RESUMO
Since 1999, the National Institute of Allergy and Infectious Diseases Division of AIDS (NIAID DAIDS) has funded the Immunology Quality Assessment (IQA) Program with the goal of assessing proficiency in basic lymphocyte subset immunophenotyping for each North American laboratory supporting the NIAID DAIDS HIV clinical trial networks. Further, the purpose of this program is to facilitate an increase in the consistency of interlaboratory T-cell subset measurement (CD3(+)4(+)/CD3(+)8(+) percentages and absolute counts) and likewise, a decrease in intralaboratory variability. IQA T-cell subset measurement proficiency testing was performed over a ten-year period (January 2003-July 2012), and the results were analyzed via longitudinal analysis using mixed effects models. The goal of this analysis was to describe how a typical laboratory (a statistical modeling construct) participating in the IQA Program performed over time. Specifically, these models were utilized to examine trends in interlaboratory agreement, as well as successful passing of proficiency testing. Intralaboratory variability (i.e., precision) was determined by the repeated measures variance, while fixed and random effects were taken into account for changes in interlaboratory agreement (i.e., accuracy) over time. A flow cytometer (single-platform technology, SPT) or a flow cytometer/hematology analyzer (dual-platform technology, DPT) was also examined as a factor for accuracy and precision. The principal finding of this analysis was a significant (p<0.001) increase in accuracy of T-cell subset measurements over time, regardless of technology type (SPT or DPT). Greater precision was found in SPT measurements of all T-cell subset measurements (p<0.001), as well as greater accuracy of SPT on CD3(+)4(+)% and CD3(+)8(+)% assessments (p<0.05 and p<0.001, respectively). However, the interlaboratory random effects variance in DPT results indicates that for some cases DPT can have increased accuracy compared to SPT. Overall, these findings demonstrate that proficiency in and among IQA laboratories have, in general, improved over time and that platform type differences in performance do exist.
Assuntos
Complexo CD3/sangue , Contagem de Linfócito CD4/normas , Linfócitos T CD4-Positivos/imunologia , Linfócitos T CD8-Positivos/imunologia , Ensaios Clínicos como Assunto/normas , Infecções por HIV/diagnóstico , Imunofenotipagem/normas , Laboratórios/normas , Ensaio de Proficiência Laboratorial/normas , Monitorização Imunológica/normas , Biomarcadores/sangue , Contagem de Linfócito CD4/estatística & dados numéricos , Linfócitos T CD4-Positivos/virologia , Linfócitos T CD8-Positivos/virologia , Ensaios Clínicos como Assunto/estatística & dados numéricos , Interpretação Estatística de Dados , Citometria de Fluxo/normas , Fidelidade a Diretrizes/normas , Infecções por HIV/sangue , Infecções por HIV/imunologia , Infecções por HIV/virologia , Humanos , Imunofenotipagem/estatística & dados numéricos , Laboratórios/estatística & dados numéricos , Ensaio de Proficiência Laboratorial/estatística & dados numéricos , Modelos Estatísticos , Monitorização Imunológica/estatística & dados numéricos , Variações Dependentes do Observador , Guias de Prática Clínica como Assunto/normas , Valor Preditivo dos Testes , Desenvolvimento de Programas , Avaliação de Programas e Projetos de Saúde , Controle de Qualidade , Melhoria de Qualidade , Indicadores de Qualidade em Assistência à Saúde/normas , Reprodutibilidade dos Testes , Manejo de Espécimes/normas , Fatores de Tempo , Fluxo de TrabalhoRESUMO
The pathogenesis of disease caused by human immunodeficiency virus (HIV) is largely attributable to the decrease in T-lymphocytes bearing the CD4 cell-surface molecule (CD4 + T-lymphocytes) (1). The percentage of CD4 + T-lymphocytes among total lymphocytes and the percentages of other lymphocyte subpopulations (e.g., CD8 + T-lymphocytes) are generally measured by flow cytometric immunophenotyping (FCl) (also called immunophenotyping by flow cytometry [2], T-lymphocyte immunophenotyping [3], and fluorescence-activated cell sorting). FCl results are frequently used to guide the treatment of HIV-infected persons. To assess the availability of FCl to hospital patients, in 1990, the National Public Health and Hospital Institute (NPHHI), a private, nonprofit research institute, surveyed hospitals about their provision of FCl to patients. This report presents findings from the survey.