precore/core mutants need to be clearly stated to justify the standardization of these methods.
Laperche
Syria
S
Centre National de Référence pour les Hépatites B et C en Transfusion, Département des Agents Transmissibles par le Sang, Institut National de la Transfusion Sanguine, Paris, France. slaperche@ints.fr
Thibault
Vincent
V
Bouchardeau
Françoise
F
Alain
Sophie
S
Castelain
Sandrine
S
Gassin
Michelle
M
Gueudin
Marie
M
Halfon
Philippe
P
Larrat
Sylvie
S
Lunel
Françoise
F
Martinot-Peignoux
Michèle
M
Mercier
Bernard
B
Pawlotsky
Jean-Michel
JM
Pozzetto
Bruno
B
Roque-Afonso
Anne-Marie
AM
Roudot-Thoraval
Françoise
F
Sauné
Karine
K
Lefrère
Jean-Jacques
JJ
D005602:France; D005838:Genotype; D006509:Hepatitis B / Q000821:virology*; D006515:Hepatitis B virus / Q000235:genetics* / Q000302:isolation & purification*; D006801:Humans; D007753:Laboratories / Q000592:standards*; D015337:Multicenter Studies as Topic / Q000592:standards; D009154:Mutation; D014758:Viral Core Proteins / Q000235:genetics*; D019562:Viral Load
D014758:Viral Core Proteins