Using Elecsys® HIV Combi PT assay to identify acute and early HIV infection in a teaching hospital of southwest China

• Published in: International journal of STD & AIDS Vol. 27; no. 3; p. 213
• Main Authors: Zhu, Siyuan, Li, Dongdong, An, Jingna, Chen, Qixia, Liu, Qianqian, Tao, Chuanmin
• Format: Journal Article
• Language: English
• Published: England 01.03.2016
• Subjects: Adult; Blotting, Western; China; Early Diagnosis; Female; HIV Antibodies - blood; HIV Antibodies - immunology; HIV Core Protein p24 - blood; HIV Core Protein p24 - immunology; HIV Infections - diagnosis; HIV-1 - isolation & purification; Hospitals, Teaching; Humans; Immunoassay - methods; Male; Mass Screening - methods; Middle Aged; RNA, Viral - blood; Sensitivity and Specificity; China; AIDS; acute and early HIV infection; diagnosis; Elecsys® HIV combi PT assay; HIV; testing
• ISSN: 1758-1052
• DOI: 10.1177/0956462415579589

This study is the first attempt to evaluate the use of the Elecsys® HIV combi PT assay in identifying acute and early HIV infection in southwest China. We also analyzed the extent of cutoff ratios overlap between false-positive and true-positive results to aid the identification of HIV infection, using samples from the West China Hospital in Chengdu, Sichuan Province from April 2012 to December 2013. Reactive results from a screening test were retested and all repeatedly reactive samples - if available - were confirmed with Western blot, HIV-1 p24 antigen, or HIV-1 RNA. Of 241,840 samples screened, the Elecsys® HIV combi PT assay identified 54 patients with acute and early HIV infection; 99.8% cases with cutoff index ratios ≥50 were proved to be true-positive HIV infection and 95.6% cases with cutoff index ratios <15 were falsely positive. In conclusion, the Elecsys® HIV combi PT assay can identify acute and early HIV infection, including those who might have been missed by third-generation HIV screening assays and Western blot. However, cutoff index ratios <15 are not always false-reactive results; a definitive result cannot be attained without further confirmation. In resource-poor regions where a HIV-1 nucleic acid test may be unaffordable, detection of HIV-1 p24 antigen can be an alternative strategy to diagnose HIV infection in individuals with a negative or indeterminate Western blot.