Pathology and immunohistochemistry of thyroid in severe acute respiratory syndrome

Abstract

To study the pathological characteristics of thyroid gland and the changes on hormone content of thyroid cells in severe acute respiratory syndrome (SARS) patients. Hematoxylin and eosin staining and light microscopy were used to examine the histology of the thyroid tissues from 4 dead SARS patients and 5 healthy thyroid samples used as negative controls. Immunohistochemistry was used, with monoclonal antibodies, to detect the thyroglobulin (TG), calcitonin and parathyroid hormone (PTH) in the thyroid glands. Deformation, enlargement, and dystrophy of follicular cells in thyroid glands were found in the SARS patients. The normal follicular epithelial cells were strongly TG positive, however, the number and intensity of TG positive follicular epithelial cells were significantly lower in the SARS patients. Calcitonin positive cells were found in the normal thyroid glands and not in the thyroid glands of the SARS patients. PTH positive cells were seen in the normal thyroid glands and those of the SARS patients with a slightly weaker intensity of reaction, however, with significant difference in IOD (P < 0.01) and without significant difference in mean slight absorption MOD (P > 0.05). The thyroid tissue structure and morphology in SARS patients were significantly changed, involving both follicular epithelial cells and parafollicular cells; which may imply that the hormonal production of follicular epithelial cells and the parafollicular cells were affected.