Severe Hyponatremia as an Early Manifestation of Peritransplant Abscess After Living Donor Kidney Transplantation: A Case Report

Electrolyte abnormalities are common after kidney transplantation, but severe hyponatremia as an early sign of occult peritransplant infection is rare.A 68-year-old woman underwent living unrelated kidney transplantation and was discharged on postoperative day 4 with a drain in place.On postoperative day 8, she developed acute kidney injury and profound hyponatremia, with a serum sodium level of 109 mmol/L, despite only mild fatigue and no fever, abdominal pain, allograft tenderness, or wound symptoms.Sodium improved with hypertonic saline, nutritional support, and fluid restriction.On postoperative day 13, she developed fever; computed tomography revealed a 16-cm peritransplant abscess, and drainage grew Escherichia coli.This case highlights severe unexplained hyponatremia as a potential early manifestation of occult infectious or surgical complications after kidney transplantation.