Organ transplantation is performed between a donor (who gives the organ) and a recipient (who receives the organ), during which the donor’s organ is transplanted into the recipient’s body.
The purpose of transplantation is to substitute one or more essential organs and certain organ functions. Transplantation can be performed as a response to a partial or complete cessation of an organ’s function. Such organ insufficiency can result from a disease, an injury, or a congenital defect.
Definitions
Donor: the individual who donates an organ or a tissue so that the organ/tissue would be transplanted into another individual, or a deceased individual after whose death, an organ or a tissue will be removed from their body so that the organ/tissue would be transplanted into another, living individual. The donation word originates from the Latin “donatio” word and describes the act of “giving”. Donors, therefore, may be living or deceased individuals.
Recipient: the individual who receives an organ or a tissue from another individual as part of the therapy. The word originates from the Latin “receptio” = “receiving” word.
Organ: a collection of specific tissues that structurally form a functional unit with function in the human body.
Organ donation: when someone donates an organ so that the organ would be transplanted. Human tissue and cell donation are also involved in this category.
Organ and tissue transplantation: organ and tissue removal from the human body so that they would be transplanted into another human being’s living body.
Clinical death: the complete cessation of breathing, blood circulation and brain activity, resulting in the irreversible decline of the body.
Brain death: is defined as the complete and irreversible loss of function of the brain, including the brain stem. The cause of brain death is the cessation of the brain’s oxygen supply.
If an accident or another kind of brain injury results in impeded blood and oxygen supply, severe damage develops. The brain begins swelling and as a result of the closed cranium, the intracranial pressure increases until it blocks the intracranial blood circulation. As a result of the cessation of circulation, the brain tissue perishes within minutes and brain death develops. Brain death is not the same as a coma. Brain death is irreversible, and the brain-dead person is unable to think, feel, or perform any kind of cognitive function.
Diagnosis of brain death
Brain death has obvious signs. Brain death is diagnosed with a series of examinations, during which the reflexes of the brain stem are examined, and they demonstrate the absence of spontaneous breathing. This process is called the observation of brain death. These examinations must be repeated multiple times during the interval observation period. At the end of the interval observation period, multiple specialists assess together the signs of brain death, again, and if the signs persist, they establish the diagnosis of brain death, of which a special medical certificate is issued. The diagnosis of brain death is the determination of death.
Presumed consent
Two principles are applied worldwide regarding deceased individuals.
In the first case, a consent form signed by the deceased person is necessary for organ donation. This is called the positive consent (“opting in”), which is less widespread in Europe. In countries where the principle of positive consent is applied, one can become a donor by signing a witnessed donor card.
In the second case, if the deceased individual previously did not sign a refusal to be a donor of solid organs and tissues or was recorded by publicly accountable authorities, their consent to organ and tissue recovery is presumed. This is called presumed consent, which policy is applied in Hungary as well. In countries applying the policy of presumed consent, one can “opt out” by signing an opting out form, which is recorded in a registry.
The transplantation process
“Organ alarm” is the course of action that lasts from the appointment of a potential donor until the start of the transplantation of a particular organ. The signs of the brain death, and the cessation of the brain stem’s function are assessed by health care professionals – usually intensive care specialists-, and they make a donor report. With the donor report submission, the logistics of the organ transplantation starts. The organ recovery happens usually 18 hours after the first call of the organ alarm. Then the race against time starts: the donor organs must be transported to the transplantation center’s operating rooms by a particular time.
The activities’ coordination and the organ donation organization are implemented by the Organ Coordination Office (Szervkoordinációs Iroda), controlled by the Hungarian National Service for Blood Supply (OVSZ, Országos Vérellátó Szolgálat). The office coordinator receives the donor report and registers the necessary data determined by strict professional protocols, based on which the possibility of the donation is established. The coordinator checks whether the deceased had opted out of organ donation during their life, or if there is any medical contraindication of the transplantation, such as infection or malignant disease. Only healthy, functioning organs can be transplanted. Each organ must be considered separately whether they are suitable for transplantation – and different organs must comply with different criteria for establishing eligibility for the donation.
A document is created that contains information about which of the donor organs are suitable for transplantation and which ones are not. This document is sent to the transplant centers. If the donation process is approved based on initial investigations, the coordinator gives notification to the other members of the transplantation process: notifies the organ recovery teams, the National Rescue Service (Országos Mentőszolgálat), who are in charge of the transportation, in case of a foreign donor, they notify the international authorities, too. The organs to be transplanted are conserved with a special solution, then placed in three, sterile packages – each layer is insolated with liquid, and they will be transported to transplantation centers on ice. Based on the immunological characteristics of the organs, transplantation centers inform the potential organ recipients on the wait lists.
Is further treatment necessary after transplantation?
The transplanted, new organ is a foreign tissue for the body; therefore, the immune system recognizes it as dangerous and initiates an immune response against it. The immune response can result in the fast decay of the transplanted organ – this is the so-called rejection reaction. The aim of the pharmacological therapy after transplantation is to hinder rejection reactions, and is achieved by suppression of the immune system. These drugs are called immunosuppressants. Some medications must be taken lifelong (this is called the maintenance therapy), while other drugs must be taken intermittently to prevent acute rejection reactions.
Besides this type of pharmacological therapy, the body is more prone to infections. Finding the balance between protecting the body against infections and defending the transplanted organ at the same time is essential and hard to establish. With time, the immune system’s defense mechanisms wear off, and the body gradually accepts the transplanted organ, which makes the gradual decrease of using immunosuppressants possible – but this does not mean that the immunosuppressant therapy can be completely stopped. A certain grade of immunosuppression might be necessary even several years after the transplantation, therefore the recommended pharmacological therapy must not be stopped or altered without medical approval.
What is the immunological compatibility?
The immunological compatibility is the extent of acceptance of the recipient’s immune system towards the donor tissue/organ. The immune system can differentiate the body’s own cells and tissues from foreign cells and tissues and initiate an immune response against the latter.
The transplantation of immunologically incompatible tissues will result in an immune response and a rejection reaction.
How many organs can be transplanted?
In most of the cases, whole organs are transplanted, but in particular cases organ parts can also be transplanted, for example during living-donor liver transplantations, where the recipient receives only one lobe of the liver, while the other lobe stays and functions in the donor’s body. A similar procedure occurs during living-donor pancreas transplantations. Obviously, heart transplantation requires the whole organ.
Generally, during kidney transplantations, the recipient receives one kidney, hence the donor can donate kidneys to two recipients. Combined pancreas-kidney transplantation is an existing method, too. Lung transplantation might occur uni- or bilaterally – based on the underlying disease. Living-donor transplantations might be performed only with abdominal-organ transplantations (liver, pancreas, kidney), and usually not performed with thoracic organs. Not only organ, but tissue transplantation is also possible, this way corneas, heart valves and connective tissue can also be transplanted.
Waiting list
According to the 287/2006. (XII.23.) decree of the government, organ transplantation procedures can exclusively be performed on patients who have been registered on the waitlist system. This means that only those recipients can receive an organ, who have been listed on the waiting list and who are listed on the waiting list at the moment of the donor-recipient crossmatch procedure. All the transplantation waitlists are handled and authorized by OVSZ, which works independently from the transplantation centers.
The Hungarian organ transplantation waitlists are integrated within the Eurotransplant international waitlists. Hence, since 1st July 2013, when Hungary joined the Eurotransplant organization, Hungarian patients waiting for transplantation (recipients), have also been listed on the Eurotransplant waitlists. A transplantation waitlist lists all the individuals waiting for a particular organ to receive. The order of the patients on the waitlist does not correlate with the time they became listed.
When a donor report is submitted, and the organ alarm procedure starts, the most suitable patient has to be chosen from the waitlist. Coordinators must seek to find the immunologically most compatible (the closest immunological match) recipient to the donor organs from the waitlist, with the highest immunological compatibility to the donor’s, therefore the transplanted organ would probably function for a longer period. Inappropriately chosen recipients may result in severe, life-threatening rejection reactions.
Some of the most important criteria: ABO blood group compatibility, matching of the six most important immunological characteristics between the donor and the recipient, waiting time, similar age, similarity in body and organ dimensions, level of urgency. There are also organ-specific emergency (acute) waitlists, of which the purpose is to establish the possibility of saving the patient’s life with transplantation in medically determined emergency situations. Emergency recipients are always listed on the top of the waitlists.
How can one get registered on the waitlist?
Based on the medical history and the clinical data, the treating physician initiates the process of waitlist acceptance at the Transplantation Committee, and then the committee decides on the patient’s acceptance on the waitlist. The same committee is responsible for keeping the recipients’ data on the waitlist up-to-date by cooperating with the patient’s treating physician.
It is also the committee’s duty to remove patients from the waitlist, of which three reasons can have: organ transplantation, incompatibility occurred during the waiting time and death. The Transplantation Committee decides on every change regarding the waitlist, and it is their responsibility to notify the patients and their treating physician about all the relevant decisions pertinent to the patient. The Central Waitlist is operated by the Hungarian National Service for Blood Supply.
How can one become a donor in Hungary?
There are two types of donors in Hungary:
- Brain dead (deceased) donor: an individual who becomes brain dead, and while living, had not registered a refusal to be a donor of solid organs and tissues, therefore their organs can be recovered and transplanted after death.
- Living donor: if the donor is the recipient’s
- direct descendant,
- a sibling of a direct descendant,
- sibling,
- sibling’s direct descendant.
Living donor transplantations can only be performed during kidney and liver transplantation. If the donor and the recipient are not related, but there is a strong emotional connection between them, organ donation is possible. In this case, the donor and the recipient submit a request form together which will be evaluated by the ethical committee of the hospital. The hospital’s ethical committee can approve organ transplantation under certain criteria. The committee must make sure that there is a strong emotional connection between the donor and the recipient, the donation happens for no consideration, without force, menace or deceit.
What is cross donation?
A special form of living donor transplantations is the cross donations, which is the donation with the cross-matching of the pairs. This might occur if the donation cannot be performed (for immunological reasons) between close relatives or individuals with strong emotional connection. If crossmatching the pairs creates immunological compatibility, and each parties approve the intervention, cross donation can be performed. In this case, one party of the pair becomes the donor of the other pair’s recipient and vice versa.
What should I do to become an organ donor?
In Hungary the presumed consent policy is applied, which means that in the absence of the opting out form, the legislator presumes the deceased individual’s consent. Consent form is not required for being a donor, hence in Hungary, there is no donor card.
I would like to opt out
If someone does not want their organs to be transplanted after their death, the principle of self-determination allows them to opt out of transplantation in case of their death. In order to do so, they must submit an opting out (refusal) form.
Refusal statement (opting out) can be made by individuals with full capacity in a written form (in a notarized deed or in a private document providing conclusive evidence). If the individual wishing to refuse cannot make a written statement or can make a written statement with significant difficulties, they can make an oral refusal statement at their GP. Minors with limited legal capacity and individuals with partially limited capacity with regard to their health-care issues can make the refusal statement without the cooperation of their legal guardian.
Legal guardians can make refusal statements on behalf of legally incapacitated individuals. The written refusal statement (opting out form) should be sent by post as a registered mail or with the help of the GP or should be submitted in person to the OVSZ’s National Organ and Tissue Donation Refusal Registry (Nemzeti Szerv- és Szövetdonációs Tiltakozások Regiszteréhez, NSZTR), which institution is legally authorized to handle and systematize these documents.
You can access the registry here: https://www.ovsz.hu/oco/nsztr
