Sjögren’s syndrome can’t be diagnosed in one fell swoop. It usually takes a few different medical professionals comparing notes before the autoimmune condition can be recognized. A dentist may notice a lack of saliva while a rheumatologist may chart the patient’s joint pains and an optometrist observes dry eye symptoms.¹ Individually, these symptoms are vague, and even when put together they only suggest Sjögren’s.¹ However, researchers are now suggesting that biomarkers found in tears may help indicate whether a patient’s dry eye is related to Sjögren’s or not.

Specifically, the investigators report that tear levels of a goblet cell–specific mucin called MUC5AC combined with interleukin (IL)-8 can help make the diagnosis.² They conducted a prospective, observational, case-controlled study of 62 patients, 21with a definitive diagnosis of Sjögren’s dry eye, another 20 with non-Sjögren’s dry eye and 21 age-matched healthy controls with no history of either. They tested subjects with noninvasive tear break-up time, tear osmolarity, tear sampling, Schirmer test without anesthesia and ocular surface staining (lissamine green and fluorescein).²

Their analysis found the conjunctival lissamine green staining score was significantly greater in patients with Sjögren’s than those with non-Sjögren’s dry eye.² This greater conjunctival staining was also associated with a reduction in tear MUC5AC. Among the tear cytokines, the researchers noted a significant association between IL-8 levels and Sjögren’s dry eye.² When the team classified the patients based on their tear MUC5AC levels, the found significantly increased tear IL-8 levels in those with Sjögren’s-related dry eye, but not those with non-Sjögren’s dry eye.²

1. Diagnosis of Sjögren’s syndrome. Johns Hopkins Sjogren’s Center.  www.hopkinssjogrens.org/disease-information/diagnosis-sjogrens-syndrome. Accessed March 27, 2020. 2. Akpek E, Wu H, Karakus S, et al. Differential diagnosis of Sjogren versus non-Sjogren dry eye through tear film biomarkers. Cornea. March 13, 2020. [Epub ahead of print].