Posted: 23.05.2024 11:45:56

Everyone has their own allele

Republican Centre for Hematology and Bone Marrow Transplantation

Finding genetically compatible stem cell donors for Belarusians may require travelling the whole world

Hematopoietic stem cells save lives of people with oncohematological diseases. According to international statistics, stem cell transplantation helps the patient achieve sustained remission in almost 80 percent of cases. This is the reason why the International Bone Marrow Transplant Registry (IBMTR) and the International Stem Cell Registry (ISCR) were created, with approximately 80 million people from Europe, Asia, Africa, Australia and America registered as donors. Belarus has a similar national registry with about 100,000 donors. This is a big number, yet it all depends on the human phenotype, the analogue of which sometimes has to be looked for in different parts of the world.

Biologist Mariya Kolbasina, Bone marrow separation and freezing laboratory, Republican Centre for Hematology and Bone Marrow Transplantation

Unique code

The National Hematopoietic Stem Cell Transplant Registry is maintained at the Republican Centre for Hematology and Bone Marrow Transplantation. This bank helps to find donors not only for Belarusians but also for foreigners. As a rule, those who wish to share their cells are between 18 and 50 years old and in good health. The selection for transplantation is based on the compatibility of phenotypes — this is where the main bottleneck lies. Belarus is located in the centre of Europe, therefore our phenotypes are mixed. According to Yelena Glaz, a transfusiologist at the Republican Centre for Hematology and Bone Marrow Transplantation, 
“Belarusians have Russian, Polish, German, Ukrainian, Japanese, Chinese and even African blood in their family history. The allele — in other words, the code — is determined thanks to HLA typing, which is carried out in three laboratories in our country. The combination of alleles makes the human phenotype. Each country has its own unique phenotypes. Thus, the A*01:02 allele is a common phenomenon in Belarus, while A*36:01 is rare. What is unusual for our country will be the norm in another area. Alleles have millions, if not billions, of variations. Phenotypes may not match even in children from the same family, because they received different combinations of genes from their parents.”

Time is ticking

About 300 new patients in our country need stem cell transplantation every year. In some diseases, it is possible to use the patient’s own cells, which makes the situation easier. Stem cells are then extracted and frozen using cryopreservation while the patient undergoes chemotherapy. About half of those in need of a transplant are children, but if the child’s phenotype coincides with that of the adult, the age difference does not matter. Belarusian doctors can apply to a medical centre for stem cells in any country and even on any continent.
How does it work? Belarusian specialists directly contact the centre to which the donor belongs. Foreign colleagues examine the donor and send the test results to Minsk. If everything is in order, the donor is prepared for the sampling procedure. Meanwhile, the Belarusian side is devising the logistics. The point is that stem cells are only viable for 72 hours at a certain temperature. Therefore, they must be delivered to Belarus and transplanted within this time.
The delivery can be arranged by plane or across the land border. Yelena Glaz shared the details, “We notify the customs and border control in advance as to when and who will transport stem cells, and attach a package of documents. If the logistics route is complex, we ask the courier company which has the right to transport biomaterial to deliver it, for example, from London to Vilnius, from where we collect it and bring to Minsk on our own.” 

Bone marrow separation and freezing laboratory, Republican Centre for Hematology and Bone Marrow Transplantation

Stem cell storage, Republican Centre for Hematology and Bone Marrow Transplantation

For each patient — €18,000

The courier is met in Vilnius by Yelena Glaz. The fastest way to get to Minsk is by bus — it takes six hours to reach the capital of Belarus. In contrast, when going by car, there is a risk of standing in the line at the border for a much longer time. Immediately upon arrival, stem cells are taken to the operating room, where the patient is already prepared and waiting for the transplant.
The delivery time has increased after the closure of the air boundaries, while not all ground checkpoints have the right to process documents for stem cells. However, despite this hindrance, the team of Belarusian specialists manages to complete delivery and transplantation within an average of 48 hours, out of 72 hours of cell viability. Sometimes it happens that the first sampling from the donor is not enough, in which case a second one must be carried out. This complicates rapid transportation, but still does not make it impossible. Belarusian doctors have even developed a 60-hour route from the US medical centre to the Belarusian one.
“I transfer the donor material in a special thermal container with refrigerating elements,” explained the transfusiologist. “When filled, it weighs about 7 kilogrammes. Stem cells are placed in numbered sealed bags. All personal information is encoded so that only designated people could relate the donor to the patient. Our courier who has a Schengen visa travels abroad several times a month. There is no time to see the world, though. After all, the viability of cells is limited.” Meanwhile, Yelena Glaz travels a lot in her free time and has visited almost every European country.   
The donor material for one patient, including delivery from Europe, costs our country an average of €18,000. The Belarusian citizen does not need to pay anything for the stem cell therapy. The main task for the patient is to recover.
“The major task for doctors is to choose an appropriate donor despite the unique phenotype,” concluded Yelena Glaz. “Thus, we have recently received a request from a patient from Sudan, where there is no stem cell transplant registry at all. We often provide stem cell therapy to patients from Kazakhstan, Uzbekistan, and other countries where stem cell transplantation is not as developed as in Belarus. We try to help everyone.” 

In search of cells

Some people’s phenotypes can be so unique and rare that it is hard to find donors for them.
In order to perform a stem cell transplant, the donor’s phenotype must correspond to that of the recipient. Phenotypes can be common and rare, when there is less than one percent of a certain set of alleles in the country. It depends on the genetics inherited from parents. Thus, the probability of finding a donor for a person who has an African in their family history is fairly low in Belarus. In this case, welcome to the international registry. 

By Yelena Basikirskaya

Photos by Aleksandr Kulevsky