Scoliosis and rare diseases: our experience with the Prader-Willi syndrome.

INTRODUCTION: Prader-Willi syndrome (PWS) represents a difficult challenge for spine surgeons, due to the association of a structural scoliosis, with a prevalence between 15 and 86%. Conservative therapy is a viable option, but surgery is increasingly becoming the treatment of choice. METHODS: The authors reviewed a series of 15 patients affected by PWS treated at their institution between 2008 and 2023. The mean age at index treatment was 9 years and 3 months (range 1-15 years) with a prevalence of female subjects. Primary scoliotic curve ranged from 14 to 102°, and mean thoracic kyphosis was 56° (range 20-75°). Eleven patients underwent conservative treatment, while four were treated surgically. RESULTS: Mean follow-up was 5 years and 3 months (range 2-12 years). Among the 11 patients treated conservatively, only two showed improvements of the coronal curve, while the remaining nine displayed a worsening of the deformity during follow-up. Complication rate after surgery was 75%. One patient developed paraplegia after pedicle screw positioning. One patient displayed rod breakage and PJK that required revision surgery proximally. Hardware deep infection was seen in one case where it was necessary to proceed with instrumentation removal after 10 years. DISCUSSION AND CONCLUSIONS: Spine surgery represents a convincing option in patients affected by PWS, but the risks of complications are high. Correct patient selection must be the main objective, and multilevel pedicle screw fixation should be the procedure of choice. Traditional growing rod should be prudently evaluated in every single case.

Double spinal cord tethering and congenital kyphosis in a 4-year-old boy.

PURPOSE: Congenital kyphosis (CK) is an uncommon condition that develops due to a defect of formation or segmentation of one or more vertebrae during the first weeks of embryonic life and can be frequently associated with abnormalities of the spinal cord. Meningocele manqué (MM) is a rare congenital malformation consisting of intradural fibrous bands tethering the spinal cord, oftentimes in combination with a split cord malformation. The aim of this manuscript is to describe combined surgical management of a rare case of CK associated with double spinal cord tethering. STUDY DESIGN: Case report. METHODS: We report the case of a 4-year-old boy presenting with a combination of congenital kyphosis due to L2 fully segmented posterior hemivertebra and double spinal cord tethering, at the level of the filum terminale and at L1-L2 due to an intradural ventral fibrous band. RESULTS: Spinal cord detethering and L2 hemivertebra resection with kyphosis correction were achieved with a single stage procedure. Segmental kyphosis was corrected from 45° to 11° post-operatively. Apart from a transitory sensory impairment, no immediate or delayed complications were noted and, at 2 years follow-up, correction and spinal alignment were stable. CONCLUSION: To the best of our knowledge, this is the first case to report the simultaneous occurrence of congenital kyphosis and double spinal cord tethering due to MM and tethering of the filum terminale. Our case report shows that surgical correction of the deformity and spinal cord detethering can be safely and effectively achieved during the same surgical procedure.

Mesenchymal Stromal Cells Induce Peculiar Alternatively Activated Macrophages Capable of Dampening Both Innate and Adaptive Immune Responses.

Mesenchymal stromal cells (MSCs) support hematopoiesis and exert immunoregulatory activities. Here, we analyzed the functional outcome of the interactions between MSCs and monocytes/macrophages. We showed that MSCs supported the survival of monocytes that underwent differentiation into macrophages, in the presence of macrophage colony-stimulating factor. However, MSCs skewed their polarization toward a peculiar M2-like functional phenotype (M(MSC) ), through a prostaglandin E2-dependent mechanism. M(MSC) were characterized by high expression of scavenger receptors, increased phagocytic capacity, and high production of interleukin (IL)-10 and transforming growth factor-ß. These cytokines contributed to the immunoregulatory properties of M(MSC) , which differed from those of typical IL-4-induced macrophages (M2). In particular, interacting with activated natural killer (NK) cells, M(MSC) inhibited both the expression of activating molecules such as NKp44, CD69, and CD25 and the production of IFNγ, while M2 affected only IFNγ production. Moreover, M(MSC) inhibited the proliferation of CD8(+) T cells in response to allogeneic stimuli and induced the expansion of regulatory T cells (Tregs). Toll-like receptor engagement reverted the phenotypic and functional features of M(MSC) to those of M1 immunostimulatory/proinflammatory macrophages. Overall our data show that MSCs induce the generation of a novel type of alternatively activated macrophages capable of suppressing both innate and adaptive immune responses. These findings may help to better understand the role of MSCs in healthy tissues and inflammatory diseases including cancer, and provide clues for novel therapeutic approaches. Stem Cells 2016;34:1909-1921.