AEGiS-15IAC: Detection of HIV-1 antibody using an indirect immunofluorescence assay based on L-2 cell line.

15th International AIDS Conference

Bangkok, Thailand - July 11-16, 2004

Detection of HIV-1 antibody using an indirect immunofluorescence assay based on L-2 cell line.

Int Conf AIDS 2004 Jul 11-16; 15:(abstract no. B10113)

Lai W, Yin Y
Institute of Dermatology, Chinese Academy of Medical Sciences, Nanjing, China

BACKGROUND: With the increase in the prevalence of human immunodeficiency virus (HIV) infection in China, there is an urgent need to explore cost-containing methods of HIV antibody detection. L-2 cell line is a T cell line persistently infected with a mutant HIV-1 subtype B strain and come from MT-4 cell line by origin, and L-2 cell can produce noninfectious HIV-1 particles and express HIV-1 antigen on cell membrane. An indirect immunofluorescence assay (IFA) based on L-2 has been established for the detection of HIV-1 antibody. Mixtures of L-2 and MT-4 cells were used in this assay. We evaluated the performance and feasibility of this IFA in the detection of HIV-1 antibodies in sera specimens from HIV/STD patients or high risk population.

METHODS: Comparing with the widely used but expensive tests, the ELISA (Organon, The Netherlands) combined with Western blot (Genelab Diagnostics, Singapore), IFA was performed in the detection of HIV-1 antibodies in 200 serum specimens from female commercial sex workers (CSWs) in a city located in Southwestern China, 100 sera form attendees in a STD clinic in Nanjing and 50 sera from the workers seeking for a healthcare examination at a factory in Nanjing. All HIV-1 positive sera were confirmed by Western blot.

RESULTS: Using IFA, 49 positive and 151 negative for HIV-1 antibodies were detected among 200 sera from female CSWs in Southwestern China, and no positive were found among other sera from STD patients and workers in Nanjing. The detection results by IFA were entirely consisitent with those by ELISA combined with WB. Both the sensitivity and the specificity of IFA were found to be 100% in this study.

CONCLUSIONS: The IFA based on L-2 cell is simple and useful for screening and confirming HIV-1 infection. And IFA appears to be a cost-containing alternative to WB in settings where immunofluorescent microscopy is routinely done. The cost of testing by IFA is less than 10% of WB testing.

Keywords: AEGIS, HIV Antibodies, Fluorescent Antibody Technique, Indirect, HIV-1, Blotting, Western, HIV Seropositivity, Cell Line, Enzyme-Linked Immunosorbent Assay, Acquired Immunodeficiency Syndrome, Sensitivity and Specificity, Netherlands, China, Singapore, Female, Humans, utilization, immunology

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B10113