Histological Study of Dysplastic Dermal Tissue in Newborn with Myelomeningocele: A Comparative Analysis of the Population of Myofibroblasts

Abstract

Objectives: Lumbar myelomeningocele is the most common type of spina bifida, a defect of embryonic development, in which an incomplete closure of the vertebral arches is observed in addition to dysplastic alterations of the nervous, meningeal, bone and cutaneous tissue. The tissue response to postoperative closure will depend, among other factors, on the population of pluripotent cells such as myofibroblasts present in the tissue at the edges of the lesion. The purpose of the following study was to determine the population of myofibroblasts in the dysplasic dermis associated with lumbar myelomeningocele, to compare the population of myofibroblasts of the edges of the lesion with those of the normal skin of the defect, and to assess the usefulness of the Ammoniac Silver Nitrate technique, in the identification of myofibroblasts. Methods: It was randomly selected 6 newborn patients who went to intervention for the surgical closure of lumbar myelomeningocele, 10 millimeters of both dysplastic and normal eutrophic skin were extracted from each patient, the histological sections were stained with hematoxylin/eosin and ammoniac silver nitrate to detect myofibroblasts. Immunohistochemistry: Anti-alpha-actin Smooth Muscle Actin (SMA) antibody was used to detect alpha actin-positive intracytoplasmic bodies and subplasmalemal pla¬cas. Results: the presence of myofibroblasts, presence of dense subplasmalemal plaques and positive immunostaining for alpha-actin in the area of dysplastic dermal tissue were identified. The amount of myofibroblasts was higher in the dysplasic zone, Ammoniac silver nitrate highlighted the dense subplasmalemal plaques of myofibroblasts. A 5:1 ratio was found when comparing the amount of myofibroblasts of the dysplastic dermis with respect to the healthy one, student's T-test showed a standard deviation between samples 1.87 and p<0.05. The differences between the two cell populations studied are statistically significant. Conclusions: The presence of myofibroblasts demonstrates the possibility of generating new post-surgical tissue in the cases studied. Ammoniac silver nitrate is a novel and reliable method in the histological determination of subplaslemal plaques of myofibroblasts.