Generales

By Andrea Carolina Vargas Malagón, Journalist at UdeA Communications Office 

Donating blood and organs saves lives. In Colombia, hematopoietic stem cell donation still struggles to grow because national donor registries remain limited and myths about the procedure continue to circulate. This safe and straightforward process, driven by the generosity of voluntary donors, is crucial for patients with certain blood diseases to survive and lead a better quality of life. 

This content comes from Alma Mater newspaper. » View PDF editions

Worldwide, 84 registries list more than 43 million adult hematopoietic stem cell donors. Photo: Freepik. 

Each year, over one million people worldwide receive a diagnosis of a blood disorder. Some cases are cancers — leukemia, myelodysplastic syndromes, lymphoma, and multiple myeloma — and others are noncancerous conditions such as aplastic anemia, primary immunodeficiencies, and congenital blood disorders. These illnesses severely reduce quality of life and can be fatal. 

Many treatments can manage these diseases and, in some cases, cure them. However, for many patients, the only option with true curative potential is a hematopoietic stem cell transplant, often called a bone marrow transplant. 

“Hematopoietic stem cells are immature cells in the bone marrow that develop into the various blood and lymphoid cells. As they grow, they become red blood cells that carry oxygen through hemoglobin to the body’s tissues; platelets that help blood clot; and white blood cells, which protect us from infections and diseases like cancer,” explained Andrés Garcés Arias, internist and hematologist, leader of the Hematopoietic Stem Cell Transplant Program at Alma Mater Hospital, and professor at the Faculty of Medicine, Universidad de Antioquia. 

Garcés Arias explains that hematopoietic stem cell transplants offer a chance to cure or enhance survival and quality of life for patients with certain blood diseases. “In some cases, the patient’s stem cells are used in autologous transplants. In other cases, doctors use stem cells from a healthy donor in allogeneic transplants, usually a relative with compatible genetics, though unrelated donors are also an option,” he said. 

To determine if someone can donate hematopoietic stem cells to a particular patient, doctors conduct compatibility tests using the HLA (Human Leukocyte Antigen) system, which serves as a unique identifier for cells. Ensuring a close genetic match between donor and recipient helps lower the chance of immune rejection. 

“The probability that a full sibling—sharing both parents—matches the patient exactly is only 25%, which means most patients don’t have a perfectly compatible sibling. Thanks to advances in treatments and immunosuppression, doctors can now safely perform transplants with related donors who match about 50%. These haploidentical donors include full siblings, half siblings, parents, and children. Still, around 20% of patients lack a suitable donor in their family and need to find unrelated donors to receive a transplant,” explained Garcés Arias. 

When patients lack a family donor, they rely on generous strangers willing to donate as unrelated donors. This reliance makes national and international stem cell donor registries vital. Unfortunately, misinformation and myths about the donation process continue to slow the expansion of this crucial network. 

Paola Cendales Rodríguez, a Public Health master’s graduate and leader of the National Registry of Hematopoietic Stem Cell Donors (Dar Células) at the District Institute of Science, Biotechnology and Innovation in Health (IDCBIS), states that around 84 registries worldwide include more than 43 million adult hematopoietic stem cell donors. Despite these numbers, patients in Colombia still face a very low chance of finding a compatible donor. 

“The German and American registries supply most of the donors worldwide. In Latin America, however, active registries remain few, leaving us underrepresented in the international database. This situation means most donors have genetic profiles that differ greatly from those of Latin Americans, which sharply reduces the chance that a Colombian will find a compatible donor,” explained Cendales Rodríguez. 

Donor registries rely on international solidarity, connecting into a single global database that makes donor searches possible across countries. To improve genetic representation from Latin America, more people in the region need to step forward and register voluntarily as hematopoietic stem cell donors. 

Donating doesn’t hurt or affect your mobility.  

Many people mistakenly believe donating hematopoietic stem cells is painful or can cause loss of mobility because they confuse bone marrow with the spinal cord and assume the process involves lumbar punctures. This confusion often comes from mixing up bone marrow with the spinal cord. 

“Bone marrow is soft tissue located inside some bones, especially flat ones like the pelvis, vertebrae, sternum, and skull. It houses hematopoietic stem cells that continuously renew and serve as a factory producing blood cells. By contrast, the spinal cord is nervous tissue protected by the spine, acting as a complex cable that carries nerve signals between the brain and the rest of the body,” explained Garcés Arias. 

Donating hematopoietic stem cells doesn’t involve the spinal cord and carries no risk to mobility. Although doctors sometimes obtain these cells through bone marrow aspiration—a procedure done under general anesthesia via a needle in the pelvic bone—medical advances now allow them to collect stem cells from the bloodstream. Using medications to release stem cells into the blood, doctors perform an intravenous procedure similar to blood donation, extracting only the needed cells and returning the rest to the body. 

“It’s a safe and straightforward procedure. A few days before, the donor receives medication that encourages hematopoietic stem cells in the bone marrow to multiply and enter the bloodstream. Then, using a process called apheresis—similar to donating blood—doctors collect mostly stem cells and return the remaining blood components to the donor. The donor fully recovers the donated hematopoietic progenitor cells within weeks and experiences no lasting side effects,” explained Garcés Arias. 

The first step is to register as a donor.  

Choosing to become a hematopoietic stem cell donor doesn’t mean you’ll donate immediately. The process begins by joining a donor registry, which collects a blood sample or cheek swab to obtain your genetic information. This information remains confidential and becomes part of a global database that enables doctors worldwide to find matching donors when patients require them. 

“Keep in mind that the odds of a voluntary, unrelated donor matching a patient remain very low. Some donors may reach the maximum donation age of 60 without ever receiving a call to donate,” said Cendales Rodríguez. 

Once the registry identifies a matching donor, it contacts the donor to confirm their willingness to donate. If the donor agrees, medical exams follow to verify their health and suitability for donation. Once approved, doctors collect the cells and transport them to the patient in need. 

Colombia’s National Registry of Hematopoietic Stem Cell Donors runs through the Dar Células program, which now includes nearly 13,000 registered donors. While HLA screening currently happens in Bogotá, people from other cities can pre-register on the program’s website. The program plans to open new collection sites soon across various regions of the country.