GUEDES, A. K. S.; CHARARA, G. C. N.; http://lattes.cnpq.br/0786501668635939; http://lattes.cnpq.br/7601853857397579; GUEDES, Anna Karenina Silva.; CHARARA, Gabriella Carvalho Napy.
Résumé:
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.