Recently, the Blood Transfusion Department of Fudan Zhongshan Xiamen Hospital discovered the first case of Ael subtype blood type globally, which is even rarer than the Rh-negative blood type commonly referred to as “panda blood.” The research findings were published in an international transfusion medicine journal and named after Fudan University-affiliated Zhongshan Hospital (Xiamen) Blood Transfusion Department at the International Society of Blood Transfusion (ISBT).
Lu Xiaoying, Deputy Director of the Blood Transfusion Department at Fudan Zhongshan Xiamen Hospital, introduced that during a routine blood type identification examination of a man in his thirties who visited the hospital’s management department for a physical examination, the department discovered that the blood type serology of the subject did not conform to the Landsteiner’s law.
Lu Xiaoying explained that Landsteiner’s law states that if an individual’s red blood cells lack A or B antigens, corresponding anti-A or anti-B should be present in the plasma. However, the subject did not conform to this rule. Fudan Zhongshan Xiamen Hospital’s Blood Transfusion Department discovered the first case of Ael subtype blood type globally.
Lu Xiaoying immediately led the team to conduct a thorough investigation, considering the subject’s blood type could be extremely rare. They initiated a difficult blood type serology testing plan immediately. Through a series of professional tests such as tube method reconfirmation, anti-H test, absorption and elution test, the serological results indicated that the man was suspected to have Ael subtype variant.
It is reported that Ael is a rare ABO subtype, inherited from rare allele genes at the ABO locus. ABO subtypes are extremely rare in populations, with a frequency of discovery even lower than that of Rh-negative people commonly referred to as “panda blood.” In the Han population, the frequency of Rh-negative individuals is 2 to 5 per 1000 people, while the probability of Ael subtype ABO in the Chinese population is approximately 1 in every 80,000 people.
The results of third-generation molecular genetic testing showed that a mutation not included in the International Society of Blood Transfusion (ISBT) was found for the first time in the first intron of the subject: c.29-10T>A. This mutation is located near the exon splice region and may affect the normal splicing of gene products, resulting in the phenotype of carrying this mutation being Ael.
Combining the test results, the blood type of the subject was ultimately confirmed to be Ael subtype.
The research findings have been published online in the international transfusion medicine journal “Vox Sanguinis.” Subsequently, the newly discovered A allele gene variant was named after Fudan University-affiliated Zhongshan Hospital (Xiamen) Blood Transfusion Department by the International Society of Blood Transfusion (ISBT). The discovery of this new allele gene not only refreshes human understanding of blood type genes but also further enhances the clinical transfusion safety coefficient.
Regarding how to transfuse rare blood type individuals, Lu Xiaoying stated that in emergencies, ABO-compatible red blood cell products from the main type could be transfused, or O-type washed red blood cells could be used, or autologous blood collection could be chosen for transfusion. Currently, the most widely used approach is pre-storing one’s own blood. Autologous blood transfusion can avoid bloodborne diseases and immune suppression, making it the best source of blood for patients with rare blood types.