IgA and secretory component (SC) in the third eyelid of domestic animals: a comparative study

Abstract

It is suggested that most of the SC is locally produced by resident plasma cells and subsequently transferred through the surface epithelium and glandular duct cells by transcytosis. This indicates that the third eyelid is an important member of the secretory immune system in domestic animals.

A preliminary study of changes in tear film proteins in the feline eye following nictitating membrane removal

“…We also observed that the overall tear IgA levels appeared to increase from week 1 and 2 post‐surgery with a subsequent decline at week 4 post‐surgery in eyes with nictitating membranes removed. This outcome suggests that an initial increase in tear IgA may be due to a direct response to the wounding and its associated inflammatory responses 10,27 . The increased level of IgA was most likely produced by the remaining nictitating gland that contains IgA‐positive plasma cells in cats 10 .…”

“…This study found significantly lower levels of IgA 4 weeks after removal, in eyes without nictitating membranes compared with eyes with nictitating membranes. The IgA protein is an immune defense immunoglobulin in tears 8,9 and is produced by ocular surface components such as the main lacrimal gland, 26 nictitating gland attached to the nictitating membrane, 10 or conjunctival‐associated lymphoid tissue (CALT) 27–29 . Schlegel et al.…”

“…Schlegel et al. 10 suggested the nictitating membranes with the attached gland to be a major contributor for IgA in tears in normal eye conditions. It is not clear whether the removal of nictitating membranes may reduce IgA production and perhaps compromise the immune defense system of the ocular surface.…”

“…IgA is a major immune defense immunoglobulin in tears 8,9 . In domestic animals, nictitating membranes are important contributors to IgA production in the ocular surface system 10 . The MMP enzymes are key effectors and regulators in inflammation, wound healing, tissue remodeling, and pathogenic processes 11–13 .…”

Calcium degeneration and ocular surface failure in the horse

“…The PTF of the horse contains IgA, IgM, IgG and IgT (Martin et al . 1997; Schlegel et al . 2003), urea (Zapata et al .…”