title: Clinical performance of an in-house real-time RT-PCR assay using a fluorogenic LUX primer for quantitation of human immunodeficiency virus type-1 (HIV-1).
abstract: The South African National Antiretroviral Treatment Guideline recommends the use of HIV viral load assays for routine monitoring of HIV-1 positive patients on Highly Active Antiretroviral Therapy (HAART). Approved commercial HIV-1 viral load assays are expensive for developing countries where a large number of patients are treated in the public sector. The evaluation of an in-house HIV-1 viral load assay (LUX assay) is described using 458 plasma specimens. Good specificity of the LUX assay was demonstrated using 50 seronegative plasma specimens. A group of 142 HIV-1 positive patients was used to assess the agreement between the LUX assay and the COBAS Amplicor assay. An intra class correlation (ICC) coefficient of 0.85 (CI 95%) indicated good agreement between the assays. The Bland-Altman model showed good agreement between the assays for approximately 87% of the results (mean 0.03 [-1.26; 1.32], CI 95%). In a cohort of 55 patients followed-up longitudinally the LUX assay showed similar declines in viral load to the COBAS Amplicor assay in response to therapy. Viral rebound was detected in 5 patients out of 55 by both assays. Thus, the LUX assay compares well to the gold standard and represents an affordable alternative for high volume testing in resource limited settings.
authors.affiliation: Department of Molecular Medicine and Hematology, National Health Laboratory Service (NHLS), University of the Witwatersrand (WITS), Faculty of Health Science, Medical School, 7 York Road, Parktown, Johannesburg 2193, South Africa. rekhn@hsc.pg.wits.ac.za
authors.forename: Natela
authors.initials: N
authors.lastname: Rekhviashvili
authors.forename: Wendy
authors.initials: W
authors.lastname: Stevens
authors.forename: Edmore
authors.initials: E
authors.lastname: Marinda
authors.forename: René
authors.initials: R
authors.lastname: Gonin
authors.forename: Gwynneth
authors.initials: G
authors.lastname: Stevens
authors.forename: James
authors.initials: J
authors.lastname: McIntyre
authors.forename: Robin
authors.initials: R
authors.lastname: Wood
mesh_terms: D023241:Antiretroviral Therapy, Highly Active; D015658:HIV Infections / Q000188:drug therapy / Q000821:virology*; D015497:HIV-1 / Q000302:isolation & purification / Q000502:physiology*; D006801:Humans; D020133:Reverse Transcriptase Polymerase Chain Reaction / Q000379:methods*; D012680:Sensitivity and Specificity; D019562:Viral Load / Q000379:methods*