Evaluation of the effect of chenodeoxycholic acid treatment on skeletal system findings in patients with cerebrotendinous xanthomatosis.

The primary purpose of the present study is to evaluate the effect of chenodeoxycholic acid treatment on skeletal system findings in patients with cerebrotendinous xanthomatosis.This retrospective study was conducted between June 2013 and December 2018 with seven patients with cerebrotendinous xanthomatosis in Cerrahpasa Medical Faculty Pediatric Nutrition and Metabolism Department. The clinical, epidemiologic, and genotypic features of the patients were reviewed in detail and the following items, especially related with skeletal system involvement, were recorded from medical data: history of a bone fracture, plasma calcium, phosphate, alkaline phosphatase and 25-hydroxy-vitamin D concentrations, bone mineral density values of the posteroanterior lumbar spine (L1-L4), and femoral neck before and after chenodeoxycholic acid treatment.Regarding the bone mineral metabolism, plasma calcium, phosphate, alkaline phosphatase levels were found in normal ranges in all patients. Plasma 25-hydroxy-vitamin D evaluation at the time of diagnosis showed deficiency in three patients and insufficiency in three patients. Following chenodeoxycholic acid therapy, 25-hydroxy-vitamin D deficiency persisted in only one patient, but insufficiency was observed in four patients. According to the bone mineral density assessments, four patients had Z-scores below the expected range for age both at initial examination and after chenodeoxycholic acid therapy. No significant difference was observed between plasma 25-hydroxy-vitamin D levels and bone mineral density Z-scores before or after treatment.This study elucidates the necessity of additional medical treatment as a part of chenodeoxycholic acid therapy to improve skeletal system findings in cerebrotendinous xanthomatosis.