Matching cord blood recipients with donors who share paternal blood markers may reduce relapse rates for certain types of leukaemia, according to a study.

Researchers have been unable to explain why umbilical cord blood, assumed to be immunologically immature, has proven effective at attacking leukaemia cells in unrelated donors. Jon J. van Rood and colleagues examined information from the New York Blood Center National Cord Blood Program and report that maternal immunities in cord blood may deter leukaemic relapse.

During pregnancy, women often become immunised against paternal antigens that the fetus inherits from the father, producing immune system cells that enter the circulation of the fetus. The authors hypothesised that these “sensitised” maternal cells in cord blood might recognise identical inherited paternal antigens (IPA) in unrelated transplant recipients and trigger a potent immune response against leukaemia cells.

The researchers observed lower relapse rates among study participants with acute myeloid and lymphoblastic leukaemia who received cord blood from donors with IPAs matching their own, compared with study participants who did not have the same blood markers as their donors.

The findings may aid future cancer surveillance studies and, according to the authors, could be incorporated into search algorithms that transplant centers currently use to help match cord blood donors with recipients.

Source: Leiden University