[Analysis of the results of the 2010 External Quality Control Program of the Spanish Society of Infectious Diseases and Clinical Microbiology for HIV-1, HCV, and HBV viral loads].
Human immunodeficiency virus type 1 (HIV-1) and hepatitis B (HBV) and C virus (HCV) viral load determinations are among the most important markers for the follow-up of patients infected with these viruses. External quality control tools are crucial to ensure the accuracy of the results obtained by microbiology laboratories. This article summarized the results obtained in the 2010 External Quality Control Program of the Spanish Society of Infectious Diseases and Clinical Microbiology for HIV-1, HCV, and HBV viral loads and HCV genotyping. In the HIV-1 program, a total of five standards were sent. One standard consisted of seronegative human plasma, while the remaining four contained plasma from three different viremic patients, in the range of 3-5 log(10) copies/mL; two of these standards were identical, with the aim of determining repeatability. A significant proportion of the laboratories (22.6% on average) obtained values out of the accepted range (mean ± 0.2 log(10)copies/mL), depending on the standard and on the method used for quantification. Repeatability was very good, with up to 95% of laboratories reporting results within the limits (Δ<0.5 log(10)copies/mL). The HBV and HCV program consisted of two standards with different viral load contents. Most of the participants, 86.1% in the case of HCV and 87.1% in HBV, obtained all the results within the accepted range (mean ± 1.96 SD log(10)UI/mL). Post-analytical errors due to mistranscription of the results were detected in these controls. Data from this analysis reinforce the utility of proficiency programs to ensure the quality of the results obtained by a particular laboratory, as well as the importance of the post-analytical phase in overall quality. Due to interlaboratory variability, use of the same method and the same laboratory for patient follow-up is advisable.
Programa de Control de Calidad Externo SEIMC, España. niormi@gmail.com
Nieves
N
Orta Mira
María del Remedio Guna
Mdel R
Serrano
José-Carlos Latorre
JC
Martínez
María Rosario
MR
Ovies
Marta
M
Poveda
Enrique Ruiz
ER
de Gopegui
Concepción Gimeno
CG
Cardona
D004279:DNA, Viral / Q000097:blood*; D015658:HIV Infections / Q000821:virology*; D015497:HIV-1 / Q000235:genetics / Q000302:isolation & purification; D016174:Hepacivirus / Q000235:genetics / Q000302:isolation & purification; D006509:Hepatitis B / Q000821:virology*; D006515:Hepatitis B virus / Q000235:genetics / Q000302:isolation & purification; D006526:Hepatitis C / Q000821:virology*; D006801:Humans; D055552:Infectious Disease Medicine / Q000592:standards*; D007753:Laboratories / Q000592:standards*; D059021:Laboratory Proficiency Testing; D008829:Microbiology / Q000592:standards*; D010949:Plasma; D016133:Polymerase Chain Reaction / Q000379:methods / Q000592:standards; D012150:Polymorphism, Restriction Fragment Length; D011785:Quality Assurance, Health Care; D012367:RNA, Viral / Q000097:blood*; D015203:Reproducibility of Results; D012958:Societies, Scientific / Q000592:standards*; D013030:Spain; D019562:Viral Load; D014766:Viremia / Q000821:virology*; D014773:Virology / Q000592:standards*
D004279:DNA, Viral; D012367:RNA, Viral