Avaliação do perfil osteometabólico em pacientes com Mucopolissacaridose IVA (Síndrome de Mórquio).

Abstract

The Mucopolysaccharidoses (MPS) are a group genetic diseases characterized by the deficiency of lysosomal enzymes involved in the degradation of glycosaminoglycans (GAGs), leading to accumulation of these substances in various organs, resulting in a multisystemic disease. The MPS-IVA is characterized by the severity of bone involvement, with dysostosis multiplex, joint hypermobility and severe low stature. It is believed that the development and bone mineralization are abnormal, in addition to immobility, low intake of nutrients and vitamin D deficiency, result in early bone loss, which is found in some studies. With the approval of specific treatment for MPS-IVA, the elosulfase enzyme, there was an improvement in quality of life, making the patients more mobile, so determining the risk of fracture is critical in the current management of the disease. This study aimed to analyze the bone metabolic profile of patients with MPS-IVA, without specific treatment, by bone density, calcium intake and bone turnover markers. Data were collected from 13 patients, 7 males and 8 females, with a mean age of 27.1 (+7.2) years. Cortical bone loss was found in all patients, 87.5% presenting osteoporosis and 12.5% with osteopenia. The marker of bone formation used was alkaline phosphatase, which was within normal limits in all patients. However, the serum-CTX, marker of bone resorption, was above the upper limit of normality in 5 patients.Calcium intake was lower than recommended for all patients. Secondary causes of osteoporosis have also been investigated, but no diagnosis was closed for such causes. The risk factor that best joined the severity of bone loss was the immobility of patients. Those who roamed had average z-score radio 33% of -2.61, opposed to an average of -3.68 in patients who did not roam. With treatment with the specific enzyme and the improvement of patient mobility, there will probably be an improvement in bone mineral density, thus studies evaluating the influence of treatment on bone metabolic profile become necessary for better planning of the clinical management of bone metabolic changes in patients with MPS-IVA.