Non-Invasive Biomarkers for Early Diagnosis of Kidney Allograft Dysfunction. Current and Future Applications in the Era of Precision Medicine

Kidney transplantation stands as the preferred treatment for end-stage kidney disease, significantly improving both the quality and longevity of life compared to dialysis. In recent years, the survival rates for patients and grafts have markedly increased thanks to innovative strategies in desensitization protocols for incompatible transplants and advancements in immunosuppressive therapies. Although the initial expenses associated with transplantation may exceed those of dialysis, it proves to be more cost-effective in the long run. Despite its numerous benefits, the widespread adoption of kidney transplantation faces several challenges, notably a scarcity of donated organs, financial limitations, and unequal access among various populations. Additionally, there is a shortage of healthcare professionals equipped with the requisite expertise. For kidney transplant recipients, preventing allograft rejection is of paramount importance, necessitating the use of immunosuppressive medications. Regular follow-up appointments are essential, as monitoring the function of the kidney allograft is critical. Currently, established biomarkers such as serum creatinine, estimated Glomerular Filtration Rate (eGFR), proteinuria, and albuminuria are commonly employed to assess allograft function. However, these biomarkers have limitations, as elevated levels often indicate significant allograft damage only after it has occurred, thereby constraining treatment options and the potential for restoring graft function. Additionally, kidney biopsies, while considered the gold standard for diagnosing rejection, are invasive and carry associated risks. Consequently, the identification and development of new, sensitive, and specific biomarkers for allograft rejection are crucial. To tackle this challenge, intensive ongoing research employing cutting-edge technologies, including “omics” approaches, is uncovering a variety of promising new biomarkers.