discovering dry eye
Future Research in Sjögren's Syndrome
BY BARBARA CAFFERY, OD, MS, FAAO
The Toronto Western Hospital established a clinic that specializes in Sjögren's Syndrome patients four years ago. We have examined the patients at this clinic in a routine and research-based way, and we decided that a research day was in order to refocus our efforts and to review the research that had been done to date. We met in July with researchers from other hospitals to discuss their interests in SS and to formulate our plans for future research.
Sjögren's Syndrome and NHL
Dr. Michael Crump discussed the association of non-Hodgkins lymphoma (NHL) and SS. Some studies have suggested that two to 13 percent of SS patients present with NHL of the parotid gland. The presentation is often heralded by persistent parotid gland enlargement, splenomegaly and lymphadenopathy. Most of these tumors are mucous associated lymphatic tissue (MALT) tumors that result from chronic antigenic stimulation.
Dr. John Rutka presented his results from four years of studying SS patients' hearing tests. Although he believed that he would find a specific hearing loss, the results showed otherwise. He found that salivary gland biopsies that were done in the otolaryngology clinic were most useful in identifying SS patients. He planned to start doing fine needle biopsies on parotid glands to determine their immune makeup in order to understand the natural history of NHL in the parotid glands of SS patients.
Dr. Florence Tsui presented another interesting paper. Her studies involve the Aquaporin (AQP) protein family that controls some of the fluid channels in secretory cells. There are, at present, 10 well characterized mammalian AQPs. The important member of this family in SS is AQP5. Salivary secretions involve a two-stage process, and AQP5 is found in the apical membranes of both types of acinar cells. There is an abnormal distribution of AQP5 in salivary glands of SS patients. Researchers found AQP5 in the basal membranes of the acinar cells of SS patients as opposed to the apical membranes in normals. This suggests a deficit in protein trafficking and secretion in SS patients.
Dr. Michael Dosch has discovered a vaccine, ABBOS, that protects mice from diabetes mellitus and also, by chance, from SS. He gave mice with full-blown SS at nine weeks a shot of ABBOS, and the mice were cured from SS in 10 weeks. This research gives a great deal of hope to those who wish to be protected from SS.
Living with SS
Dr. Arthur Bookman presented the results of a quality of life study on SS patients. Patients with SS reported that the disease greatly affected their quality of life. They scored higher than dialysis patients and equal to multiple sclerosis patients. It is clear from these results that we must better understand the impact of dry eye disease, especially SS, on our patients.
Sjögren's Syndrome is a complicated autoimmune disease that is not well understood. There are many researchers in many fields looking into the pathophysiology of this disease so that we can prevent it in the future. A better understanding of this disease will benefit all autoimmune diseases and patients. As clinicians we must continue to observe and follow these patients and contribute to the understanding of the disease.
Dr. Caffery has practiced optometry in Toronto, Canada, in a group setting dedicated to contact lens and tear film research since 1977.