Primary hyperoxaluria type 1 in children: Clinical classification, renal replacement therapy, and outcome in a single centre experience.

Primary hyperoxaluria type 1 (PH1) is a rare disease that is challenged by the overproduced oxalate and commonly presented with radiopaque renal stones or obstructive uropathy. This study aimed to report clinical presentations, renal replacement therapy (RRT), and outcome of PH1 in end stage kidney disease (ESKD) children. This is an observational cohort study. Data of 22 patients with ESKD due to PH1 were analyzed at Pediatric Nephrology Unit, Faculty of Medicine Cairo University. Infantile onset patients (n = 10) had worst renal outcome (80% with ESRD at presentation, p = 0.019) and worse patient outcome (mortality 40%, p = 0.016) than juvenile (n = 9) and late onset (PH1 n = 3) patients. RRT modalities include peritoneal dialysis (PD) in 7 (31.8%), hemodialysis (HD) in 11 (50%), and combined liver kidney transplantation (CLKT) in 4 (18.2%) patients. Infectious complications were encountered in 42.8% of PD patients. Better HD adequacy was observed with frequent HD (n = 6) and/or HD via arteriovenous fistula (AVF) than with infrequent dialysis (n = 5) and/or via central venous line (CVL) (p = 0.0001 and 0.0047, respectively). Morbidity and mortality (infection related) rates of the whole cohort were 63.6% and 31.8%, respectively. Clinical presentation of PH1 varies according to the age of onset (infantile onset being the most aggressive form). Aggressive HD (better through AVF) is needed to achieve acceptable HD adequacy, PD was challenged by infection. Infection found to be the main cause of mortality even after successful CLKT.