Background: Fabry disease is characterized by the systemic accumulation of glycosphingolipids, particularly in the lysosomes of vascular endothelial cells of most organs due to the deficient activity of α - galactosi...Background: Fabry disease is characterized by the systemic accumulation of glycosphingolipids, particularly in the lysosomes of vascular endothelial cells of most organs due to the deficient activity of α - galactosidase A. The major glycolipid accumulated in tissue is globotriaosylceramide (GL- 3). To date, no direct detection of GL- 3 by immunoelectron microscopy has been reported. Objectives: To examine whether GL- 3 is accumulated exclusively in lysosomes of cutaneous cells using an anti- GL- 3 monoclonal antibody (mAb) and immunoelectron microscopy. Methods: Skin specimens from seven patients with Fabry disease were examined immunohistochemically by light and electronmicroscopy using an anti- GL- 3mAb. Results: By light microscopy, the cytoplasm of vascular endothelial cells, eccrine gland cells, and perineurium was stained with mouse anti- GL- 3 antibody. Electronmicroscopically, positive signals for GL- 3 were limited to dilated lysosomes in the cytoplasm of endothelial cells, pericytes, eccrine gland cells, dermal fibroblasts and perineurium. Conclusions: Our results demonstrate that the cytoplasmic deposit in Fabry disease was GL- 3 and the accumulated GL- 3 was localized essentially to lysosomes.展开更多
The usual method for detecting spirochetes in tissue sections is the silver stain; however, they are often difficult to detect due to marked background staining commonly seen with this technique. In certain clinical s...The usual method for detecting spirochetes in tissue sections is the silver stain; however, they are often difficult to detect due to marked background staining commonly seen with this technique. In certain clinical settings, such as neurosyphilis, congenital syphilis, and immunosuppressive conditions including human immunodeficiency virus (HIV) infection, a better method of detecting spirochetes in tissue sections is needed. We compare irnmunohistochemistry (IHC) with a monoclonal antibody to Treponema pallidum to silver staining in 19 biopsies from 17 patients with serologic evidence of secondary syphilis. IHC demonstrated a sensitivity of 71%, which was superior to the 41%sensitivity of the silver stain (p = 0.084). Furthermore, specificity was improved with IHC, as background artifacts were markedly reduced. Dermal spirochetes were visualized in all 12 positive cases, while epidermal organisms were seen in only eight cases. This finding lies contrary to accepted teaching that organisms are most commonly seen at the dermal epidermal junction. Of interest, perineural plasmacellular infiltrates were frequently seen in our cases (74%). Spirochetes were not seen in any of 14 control cases with similar histopathologic patterns. Although serologic studies remain the gold standard, IHC is more sensitive and specific than silver stain for detecting T. pallidum in biopsies of secondary syphilis.展开更多
文摘Background: Fabry disease is characterized by the systemic accumulation of glycosphingolipids, particularly in the lysosomes of vascular endothelial cells of most organs due to the deficient activity of α - galactosidase A. The major glycolipid accumulated in tissue is globotriaosylceramide (GL- 3). To date, no direct detection of GL- 3 by immunoelectron microscopy has been reported. Objectives: To examine whether GL- 3 is accumulated exclusively in lysosomes of cutaneous cells using an anti- GL- 3 monoclonal antibody (mAb) and immunoelectron microscopy. Methods: Skin specimens from seven patients with Fabry disease were examined immunohistochemically by light and electronmicroscopy using an anti- GL- 3mAb. Results: By light microscopy, the cytoplasm of vascular endothelial cells, eccrine gland cells, and perineurium was stained with mouse anti- GL- 3 antibody. Electronmicroscopically, positive signals for GL- 3 were limited to dilated lysosomes in the cytoplasm of endothelial cells, pericytes, eccrine gland cells, dermal fibroblasts and perineurium. Conclusions: Our results demonstrate that the cytoplasmic deposit in Fabry disease was GL- 3 and the accumulated GL- 3 was localized essentially to lysosomes.
文摘The usual method for detecting spirochetes in tissue sections is the silver stain; however, they are often difficult to detect due to marked background staining commonly seen with this technique. In certain clinical settings, such as neurosyphilis, congenital syphilis, and immunosuppressive conditions including human immunodeficiency virus (HIV) infection, a better method of detecting spirochetes in tissue sections is needed. We compare irnmunohistochemistry (IHC) with a monoclonal antibody to Treponema pallidum to silver staining in 19 biopsies from 17 patients with serologic evidence of secondary syphilis. IHC demonstrated a sensitivity of 71%, which was superior to the 41%sensitivity of the silver stain (p = 0.084). Furthermore, specificity was improved with IHC, as background artifacts were markedly reduced. Dermal spirochetes were visualized in all 12 positive cases, while epidermal organisms were seen in only eight cases. This finding lies contrary to accepted teaching that organisms are most commonly seen at the dermal epidermal junction. Of interest, perineural plasmacellular infiltrates were frequently seen in our cases (74%). Spirochetes were not seen in any of 14 control cases with similar histopathologic patterns. Although serologic studies remain the gold standard, IHC is more sensitive and specific than silver stain for detecting T. pallidum in biopsies of secondary syphilis.
