Development of non-ABO RBC alloantibodies in patients undergoing allogeneic HPC transplantation. Is ABO incompatibility a predisposing factor?

BACKGROUND

Data from the appearance of RBC antibodies other than ABO in patients undergoing HPC transplantation are limited.

STUDY DESIGN AND

METHODS

The incidence and specificity of non-ABO RBC alloantibodies are described in a series of 217 patients undergoing allogeneic HPC transplantation because of various hematologic malignancies.

RESULTS

Eight patients (3.7%) developed 10 antibodies after transplant. None of these patients had previously been immunized. Seven patients had one RBC antibody and one patient had three RBC antibodies. Antibody specificity were anti-Jk(b) (2 patients), -Kell (2), -M (2), -Le(b) (1), and -D (1). Finally, two patients had a panagglutinin. The mean time between transplant and antibody detection was 23 days (range, 16-672). The source of the HPCs, the conditioning regimen administered, and the type of GVHD prophylaxis administered did not influence the rate of antibody formation. On multivariate analysis, ABO blood group incompatibility (p = 0.005) and patient's age (p = 0.02) were the only two variables significantly associated with the development of RBC alloantibodies.

CONCLUSION

Patients undergoing allogeneic HPC transplantation are at risk of developing RBC-specific antibodies despite the immunosuppressive therapy administered. Antibody formation was more frequently observed in ABO-mismatched cases, which suggests a potential role of this incompatibility in facilitating antibody production.