The Recurrence of Systemic Diseases in Kidney Transplantation.

Kidney transplantation is the most effective replacement therapy for kidney failure, providing the best outcomes in terms of patient survival and offering a better quality of life. However, despite the progressive improvement in kidney survival, the recurrence of original disease remains one of the most important causes of graft loss and a major challenge that requires clinical vigilance throughout the transplant's duration. Additionally, the type and severity of recurrence affect both treatment options and graft survival. This is especially true for the recurrence of systemic diseases. In this narrative review, we will discuss the timing, frequency, severity, and treatment of post-transplant recurrence in three systemic diseases: lupus nephritis (LN), Antineutrophil Cytoplasmic Antibodies (ANCA)-associated glomerulonephritis (ANCA-GN), and Henoch-Schönlein purpura (HSP). The recurrence of lupus nephritis is less common than that of primary focal segmental glomerulosclerosis or C3 glomerulopathy. Its severity can range from mild mesangial to diffuse proliferative forms, with varying prognoses and treatment options, much like the original disease. In some patients with LN, as well as in those with ANCA-GN or HSP, the reactivation of the primary disease can affect other organs besides the kidneys, potentially leading to life-threatening conditions. These cases may require a multidisciplinary approach, making these transplants clinically more challenging. Extrarenal flare-ups often necessitate an increase in immunosuppression, which in turn raises the risk of infections. In these autoimmune diseases, the role of immunological tests in determining the timing of kidney transplants remains a topic of ongoing debate. However, elevated levels of certain immunological markers, such as anti-dsDNA antibodies, ANCA titers, or serum immunoglobulin A may indicate a reactivation of the disease, suggesting the need for more intensive patient monitoring.