Did You Know? Blood Group Serology in Asia

• Pretransfusion antibody screen is not universal!  A hematologist in charge of a blood bank of a private hospital in Malaysia said, “my patients are not willing to pay for such tests as I am not transfusing them with antibody screening cells but donors! A one tube IAT XM is all I need”. I told him about our practice and elaborated on the benefit such as prior knowledge of presence of antibody, dosage, sensitivity, incidence of delayed hemolytic transfusion reactions…….  He simply replied, “I rarely encounter these cases , perhaps my patient population are mostly ethnic Chinese,  they are less prone to be alloimmunized by blood transfusion!”

 

• In some small inland cities in China, manual polycation technique commonly known as the polybrene-IAT test is the choice methodology for crossmatch  (Lalezari and Jiang. Transfusion 1980; 20:206-211). Polybrene is easy to use - it requires only one minute incubation at room temperature and it is sensitive to detect Rh, Kidd and Duffy antibodies. The down side of this method is that it misses 40 - 50% of Kell system antibody (personal  unpublished observation). This method has been adopted for many years and found to be practical, because Kel1 (K),Kel3 (Kp^a) and Kel6 (Js^a) are extremely rare among Chinese (<0.01%).

 

• Le(a+b+) is usually found in genetically Le(b+) babies between  2-24 months after birth. In Hong Kong and Taiwan, the incidence of Le(a+b+) adults can be as high as 27% while the incidence in Japan is 17%. This phenotype is a result of a mutation of FUT2(SE) gene: 385A>T; Ile129Phe.

 

• Anti-D and anti-Fy^a pose huge challenges to patients in Asia similar to anti-k found here in Canada. Incidentally, one third of the rare D- Chinese are Del which lacks most of the epitopes and fewer in numbers.

 

• I recall an Rh negative new immigrant from Canton (now Guangzhou), China who lost her second and third baby due to high titred anti-D. With proper perinatal care in Calgary, her 4^th and 5^th baby survived!

 

• Asian countries  in the north such as Mongolia, Japan, Korea and northern China,  Di^a is required on one of the antibody screening cells while southern China, Taiwan, Hong Kong and Thailand, GPMur+  is required. These two antigens are the Kell counterparts in Asia. Bob advocated screening for anti-Di^a among the Chippewa’s in Manitoba as the incidence is 11%.  GPMur is glycophorin (B-A-B) hybrid having frequencies of 9-10% in Thailand and 6-7% in Hong Kong and Taiwan.  

 

• Most of us are aware Jk(a-b-) donors can be found more frequently among Polynesians and these donors are readily located from Hawaii and New Zealand. Little did I know that Jk-3 donors can also be found in Hong Kong and Manila. The chief technologist at the Blood Bank of Hawaii told me that his last 5 Jk-3 donors are ethnic Filipinos!

 

• Bombay and Para Bombay: It is well known that Bombay Phenotype (H-deficient, non-secretor) is less rare in India while Para Bombay (H-deficient, secretor) is less rare in East Asian countries, China including Hong Kong,  Japan and  Taiwan.  

 

• Inb, the less known  high frequency blood group antigen is less rare among Indians and Arabs; it may cause transfusion reactions but is insignificant in terms of HDFN. I heard of a prenatal sample of Inb found in Vancouver a few years ago and the infant was not affected.

 

• Weak subgroups of B are more prevalent among south and southeast Asian countries. When there is an “forward O and reverse B”  ABO discrepancy, look at the patient’s last name, it may help!