AABB2026: When Rare Blood Isn’t on the Shelf, Plan and Communicate

When a kidney transplant candidate with an extremely rare antibody needed blood, a national search found only two units. The case was presented in Monday’s session titled “Your Patient Needs Rare Blood, Who Are You Going to Call?” The session’s speakers were Cami Singer, MLS(ASCP)CM, SBB, of Vitalant; Paul M. Mansfield, MLS(ASCP)SBBCM, of American Red Cross Biomedical Services; and Mary Berg, MD, of the University of Colorado Anschutz Medical Campus. 

They said success in such cases depends as much on communication and backup plans as on the search itself. 

A Patient with Few Options 

Singer described a 50-year-old woman with kidney failure and group A-positive blood. An antibody called anti-Ku was identified in her blood 2023. The blood she needs would have to come from a donor or donors with the K0 phenotype, which lacks both K and k antigens. Its frequency stands at about 1 in 1 million or less in most populations. 

The patient was a kidney transplant candidate with other health problems. Her hemoglobin was stable at 9.3 g/dL. She was adopted, so there were no relatives to test as possible donors. 

The transplant team planned to use cell salvage during surgery, but was concerned about needing a transfusion and asked for several units of red cells. No products were found within Vitalant’s system, so Singer’s team sent a request to the American Rare Donor Program (ARDP). 

How the National Search Works 

Mansfield said the ARDP was formed in 1998 by merging the AABB Rare Donor File and the American Red Cross Rare Donor Registry. It has 89 member facilities, 85 in the United States and three outside it. Of those, 78 are blood collectors. 

Hospitals whose immunohematology reference laboratory is not a member can ask a member to serve as their portal to the program. “Anyone who needs rare blood has access to rare blood within ARDP,” Mansfield said. 

When a case is especially hard, the ARDP hosts a conference call. It brings together ARDP staff and physicians, the blood center’s reference lab, hospital blood bank staff and the patient’s clinical team. They review the patient’s status, the search so far, blood product options, logistics and next steps. 

For this patient, the ARDP found three compatible donors in the United States. One was temporarily deferred, and the other two could not be recruited and scheduled. One possible donor was identified in Japan. 

Importing blood from outside the country is a last resort, Mansfield said. It requires an FDA emergency Investigational New Drug application, with a physician care plan and patient consent. It typically takes weeks if a donor must be recruited and the unit collected, processed and shipped. The hospital pays for the unit, shipping and broker fees, and the unit can be used only for that patient. 

Limiting the Request 

Berg, the patient’s physician, said kidney transplants normally need no transfusion. After reviewing the patient’s history, she and the hematologist agreed that two units would be enough. 

Having the patient donate her own blood was not an option. Berg said people with kidney failure are generally anemic, and the patient’s hemoglobin was too low when she tried to donate. 

Berg also urged care over who tells patients about the problem. “You do not want a surgeon having that conversation,” she said. In this case, the patient’s hematologist explained it to her and to the surgical team. 

She said phone calls work better than email with the blood supplier. Clinicians should give as much information as possible up front, explain unfamiliar clinical terms and be patient with the paperwork. The patient had to sign a form acknowledging that an imported unit might not meet all FDA requirements. 

The Outcome 

Two units were found, one frozen and one liquid. The surgery date occurs soon. 

The patient has continued dialysis and takes erythropoietin, B12, folate and iron to raise her hemoglobin. Berg said the likelihood of needing a transfusion is much higher when hemoglobin is below 10. The team also plans to use blood salvage during surgery and to hold the patient’s blood thinners before the operation. 

Berg’s main recommendation was to prepare for things to go wrong: a donor deferred, a relative unable to donate, a surgery rescheduled or a change to a procedure that needs more blood. 

“I always say we always have a plan B and a plan C and a plan D,” she said.