HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Full Text Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Citation Map Services Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Request Permissions Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Hale, L. P. Articles by Markert, M. L. Search for Related Content PubMed PubMed Citation Articles by Hale, L. P. Articles by Markert, M. L. Pubmed/NCBI databases Compound via MeSH Substance via MeSH Hazardous Substances DB HYDROCORTISONE Medline Plus Health Information Steroids

Corticosteroids Regulate Epithelial Cell Differentiation and Hassall Body Formation in the Human Thymus¹

Laura P. Hale^2,* and M. Louise Markert

Departments of ^* Pathology and Pediatrics, Duke University Medical Center, Durham, NC 27710

The presence of characteristic epithelial swirls called Hassall bodies within the human thymic medulla has been used as an indicator of ongoing or recent thymopoiesis. We present a case where Hassall bodies were present in the absence of current or past thymopoiesis. The patient had been treated with corticosteroids for presumed asthma before his diagnosis of X-linked SCID. Two other cases of nonimmunodeficient patients treated with high-dose corticosteroids had markedly increased numbers of thymic Hassall bodies. To determine whether corticosteroid treatment induces thymic epithelial (TE) differentiation to form Hassall bodies, mAbs reactive with specific cytokeratins (CKs), filaggrin, and involucrin were used to define distinct stages of TE cell differentiation. Treatment of primary TE monolayers with hydrocortisone in vitro induced expression of involucrin and high-molecular-mass CKs that are characteristic of TE differentiation. Treatment of thymic organ cultures with hydrocortisone induced both medullary and subcapsular cortical TE cells to express CK6, a differentiation marker that is normally expressed only by Hassall bodies in vivo. These experimental studies combined with the case observations indicate that exogenous corticosteroids can regulate terminal differentiation of TE cells both in vitro and in vivo. Thus, the presence of Hassall bodies in thymus from corticosteroid-treated patients cannot be taken as an absolute indication of previous thymopoiesis. Because corticosteroids are also made within the thymus under normal physiologic conditions, these studies support the hypothesis that endogenous corticosteroids may play a role in normal TE differentiation and Hassall body formation in vivo.

This article has been cited by other articles:

				M. Yano, N. Kuroda, H. Han, M. Meguro-Horike, Y. Nishikawa, H. Kiyonari, K. Maemura, Y. Yanagawa, K. Obata, S. Takahashi, et al. Aire controls the differentiation program of thymic epithelial cells in the medulla for the establishment of self-tolerance J. Exp. Med., November 24, 2008; 205(12): 2827 - 2838. [Abstract] [Full Text] [PDF]

				S. Cloosen, J. Arnold, M. Thio, G. M.J. Bos, B. Kyewski, and W. T.V. Germeraad Expression of Tumor-Associated Differentiation Antigens, MUC1 Glycoforms and CEA, in Human Thymic Epithelial Cells: Implications for Self-Tolerance and Tumor Therapy Cancer Res., April 15, 2007; 67(8): 3919 - 3926. [Abstract] [Full Text] [PDF]

				K. List, R. Szabo, A. Molinolo, B. S. Nielsen, and T. H. Bugge Delineation of Matriptase Protein Expression by Enzymatic Gene Trapping Suggests Diverging Roles in Barrier Function, Hair Formation, and Squamous Cell Carcinogenesis Am. J. Pathol., May 1, 2006; 168(5): 1513 - 1525. [Abstract] [Full Text] [PDF]