Investigating the utility of tear samples for the diagnosis of ocular mucous membrane pemphigoid

Brief plain language background 

Mucous membrane pemphigoid (MMP) is a disease that can cause ulceration and scarring on the skin and the surface of the eyes, mouth, airways and genitals. The disease is caused by antibodies, which are proteins in the blood that bind to these body sites and result in inflammation and tissue damage. MMP can be very severe and if untreated eye involvement results in blindness in about one third of people. 

What problem/knowledge gap does it help address 

Currently MMP is usually diagnosed by taking a biopsy from the surface of the eye because blood tests to measure antibodies are unreliable. Antibodies are present in tears and saliva but it is not known whether they can be used to diagnose the disease or whether they are associated with MMP lesions at different body sites or more active disease. 

Patients with MMP therefore need to undergo invasive diagnostic tests and travel to specialist centres to have these performed. There is also no way of predicting how severe their disease will be or which body sites will be affected. 

Aim of the project 

To measure antibody levels in tears, saliva and blood. It will assess whether tears can be used to diagnose MMP and whether certain antibodies associate with body site involvement. Lastly, it will investigate whether antibody levels are linked to disease activity and whether they could monitor the disease. 

Potential impact on people with sight loss 

This project could lead to new methods of non-invasive testing and disease monitoring for MMP. We would anticipate this could happen within the next 5 years. As tear and saliva samples can be collected at home, it could also enable tests to be performed away from the clinic and prevent patients travelling long distances to specialist centres. This project will also identify whether antibodies in tears can predict eye involvement and therefore could enable doctors to treat the disease more intensively to prevent inflammation and damage to the eye, potentially delaying or preventing sight loss.