Organ transplants: when immunity is the problem

Naiara, a two-month-old baby, made history by becoming the recipient of the world's first heart transplant from an arrested infant, even with a blood incompatibility with the donor. To recover the deceased's organ before it was removed, a procedure called cardiopulmonary bypass was used, which oxygenates the heart with a device. As the team that worked with little Naiara at the Gregorio Marañón Hospital in Madrid explained, this type of transplant, until recently viable, considerably increases the life expectancy of pediatric patients, for whom there are very few gifts.

Not a week energies by without us knowing about a new discovery in the field of transplants. A child with a severe intestinal malformation leaves the operating table at La Paz University Hospital in Madrid with a new intestinal, liver, duodenum, small intestine, colon piece and pancreas. Still in the capital, but at the Puerta de Hierro hospital, the medical team is facing a simultaneous two-heart transplant for the first time. And at the clinical hospital in Barcelona, ​​a patient receives a uterine transplant from a living donor, which has opened the possibility of becoming pregnant.

Donation and transplant activity in 2020 was marked by the COVID-19 crisis, but, despite many difficulties, 4,427 organ transplants were achieved in Spain, which resembles to a rate of 93.3 per million patients. population (pmp). The figure is abundant higher than the rest of the pre-pandemic countries, so our country is an international landmark. However, at the end of the year, 4,794 patients were on the waiting list, including 92 children. "There is a huge discrepancy between source and petition or an inability to meet the needs of organs for transplantation of the people, which ages and develops pathologies," explains Beatriz Domínguez-Gil, director general of the National Transplant Organization (NTO).

A transplant involves replacing a diseased organ or tissue with one that is functioning correctly. It can be a solid structure (kidney, heart, liver), tissue (bone, tendon, cornea, skin) or hematopoietic progenitors (those that generate blood, ie bone marrow). In any circumstance, it is the best solution - and occasionally the only one - to prevent death or improve the lives of individuals who agonize irreversible damage to one of their organs. In Spain, this procedure is governed by a law that guarantees altruism in donation and fairness in access to movement.

The implantation of a far-off body in the body is a major medical and pharmacological struggle. Unlike blood transfusions, transplanted organs, although highly compatible, are usually disallowed, either immediately or in the long term. For example, the ending date of a kidney is ten years; that of a lung, five; that of a heart, thirteen; and that of a liver, XVII. In children and adolescents, this means that they may need to be replaced several times in a lifetime, when organ availability in children is also very low.

Pharmacologic immunosuppressions

Rejection occurs since the immune system is designed to pursue out and destroy cells that it recognizes as foreign. To avoid this, the body's defenses are minimized due to immunosuppressive drugs. "Most patients essential this therapy for life," explains the ONT director. The problematic is that "immunosuppression generates pathology and, on the other hand, the transplant patient previously has, in a large percentage, a lot of related comorbidities." This is why you are more likely to develop serious diseases, from kidney problems to infections, osteoporosis and even cancer. In addition, growth and cognitive problems can occur in children, among others.

So scientists around the biosphere are working to develop strategies to minimize dependence on pharmacological immunosuppression, avoid rejection of solid organs, and ensure a "transplanted organ for life," in words. By Antonio Pérez, Head of the Department of Pediatric Hematology. Department of Oncology and Hematopoietic Transplant in La Paz.

This hospital in Madrid is a pioneer in inducing immunological tolerance, a strategy that proposes the transfer, with the organ, of hematopoietic progenitors from the same donor. "This approach is based on the remark that, in bone marrow transplants, almost 90% of patients eliminate immunosuppressive drugs after one or two years," explains Dr.