Until recently, there have been cases of bone marrow transplants with 100% compatible donors who have the same HLA type (human leukocyte antigen) socalled allogeneic and in certain situations with the patient’s own bone marrow autologous.
But about 7 months ago, Pietro Basso Correia, 7, underwent a bone marrow transplant that was donated by his older brother Enzo, 11. What makes the episode different is that the compatibility between them is 50%.
The procedure, described as haploidentical, was performed at the BMT (Bone Marrow Transplantation) Center of the GRAACC Hospital (Support Group for Adolescents and Children with Cancer).
Benefits, explains Adriana Seber, hematologist, oncopediatrician and BMT coordinator at Hospital do GRAACC, include agility in administration and increased chances of recovery, with results comparable to those of a 100% compatible bone marrow procedure at the bone marrow bank.
The number of procedures of this type has increased. At GRAACC, there were 15 in 2019; In 2020 there were 24, in 2021 there were 35. Last year, out of the 99 transplants performed, the referral hospital performed 29 bone marrow transplants with 50% compatible donors.
The symptoms of the leukemia began at the age of 3 years
Image: Personal archive
Pietro was diagnosed with ALL (acute lymphocytic leukemia) in November 2018 after frequently complaining of fever, sore throat, loss of appetite, tiredness and fatigue. The first symptoms started in September when he was just 3 years old.
His mother Aline Fernanda Machado, 42, a social worker, recalls that despite her work in the healthcare field, it took her a while to suspect it could be something more serious. He, with a neurologist friend, commented on their youngest son’s symptoms, including an already yellowing appearance, and asked her to show a recent photograph of the boy.
Looking at her, he advised her to rush him to the hospital because if it wasn’t leukemia, it could be internal bleeding.
And so he went to a hospital specializing in childhood cancer, where Pietro was admitted and treatment began. The last chemotherapy was performed on December 11, 2020 and during the following year he was regularly consulted and examined.
Cancer is coming back, aggressively
However, in early 2022, he began complaining of back and neck pain. Aline remembers already suspecting something was wrong. “When we have a child with leukemia, we notice that the color of the mouth changes very quickly, discoloring and going back to normal.”
In March, they returned to GRAACC for routine checkups and learned the leukemia had returned even more aggressively.
With the new diagnosis, a bone marrow transplant was immediately indicated.
“Pietro was taken to the hospital and was already on morphine, that’s how bad the pain he was feeling. He stayed in the hospital for 21 days and returned for medication and other procedures. He also underwent radiation therapy to actually zero out all cancer cells,” his mother says.
Enter the older brother
Enzo conducts tests and draws blood prior to the procedure
Image: Personal archive 
Enzo and the bag of bone marrow that would go to his brother moments later
Image: Personal archive
While the patient is being treated, family members are tested for compatibility and the hospital begins searching for matches in the Redome (National Registry of Volunteer Bone Marrow Donors).
“When we went to the lab for the blood test, Enzo said to me like, ‘Mom, I think I’ll be compatible with Pietro,'” she recalls. Genetic test results usually take 20 days.
During this time, the hospital even identified a possible donor in Portugal, but the mother recalls that cases of Covid19 had increased, which would complicate procedures.
The good news was the confirmation that his brother’s bone marrow was 50% compatible and also Pietro had completed all the protocols and was ready to receive the new bone marrow so the medical team decided on the haploidentical transplant.
Since fathers and mothers are always 50 percent compatible, so was Aline, but Enzo had better conditions compared to her, mainly because of his age: “The doctors said that because he was the son of the same father and the same mother, of the same sex and blood type, he had the same ideal conditions for the success of the procedure”.
The mother emphasizes that Enzo had a 100 percent stake.
It was heart and soul, also because of the isolation he had to go through as he couldn’t get infections, care in food and even online classes. After the donation, he was in severe pain for five days, but by the sixth day he was well and recovering.
The procedure and “taking” of the bone marrow
Pietro receives bone marrow from his brother
Image: Personal archive 
Pietro one day after the transplant
Image: Personal archive
Under anesthesia, the bone marrow was removed through a special needle on the morning of May 12 and received by the brother in a 4hour transfusion in the afternoon.
“He had no complications, apart from those already expected, and the bone marrow injury happened on the 17th day after the transplant. Pietro said that his back hurt and I noticed that his cheeks were pinker. These are some signs that the doctors themselves comment: The next day, Sunday May 29th, we went home.”
Bone marrow “uptake” occurs when leukocytes and platelets reach a certain level without transfusion in the transplant recipient’s body.
Today, Pietro has 100% of his older brother’s bone marrow and no longer needs to take immunosuppressants drugs that prevent rejection.
The routine still needs care to prevent infection, such as the use of masks, hygiene upon arrival from the street and even baths with mineral water. After a precautionary separation, the brothers are already living in the same house again.