Long-term follow-up testing of red cell alloantibodies


1United Blood Services; Assistant Professor, Department of Pathology, Northwestern University Medical School; and Co-Director, Blood Bank, Northwestern Memorial Hospital, Passavant 102, 303 East Superior Street, Chicago, IL 60611.


Background: In previous studies, 29 to 34 percent of potentially hemolytic red cell antibodies were not detected after short-term follow- up.

Study Design and Methods: To examine long-term detection, records were reviewed for 44 consecutive patients who were tested more than 5 years after their potentially hemolytic red cell antibodies were first identified in this hospital.

Results: After 5 to 10 years, 14 (39%) of 36 Rh, Kell, and Duffy system antibodies were not detected on at least one occasion. Twenty-two other such antibodies were sought again after more than 10 years; 10 (45%) were not detected. When restimulation by pregnancy was excluded, these rates were 42 and 48 percent, respectively.

Conclusion: Clinically significant red cell antibody formation is probably more common than previously realized, because nearly half of these antibodies are undetected after long-term follow- up.