Scientific Publications by FDA Staff

AIDS Res Hum Retroviruses 2012 Jun;28(6):594-606

Pilot Studies for Development of an HIV Subtype Panel for Surveillance of Global Diversity.

Manak M, Sina S, Anekella B, Hewlett I, Sanders-Buell EE, Ragupathy V, Kim JH, Vermeulen M, Stramer S, Sabino E, Grabarczyk P, Michael NL, Peel S, Garrett PE, Tovanabutra S, Busch M, Schito M

The continued global spread and evolution of HIV diversity poses significant challenges to diagnostics and vaccine strategies. NIAID partnered with the FDA, WRAIR, academia and industry to form a Viral Panel Working Group to design and prepare a panel of well-characterized current and diverse HIV isolates. Plasma samples which had screened positive for HIV infection and had evidence of recently acquired infection were donated by blood centers in North and South America, Europe and Africa. A total of 80 plasma samples were tested by quantitative nucleic acid tests, p24 antigen, EIA, and Western blot to assign a Fiebig stage indicative of approximate time from initial infection. Evaluation of viral load using FDA-cleared assays showed excellent concordance when subtype B virus was tested, but lower correlations for subtype C. Plasma samples were co-cultivated with PHA-stimulated PBMC from normal donors to generate 30 viral isolates (50-80% success rate for samples with viral load > 10,000 copies/mL), which were then expanded to 107 - 109 virus copies per mL. Analysis of env sequences showed that sequences derived from cultured PBMC were not distinguishable from those obtained from the original plasma. The pilot collection includes 30 isolates representing subtypes B, C, B/F, CRF04_cpx and CRF02_AG. These studies will serve as a basis for the development of a comprehensive panel of highly characterized viral isolates which reflect the current dynamic and complex HIV epidemic, and will be made available through the External Quality Assurance Program Oversight Laboratory (EQAPOL).