Ultrastructural Studies in Langerhans Cell Histiocytosis: A Search for Evidence of Viral Etiology

Abstract

The ultrastructure oflesional cells in biopsy material from 50 cases of Langerhans cell histiocytosis (LCH) was studied for the effects of virus and/or cytokines. Viral “footprints,' which actually represent ultrastructural signs of the effects of cytokines on cells, were found in 76% of the cases. These were detected in lesional Langerhans cells, endothelial cells, and lymphocytes and consisted of tubuloreticular structures, cylindrical confronting cisternae, and curvilinear membranous formations. No virus particles or virus-specific cell products were found. These studies suggest that LCH cells are subject to cytokine stimulation but provide no evidence to implicate a virus in the disease process.

Key Words:

• cytokines
• Langerhans cell histiocytosis
• transmission electron microscopy
• viruses