Type 1 Renal Tubular Acidosis Secondary to Chronic Kidney Transplant Rejection: A Case Report

Abstract

Distal renal tubular acidosis (Type 1 RTA) is a rare but significant complication in kidney transplant recipients, particularly when associated with chronic graft rejection. This report describes a 52-year-old male patient with a history of chronic kidney disease and kidney transplantation who developed secondary Type 1 RTA. The patient initially presented with acute pyelonephritis and worsening renal function, later progressing to severe hypokalemia, hypomagnesemia, and hyperuricemia. Laboratory investigations confirmed the diagnosis of Type 1 RTA, characterized by impaired hydrogen ion secretion in the distal tubule, leading to normal anion gap metabolic acidosis and severe electrolyte disturbances. In this context, Type 1 RTA may be linked to the prolonged use of calcineurin inhibitors, such as tacrolimus, which alter the expression and distribution of key acid-base transport proteins, as well as cause functional tubular damage. The management of this condition included electrolyte replacement and adjustments in immunosuppressive therapy, resulting in clinical improvement. This case underscores the importance of early detection and appropriate management of Type 1 RTA to prevent severe complications and preserve graft function in kidney transplant recipients.