Clinical experience of using denosumab in the treatment of hypercalcemia and oxalate osteopathy for a young patient with primary hyperoxaluria type 1.

Primary hyperoxaluria are a group of rare genetic diseases caused by defective glyoxylate metabolism leading to excessive oxalate production and deposition into the tissues (oxalosis). Clinical manifestations include recurrent nephrolithiasis and nephrocalcinosis, rapidly progressive chronic kidney disease subsequently leading to end-stage renal disease, systemic oxalosis, PTH-independent hypercalcemia, pancytopenia, oxalate osteopathy with osteosclerosis, pathological fractures and endocrinopathy. Regardless of the type of primary hyperoxaluria any conservative therapy is palliative and can only slow the progression of the disease but not prevent it completely. We report the case of a young male patient with genetically confirmed primary hyperoxaluria type 1 complicated by severe oxalate osteopathy and hypercalcemia, who received a combined liver/ kidney transplant after 10 years from the disease. Treatment with human monoclonal antibody to the receptor activator of nuclear factor kappa B ligand (RANKL) — denosumab allowed achieving normalization of calcium-phosphorus metabolism, significantly reduce the activity of bone resorption and improve clinical performance. Knowledge of the features of clinical manifestations, timely diagnosis and treatment of primary hyperoxaluria are important prognostic value for patients.