Clinical Approaches and Emerging Therapeutic Horizons in Primary Hyperoxaluria.

Primary hyperoxalurias (PHs) are rare autosomal recessive disorders characterized by overproduction of oxalate, a metabolic end product that readily forms calcium oxalate crystals. Excess hepatic oxalate leads to recurrent kidney stones, nephrocalcinosis, and progressive renal injury, often culminating in end-stage kidney disease (ESKD). Once renal clearance declines, systemic oxalate accumulation can cause multisystem deposition. PH encompasses three types-PH1, PH2, and PH3-caused by deficiencies in the hepatic enzymes AGT, GRHPR, and HOGA1, respectively, resulting in accumulation of glyoxylate and subsequent oxalate overproduction. Clinical presentation varies from infantile oxalosis to adult-onset recurrent nephrolithiasis, with PH1 generally being the most severe. Diagnosis relies on urinary oxalate measurements, plasma oxalate in advanced chronic kidney disease, urinary metabolite profiling, imaging, and genetic testing. Management includes hyperhydration, citrate supplementation, pyridoxine for responsive PH1 patients, dialysis and transplantation when required, while RNA interference therapies targeting glycolate oxidase or LDHA have demonstrated substantial biochemical efficacy in PH1 and represent promising emerging therapeutic options, although long-term clinical outcome data remain limited and broader applicability to other PH types is still under investigation. Future strategies focus on modulating intestinal oxalate absorption, gut microbiome therapies, oxalate-degrading enzymes, and novel gene-editing approaches. Early diagnosis and individualized management are critical to prevent kidney injury and systemic oxalosis. In this review, we summarize the genetic, biochemical, and clinical features of PH and discuss current and emerging therapeutic strategies.