A Case Report of Primary Hyperoxaluria Type 1 Diagnosed in a Geriatric Patient Receiving Dialysis: Unique Clinical Course With Lumasiran.

Primary hyperoxaluria type 1 (PH1) is a rare inherited disorder that typically presents in childhood and often progresses to kidney failure. We report an 83-year-old woman with kidney failure of unknown etiology, recurrent calcium oxalate nephrolithiasis beginning at age 50, and a family history of nephrolithiasis and kidney failure. After starting hemodialysis, evaluation revealed marked hyperoxaluria (194 mg/d), elevated plasma oxalate (34 μmol/L), and homozygous AGXT p.Pro11Arg mutations consistent with PH1. Treatment with pyridoxine and lumasiran was initiated. Five months later, approximately one year after dialysis initiation, the patient discontinued hemodialysis because of post-dialysis fatigue. During 12 months of follow-up, dialysis was not required, creatinine clearance remained 19 mL/min, plasma oxalate normalized or remained near normal, and stone burden remained stable. To our knowledge, this is the first reported non-transplanted PH1 patient to successfully discontinue hemodialysis following lumasiran therapy, highlighting the potential benefit of RNA interference therapy even in advanced disease.