Living kidney donation offers the best outcomes for patients needing a transplant, but the process prioritizes protecting the donor’s health. The evaluation of any potential living donor is an extensive, multi-phase screening process. It is designed to ensure the individual is healthy enough to undergo major surgery and live a long, healthy life with only one kidney. This rigorous assessment must consider any pre-existing medical conditions, such as the blood disorder anemia.
Anemia and Donor Disqualification
Anemia, defined by low levels of hemoglobin or red blood cells, generally serves as a direct disqualifier for a potential living kidney donor. The primary concern is the increased risk to the donor during and immediately following the surgical procedure. Living donor nephrectomy, the operation to remove the kidney, involves a degree of blood loss. A person who is already anemic has a reduced oxygen-carrying capacity in their blood before the procedure begins.
Starting with a compromised blood count significantly increases the risks associated with general anesthesia and the physical stress of major surgery. A donor with moderate to severe anemia is more likely to require a blood transfusion during or after the operation, which introduces additional risks. The body’s ability to recover from the trauma of surgery and replenish lost blood is compromised when the red blood cell count is already low. Because the safety and long-term well-being of the donor is the paramount consideration, any condition that substantially elevates surgical risk typically results in temporary or permanent exclusion from donation.
How Kidney Function Relates to Blood Health
The strict screening for anemia is directly linked to a fundamental biological function of the organ itself. Healthy kidneys play a significant role in blood production by releasing the hormone Erythropoietin (EPO). Specialized cells within the kidneys monitor oxygen levels in the blood. When these levels drop, they increase EPO production.
The EPO hormone travels through the bloodstream to the bone marrow, stimulating the production of new red blood cells. This mechanism is the body’s primary way of regulating red blood cell mass and maintaining adequate oxygen delivery to tissues. Anemia frequently occurs in patients with advanced kidney disease because their damaged kidneys cannot produce enough EPO, resulting in renal anemia.
Removing one kidney means that the body loses approximately half of its EPO-producing tissue. While the remaining kidney typically compensates by increasing its EPO production, a person struggling with a reduced blood count before donation may not be able to compensate effectively after the surgery. This creates a substantial risk of developing chronic anemia after the donation, which would compromise the donor’s long-term health and vitality.
Evaluation of Temporary vs. Chronic Anemia
When a potential donor is found to be anemic during initial screening, the transplant team investigates the underlying cause to determine if the condition is temporary or chronic. The evaluation begins with a comprehensive blood analysis, including a complete blood count, to determine the severity and type of anemia. Further specialized testing, such as measuring serum ferritin, transferrin saturation (TSAT), and levels of vitamin B12 and folate, helps pinpoint the specific deficiency or disease process.
If the anemia is secondary to a reversible nutritional deficiency, such as low iron or B12, the donation process is typically put on hold. The medical team works with the donor to resolve the deficiency through supplements, dietary changes, or other medical interventions. Once the donor’s blood counts return to normal and remain stable for a set period, they may resume the evaluation process.
If the anemia is chronic, progressive, or linked to an underlying systemic disease that cannot be fully corrected, the potential donor is permanently disqualified. Examples include certain genetic blood disorders or anemia related to chronic inflammation. These conditions could be worsened by the stress of surgery or the loss of EPO production capacity. The goal of this evaluation is to distinguish between a fixable issue and a permanent contraindication, ensuring donation does not introduce an unacceptable long-term health risk.