‘Rare blood’ is identified in three Brazilians – 03/27/2023 – Health

Anyone who thinks that blood types boil down to A, B, AB and O, positive and negative, is wrong. These are the typings of the system known as ABO and are, in fact, the most common and, consequently, the best known by the general population.

However, the International Society of Blood Transfusion (ISBT) has already identified at least 43 systems that describe more than 373 different blood antigens and this number is not definitive. Its differentiation is mainly in the proteins that compose it.

Among the known antigens, some are extremely rare, such as kell-null, also known as blood with the Bombay phenotype. This type of phenotype is found in greater numbers in the population of countries such as Finland, Japan and the United Kingdom.

According to the National Register of Rare Blood (CNSR), from the Brazilian Ministry of Health, there are only three people registered in the country with this blood type. The CNSR was created to register the number of rare blood donors in public blood centers in the country and, thus, be able to locate them in case there is a need for donation.

The Bombay phenotype is rare because it lacks the H antigen on red blood cells.

Patients with this type of “modification” in their blood can only receive donations from people who have the same blood type and with the same “modification”.

This blood group — also known as the “false O” — does not have any ABO antigens, nor H.

“Each blood type has unique characteristics. In the case of the Kell-Null phenotype, the patient cannot receive a transfusion of any blood that has the Kell protein, present in virtually all blood types. If that happens, he may have a reaction and go to death”, explains Cláudio Lucas Miranda, director of the Blood Center of the Hospital das Clínicas of the Faculty of Medicine of Botucatu (HCFMB).

Rare Donation Task Force

At the beginning of the month, the general coordination of blood and blood products of the Ministry of Health called the country’s blood centers to help in the search for a rare blood bag for a woman, hospitalized in serious condition, who needed a blood transfusion in Teresina, in Piauí.

To help the patient, a task force was set up. After identifying that there was a possible donor in Botucatu (SP), the hospital in the north of the country contacted the hospital in the interior of São Paulo. Who, in turn, needed to locate the registered donor who has the rare blood and invite him to donate.

The blood bag traveled 2,600 km to reach its destination.

“A blood bag preserved at a suitable temperature, from 2 to 8 degrees, can last for up to 35 days, which makes transfusion between patients who live so far away, as in this case, quite feasible”, explains Miranda.

Rare blood was transported by plane. He was taken to Piauí on the same day and the patient can now receive him. The woman is still undergoing treatment.

“There is no way we can make a blood modification in the laboratory. As with organ donation, blood donation needs to happen between two people and that they are compatible”, explains Garcia.

For Rafael Pereira Nogueira, who donated the so-called rare blood, being able to help is more than an act of solidarity and love for others. “Knowing that I could help save a life, that I did good for someone in need and that I can even do that for someone in another state makes me very happy.”

Identifying a rare blood

All blood donated in the country’s blood centers undergoes a detailed analysis in which its characteristics are raised.

Only after this blood is fully described (what are its proteins, carbohydrates, antibodies and phenotyping), it is sent for transfusion. This process takes around 24 hours.

“When a person donates blood, they undergo a procedure called erythrocyte phenotyping, which allows identifying more characteristics in addition to the well-known ABO and RhD blood groups — which, together, form the popularly called blood types, such as AB positive or O negative, for example. By doing this, the Blood Center makes transfusions safer for patients who need transfusion therapy”, says Patrícia Carvalho Garcia, coordinator of the Hemotherapy Center at the Blood Center of HCFMB.

Importance of blood donation

A single blood donation can help save up to four lives. The Ministry of Health explains that the scholarships are intended for patients undergoing large-scale and complex medical interventions, such as transfusions, transplants, oncological procedures and surgeries. In addition to patients with serious chronic diseases — such as Sickle Cell Disease and Thalassemia.

“In addition to keeping enough stock to serve all the patients in need, the more people who are willing to be donors, the greater the possibility of finding people with these rare phenotypes. We need to open our eyes to this as well. The more people with rare blood discoveries, the greater the chance of the patient with this peculiarity to be saved”, adds Miranda.