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A colleague in Texas wonders how other transfusion services handle notifications when a blood product is recalled because the donor now tests positive in an EIA for HIV antibodies but indeterminate in an HIV-1 Western Blot and also negative for HIV-1 RNA by NAT. She is aware of the previous related discussions at:
The Texan's transfusion service recently received a notification from their blood supplier concerning a product that was collected from a donor who months ago passed all donor eligibility criteria and FDA required tests, but now shows the aforementioned test results. She wonders what other institutions tell the patient's physician. She also wonders if transfusion services provide follow up HIV testing for the recipient (and if so at what charge), or if recipients are referred to the blood collection agency for testing? She indicates that their local practice is to send a letter to the patient's physician, along with a copy of the notification that they received from the blood product supplier. An example of the notification letter is as follows: PATIENT'S NAME (DOB ) received a unit of packed red cells on DATE. The unit tested negative for all infectious markers. However, we have received notification from the supplier of that unit of packed red cells that the donor has now, on a subsequent donation, tested positive with a screening test for HIV. Further testing shows the donor to be negative for HIV using the NAT (Nucleic Acid Testing), but "indeterminate" for HIV using the Western Blot. The Western Blot test is a confirmatory test that is the most specific for HIV. "Indeterminate" results may be due to a low titer of antibodies to a developing HIV infection, or a variety of conditions yielding "false positive" results. The general recommendation is to repeat testing in 2-3 months. Unfortunately, this donor will be permanently deferred and will not be tested again by the blood product supplier. Finally, in her opinion the blood product supplier should perform "follow-up" Western Blot testing on the donor in 1-2 months. Such testing may clarify whether the donor is truly infected or not, and help guide the transfusion service as to the most appropriate plan of action. The lack of donor follow up puts a hospital transfusion service in a position of not knowing whether the donor is demonstrating a false positive HIV screen, or if something more serious has occurred. The following comments have been received. ADDENDA Nov. 18, 2007 1. Dr. Chris Gresens of BloodSource in Sacramento, California (attribution used with permission) has graciously provided several relevant references (with data) plus his analysis of the data for consideration by the e-Network Forum. The first reference (J.B. Jackson et al. Long-term follow-up of blood donors with indeterminate human immunodeficiency virus type I results on Western blot. Transfusion 1995; 35: 98-102.) looked at 66 blood donors with repeatedly reactive anti-HIV-1 screening results who initially had indeterminate HIV-1 Western blots. Over the course of 5-to-7 years' follow-up, none of these individuals ever showed evidence of true HIV infection. The second reference (M.P. Busch et al. Frequency of human immunodeficiency virus (HIV) infection among contemporary anti-HIV-1 and anti-HIV-1/2 supplemental test-indeterminate blood donors. Transfusion 1996; 36: 37-44.) involved 355 donors with indeterminate HIV-1 Western blot results. Over the duration of the follow-up study (and, similar to the first study), none of these donors ever developed evidence of HIV infection. Given these two published reports it seems exceedingly unlikely that a blood donor with an indeterminate Western blot result is truly infected with HIV (especially if his/her HIV nucleic acid test result is negative, which virtually always would be the case). By extension, the likelihood that a Western blot-indeterminate/HIV-NAT-negative donor would have been infectious for HIV at the time of a PREVIOUS donation is even more remote. Dr. Gresens continues by saying, "If I were the transfusion service medical director for a hospital that received notification from its blood center of such a blood product recall, I would first remember that I have no strict requirement to share this information with the transfusion recipient's physician. This is because: (1) the likelihood that this donor's blood transmitted HIV to the recipient of his/her blood component is exceedingly low, and (2) I am allowed to exercise clinical discretion about when -- and when not -- to convey post-donation information to the transfusing physician. By that I mean that the decision of whether or not to notify generally is in the hands of the transfusion service medical director (except where specifically stated otherwise by AABB Standards or FDA regulations). Moreover, in exceedingly-low-risk situations such as this one, I would wish to invoke what some experts call the corollary to the "patient's right to know" principle -- that is, that the patient also has a right not to know information that doesn't in any meaningful way benefit him/her and would also cause needless worry." As a final related aside, Dr. Gresens provides two additional references that readers may also find helpful:
ADDENDA Nov. 27, 2007 2. In response to the question by the Texas colleague, and in response to the answer provided by Dr Chris Gresens, Dr. Patricia Hewitt, a Consultant Specialist in Transfusion Microbiology for the National Blood Service (NBS) in England (attribution used with permission), endorses Dr Gresen's comments about recipient notification. Dr. Hewitt points out that the NBS collects all the blood used within England and can therefore systematically assess possible false positive HIV donor screening results in a standardized manner. As part of their routine procedure, they would obtain a further blood sample from a suspected false positive donor (generally not less than 12 weeks after the donation) and re-test for markers of HIV with a view to reinstatement to the donor panel using alternative assays. In a case of suspected seroconversion, however, they would obtain a further sample sooner (not less than 2 weeks, but more often 3-4 weeks after donation). They would then be able to assess whether the new reactivity represents new infection or false positive results. But given the HIV test results reported by the Texas colleague for their donor (HIV WB "indeterminate", HIV NAT negative), it is very unlikely that the donor has seroconverted for HIV, as the HIV NAT test would be expected to be positive in this situation. According to Dr. Hewitt, they do not rely exclusively on Western Blot results. As part of the confirmatory protocol, they carry out a full assessment of all blood samples which are reactive in the primary HIV screening assay (EIA) by using at least two alternative EIAs, as well as HIV antigen tests, a blot assay and an individual sample HIV PCR. All samples undergo pooled HIV NAT testing as a primary screening assay. On the basis of these results, they are very rarely faced with a situation where they cannot confidently decide whether a test result is "false positive" or a true seroconversion. The ability to test a follow-up sample allows them to confirm whether there has been a seroconversion. They also have the facility to retrieve the archive sample from the last negative donation and to re-test that sample by individual PCR, in the case of any seroconversion. They would then provide the information to the clinician caring for the recipient, in order to inform the discussion with the recipient and provide as much information as possible so that the recipient can decide whether to undergo an HIV test. In the circumstances described by the Texas colleague, they would not carry out any notifcation of the recipient hospital. They would not carry out a notification because they would not assess the donation as being a risk for the recipient. |
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Please submit comments to the e-Network Forum. Ira A. Shulman, MD W. Tait Stevens, MD |
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