Immunological characterization of anti-Mi(a), a red blood cell alloantibody, in Taiwan.
OBJECTIVE
The red blood cell Mi III phenotype is prevalent in Asia, and its corresponding alloantibody, anti-Mi(a), has been reported to cause haemolytic transfusion reactions and haemolytic disease of the newborn. However, a complete picture of the immunological characteristics of anti-Mi(a) is still lacking. We therefore conducted a systematic study to evaluate the potential clinical significance of this antibody.


METHODS
From April 1999 to March 2000, we identified 60 sera containing anti-Mi(a) among pretransfusion samples at a teaching hospital in Taiwan. These antibodies were tested for immunoglobulin class, thermal range and activity in a monocyte monolayer assay.


RESULTS
Thirty-four (57%) of the antibodies were immunoglobulin M (IgM), and 15 retained their activity at 37 degrees C. Of those that were immunoglobulin G (IgG), 96% were of subclasses IgG1 and/or IgG3. Monocyte monolayer assay studies showed that 69% (18/26) of the IgG anti-Mi(a) sera were reactive.


CONCLUSIONS
Our study justifies the implementation of anti-Mi(a) screening in Taiwan.
Department of Laboratory Medicine, National Taiwan University Hospital, 7 Chung-Shan South Road, Taipei 10018, Taiwan.
S-C
SC
Lo
J-S
JS
Chang
S W-S
SW
Lin
D-T
DT
Lin
D004912:Erythrocytes / Q000276:immunology; D006801:Humans; D007136:Immunoglobulins / Q000097:blood / Q000145:classification; D007518:Isoantibodies / Q000097:blood / Q000276:immunology*; D008951:MNSs Blood-Group System / Q000276:immunology*; D008403:Mass Screening; D010641:Phenotype; D013624:Taiwan / Q000453:epidemiology
D007136:Immunoglobulins; D007518:Isoantibodies; D008951:MNSs Blood-Group System