hylkäämisreaktion

Hylkäämisreaktio, known in English as rejection reaction or rejection response, refers to the immunological process by which a recipient's immune system attacks and destroys a transplanted organ or tissue. This occurs because the recipient's immune cells recognize the transplanted cells as foreign due to differences in their surface proteins, particularly human leukocyte antigens (HLAs).

The immune response can be acute or chronic. Acute rejection typically happens within the first few months after transplantation and is often mediated by T cells and antibodies. Chronic rejection develops over months or years and involves a gradual damage to the graft, leading to its functional decline. Symptoms can vary depending on the organ transplanted but may include fever, pain at the transplant site, and signs of organ dysfunction.

To prevent or manage rejection, recipients are given immunosuppressive medications, which dampen the immune system's activity. These drugs are crucial for the long-term success of transplantation but can also increase the risk of infections and other side effects. Monitoring for signs of rejection through regular check-ups, blood tests, and sometimes biopsies is essential. Early detection and intervention can often reverse or slow down the rejection process, preserving the function of the transplanted organ.