Abstract: FR-PO592
X-Linked Recessive Nephrogenic Diabetes Insipidus Cured with Bilateral Native Nephrectomy Following Living Donor Renal Transplant
Session Information
- Trainee Case Reports - III
October 26, 2018 | Location: Exhibit Hall, San Diego Convention Center
Abstract Time: 10:00 AM - 12:00 PM
Category: Trainee Case Reports
- 902 Fluid and Electrolytes: Clinical
Authors
- Rangavajla, Gautam, Vanderbilt University School of Medicine, Nashville, Tennessee, United States
- Arroyo, Juan Pablo, Vanderbilt University Medical Center, Nashville, Tennessee, United States
- Langone, Anthony J., Vanderbilt University Medical Center, Nashville, Tennessee, United States
Introduction
X-linked recessive nephrogenic diabetes insipidus (X-NDI) is the most common subtype of congenital nephrogenic diabetes insipidus (CNDI) and is caused by mutations in the AVPR2 gene. This results in dehydration which increases the risk of urinary tract damage. Current treatment for CNDI aims to reduce free water loss through low-solute diets, HCTZ and potassium-sparing diuretics, as well as NSAIDs. Diuretics enhance sodium and water reabsorption in the proximal nephron, and NSAIDs inhibit prostaglandin-meditated free water excretion. However, this treatment only reduces urine output by 25-50%, leaving a considerable aquaresis that impacts quality of life.
Case Description
A 19 year-old man with X-NDI with an AVPR2 mutation and neurogenic bladder underwent a Mitrofanoff procedure for neurogenic bladder at age 6. Despite intermittent catheterization several times a day, he developed recurrent UTIs, and eventually CKD IV secondary to chronic hydronephrosis. He had poor quality of life given need for q1-2 hr catheterizations with aprox. 600 cc of urine each time. Pre-transplant his creatinine baseline was 8.5 mg/dL. His medications included amiloride, HCTZ, and oxybutynin. He underwent a living related kidney transplant and was discharged on standard immunosuppression and antibiotics, amiloride, and HCTZ. He continued urinary catheterizations following discharge, with Cr stabilizing to a baseline of 1.7. His urine output continued at above 3L per day. He then underwent bilateral native nephrectomy in an attempt to cure his X-NDI and improve his quality of life. Labs following bilateral nephrectomy showed normal serum (289 mOsm) and urine (528 mOsm) osmolality with a urine output of 1.6L per day, and his Cr decreased to 1.1 mg/dL on discharge.
Discussion
Current research into new therapeutic strategies for X-NDI focuses on AVPR2 chaperones, methods to biochemically bypass the AVPR2 receptor, and existing drugs that affect AVPR2’s signaling pathway. This case represents, to our knowledge, the first X-NDI patient cured with bilateral native nephrectomy following living related donor transplant for X-NDI complications. This suggests a role for renal transplantation and native nephrectomy as a definitive treatment of X-NDI and possibly CNDI, with a marked improvement in patients' quality of life.