How good is HIV NAT for detection of HIV-1 Group O infection?

An e-network colleague wonders if there has been any evaluation of HIV NAT for the detection of HIV-1 Group O Infection? Her blood donor center has a repeat donor who is married to a lady that moved to the United States from Nigeria 22 years ago. The donor has given blood many times, and at each donation has tested negative in all FDA required donor screening tests. Only recently has the inquiring colleagues Blood Donor Center discovered that the wife of this donor is from Nigeria, and is concerned about compliance with the FDA Memorandum dated December 11, 1996 “Interim Recommendations for Deferral of Donors at Increased Risk for HIV-1 Group O Infection. The inquiring colleague is of the opinion that if the donor's wife had an infection with HIV-1 Group O, such an infection would be obvious by now, but also understands the need to defer the donor from this point on, over concerns of possible HIV-1 Group O Infection risk, because the inquiring colleague believes that current serologic testing is not reliable for detection of HIV-1 Group O.

Before sharing the above scenario with the full e-network forum, this interesting case was sent to an expert in donor screening for HIV for comment. She reports that at least one HIV NAT test kit manufacturer, for whom she has seen data, has a considerable volume of data demonstrating HIV-1 Group O detectability at the same analytic sensitivity as that of HIV-1 group M. Also, she comments that one should not underestimate the sensitivity of the HIV antibody tests to detect HIV-1 Group O; in data that she has seen, the assays detect as reactive 80-100% of samples tested. She concludes by cautioning that in spite of the above reported test performance, it is prudent to follow current FDA guidelines for donor deferral and to follow established product recall procedures, as appropriate (Editor's NOTE: see discussion here.)

The following comments have been received.

ADDENDA Aug. 23, 2003

1. A transfusion medicine physician affiliated with Chiron, who is very familiar with the circumstances of HIV NAT testing, reports that two HIV NAT assays have been approved for screening donated blood for HIV-1. He comments (verbatim) "The detection level of HIV-1 Group O is specified in the package inserts of each assay. In addition to the registration studies included in the package insert, other studies have also been published on the detection of HIV-1 Group O using HIV NAT testing. These suggest that some assays may detect HIV Type O more consistently than others."
   
   Colleagues might find the following references to be germane to this discussion:
   1. Berger A, Rabenau HF, Stief A, Troonen H, Doerr HW. Evaluation of the new LCx HIV RNA quantitative assay comparison with the Cobas Amplicor HIV Monitor assay. Med Microbiol Immunol (Berl) 2001 Dec;190(3)129-34.
   2. Yang Y, Lamendola M-H, Mendoza M, Xu D, Nguyen M, Yeh S, Wu Y, Ku J, Rosenstraus M and Sun R. Performance characteristics of the COBAS AmpliScreen HIV-1 test, version 1.5, an assay designed for screening plasma mini-pools. Transfusion Volume 41 Issue 5 Page 643 - May 2001.
   3. Swanson P, Soriano V, Devare SG, Hackett J Jr. Comparative performance of three viral load assays on human immunodeficiency virus type 1 (HIV-1) isolates representing group M (subtypes A to G) and group O LCx HIV RNA quantitative, AMPLICOR HIV-1 MONITOR version 1.5, and Quantiplex HIV-1 RNA version 3.0. J Clin Microbiol 2001 Mar;39(3)862-70.
   4. Linnen JM, Gilker JM, Menez A, Vaughn A, Broulik A, Dockter J, Gillotte-Taylor K, Greenbaum K, Kolk DP, Mimms LT, Giachetti C. Sensitive detection of genetic variants of HIV-1 and HCV with an HIV-1/HCV assay based on transcription-mediated amplification. J Virol Methods 2002 Apr;102(1-2)139-55.
   5. Defer C., Lepot I., Givais C., Bodel C. Comparative Study of 2 NAT Assays Procleix, Multiprep/Ampliscreen. Transfusion (supplement) Sept 2002. Vol 42 No. 95, pg 83S.

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Ira A. Shulman, MD
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W. Tait Stevens, MD
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Elizabeth M. St. Lezin, MD
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