Clinical Features Identified in Pediatric Patients With Primary Hyperoxaluria Type 1

Disease presentation before adolescence, nephrocalcinosis, decreased estimated glomerular filtration rate (eGFR) at diagnosis, and calcium oxalate monohydrate stone composition are defining clinical features of primary hyperoxaluria type 1 (PH1) in pediatric patients, according to the results of a recent study.

“We hypothesized that a parsimonious set of features could be identified that differentiate patients with PH1 from patients with non-primary hyperoxaluria-associated causes of early-onset kidney stone disease,” the authors wrote of their study objective.

Included were patients aged younger than 21 years from one of eight US pediatric health systems within the PEDSnet clinical research network from 2009 to 2021. A total of 37 patients with genetically confirmed PH1 and 147 control patients with kidney stones without any type of PH were included. All characteristics and diagnostic testing results before and in the 6 months after each patient’s study entrance was included.

The results indicated that patients with PH1 were younger at diagnosis than the control group (median age of 3 years vs 13.5 years). Further, 75% of those with PH1 were younger than 8 years of age.

The PH1 group were more likely to have combinations of nephrocalcinosis on ultrasonography or computed tomography compared with the control group (43% vs 3%, respectively). The PH1 group were also more likely to have lower eGFR at diagnosis (median = 52 mL/min/1,73 m2 vs 114 mL/min/1.73 m2, respectively) and mobility within normal limits. A higher proportion of calcium oxalate monohydrate kidney stones were observed in the PH1 group (median = 100%) vs the control group (median = 10%). No differences were observed between the two study groups for failure to thrive diagnoses, stone size, or echocardiography results.

The researchers concluded, “If externally validated, these characteristics could facilitate earlier diagnosis and treatment of children with PH1.”

Reference:

Tasian GE, Dickinson K, Park G, et al. Distinguishing characteristics of pediatric patients with primary hyperoxaluria type 1 in PEDSnet. J Pediatr Urol. 2024;20(1):88.e1-88.e9. doi:10.1016/j.jpurol.2023.10.001