Homeobox A5 and A9 expression and beta-thalassemia

Background and aim: The pathogenesis of β-thalassemia has been attributed to ineffective erythropoiesis. The function of Hox genes in normal haematopoiesis has been widely studied using gene expression analysis. The aim of this study is to evaluate the expression of HoxA9, and HoxA5 genes in beta-thalassemia.Materials and methods: Children with thalassemia major, thalassemia intermediate, and age and sex-matched healthy controls (n = 50/group) were enrolled. Detection of HoxA5 and HoxA9 mRNA expression was performed by real-time polymerase chain reaction (RT-PCR).Results: Expression of HoxA9 increased in a direct linear trend (median 0.5 in controls, 2.4 in intermediate disease, 4.1 in major disease, p = 0.001) and generally correlated with the red cell count, haematocrit, ferritin and levels of beta-globin. In those with thalassemia major, the relative change of HoxA9 was linked to transfusion history, the white blood cell count, ferritin, and beta-globin (all r > 0.5, p < 0.001). Levels of HoxA9 were superior to HoxA5 in differentiating controls from thalassemia intermedia, whilst both differentiated major from the intermediate disease.Conclusion: This study highlights the importance of HoxA genes in early identification of patients, at high risk of developing complications, as it allows specific measures to delay the progression of the disease. HoxA gene expression is a promising diagnostic and prognostic marker in patients with β-thalassemia.

Positional disappearance of motor evoked potentials is much more likely to occur in non-idiopathic scoliosis

PURPOSE

This study evaluates intraoperative disappearance of motor waveforms related to patient positioning in neurologically asymptomatic patients with spinal deformity.

METHODS

This is a retrospective review of 190 neurologically asymptomatic patients aged seven to 17 years planned for posterior instrumentation under neuromonitoring. There were 159 patients with adolescent idiopathic scoliosis and 31 patients with secondary scoliosis. Patients underwent surgery with transcranial electric stimulation motor evoked potentials (TES-MEPs). In case of abnormal findings, surgery was temporarily discontinued and necessary measures undertaken. In case of permanent signal disappearance surgery was definitively discontinued.

RESULTS

Six patients showed permanent loss of signal during early stages of surgery. These patients had a mean major curve of 64° Cobb angle and a mean thoracic kyphosis (D2 to D12) of 72°. The 184 remaining patients had a mean major curve of 50° Cobb angle and a thoracic kyphosis of 35°. A retrospective descriptive review of the patients' radiographs shows hyperkyphosis to be the common ground between the six secondary scoliosis cases. Gradual preoperative traction maintained during the surgery applied in two of these patients taken back to surgery six months later was associated with maintenance of TES-MEP signals throughout the surgery.

CONCLUSION

This study shows that positional permanent loss of neuromonitoring signals is more likely to occur in patients with secondary scoliosis and hyperkyphosis shown to have sharper spine deformity and suspected to have a more vulnerable spinal cord. Gradual skeletal traction performed in two of these patients and maintained during surgery showed promising results.

LEVEL OF EVIDENCE

IV.