Immunohistochemical Insight Into the Association Between the Collapse of Immune Privilege in the Sweat Gland and Syringotropic Immune Cell Infiltrates in Collagen Diseases

The study from 2017 examined the collapse of immune privilege (IP) in sweat glands (SwG) and its link to syringotropic immune cell infiltrates in collagen diseases such as lupus erythematosus (LE), Sjögren syndrome (SjS), and systemic sclerosis/morphea (SSc/morph), with three cases for each disease. Using immunohistochemistry, the study found that normal SwG downregulates MHC class Ia expression and upregulates immunosuppressive molecules like macrophage migration inhibitory factor (MIF), particularly in the secretory portion. In contrast, diseased SwG showed upregulated MHC class Ia and downregulated MIF and CD200, an immunosuppressive marker, especially in areas with lymphocytic cell infiltration. The results indicate that SwG possesses an immune privilege similar to hair follicles, and disruptions in this system may play a role in the development of skin diseases that affect SwG.