Some blood centers are testing for Zika viral RNA using investigational new drug (IND) protocols cleared by the Food and Drug Administration (FDA) and more will soon or are considering doing so. FDA has required that test-negative blood components be labeled "negative for Zika virus by an investigational test". The FDA also recommends that an appropriate "acknowledgment" or consent be obtained prior to transfusion of high-risk recipients via a labeling supplement or modification of the circular of information. Here is language accepted by FDA for one IND participant. For "areas of active transmission or donations collected from individuals with known risk factors, it is recommended that an appropriate acknowledgment or consent be obtained prior to trans-fusion of a high risk recipient, e.g., a fetus in utero or pregnant woman." You can imagine that this is causing some consternation at centers and hospitals. Dr. Susan Stramer at the American Red Cross and I are fielding urgent inquiries from our clinical friends asking what they should be doing (and why).
Untested units require no such labeling and there is no recommendation they be infused with recipient consent or acknowledgment regarding Zika. The agency's intent is to ensure that recipients of blood components are aware that because of a potential risk of acquiring Zika virus through transfusion and its consequences, the blood was tested for Zika with an investigational assay. The language about informing and consenting patients and their surrogates is a recommendation that FDA required in the INDs-FDA has not previously tried to regulate the bedside interactions of clinicians with individual patients when testing INDs were used (e.g. HIV, HCV and WNV).
Some questions come to mind:
1. How was it determined that the risk from Zika-tested components justifies these actions?
2. Who, other than a fetus in utero or a pregnant woman, is at high risk-i.e. what patients are subject to the recommendation?
3. If you were a "high risk recipient", would you accept such a unit or prefer an untested unit with no such "warning"? Is the unintended message that the tested unit is somehow "less safe"? Is it possible that necessary transfusion will be delayed or refused?
4. Why are we not recommending the approach for other individual recognized transfusion-transmitted pathogen-especially those for which we expect the risk is higher than for Zika e.g. WNV, babesiosis in highly endemic states, bacteria in platelets? Serious non-infectious hazards that are more common and arguably cause more morbidity?
5. Is it appropriate that the agency inserts itself at the bedside, where its regulatory authority is limited, via the IND process where its authority is unchallenged as opposed to via more transparent routes like the guidance process?
Louis Katz, MD; Chief Medical Officer