Case report
Nephrolithiasis in a Second Renal Allograft Recipient: A RaNephrolithiasis in a Second Renal Allograft Recipient: A Rare Cause of Graft Dysfunctionre Cause of Graft Dysfunction
OD01-OD03
Correspondence
Dr. Aalaya Haridas,
112, First Leaf Villas, Hyderabad, Telangana, India.
E-mail: haridasaalaya@gmail.com
Renal allograft nephrolithiasis is an uncommon but clinically significant complication which may compromise graft function. While structural and infective factors are well recognised, metabolic abnormalities such as hyperoxaluria and hypocitraturia are increasingly being recognised as contributors to post renal transplant nephrolithiasis. This case describes a 49-year-old male, a second renal transplant recipient who developed de novo nephrolithiasis with ureteric obstruction in the transplanted kidney, complicated by a urinary tract infection and graft dysfunction. His first transplanted renal graft failure was due to chronic active Antibody mediated rejection and recurrent chronic pyelonephritis, which required a graft nephrectomy. He subsequently underwent a deceased donor renal transplantation. He had episodes of urinary tract infection and was treated with antibiotics. One month later he was presented with graft dysfunction, imaging revealed multiple renal calculi with proximal ureteric calculi with mild hydroureteronephrosis. He underwent ureteroscopy lithotripsy with double-J stenting, after which there was stabilisation of graft function. Metabolic evaluation showed hyperoxaluria, 24-hour urine oxalate level was 77.5 mg/day (normal range 7-44), along with significant hypocitraturia with urinary citrate excretion of 50 mg/day (normal range 116-924). Serum calcium, phosphorous and uric acid were within normal range, while parathyroid hormone was elevated, with vitamin D deficiency. This suggested an oxalate driven lithogenic mechanism. Associated hypocitraturia may have further promoted calcium oxalate crystal stone formation. This case highlights hyperoxaluria and hypocitraturia as an important metabolic contributor to post renal transplant nephrolithiasis and emphasises the need for metabolic evaluation. Early imaging, timely urology intervention, prevention of urinary tract infections, correcting metabolic and mineral bone abnormalities and optimisation of immunosuppressive therapy are essential to maintain graft function.