Tubuloreticular structures in rubella virus-infected human fetuses

Abstract

Tubuloreticular structures (TRS) consisting of branching tubules of variable length and with a diameter of 18-30 nm have been described within dilated endoplasmic reticulum cisternae of endothelial and other cells in a variety of conditions. Thus, TRS have been observed in apparently normal human and animal cells, in cells of patients with auto-immune disease (e. g. systemic lupus erythematodes), with neoplasia (leukemias, carcinomas, sarcomas) as well as with a number of viral infections caused by both DNA or RNA viruses. Whereas earlier investigators regarded TRS as viral or virus-like in nature, it is now widely accepted that these structures represent focal proliferations of ER-membranes and that they reflect a cellular response to a broad range of stimuli. The biological significance of TRS has, however, not been resolved.In rubella-infected human embryos and fetuses, vascular lesions are the most frequently observed light microscopical findings.