Aspectos genéticos da escoliose idiopática do adolescente

GENETIC ASPECTS OF IDIOPATHIC ESCOLIOSIS - A LITERATURE REVIEW

ABSTRACT The idiopathic scoliosis (IS) is the most common form of spinal deformity. The pathogenesis of IS is still poorly understood. Several studies show evidence that the genetic component is determinant to the development of IS. In this setting, a crescent focus has been placed on the identification of genes, associated genetic polymorphisms, and multiple susceptibility loci. This review highlights the genes and genetic polymorphisms currently studied, identified as influential in the genesis of IS, such as MMP-3, IL-6, type I collagen, and vitamin D and estrogen receptors. We concluded that IS remains a complex disease with a polygenic background and that genetic polymorphisms are intrinsically related to this condition. Level of evidence III; Narrative Review.

Histochemical analysis of paraspinal rotator muscles from patients with adolescent idiopathic scoliosis: a cross-sectional study

Morphological, biochemical, and histopathological alterations in the paraspinal skeletal muscle of patients with adolescent idiopathic scoliosis (AIS) have been extensively reported. We evaluated rotator muscle fibers from the apex vertebra of AIS patients through histological and immunohistochemical analysis. A population of 21 female AIS patients who underwent corrective surgery between 2010 and 2013 had biopsies taken from the paraspinal muscle in the convex and concave sides of the thoracic curve apical vertebra. Serial sections were stained following routine protocols for hematoxylin and eosin (HE), Sudan red, Gomori trichrome, NADH, ATPase, and cytochrome oxidase. We assessed muscular atrophy and hypertrophy, fatty proliferation, endomysial and perimysial fibrosis, the presence of hyaline fibers, mitochondrial proliferation, muscular necrosis, nuclear centralization, and inflammation. Two independent professionals evaluated the slices. The thoracic curves had an average Cobb angle of 68 degree. Comparative analysis of the concave and convex sides was performed with McNemar test at a significance level of 5%. Results showed significant differences in both endomysial and perimysial fibrosis and fatty involution between the two sides of the apex vertebra. Paraspinal muscles in the concave side of the scoliosis apex had significantly more fibrosis and fatty involution. However, both sides showed signs of myopathy, muscular atrophy due to necrosis, presence of hyaline fibers, and mitochondrial proliferation.

Association between vitamin d levels and adolescent idiopathic scoliosis

Objective: To compare the levels of 25-hydroxyvitamin D in patients with AIS and a control group. Methods: The patients were recruited from the outpatient clinic of our institution during the year of 2013. Children diagnosed with scoliosis before 10 or after 18 years of age, and those suffering from neurological or muscular disorders, congenital malformations or genetic syndromes were excluded. The 25-OHD levels were determined by a fully automated electrochemiluminescence test. The appropriate level of 25-OHD was defined as greater than 30 ng/mL. The results were compared to a group of healthy individuals. Results: In group 1 (control) 63,3% showed abnormal vitamin D levels, while 91% of patients with AIS presented a low level of vitamin D. The mean BMI was 19.6 kg/m2 for controls and 20.3 kg/m2 for group 2. Statistical analysis showed significant difference (p<0.0001) between the levels of vitamin D. The average and minimum levels of vitamin D were respectively 27 and 13.6 ng/mL for group 1 and 18.8 and 3.13 ng/mL for AIS group. Conclusions: Patients with AIS had statistically significant lower levels of 25-OHD than healthy patients. Further research should be conducted to investigate the actual impact of serum vitamin D levels on the pathophysiology of AIS.